A parameter detection method, system, device and storage medium of an optical element

Abstract

The application discloses a parameter detection method, system and device of an optical element and a storage medium, and belongs to the technical field of profile measurement. The parameter detection method of the optical element comprises the following steps: controlling a rotary table to drive the optical element to rotate around a Z axis; controlling a first motion platform to drive a first displacement sensor to move, so that profile data collected by the first displacement sensor is obtained; controlling a second motion platform to drive a second displacement sensor to move, so that normal displacement data collected by the second displacement sensor is obtained; determining an upper surface tilt vector and an upper surface eccentric vector of the optical element according to the profile data, and determining a lower surface tilt vector and a lower surface eccentric vector of the optical element according to the normal displacement data; and determining a relative tilt vector according to the upper surface tilt vector and the lower surface tilt vector, and determining a relative eccentric vector according to the upper surface eccentric vector and the lower surface eccentric vector. The application can accurately detect the tilt vector and the eccentric vector of the optical element.

Description

Technical Field

[0001] This application relates to the field of contour measurement technology, and in particular to a method, system, device and storage medium for parameter detection of optical elements. Background Technology

[0002] With the continuous advancement of advanced scientific facilities such as deep space exploration, extreme ultraviolet lithography, and synchrotron radiation, the size of optical system components is gradually increasing and their surface shapes are becoming increasingly complex, placing sub-nanometer or even picometer-level demands on the manufacturing precision of optical components. The final performance of optical components depends not only on surface shape errors but also highly on geometric quantities such as center thickness, surface tilt, and surface eccentricity. These geometric quantities directly affect optical path alignment, aberrations, assembly accuracy, and system stability.

[0003] In existing technologies, surface shape inspection often employs interferometers or profilometers, while geometric quantity inspection is typically a separate process. Mainstream geometric quantity inspection is based on profilometers, but it is generally difficult to simultaneously acquire data for the upper and lower surfaces under the same reference coordinate system and clamping condition, leading to uncontrollable uncertainties introduced by clamping errors.

[0004] Therefore, how to accurately detect the tilt vector and eccentricity vector of optical elements is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a method, system, device, and storage medium for detecting the parameters of an optical element, which can accurately detect the tilt vector and eccentricity vector of the optical element.

[0006] To address the aforementioned technical problems, this application provides a parameter detection method for optical components, applied to an integrated testing device. The integrated testing device includes a turntable, an upper surface measurement assembly, and a lower surface measurement assembly. The turntable is used to clamp the optical component. The upper surface measurement assembly includes a first motion platform and a first displacement sensor. The first motion platform drives the first displacement sensor to move above the upper surface of the optical component, so that the first displacement sensor measures the upper surface. The lower surface measurement assembly includes a second motion platform and a second displacement sensor. The second motion platform drives the second displacement sensor to move below the lower surface of the optical component, so that the second displacement sensor measures the lower surface. The parameter detection method for the optical component includes: The turntable is controlled to drive the optical element to rotate around the Z-axis; The first displacement sensor is activated, and the first motion platform is controlled to drive the first displacement sensor to perform motion that meets the constraints, thereby obtaining the contour data collected by the first displacement sensor; wherein, the constraints are: the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point; The second displacement sensor is activated, and the second motion platform is controlled to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor; wherein, the measurement direction of the second displacement sensor when collecting the normal displacement data is perpendicular to the tangent plane of the current measurement point; The upper surface tilt vector and upper surface eccentricity vector of the optical element are determined based on the contour data, and the lower surface tilt vector and lower surface eccentricity vector of the optical element are determined based on the normal displacement data. The relative tilt vector of the optical element is determined based on the tilt vector of the upper surface and the tilt vector of the lower surface, and the relative eccentricity vector of the optical element is determined based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface.

[0007] Optionally, the first motion platform includes a first X-axis linear motion platform, a first Z-axis linear motion platform, and a first rotary platform, with the first displacement sensor mounted on the first rotary platform; the first X-axis linear motion platform is used to drive the first displacement sensor to move linearly in the X-axis direction, the first Z-axis linear motion platform is used to drive the first displacement sensor to move linearly in the Z-axis direction, and the first rotary platform is used to drive the first displacement sensor to rotate around a first rotation axis, the first rotation axis being parallel to the Y-axis; Accordingly, controlling the first motion platform to drive the first displacement sensor to perform motion that meets the constraints includes: A first control command is sent to the first X-axis linear motion platform to adjust the X-axis coordinate of the first displacement sensor; A second control command is issued to the first Z-axis linear motion platform to keep the distance between the first displacement sensor and the upper surface within the effective working distance. A third control command is sent to the first rotating platform to make the measurement direction of the first displacement sensor perpendicular to the tangent plane of the current measurement point.

[0008] Optionally, the turntable has a hollow structure, and the lower surface measuring component is disposed within the hollow structure. When the optical element is clamped on the turntable, the optical element is located above the hollow structure. The second motion platform includes a second X-axis linear motion platform, a second Z-axis linear motion platform, and a second rotary platform. The second X-axis linear motion platform drives the second displacement sensor to move linearly in the X-axis direction, and the second Z-axis linear motion platform drives the second displacement sensor to move linearly in the Z-axis direction. The second rotary platform has a connecting bracket, which includes a first end and a second end. The first end of the connecting bracket is connected to the second displacement sensor, and the second rotary platform drives the connecting bracket and the second displacement sensor to rotate around a second rotation axis parallel to the Y-axis. The measurement point of the second displacement sensor coincides with the rotation center of the second rotary platform. Accordingly, controlling the second motion platform to move the second displacement sensor to the position corresponding to the multiple measurement radius rings includes: A fourth control command is sent to the second X-axis linear motion platform and the second Z-axis linear motion platform to make the second displacement sensor move to the position corresponding to the current measurement radius ring; A fifth control command is sent to the second rotating platform to make the measurement direction of the second displacement sensor perpendicular to the tangent plane of the current measurement point.

[0009] Optionally, determining the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data includes: The fitting surface is determined based on the contour data, and the theoretical upper surface is determined based on the design parameters of the optical element. The fitting surface is compared with the theoretical upper surface to obtain the upper surface tilt vector and the upper surface eccentricity vector.

[0010] Optionally, determining the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data includes: Perform a Fourier transform on the normal displacement data corresponding to each measurement radius ring to extract the first harmonic component corresponding to each measurement radius ring; A set of target equations is constructed based on the geometric parameters and first harmonic components of the measurement radius ring; wherein, the set of target equations is used to describe the relationship between the lower surface tilt vector and the lower surface eccentricity vector and the first harmonic components; By solving the objective equations, the tilt vector of the lower surface and the eccentricity vector of the lower surface are obtained.

[0011] Optionally, determining the relative eccentricity vector of the optical element based on the upper surface eccentricity vector and the lower surface eccentricity vector includes: Determine the center thickness of the optical element; wherein the center thickness is the distance between the vertex of the upper surface and the vertex of the lower surface along the optical axis; The relative eccentricity vector of the optical element is determined based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector.

[0012] Optionally, determining the relative eccentricity vector of the optical element based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector includes: Substituting the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector into the relative eccentricity calculation formula, the relative eccentricity vector of the optical element is obtained; The formula for calculating relative eccentricity is as follows: ; Represents the relative eccentricity vector. Indicates the eccentricity vector of the lower surface. This represents the eccentricity vector of the upper surface. Indicates the center thickness. This represents the tilt vector of the upper surface.

[0013] This application also provides a parameter detection system for optical elements, applied to an integrated inspection device. The integrated inspection device includes a turntable, an upper surface measurement component, and a lower surface measurement component. The turntable is used to clamp optical elements. The upper surface measurement component includes a first motion platform and a first displacement sensor. The first motion platform is used to drive the first displacement sensor to move above the upper surface of the optical element, so that the first displacement sensor measures the upper surface. The lower surface measurement component includes a second motion platform and a second displacement sensor. The second motion platform is used to drive the second displacement sensor to move below the lower surface of the optical element, so that the second displacement sensor measures the lower surface. The parameter detection system for optical elements includes: A rotation control module is used to control the turntable to drive the optical element to rotate around the Z-axis; The first detection and control module is used to activate the first displacement sensor and control the first motion platform to drive the first displacement sensor to perform motion that meets the constraint conditions, thereby obtaining the contour data collected by the first displacement sensor; wherein, the constraint condition is: the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point; The second detection and control module is used to activate the second displacement sensor and control the second motion platform to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor; wherein, the measurement direction of the second displacement sensor when collecting the normal displacement data is perpendicular to the tangent plane of the current measurement point; The data processing module is used to determine the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data, and to determine the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data. The result calculation module is used to determine the relative tilt vector of the optical element based on the tilt vector of the upper surface and the tilt vector of the lower surface, and to determine the relative eccentricity vector of the optical element based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface.

[0014] This application also provides a storage medium storing a computer program thereon, which, when executed, implements the steps of the parameter detection method for the optical element described above.

[0015] This application also provides a device including a memory and a processor, wherein the memory stores a computer program, and the processor, when calling the computer program in the memory, implements the steps of the parameter detection method for the optical element described above.

[0016] This application provides a parameter detection method for optical components, applied to an integrated testing device. The integrated testing device includes a turntable, an upper surface measurement component, and a lower surface measurement component. When the optical component rotates with the turntable, the upper and lower surface measurement components can respectively detect the upper and lower surfaces of the optical component, avoiding clamping errors introduced by multiple clamping measurements and ensuring measurement accuracy. The upper surface measurement component includes a first motion platform and a first displacement sensor. During parameter detection, the first displacement sensor, driven by the first motion platform, measures perpendicular to the tangent plane of the current measurement point, eliminating measurement errors introduced by incident angle deviation. The lower surface measurement component includes a second motion platform and a second displacement sensor. The second displacement sensor collects normal displacement data on multiple measurement radius rings, ensuring that the measurement direction is perpendicular to the tangent plane at each ring. After obtaining the tilt vector and eccentricity vector of each of the upper and lower surfaces, this application can calculate the relative tilt vector and relative eccentricity vector of the upper and lower surfaces of the optical component. The above process eliminates the need for separate clamping and measurement of the optical element; measurements of the upper and lower surfaces are performed simultaneously, and there are no restrictions on the surface shape of the optical element. Therefore, this application enables precise detection of the tilt vector and eccentricity vector of the optical element. This application also provides a parameter detection system for optical elements, a storage medium, and a device, all possessing the aforementioned advantages, which will not be elaborated upon further here. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a parameter detection method for an optical element provided in an embodiment of this application; Figure 2 This is a schematic diagram of an integrated detection device for detecting absolute surface shape and geometric quantities, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a parameter detection system for an optical element provided in an embodiment of this application.

[0019] In the above figure, 1—vibration isolation platform, 2—isolation cover, 3—marble base, 4—hollow high-precision turntable, 5—lower surface X-axis motion platform, 6—lower surface Z-axis motion platform, 7— 8—Z-shaped rigid body connecting bracket, 9—First probe, 10—X-axis calibration reference mirror, 11—Z-axis calibration reference mirror, 12—Upper surface X-axis motion platform, 13—Upper surface Z-axis motion platform, 14—Second probe, 15—Third probe, 16—θ-axis rotation platform, 17—Fourth probe, 18—Fifth probe, 19—Sixth probe, 20—Seventh probe. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Please see below. Figure 1 , Figure 1 This is a flowchart of a parameter detection method for an optical element provided in an embodiment of this application.

[0022] Specific steps may include: S101: Control the turntable to drive the optical element to rotate around the Z-axis.

[0023] The parameter detection method for optical components described in this solution is applied to an integrated testing device, which includes a turntable, an upper surface measurement component, and a lower surface measurement component.

[0024] The aforementioned turntable is used to clamp optical components. The rotation axis of the turntable serves as the reference benchmark for the integrated testing equipment. Both the upper and lower surface measurement components use the rotation axis of the turntable as a unified benchmark for measurement, ensuring the consistency of the upper and lower surface data. As a feasible implementation, the turntable can be a turntable with a hollow structure. When the optical component is clamped on the turntable, the upper surface measurement component is positioned above the optical component for measuring its upper surface; the lower surface measurement component is at least partially located within the hollow structure of the turntable for measuring the lower surface of the optical component.

[0025] The upper surface measurement assembly includes a first motion platform and a first displacement sensor. The first motion platform drives the first displacement sensor to move above the upper surface of the optical element, so that the first displacement sensor can measure the upper surface. As a possible implementation, the first displacement sensor can be a non-contact displacement sensor, such as a laser interferometer or a laser displacement sensor, used to acquire surface contour data of the upper surface.

[0026] The lower surface measurement assembly includes a second motion platform and a second displacement sensor. The second motion platform drives the second displacement sensor to move below the lower surface of the optical element, so that the second displacement sensor can measure the lower surface. As a possible implementation, the second displacement sensor can be a non-contact displacement sensor, such as a capacitive displacement sensor or a laser displacement sensor, used to acquire normal displacement data of the lower surface.

[0027] After mounting the optical element onto the turntable, this solution can control the turntable to rotate at a set speed, thereby causing the optical element to rotate around the Z-axis. The Z-axis is the rotation axis of the turntable and also the unified reference datum of the integrated testing equipment. By driving the optical element to rotate around the Z-axis, the upper surface measurement component and the lower surface measurement component can perform full-circumferential scanning or circumferential data acquisition on the upper and lower surfaces respectively during the continuous rotation of the optical element, thereby obtaining complete surface contour information and normal displacement information.

[0028] As a feasible implementation, the aforementioned turntable can be driven by a servo motor and equipped with an angle encoder to achieve high-precision control and real-time feedback of the rotation angle. Optical components are securely mounted on the turntable via vacuum adsorption or mechanical clamping to ensure that no relative slippage or loosening occurs during rotation.

[0029] S102: Activate the first displacement sensor and control the first motion platform to drive the first displacement sensor to perform motion that meets the constraints, thereby obtaining the contour data collected by the first displacement sensor.

[0030] The first displacement sensor collects the sag data and corresponding polar coordinate positions of each measurement point during the scanning process, thereby obtaining contour data covering the entire diameter of the upper surface.

[0031] The first displacement sensor is mounted on the first motion platform. The first motion platform changes the position and orientation of the first displacement sensor and makes the first displacement sensor meet the constraint conditions when collecting contour data. The constraint condition is that the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point.

[0032] Specifically, after activating the first displacement sensor, the first motion platform can be controlled to drive the first displacement sensor to move along a preset scanning path (such as a spiral path). The first motion platform adjusts the attitude of the first displacement sensor in real time according to the local normal direction of the upper surface at the current measurement point, so that the measurement direction of the first displacement sensor is always perpendicular to the tangent plane of the current measurement point, that is, the measurement is performed along the normal direction of that point. The above-mentioned normal tracking measurement method can effectively eliminate the measurement error introduced by the incident angle deviation, ensuring that the collected sag data truly reflects the topographic features of the upper surface, thereby obtaining accurate contour data. The above contour data is the sag distribution of each point on the upper surface, used to calculate the absolute surface shape, tilt vector, and eccentricity vector of the upper surface.

[0033] S103: Start the second displacement sensor and control the second motion platform to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor.

[0034] Wherein, the measurement direction of the second displacement sensor when acquiring the normal displacement data is perpendicular to the tangent plane of the current measurement point; A measurement radius ring refers to a pre-defined circular measurement path centered on the rotation axis of the turntable on the lower surface of the optical element. Each measurement radius ring corresponds to a fixed radial distance (i.e., the radius of the ring). The number of measurement radius rings is usually no less than two, and their specific values ​​are pre-planned based on the design parameters of the optical element (such as radius of curvature, aspheric coefficient, aperture size, etc.). For example, for a spherical lens, two radius rings can be selected, one near the center and one near the edge; for an aspherical lens, measurement rings can be densely arranged in areas with large curvature changes based on the rate of surface shape change.

[0035] During the measurement process, the second motion platform moves the second displacement sensor to the radial position and working distance corresponding to the first measurement radius ring. Upon reaching this position, the second rotation platform adjusts the measurement direction of the second displacement sensor so that its measurement direction is along the normal direction of the lower surface of that measurement radius ring. Subsequently, the turntable drives the optical element to rotate uniformly around the Z-axis for one revolution (or continuously rotates for one complete cycle), while the second displacement sensor synchronously acquires normal displacement data at various angular positions on that measurement radius ring at a high-frequency sampling rate, obtaining a displacement signal for one complete cycle. After completing the data acquisition for the first measurement radius ring, the second motion platform moves the second displacement sensor to the radial position and working distance corresponding to the next measurement radius ring, and the measurement direction is adjusted again to be perpendicular to the normal direction of the lower surface of that ring. The turntable then drives the optical element to rotate one revolution to acquire data. This process is repeated to sequentially acquire data for all preset measurement radius rings, obtaining the normal displacement data corresponding to each measurement radius ring.

[0036] The aforementioned normal displacement data represents the displacement change collected by the second displacement sensor along its measurement direction (i.e., along the normal direction of the lower surface), reflecting the distance fluctuation of the lower surface relative to the second displacement sensor during the rotation of the turntable. The normal displacement data is predominantly composed of first-order harmonic components, including information contributed by the tilt vector and eccentricity vector of the lower surface. The tilt vector and eccentricity vector of the lower surface can be solved by decoupling multi-loop data.

[0037] To improve data acquisition accuracy, this solution can be implemented as follows: Two identical second displacement sensors are arranged symmetrically on the turntable (180° apart), and both sensors simultaneously measure the same measurement radius ring. The measurement signals from the two second displacement sensors are subtracted to obtain the normal displacement data corresponding to each measurement radius ring. This suppresses common-mode errors such as turntable axial runout, temperature drift, and airflow disturbance, retaining only the differential-mode signal related to the lower surface morphology, thereby improving the measurement accuracy of the lower surface normal displacement data.

[0038] Changes in ambient temperature can cause changes in the relative positions of the first and second displacement sensors and the optical element. To improve data acquisition accuracy, a feasible approach is to arrange multiple temperature sensors around the turntable and the optical element to monitor the ambient temperature and the temperature distribution of key components in real time. Using a finite element thermal simulation model, the thermal deformation of the turntable, connecting bracket, and optical element under the current temperature field is estimated in real time, and the displacement caused by thermal deformation is pre-compensated during measurement data processing. Specifically, this scheme can calculate the offset of the turntable axis, the change in the length of the connecting bracket, and the surface distortion of the optical element under the current temperature field based on the real-time data from each temperature sensor, combined with the material thermal expansion coefficient and geometric parameters of each component. During data processing, the aforementioned thermal deformation is used as a correction term and subtracted from the raw data collected by the first and second displacement sensors, thereby eliminating the displacement caused by thermal deformation and obtaining measurement data that truly reflects the geometric parameters and surface characteristics of the optical element.

[0039] S104: Determine the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data, and determine the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data.

[0040] After obtaining the contour data, the tilt vector and eccentricity vector of the upper surface of the optical element can be calculated. The tilt vector characterizes the angle and orientation between the upper surface normal and the Z-axis, while the eccentricity vector characterizes the lateral displacement and orientation of the geometric center of the upper surface away from the Z-axis. Specifically, the contour data includes the sag values ​​and coordinates of each measurement point across the full aperture of the upper surface. By performing surface fitting on the contour data, the fitted surface shape of the upper surface can be obtained. By comparing the fitted surface shape with the ideal upper surface, the tilt vector and eccentricity vector of the upper surface relative to the rotation axis of the turntable can be calculated, thus obtaining the upper surface tilt vector and upper surface eccentricity vector.

[0041] The normal displacement data includes normal displacement values ​​at various angular positions on multiple measurement radius rings. A Fourier transform is performed on the normal displacement data corresponding to each measurement radius ring to extract the first harmonic components of each ring. These first harmonic components are contributed by the tilt vector and eccentric vector of the lower surface. Based on the geometric parameters at different measurement radius rings (such as measurement radius, distance of the measurement point from the origin, angle between the position vector and the Z-axis, and angle between the lower surface normal and the Z-axis), a system of equations can be established between each first harmonic component and the lower surface tilt vector and eccentric vector. Solving this system of equations decouples the lower surface tilt vector and eccentric vector from the first harmonic components, yielding the lower surface tilt vector and eccentric vector. The lower surface tilt vector characterizes the angle and orientation between the lower surface normal and the Z-axis, while the lower surface eccentric vector characterizes the magnitude and orientation of the lateral displacement of the lower surface's geometric center away from the Z-axis.

[0042] S105: Determine the relative tilt vector of the optical element based on the tilt vector of the upper surface and the tilt vector of the lower surface, and determine the relative eccentricity vector of the optical element based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface.

[0043] The relative tilt vector is the difference between the tilt vector of the lower surface and the tilt vector of the upper surface, used to characterize the degree of tilt of the lower surface relative to the upper surface, that is, the magnitude and orientation of the deflection angle of the lower surface normal relative to the upper surface normal. The relative eccentricity vector is the lower surface eccentricity vector minus the upper surface eccentricity vector, minus the product of the upper surface tilt vector and the center thickness, used to characterize the degree of lateral offset of the lower surface relative to the upper surface, that is, the magnitude and orientation of the offset of the lower surface geometric center relative to the upper surface geometric center. The center thickness is the distance along the Z-axis between the vertices of the upper and lower surfaces of the optical element.

[0044] All the above calculations were performed in a unified reference coordinate system with the rotation axis of the turntable as the Z-axis, ensuring the consistency of the upper and lower surface data, thereby guaranteeing the calculation accuracy of the relative tilt vector and the relative eccentric vector.

[0045] After obtaining the relative tilt vector and the relative eccentricity vector, the processing quality of the optical element can be determined based on the relative tilt vector and the relative eccentricity vector. The assembly parameters of the optical element can also be generated based on the relative tilt vector and the relative eccentricity vector.

[0046] This embodiment applies to an integrated testing device, which includes a turntable, an upper surface measurement component, and a lower surface measurement component. As the optical element rotates with the turntable, the upper and lower surface measurement components can respectively measure the upper and lower surfaces of the optical element, avoiding clamping errors introduced by separate clamping measurements and ensuring measurement accuracy. The upper surface measurement component includes a first motion platform and a first displacement sensor. During parameter detection, the first displacement sensor, driven by the first motion platform, measures perpendicular to the tangent plane of the current measurement point, eliminating measurement errors introduced by incident angle deviation. The lower surface measurement component includes a second motion platform and a second displacement sensor. The second displacement sensor collects normal displacement data on multiple measurement radius rings, ensuring that the measurement direction is perpendicular to the tangent plane at each ring. After obtaining the tilt vector and eccentricity vector of each of the upper and lower surfaces, this embodiment can calculate the relative tilt vector and relative eccentricity vector of the upper and lower surfaces of the optical element. The above process does not require the optical element to be clamped and measured in stages. The measurement of the upper and lower surfaces is carried out simultaneously, and there are no restrictions on the surface shape of the optical element. Therefore, this embodiment can accurately detect the tilt vector and eccentricity vector of the optical element.

[0047] As for Figure 1 In a further description of the corresponding embodiment, the first motion platform includes a first X-axis linear motion platform, a first Z-axis linear motion platform, and a first rotary platform. The first displacement sensor is mounted on the first rotary platform. The first X-axis linear motion platform is used to drive the first displacement sensor to move linearly in the X-axis direction. The first Z-axis linear motion platform is used to drive the first displacement sensor to move linearly in the Z-axis direction. The first rotary platform is used to drive the first displacement sensor to rotate around a first rotation axis, which is parallel to the Y-axis.

[0048] This scheme establishes a spatial rectangular coordinate system O-XYZ based on the rotation axis of the turntable, with the Z-axis of the spatial rectangular coordinate system being the rotation axis of the turntable. The first X-axis linear motion platform and the first Z-axis linear motion platform are used to adjust the position of the first displacement sensor in the horizontal radial and vertical directions, respectively, so that the first displacement sensor can reach the radial position and height of any measurement point on the upper surface. The first rotation platform is used to adjust the pitch angle of the first displacement sensor in the XOZ plane, so that the measurement direction of the first displacement sensor can be adjusted in real time according to the local normal direction of the current measurement point on the upper surface, thereby satisfying the constraint that the measurement direction is perpendicular to the tangent plane of the current measurement point. As a feasible implementation, the first displacement sensor is mounted on the first rotation platform, the first rotation platform is mounted on the first Z-axis linear motion platform, and the first Z-axis linear motion platform is mounted on the first X-axis linear motion platform.

[0049] Based on the aforementioned first motion platform, the first motion platform can be controlled to drive the first displacement sensor to perform motion that meets the constraint conditions in the following manner: A first control command is issued to the first X-axis linear motion platform to adjust the X-axis coordinate of the first displacement sensor; a second control command is issued to the first Z-axis linear motion platform to ensure that the distance between the first displacement sensor and the upper surface is within the effective working distance; a third control command is issued to the first rotary platform to ensure that the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point.

[0050] The aforementioned first, second, and third control commands can be executed collaboratively or sequentially and independently during the measurement process. When the turntable drives the optical element to rotate uniformly around the Z-axis, the first X-axis linear motion platform can adjust the radial position of the first displacement sensor in real time according to a preset scanning path (such as a concentric circle path or a spiral path); the first Z-axis linear motion platform can adjust the vertical position of the first displacement sensor in real time according to the surface undulations of the upper surface, ensuring that the distance between the sensor and the upper surface remains within the effective working distance range of the first displacement sensor, avoiding signal attenuation due to excessive distance or collision due to excessively close distance; the first rotating platform can adjust the pitch angle of the first displacement sensor in real time according to the local normal direction of the upper surface at the current measurement point, ensuring that its measurement direction is always perpendicular to the tangent plane of the current measurement point, i.e., measuring along the normal direction of that point.

[0051] The first, second, and third control commands can be generated and issued by the integrated detection equipment's control system based on a preset scanning path and real-time position feedback information. The aforementioned control system may include motion controllers, drivers, and position feedback elements such as angle encoders and linear encoders to achieve high-precision closed-loop control of each motion platform.

[0052] As for Figure 1 In a further description of the corresponding embodiment, the turntable has a hollow structure, the lower surface measuring component is disposed within the hollow structure, and when the optical element is clamped on the turntable, the optical element is located above the hollow structure; The second motion platform includes a second X-axis linear motion platform, a second Z-axis linear motion platform, and a second rotary platform. The second X-axis linear motion platform drives the second displacement sensor to move linearly in the X-axis direction, and the second Z-axis linear motion platform drives the second displacement sensor to move linearly in the Z-axis direction. The second rotary platform has a connecting bracket, which includes a first end and a second end. The first end of the connecting bracket is connected to the second displacement sensor, and the second rotary platform drives the connecting bracket and the second displacement sensor to rotate around a second rotation axis parallel to the Y-axis. The measurement point of the second displacement sensor coincides with the rotation center of the second rotary platform.

[0053] The second X-axis linear motion platform is used to adjust the position of the second displacement sensor in the horizontal radial direction so that it can be aligned with the radial position corresponding to different measuring radius rings; the second Z-axis linear motion platform is used to adjust the position of the second displacement sensor in the vertical direction so that the distance between it and the lower surface is kept within the effective working distance range.

[0054] The second rotating platform drives the second displacement sensor to rotate around a second rotation axis parallel to the Y-axis via the connecting bracket, thereby adjusting the pitch angle of the second displacement sensor in the XOZ plane. This allows the measurement direction of the second displacement sensor to be adjusted according to the local normal direction of the lower surface at the current measurement radius ring, satisfying the constraint that the measurement direction is perpendicular to the tangent plane of the current measurement point. The connecting bracket is preferably a rigid structure, such as a Z-shaped connecting rod, to ensure sufficient structural rigidity within a limited space and avoid vibration or deformation errors introduced by excessive cantilever length.

[0055] As a feasible implementation method, the second X-axis linear motion platform, the second Z-axis linear motion platform, and the second rotary platform can be driven by a precision ball screw pair in conjunction with a servo motor, or by a linear motor directly, to achieve high-precision position control and angle control.

[0056] As a feasible implementation, the second rotating platform is equipped with an arc-shaped track. The measurement direction of the second displacement sensor can be adjusted by controlling the movement of the second end of the connecting bracket on the arc-shaped track. This solution can achieve this by setting the installation angle between the second end of the connecting bracket and the second rotating platform, ensuring that the line connecting the second end of the connecting bracket to the first end always points towards the center of the arc-shaped track. Since the line connecting the second end of the connecting bracket to the first end is the measurement direction of the second displacement sensor, the measurement direction of the second displacement sensor always passes through the center of the arc-shaped track during the rotation of the second end of the connecting bracket around the second rotating axis controlled by the second rotating platform.

[0057] Since the connecting bracket is a rigid structure, as long as the installation angle between its second end and the rotating platform is fixed in the direction pointing towards the center, the line connecting the first and second ends will always point towards the center, no matter where the second end moves along the track. Through the structural design of the second rotating platform described above, it can be ensured that the measurement direction of the second displacement sensor always passes through the center of the arc-shaped track during the adjustment process, thereby simplifying the calibration process of the measurement direction and improving measurement accuracy.

[0058] Based on the aforementioned second motion platform, this application can control the second motion platform to move the second displacement sensor to the positions corresponding to multiple measurement radius rings in the following manner: A fourth control command is issued to the second X-axis linear motion platform and the second Z-axis linear motion platform to move the second displacement sensor to the position corresponding to the current measurement radius ring; a fifth control command is issued to the second rotation platform to make the measurement direction of the second displacement sensor perpendicular to the tangent plane of the current measurement point.

[0059] The second X-axis linear motion platform moves the second displacement sensor along the X-axis to the radial coordinate position of the preset measurement radius ring. The second Z-axis linear motion platform adjusts the position of the second displacement sensor in the Z-axis direction according to the sag of the lower surface at the radius ring, keeping the distance between it and the lower surface within the effective working distance range. The second rotary platform adjusts the measurement direction of the second displacement sensor according to the local normal direction of the lower surface at the current measurement radius ring, making it perpendicular to the tangent plane at that ring. After completing the data acquisition of one measurement radius ring, the above process is repeated, moving the second displacement sensor to the position corresponding to the next preset measurement radius ring and adjusting the measurement direction, until the data acquisition of all preset measurement radius rings is completed.

[0060] The fourth and fifth control commands can be generated and issued by the control system of the integrated detection equipment based on the preset measurement radius ring parameters and real-time position feedback information.

[0061] As for Figure 1 A further description of the corresponding embodiment: the process of determining the upper surface tilt vector and the upper surface eccentricity vector of the optical element based on the contour data includes: determining a fitting surface based on the contour data, determining a theoretical upper surface based on the design parameters of the optical element, comparing the fitting surface with the theoretical upper surface, and obtaining the upper surface tilt vector and the upper surface eccentricity vector.

[0062] The aforementioned contour data includes the sag values ​​and position coordinates of each measurement point across the full diameter of the upper surface. By performing surface fitting on the contour data, a fitted surface capable of characterizing the actual morphology of the upper surface is obtained. Specifically, this scheme can use methods such as least squares fitting, polynomial fitting, or spline fitting to determine the expression of the fitted surface.

[0063] The theoretical surface is the theoretically designed surface of the optical element, such as an ideal sphere, an ideal aspherical surface, or an ideal plane. By comparing the fitted surface with the theoretical surface, the pose deviation of the upper surface of the optical element relative to the theoretical surface in space can be calculated. This pose deviation includes two parts: tilt deviation and eccentricity deviation. The tilt deviation is the deflection of the normal direction of the fitted surface relative to the normal direction of the theoretical surface (i.e., the Z-axis direction) (i.e., the upper surface tilt vector), expressed in the form of tilt magnitude and tilt azimuth angle; the eccentric deviation is the lateral offset of the geometric center of the fitted surface relative to the geometric center of the theoretical surface (i.e., the Z-axis) in the direction perpendicular to the Z-axis (i.e., the upper surface eccentric vector), expressed in the form of eccentric magnitude and eccentric azimuth angle.

[0064] As for Figure 1 A further description of the corresponding embodiment involves determining the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data, including: Perform a Fourier transform on the normal displacement data corresponding to each measurement radius ring to extract the first harmonic component corresponding to each measurement radius ring; construct a set of target equations based on the geometric parameters of the measurement radius ring and the first harmonic component; wherein, the set of target equations is used to describe the relationship between the lower surface tilt vector and the lower surface eccentricity vector and the first harmonic component; by solving the set of target equations, the lower surface tilt vector and the lower surface eccentricity vector are obtained.

[0065] The aforementioned normal displacement data is a displacement signal collected by the second displacement sensor during one revolution of the optical element driven by the turntable. This signal exhibits periodic changes. By performing a Fourier transform on the normal displacement data, it can be decomposed into a DC component, a first-order harmonic component, and higher-order harmonic components. The amplitude and phase of the first-order harmonic component reflect the magnitude and direction of the normal displacement fluctuation caused by the combined effects of the lower surface tilt and eccentricity, respectively.

[0066] The geometric parameters of the measurement radius rings include the radius of each measurement radius ring, the distance of the measurement point from the origin, the angle between the position vector and the Z-axis, and the angle between the normal of the lower surface and the Z-axis. These geometric parameters are determined by the design parameters of the optical element and the preset position of the measurement radius rings.

[0067] The objective equations are constructed by representing the first harmonic components of each measurement radius ring as a linear combination of the lower surface tilt vector and the lower surface eccentricity vector. Since the geometric parameters at different measurement radius rings are different, the contribution weights of tilt and eccentricity to the first harmonic components of each ring are also different. Therefore, the decoupling of tilt and eccentricity can be achieved by simultaneously solving the equations of multiple measurement radius rings.

[0068] When solving the objective equations, if there are two measurement radius loops, the objective equations have a unique solution; if there are more than two measurement radius loops, the objective equations can be solved using the least squares method to obtain the optimal estimate. The solution to the objective equations is the lower surface tilt vector and the lower surface eccentricity vector.

[0069] As for Figure 1 A further description of the corresponding embodiment involves determining the relative eccentricity vector of the optical element based on the upper surface eccentricity vector and the lower surface eccentricity vector, including: Determine the center thickness of the optical element; wherein the center thickness is the distance between the vertex of the upper surface and the vertex of the lower surface along the optical axis; determine the relative eccentricity vector of the optical element based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector.

[0070] Specifically, this solution can obtain the first axial deviation of the first displacement sensor at the vertex of the upper surface and the second axial deviation of the second displacement sensor at the vertex of the lower surface; based on the first axial deviation, the second axial deviation, and the nominal distance between the first and second displacement sensors, the center thickness of the optical element is determined. The nominal distance between the first and second displacement sensors refers to the distance along the Z-axis between the measurement reference point of the first displacement sensor and the measurement reference point of the second displacement sensor under system calibration conditions.

[0071] Furthermore, the process of determining the relative eccentricity vector of the optical element based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector includes: Substituting the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector into the relative eccentricity calculation formula, the relative eccentricity vector of the optical element is obtained; The formula for calculating relative eccentricity is as follows: ; Represents the relative eccentricity vector. Indicates the eccentricity vector of the lower surface. This represents the eccentricity vector of the upper surface. Indicates the center thickness. This represents the tilt vector of the upper surface.

[0072] The center thickness directly affects the optical focal length, aberrations, and overall system length; the relative tilt and relative eccentricity of the upper and lower surfaces are the primary sources of aberrations in the assembled system. In this scheme, relative tilt refers to the relative angle between the normal vectors of the front and rear surfaces of the lens; relative eccentricity refers to the positional deviation of the vertex (or geometric center) in a plane perpendicular to the optical axis, in the ideal case where there is no relative angle between the two surfaces. When the surface is spherical, the two will be fully coupled, and the concepts of tilt and eccentricity can be reduced to the relative geometrical position of the sphere's center relative to the optical axis.

[0073] The process described in the above embodiments is illustrated below through examples in practical applications.

[0074] Currently, there are three methods in this field for detecting center thickness, relative tilt, and relative eccentricity: The first approach primarily utilizes a coordinate measuring machine (CMM) to collect coordinate data at multiple points on the front and back surfaces of the component using contact probes. The respective plane equations are then fitted, and the tilt angle between the normals of the two planes is calculated using the spatial vector angle. This approach can establish a unified reference coordinate system for the upper and lower surfaces using markers on the outer cylindrical surface of the component, thereby reducing or avoiding flipping during clamping. However, the accuracy of the unified outer cylindrical datum is poor, easily introducing significant datum conversion errors. The second approach uses an optical center deviation measuring instrument from a certain company. It uses the rotation axis of a high-precision air bearing turntable as a unified reference datum and employs an electronic autocollimator measuring head to measure the upper and lower surfaces of the lens. Data can be collected simultaneously from both sides using dual measuring heads, or sequentially using a single measuring head, to obtain the eccentricity and tilt angle of the upper and lower surfaces relative to the turntable axis. Finally, the relative tilt and relative eccentricity of the two surfaces are calculated. This approach is a non-contact optical measurement method, offering high accuracy and eliminating the need to flip the workpiece. However, it relies heavily on optical imaging and has high selectivity for the measured component. The third approach is to use a non-contact 3D optical profilometer. The probe position and swing angle are calculated using the ideal shape of the component. The laser passes through the front surface and is perpendicularly incident on the rear surface and returns along the same path. The sag data of the annulus on the rear surface is collected by rotating the turntable, and the relative tilt and eccentricity of the rear surface are calculated based on this data. This approach has a simple structure, but it is not well adapted to thick or non-transparent components.

[0075] Of the three existing solutions: the coordinate measuring machine (CMM) has the risk of contact measurement, easily causing scratches or indentations on soft, high-precision optical surfaces; it usually requires flipping the workpiece or relying on the outer cylindrical surface to establish a unified datum, resulting in secondary clamping errors or poor datum conversion accuracy; the overall measurement efficiency is low, making it unsuitable for batch inspection; and it has poor adaptability to thin-walled or easily deformable components, easily introducing additional deformation during clamping and support. Although the optical center deviation measuring instrument is a non-contact measurement with high accuracy and no need to flip the workpiece, it mainly relies on optical imaging, making it completely unable to measure non-transparent or strongly absorptive components, and poorly adaptable to thick components; in addition, for aspherical components, an additional aspherical center deviation and tilt measurement module is required to effectively separate tilt and eccentricity, significantly increasing system complexity and cost, while also requiring high surface cleanliness, coating reflectivity, and environmental stability. Although the non-contact 3D optical profilometer solution is simple in structure and fast in measurement, it has poor adaptability to thick components (the long round-trip optical path of the laser causes signal attenuation or failure to return), it is completely unable to measure non-transparent or absorbent components, and it is highly dependent on the ideal shape of the component. When the actual shape deviates significantly, it is easy to introduce calculation errors. At the same time, it has high requirements for surface cleanliness.

[0076] Please see Figure 2 , Figure 2 This is a schematic diagram of an integrated inspection device for detecting absolute surface shape and geometric quantities, provided in an embodiment of this application. Addressing the shortcomings of the aforementioned related technical solutions, this application provides an integrated inspection solution for absolute surface shape and geometric quantities. Using a hollow high-precision turntable 4 as a unified reference, a completely integrated mechanical structure is constructed. Under the same clamping condition, high-precision inspection of the absolute surface shape, center thickness, relative tilt, and relative eccentricity of the upper and lower surfaces is achieved simultaneously, fundamentally eliminating clamping errors, improving inspection accuracy and efficiency, and meeting the requirements of picometer-level extreme manufacturing for precise control of the geometric quantities of optical elements of arbitrary shapes and sizes. This solution supports geometric quantity inspection of lens elements of various shapes and materials, including but not limited to spherical / aspherical, double aspherical, double spherical, planar, thick lens elements, and non-transparent elements.

[0077] This solution performs integrated inspection of the upper and lower surfaces of optical components under the same clamping condition: the upper surface uses a non-contact ultra-precision contour scanning inspection device to simultaneously acquire the absolute surface shape of the upper surface and its tilt and eccentricity relative to the hollow high-precision turntable 4; the lower surface is obtained by a precision motion system arranged inside the hollow high-precision turntable 4 in conjunction with the rotation of the hollow high-precision turntable 4, the displacement change curve is acquired and the geometric quantities of the lower surface relative to the hollow high-precision turntable 4 are calculated; finally, combined with the center thickness measurement, the relative tilt, relative eccentricity and center thickness of the upper and lower surfaces are accurately characterized.

[0078] exist Figure 2In the corresponding embodiment, the upper surface X-axis motion platform 12 can be selected from the first X-axis linear motion platform in the previous embodiment, the upper surface Z-axis motion platform 13 can be selected from the first Z-axis linear motion platform in the previous embodiment, the θ-axis rotation platform 16 can be selected from the first rotation platform in the previous embodiment, the fourth probe 17 can be selected from the first displacement sensor in the previous embodiment, the lower surface X-axis motion platform 5 can be selected from the second X-axis linear motion platform in the previous embodiment, and the lower surface Z-axis motion platform 6 can be selected from the second Z-axis linear motion platform in the previous embodiment. The axis rotation platform 7 can be the second rotation platform in the previous embodiment, and the first probe 9 can be the second displacement sensor in the previous embodiment.

[0079] Based on the aforementioned integrated testing equipment, this embodiment provides an integrated testing solution for absolute surface shape and geometric quantities, which includes the following steps: Step 1: Mount the lens element and establish a reference.

[0080] The lens element to be tested is securely clamped on the hollow high-precision turntable 4, ensuring a stable and secure clamping without any looseness. Through precise calibration, the rotation axis of the hollow high-precision turntable 4 is established as the unified reference coordinate system for the entire testing system. All geometric quantities are characterized relative to this reference, fundamentally ensuring the consistency of the data on the upper and lower surfaces. Figure 1 The turntable in the corresponding embodiment can be a turntable with a hollow structure, namely a hollow high-precision turntable 4.

[0081] Step 2: Measure the absolute shape and geometric quantities of the upper surface.

[0082] The upper part of the integrated testing equipment adopts a non-contact ultra-precision contour scanning testing device. The device is supported by a vibration isolation platform 1, an isolation cover 2, and a marble base 3, and is equipped with an upper surface X-axis motion platform 12, an upper surface Z-axis motion platform 13, and a θ-axis rotation platform 16.

[0083] To ensure the accuracy of the upper surface measurement, the system is also equipped with a second probe 14 and a third probe 15. Based on a laser interferometer, and in conjunction with the Z-axis calibration reference mirror 11 and the X-axis calibration reference mirror 10, high-precision calibration is achieved. Since the laser interferometer is sensitive to ambient airflow, an isolation enclosure 2 is installed to reduce external interference. Furthermore, to further eliminate residual motion errors during the rotation of the hollow high-precision turntable 4, a fifth probe 18, a sixth probe 19, and a seventh probe 20 are fixedly installed on the marble base 3 for real-time calibration of unnecessary lateral and longitudinal runout errors of the hollow high-precision turntable 4.

[0084] During measurement, the fourth probe 17, while rotating the component on the hollow high-precision turntable 4, adjusts its own posture along with the upper surface X-axis motion platform 12 and the upper surface Z-axis motion platform 13 to ensure its orientation remains perpendicular to the component surface and simultaneously acquires upper surface contour data. This part of the device simultaneously acquires the full-diameter surface profile sagittal data of the upper surface while the hollow high-precision turntable 4 rotates the component, and directly calculates the tilt and eccentricity of the upper surface relative to the rotation axis of the hollow high-precision turntable 4. This step simultaneously obtains high-precision absolute surface profile and upper surface geometric information, providing reference data for subsequent relative geometric calculations.

[0085] Step 3: Measure the geometry of the lower surface.

[0086] This solution involves arranging a precision motion measurement system inside the hollow high-precision turntable 4. This system includes the following components: The lower surface X-axis motion platform 5 is used for radial adjustment of the measurement position; The lower surface Z-axis motion platform 6 is used for axial adjustment of the sensor's working distance; Axis rotary platform 7 is used to provide precise rotational capability in the detection direction; The Z-shaped rigid body connecting bracket 8 adopts a Z-shaped connecting rod design to maximize the use of the rotating platform space while ensuring rigidity; The first probe 9 is used to detect the lower surface in a non-contact manner.

[0087] The measuring point of the first probe 9 is precisely aligned with... The centers (i.e., rotation centers) of the rotating platform 7 coincide, ensuring that the geometric position remains unchanged during rotation. The lower surface X-axis motion platform 5 and the lower surface Z-axis motion platform 6 are responsible for adjusting the first probe 9 to the target measurement ring position, supporting the acquisition of normal displacement data for spherical or aspherical surfaces with different basic parameters and rings of different radii. The initial position of this motion system needs to be precisely calibrated so that the measurement point is located at the rotation center of the hollow high-precision turntable 4 and its measurement direction is perpendicular to the turntable plane. In addition, its initial measurement point needs to be calibrated in the local coordinate system of the upper surface measurement system to establish the connection between the local coordinate systems of the upper and lower measurement systems.

[0088] During testing, the hollow high-precision turntable 4 drives the component to rotate at a constant speed. The axis rotation platform 7 is rotated and positioned as needed. The sensor synchronously collects the precise displacement change curve in the measurement direction and collects the data of the complete rotation cycle of multiple radius rings as the basis for calculation. The axis is parallel to the Y-axis in the global reference coordinate system O-XYZ.

[0089] Step 4: Solve for relative geometric quantities.

[0090] For center thickness It is defined as the distance between the vertices of the upper and lower surfaces of the lens along the optical axis. It can be obtained by measuring the height of the vertices of the upper and lower surfaces using the fourth probe 17 and the first probe 9 respectively before the formal measurement. Equation (1); in, The nominal distance between the measurement points of the upper and lower probes is given for system calibration. This represents the measured axial deviation of the upper probe at its apex. This represents the measured axial deviation of the lower probe at the apex.

[0091] A global reference coordinate system O-XYZ is established with the rotation axis of the hollow high-precision turntable 4 as the Z-axis. Point O is set as the ideal geometric center between the lower surface of the lens and the cross-sectional plane of the outer cylindrical surface, and the XOY plane is perpendicular to the rotation axis of the hollow high-precision turntable 4. All tilt, eccentricity, and thickness parameters are uniformly characterized in this coordinate system to ensure the consistency of the upper and lower surface data.

[0092] From step 2, the fitted surface obtained by ultra-precise profile detection of the upper surface is compared with the ideal upper surface, and the following geometric quantities of the upper surface relative to the O-XYZ reference system are calculated: Upper surface tilt vector The angle vector between the normal to the upper surface and the Z-axis of the hollow high-precision turntable 4 is expressed in polar coordinates as follows: ,in The tilt amplitude, The azimuth angle corresponding to the included angle vector; the eccentricity vector of the upper surface. The lateral displacement vector of the actual geometric center of the upper surface and the outer cylindrical cross-section deviating from the axis of the hollow high-precision turntable 4, expressed in polar coordinates as: ,in This is a deviation value. This is the azimuth angle corresponding to the lateral displacement vector.

[0093] Equation (2); In the above formula, The unit vector representing the X-axis direction. The unit vector representing the Y-axis direction.

[0094] From step 3, in n measurement radius rings The normal displacement signal of the hollow high-precision turntable 4 during its complete rotation cycle was collected at each location. It can be represented as: Equation (3); in It is a constant (reflecting the probe's working distance reference). For noise, The amplitude of the first harmonic. The phase of the first harmonic. and As the main component of the signal, higher harmonics (m≥2) correspond to the surface shape error of the lower surface and are not included in the geometric calculation. M represents the maximum harmonic order involved in the calculation, and m represents the harmonic order. This represents the amplitude of the m-th harmonic. This indicates the rotation angle of the hollow high-precision turntable 4. Let represent the phase of the m-th harmonic. Using Fourier transform to extract its first harmonic and preserving it in complex form, we have: Equation (4); Let be the complex representation of the first harmonic component on the k-th measurement radius ring; Let be the amplitude of the first harmonic on the k-th measurement radius ring; It is a complex exponential function used to represent first-order harmonics in complex form.

[0095] The lower surface is tilted relative to the hollow high-precision turntable 4 (normal vector deflection angle). azimuth ) and eccentricity (lateral displacement of the geometric center of the cutting plane) azimuth Both contribute to the first harmonic and require decoupling through multi-loop data. (In the measurement radius...) At this location, the theoretical model for the first harmonic complex vector of the normal displacement caused by tilt and eccentricity is as follows: Equation (5); in , Divided into measurement radii The distance from the measurement point on the measurement radius ring to the origin, and the angle between the position vector and the Z-axis. For the lower surface at the measured radius The angle between the surface normal at that location and the Z-axis.

[0096] This represents a theoretical model of the first harmonic of the normal displacement caused by the inclination and eccentricity of the lower surface on the k-th measurement radius ring. Indicates the tilt magnitude of the lower surface (the angle between the normal to the lower surface and the Z-axis); The base of the natural logarithm; Represents the imaginary unit; This indicates the rotation angle of the hollow high-precision turntable 4; Indicates the azimuth angle of the lower surface inclination (the angle between the projection direction of the lower surface normal in the XOY plane and the positive X-axis direction). This indicates the magnitude of the eccentricity of the lower surface (the vertical distance between the geometric center of the lower surface and the Z-axis). It represents the eccentricity azimuth angle of the lower surface (the angle between the offset direction of the geometric center of the lower surface in the XOY plane and the positive direction of the X-axis).

[0097] Combining equations (4) and (5), the following system of equations (i.e., the target equation system) is established for n (≥2) measurement loops: Equation (6); , … This represents the spatial distance from the origin to each measurement point on the measurement radius ring; , … This represents the angle between the position vector of each measurement point on the measurement radius ring and the Z-axis; , … This indicates the angle between the normal to the lower surface at each measurement radius ring and the Z-axis; , … This represents the first-order harmonic complex component extracted from the actual measurements on each measurement radius ring.

[0098] The equation has a unique solution when n=2, and a least-squares solution when n>2. The tilt vector of the lower surface can be calculated using the equation. and the lower surface eccentricity vector .

[0099] Therefore, the relative tilt vector of the two surfaces of the lens (with the upper surface as the reference) and relative eccentricity vector It can ultimately be expressed as: Equation (7); Equation (8).

[0100] The high-precision displacement sensors in the above scheme (such as the first probe 9, the second probe 14, the third probe 15, the fourth probe 17, the fifth probe 18, the sixth probe 19, and the seventh probe 20) can be replaced with other types of high-precision non-contact sensors (such as laser triangulation, confocal sensors, white light interferometers, etc.), or low-risk contact probes can be used under specific working conditions. The lower surface motion system in the above scheme can adjust the degree of freedom configuration according to the component size and detection requirements (such as adding more adjustment axes, using a fixed multi-probe array, or simplifying with a single probe). (Axis). The upper surface detection device in the above scheme can adopt other self-developed or commercial high-precision contour scanning systems as needed, as long as they can provide high-precision tilt / eccentricity data relative to the hollow high-precision turntable 4. The above scheme is applicable to optical lenses, flat plate elements or mirrors of various curved surface types such as plane, spherical, and aspherical surfaces. More auxiliary measurement modules (such as automatic centering and automatic leveling devices) can be integrated and expanded.

[0101] The relevant principles and key components of this solution have been verified by laboratory experiments. The results are highly consistent with the theoretical derivation, proving that the solution is practical and effective and can meet extreme manufacturing requirements.

[0102] This solution supports precise measurement of the absolute surface shape and geometry of components of arbitrary thickness and non-transparent surfaces. It employs a non-contact probe, avoiding the risk of scratches, and can directly measure the center thickness. Measurements of the upper and lower surfaces can be performed simultaneously, and the absolute surface shape and relative geometry of the upper surface can be obtained in a single measurement, resulting in high detection efficiency. For double aspherical surfaces, this solution supports directly handling tilt-eccentric coupling problems by measuring multiple rings on the lower surface. This solution has no restrictions on component surface shape type and is applicable to spherical / aspherical, double aspherical, double spherical, and planar surfaces. This solution has a compact structure, primarily relying on mature motion components and high-precision sensors, making it easy to integrate into engineering and for widespread application.

[0103] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a parameter detection system for an optical element provided in an embodiment of this application. The system is applied to an integrated testing device, which includes a turntable, an upper surface measurement assembly, and a lower surface measurement assembly. The turntable is used to clamp the optical element. The upper surface measurement assembly includes a first motion platform and a first displacement sensor. The first motion platform drives the first displacement sensor to move above the upper surface of the optical element, so that the first displacement sensor measures the upper surface. The lower surface measurement assembly includes a second motion platform and a second displacement sensor. The second motion platform drives the second displacement sensor to move below the lower surface of the optical element, so that the second displacement sensor measures the lower surface. The parameter detection system for the optical element includes: A rotation control module is used to control the turntable to drive the optical element to rotate around the Z-axis; The first detection and control module is used to activate the first displacement sensor and control the first motion platform to drive the first displacement sensor to perform motion that meets the constraint conditions, thereby obtaining the contour data collected by the first displacement sensor; wherein, the constraint condition is: the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point; The second detection and control module is used to activate the second displacement sensor and control the second motion platform to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor; wherein, the measurement direction of the second displacement sensor when collecting the normal displacement data is perpendicular to the tangent plane of the current measurement point; The data processing module is used to determine the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data, and to determine the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data. The result calculation module is used to determine the relative tilt vector of the optical element based on the tilt vector of the upper surface and the tilt vector of the lower surface, and to determine the relative eccentricity vector of the optical element based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface.

[0104] This embodiment applies to an integrated testing device, which includes a turntable, an upper surface measurement component, and a lower surface measurement component. As the optical element rotates with the turntable, the upper and lower surface measurement components can respectively measure the upper and lower surfaces of the optical element, avoiding clamping errors introduced by separate clamping measurements and ensuring measurement accuracy. The upper surface measurement component includes a first motion platform and a first displacement sensor. During parameter detection, the first displacement sensor, driven by the first motion platform, measures perpendicular to the tangent plane of the current measurement point, eliminating measurement errors introduced by incident angle deviation. The lower surface measurement component includes a second motion platform and a second displacement sensor. The second displacement sensor collects normal displacement data on multiple measurement radius rings, ensuring that the measurement direction is perpendicular to the tangent plane at each ring. After obtaining the tilt vector and eccentricity vector of each of the upper and lower surfaces, this embodiment can calculate the relative tilt vector and relative eccentricity vector of the upper and lower surfaces of the optical element. The above process does not require the optical element to be clamped and measured in stages. The measurement of the upper and lower surfaces is carried out simultaneously, and there are no restrictions on the surface shape of the optical element. Therefore, this embodiment can accurately detect the tilt vector and eccentricity vector of the optical element.

[0105] Furthermore, the first motion platform includes a first X-axis linear motion platform, a first Z-axis linear motion platform, and a first rotary platform, with the first displacement sensor mounted on the first rotary platform; the first X-axis linear motion platform is used to drive the first displacement sensor to move linearly in the X-axis direction, the first Z-axis linear motion platform is used to drive the first displacement sensor to move linearly in the Z-axis direction, and the first rotary platform is used to drive the first displacement sensor to rotate around a first rotation axis, which is parallel to the Y-axis; Accordingly, the process by which the first detection and control module controls the first motion platform to drive the first displacement sensor to perform motion that meets the constraints includes: A first control command is sent to the first X-axis linear motion platform to adjust the X-axis coordinate of the first displacement sensor; A second control command is issued to the first Z-axis linear motion platform to keep the distance between the first displacement sensor and the upper surface within the effective working distance. A third control command is sent to the first rotating platform to make the measurement direction of the first displacement sensor perpendicular to the tangent plane of the current measurement point.

[0106] Furthermore, the turntable has a hollow structure, and the lower surface measuring component is disposed within the hollow structure. When the optical element is clamped on the turntable, the optical element is located above the hollow structure. The second motion platform includes a second X-axis linear motion platform, a second Z-axis linear motion platform, and a second rotary platform. The second X-axis linear motion platform drives the second displacement sensor to move linearly in the X-axis direction, and the second Z-axis linear motion platform drives the second displacement sensor to move linearly in the Z-axis direction. The second rotary platform has a connecting bracket, which includes a first end and a second end. The first end of the connecting bracket is connected to the second displacement sensor, and the second rotary platform drives the connecting bracket and the second displacement sensor to rotate around a second rotation axis parallel to the Y-axis. The measurement point of the second displacement sensor coincides with the rotation center of the second rotary platform. Accordingly, the process by which the second detection and control module controls the second motion platform to move the second displacement sensor to the position corresponding to the multiple measurement radius rings includes: A fourth control command is sent to the second X-axis linear motion platform and the second Z-axis linear motion platform to make the second displacement sensor move to the position corresponding to the current measurement radius ring; A fifth control command is sent to the second rotating platform to make the measurement direction of the second displacement sensor perpendicular to the tangent plane of the current measurement point.

[0107] Furthermore, the process by which the data processing module determines the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data includes: The fitting surface is determined based on the contour data, and the theoretical upper surface is determined based on the design parameters of the optical element. The fitting surface is compared with the theoretical upper surface to obtain the upper surface tilt vector and the upper surface eccentricity vector.

[0108] Furthermore, the process by which the data processing module determines the tilt vector and eccentricity vector of the lower surface of the optical element based on the normal displacement data includes: Perform a Fourier transform on the normal displacement data corresponding to each measurement radius ring to extract the first harmonic component corresponding to each measurement radius ring; A set of target equations is constructed based on the geometric parameters and first harmonic components of the measurement radius ring; wherein, the set of target equations is used to describe the relationship between the lower surface tilt vector and the lower surface eccentricity vector and the first harmonic components; By solving the objective equations, the tilt vector of the lower surface and the eccentricity vector of the lower surface are obtained.

[0109] Furthermore, the process by which the result calculation module determines the relative eccentricity vector of the optical element based on the upper surface eccentricity vector and the lower surface eccentricity vector includes: Determine the center thickness of the optical element; wherein the center thickness is the distance between the vertex of the upper surface and the vertex of the lower surface along the optical axis; The relative eccentricity vector of the optical element is determined based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector.

[0110] Furthermore, the process by which the result calculation module determines the relative eccentricity vector of the optical element based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector includes: Substituting the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector into the relative eccentricity calculation formula, the relative eccentricity vector of the optical element is obtained; The formula for calculating relative eccentricity is as follows: ; Represents the relative eccentricity vector. Indicates the eccentricity vector of the lower surface. This represents the eccentricity vector of the upper surface. Indicates the center thickness. This represents the tilt vector of the upper surface.

[0111] Since the embodiments of the system part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the system part, and they will not be repeated here.

[0112] This application also provides a storage medium on which a computer program is stored, which, when executed, can perform the steps provided in the above embodiments. The storage medium may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0113] This application also provides a device (i.e., an electronic device) that may include a memory and a processor. The memory stores a computer program, and when the processor calls the computer program in the memory, it can implement the steps provided in the above embodiments. Of course, the device may also include various network interfaces, power supplies, and other components.

[0114] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

[0115] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for detecting parameters of an optical element, characterized in that, An integrated testing device is used, comprising a turntable, an upper surface measurement assembly, and a lower surface measurement assembly. The turntable is used to clamp optical elements. The upper surface measurement assembly includes a first motion platform and a first displacement sensor. The first motion platform drives the first displacement sensor to move above the upper surface of the optical element, so that the first displacement sensor measures the upper surface. The lower surface measurement assembly includes a second motion platform and a second displacement sensor. The second motion platform is used to drive the second displacement sensor to move below the lower surface of the optical element, so that the second displacement sensor can measure the lower surface. The parameter detection method of the optical element includes: The turntable is controlled to drive the optical element to rotate around the Z-axis; The first displacement sensor is activated, and the first motion platform is controlled to drive the first displacement sensor to perform motion that meets the constraints, thereby obtaining the contour data collected by the first displacement sensor; wherein, the constraints are: the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point; The second displacement sensor is activated, and the second motion platform is controlled to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor; wherein, the measurement direction of the second displacement sensor when collecting the normal displacement data is perpendicular to the tangent plane of the current measurement point; The upper surface tilt vector and upper surface eccentricity vector of the optical element are determined based on the contour data, and the lower surface tilt vector and lower surface eccentricity vector of the optical element are determined based on the normal displacement data. The relative tilt vector of the optical element is determined based on the tilt vector of the upper surface and the tilt vector of the lower surface, and the relative eccentricity vector of the optical element is determined based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface. The determination of the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data includes: Perform a Fourier transform on the normal displacement data corresponding to each measurement radius ring to extract the first harmonic component corresponding to each measurement radius ring; A set of target equations is constructed based on the geometric parameters and first harmonic components of the measurement radius ring; wherein, the set of target equations is used to describe the relationship between the lower surface tilt vector and the lower surface eccentricity vector and the first harmonic components; By solving the objective equations, the tilt vector of the lower surface and the eccentricity vector of the lower surface are obtained.

2. The parameter detection method for an optical element according to claim 1, characterized in that, The first motion platform includes a first X-axis linear motion platform, a first Z-axis linear motion platform, and a first rotary platform. The first displacement sensor is mounted on the first rotary platform. The first X-axis linear motion platform is used to drive the first displacement sensor to move linearly in the X-axis direction. The first Z-axis linear motion platform is used to drive the first displacement sensor to move linearly in the Z-axis direction. The first rotary platform is used to drive the first displacement sensor to rotate around a first rotation axis, which is parallel to the Y-axis. Accordingly, controlling the first motion platform to drive the first displacement sensor to perform motion that meets the constraints includes: A first control command is sent to the first X-axis linear motion platform to adjust the X-axis coordinate of the first displacement sensor; A second control command is issued to the first Z-axis linear motion platform to keep the distance between the first displacement sensor and the upper surface within the effective working distance. A third control command is sent to the first rotating platform to make the measurement direction of the first displacement sensor perpendicular to the tangent plane of the current measurement point.

3. The parameter detection method for an optical element according to claim 1, characterized in that, The turntable has a hollow structure, and the lower surface measuring component is disposed inside the hollow structure. When the optical element is clamped on the turntable, the optical element is located above the hollow structure. The second motion platform includes a second X-axis linear motion platform, a second Z-axis linear motion platform, and a second rotary platform. The second X-axis linear motion platform drives the second displacement sensor to move linearly in the X-axis direction, and the second Z-axis linear motion platform drives the second displacement sensor to move linearly in the Z-axis direction. The second rotary platform has a connecting bracket, which includes a first end and a second end. The first end of the connecting bracket is connected to the second displacement sensor, and the second rotary platform drives the connecting bracket and the second displacement sensor to rotate around a second rotation axis parallel to the Y-axis. The measurement point of the second displacement sensor coincides with the rotation center of the second rotary platform. Accordingly, controlling the second motion platform to move the second displacement sensor to the position corresponding to the multiple measurement radius rings includes: A fourth control command is sent to the second X-axis linear motion platform and the second Z-axis linear motion platform to make the second displacement sensor move to the position corresponding to the current measurement radius ring; A fifth control command is sent to the second rotating platform to make the measurement direction of the second displacement sensor perpendicular to the tangent plane of the current measurement point.

4. The parameter detection method for an optical element according to claim 1, characterized in that, Determining the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data includes: The fitting surface is determined based on the contour data, and the theoretical upper surface is determined based on the design parameters of the optical element. The fitting surface is compared with the theoretical upper surface to obtain the upper surface tilt vector and the upper surface eccentricity vector.

5. The parameter detection method for an optical element according to claim 1, characterized in that, Determining the relative eccentricity vector of the optical element based on the upper surface eccentricity vector and the lower surface eccentricity vector includes: Determine the center thickness of the optical element; wherein the center thickness is the distance between the vertex of the upper surface and the vertex of the lower surface along the optical axis; The relative eccentricity vector of the optical element is determined based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector.

6. The parameter detection method for an optical element according to claim 5, characterized in that, The relative eccentricity vector of the optical element is determined based on the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector, including: Substituting the upper surface eccentricity vector, the lower surface eccentricity vector, the center thickness, and the upper surface tilt vector into the relative eccentricity calculation formula, the relative eccentricity vector of the optical element is obtained; The formula for calculating relative eccentricity is as follows: ; Represents the relative eccentricity vector. Indicates the eccentricity vector of the lower surface. This represents the eccentricity vector of the upper surface. Indicates the center thickness. This represents the tilt vector of the upper surface.

7. A parameter detection system for an optical element employing the parameter detection method of any one of claims 1 to 6, characterized in that, An integrated testing device is used, comprising a turntable, an upper surface measurement assembly, and a lower surface measurement assembly. The turntable is used to clamp optical elements. The upper surface measurement assembly includes a first motion platform and a first displacement sensor. The first motion platform drives the first displacement sensor to move above the upper surface of the optical element, so that the first displacement sensor measures the upper surface. The lower surface measurement assembly includes a second motion platform and a second displacement sensor. The second motion platform is used to drive the second displacement sensor to move below the lower surface of the optical element, so that the second displacement sensor can measure the lower surface. The parameter detection system of the optical element includes: A rotation control module is used to control the turntable to drive the optical element to rotate around the Z-axis; The first detection and control module is used to activate the first displacement sensor and control the first motion platform to drive the first displacement sensor to perform motion that meets the constraint conditions, thereby obtaining the contour data collected by the first displacement sensor; wherein, the constraint condition is: the measurement direction of the first displacement sensor is perpendicular to the tangent plane of the current measurement point; The second detection and control module is used to activate the second displacement sensor and control the second motion platform to move the second displacement sensor to the position corresponding to multiple measurement radius rings, so as to obtain the normal displacement data corresponding to each measurement radius ring collected by the second displacement sensor; wherein, the measurement direction of the second displacement sensor when collecting the normal displacement data is perpendicular to the tangent plane of the current measurement point; The data processing module is used to determine the upper surface tilt vector and upper surface eccentricity vector of the optical element based on the contour data, and to determine the lower surface tilt vector and lower surface eccentricity vector of the optical element based on the normal displacement data. The result calculation module is used to determine the relative tilt vector of the optical element based on the tilt vector of the upper surface and the tilt vector of the lower surface, and to determine the relative eccentricity vector of the optical element based on the eccentricity vector of the upper surface and the eccentricity vector of the lower surface.

8. A device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor, when calling the computer program in the memory, implements the steps of the parameter detection method for the optical element as described in any one of claims 1 to 6.

9. A storage medium, characterized in that, The storage medium stores computer-executable instructions, which, when loaded and executed by a processor, implement the steps of the parameter detection method for the optical element as described in any one of claims 1 to 6.

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