A spectral confocal and precise position feedback cooperative lens full topography measurement system

Abstract

The application provides a lens full-morphology measurement system with spectrum confocal and precise position feedback cooperation, and belongs to the technical field of precise optical component detection, and comprises a grating ruler feedback unit, an optical measurement module is fixedly connected to the upper end face of the grating ruler feedback unit, and a precise displacement module is used for driving the second lifting module to move horizontally; through cooperation of various modules, the problems of morphology reconstruction distortion and mapping coordinate dislocation caused by software timing acquisition in traditional multi-axis linkage detection are solved; the system passes through a non-contact optical light path, and physical stylus micro-scratch damage to the precise optical coating surface is avoided; meanwhile, the system integrates a multi-stage dynamic height compensation module, so that the measured lens can still obtain high positioning repeatability, axial focal depth consistency and sub-micron level dynamic calculation accuracy under the conditions of large slope edge area and transparent multi-interface reflection interference, and the system is particularly suitable for high standard requirements of precise optical components in intelligent production line high-frequency online detection.

Description

Technical Field

[0001] This invention relates to the field of precision optical component testing technology, specifically a lens full-shape measurement system that combines spectral confocalization and precision position feedback. Background Technology

[0002] The accuracy of geometric parameter detection for precision optical components (such as aspherical lenses and freeform lenses) has leaped from the micrometer level to the submicrometer and even nanometer level. Existing measurement technologies are mainly divided into two categories: contact and non-contact. Contact measurements, represented by stylus profilometers and coordinate measuring machines (CMMs), rely on a probe sliding along the measured surface to acquire profile data. Their inherent drawbacks include: physical contact easily scratches precision coatings or soft lenses, causing irreversible damage; limited by mechanical transmission inertia, measurement efficiency is low, making it difficult to meet the demands of high-speed online full inspection; and when facing surfaces with high steepness and small curvature radii, the probe is prone to bouncing, making it impossible to reproduce the true microscopic morphology. In non-contact measurements, although laser interferometry can achieve nanometer-level resolution, it is extremely sensitive to environmental vibrations and airflow disturbances, requiring stringent laboratory conditions, and has a measurement blind zone in areas with large tilt angles at the lens edges. When measuring transparent materials using laser triangulation, stray light from the front and back surfaces of the lens interferes with each other, and the measurement accuracy is significantly reduced in areas with large slopes due to limitations in spot diameter and depth of field.

[0003] A more prominent problem is that existing measurement systems generally suffer from limitations such as thickness measurement and topography scanning being independent of each other, or lacking a high-precision real-time synchronization mechanism. Position feedback elements and ranging elements typically collect data through software-based periodic polling. Factors such as mechanical transmission backlash, shaft vibration, and misalignment of the sampling time axis can couple and introduce significant dynamic mapping errors, becoming a technical bottleneck restricting the accurate reconstruction of the entire lens topography.

[0004] In view of the above situation, there is an urgent need to develop a precision testing device that can overcome existing measurement blind spots, reduce environmental interference, and has a hardware-level real-time synchronization mechanism. This device aims to solve the prominent problems of low spatial mapping accuracy, large dynamic error, and weak anti-interference ability in existing optical measurement systems, so as to meet the high standards required by the precision optics industry for high-quality lens testing. Summary of the Invention

[0005] The purpose of this invention is to provide a lens full-shape measurement system that combines spectral confocalization and precise position feedback to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a lens full-shape measurement system with spectral confocalization and precise position feedback coordination, comprising a mounting base, an optical measurement module fixedly connected to the upper surface of the mounting base, a precision displacement module fixedly connected to the upper surface of the mounting base on the side of the optical measurement module 100, the precision displacement module being used to drive a second lifting module to move horizontally, the second lifting module being fixedly connected to a connecting frame, and a sample carrying module fixedly connected to the upper surface of the connecting frame, the sample carrying module being used to clamp and position the lens to be measured, thereby solving the problem of traditional multi-axis linkage inspection through the cooperation of various modules. The system addresses the issues of morphological reconstruction distortion and mapping coordinate misalignment caused by timed data acquisition in the software. Its through-beam non-contact optical path completely eliminates micro-scratches that could damage the precision optical coating surface from physical contact. Furthermore, the system integrates a multi-level dynamic height compensation module encompassing the sample-carrying module, the optical measurement module, and the second lifting module. This ensures that the lens under test maintains extremely high positioning repeatability, axial depth-of-focus consistency, and sub-micron-level dynamic calculation accuracy even in high-angle edge regions and under transparent multi-interface reflection interference. This is particularly well-suited to the high standards required for high-frequency online inspection of precision optical components in intelligent production lines.

[0007] Preferably, the optical measurement module includes a first fixing plate fixedly connected to the upper surface of the mounting base, a second fixing plate provided on the upper side of the first fixing plate, and a first lifting module fixedly connected between the second fixing plate and the first fixing plate. The first lifting module is used to lift the second fixing plate to adjust its height. A lower spectral confocal probe is engaged with the first fixing plate, and an upper spectral confocal probe is engaged with the second fixing plate. The upper spectral confocal probe and the lower spectral confocal probe are coaxially opposed to each other. The lower spectral confocal probe and the upper spectral confocal probe are used to adjust the depth of focus and physical working distance in the vertical axis. This achieves the purpose of aligning the reference focus with lenses of different thicknesses and curvature radii. Preferably, the precision displacement module includes a slide rail fixedly connected to the upper surface of the mounting base. The slide rail is located on the side of the measurement position of the optical measurement module. A sliding frame is slidably connected to the slide rail. A precision servo motor is fixedly connected to the slide rail. The precision servo motor is used to drive the sliding frame to move horizontally. The sliding frame is fixedly connected to the second lifting module. The second lifting module is used to lift the connecting frame and the sample carrier module for height adjustment, thereby performing reciprocating motion to enter or exit the detection range or reset and exit, thus ensuring the straightness characteristics and positioning accuracy attributes of the dynamic scanning path, and realizing multi-level dynamic height compensation. Preferably, the sample carrying module includes a clamping driver fixedly connected to the upper end face of the connecting frame. The clamping driver is used to drive two symmetrical V-shaped tray frames to clamp the lens to be tested. The V-shaped tray frames are used for high-precision positioning and clamping. Together with the second lifting module and the first lifting module, they form a multi-level vertical axis motion compensation architecture, which is used to dynamically adjust the vertical height of the lens tray and the infeed and outfeed paths during the scanning process. The V-shaped tray frames use the inclined side walls on both sides to perform double-point contact non-destructive clamping on the outer edge of the lens to be tested, thereby performing automatic centering axis alignment operation on the lens to be tested with different outer diameter specifications. Preferably, the upper surface of the mounting base is fixedly connected to a photoelectric sensor and a grating ruler feedback unit located on the side of the precision displacement module. The photoelectric sensor is installed at a specific starting node of the horizontal reciprocating scanning path. The grating ruler feedback unit records the spatial displacement data of the precision displacement scanning module in the horizontal direction in real time and outputs a high-frequency position pulse trigger signal to the processing system in real time. The photoelectric sensor is used to sense the spatial edge cutting state of the lens in real time and establish the zero point of the displacement reference coordinate. The processor is configured to determine the initial boundary based on the reference signal output by the photoelectric sensor and follow the position pulse trigger signal output by the grating ruler feedback unit. In real time, the lower spectral confocal probe and the upper spectral confocal probe are synchronously driven to perform real-time synchronous data sampling of the spectral signal in a hardware circuit hard trigger mode. This aims to eliminate the sampling lag caused by software timing polling, thereby enabling the hardware-level synchronous mapping and solution of the horizontal spatial position coordinate and the two sets of vertical distance and thickness data to be achieved.

[0008] Compared with the prior art, the beneficial effects of the present invention are: This invention incorporates an optical measurement module and a first lifting module. The optical measurement module and a first fixing plate clamp the upper and lower spectral confocal probes. The first lifting module adjusts the distance between the upper and lower spectral confocal probes, ensuring precise coaxial alignment. A hardware-level position pulse synchronous triggering mechanism deeply couples the spatial feedback of the grating ruler feedback unit with the spectral confocal ranging execution, completely resolving the problems of morphology reconstruction distortion and mapping coordinate misalignment caused by software-timed acquisition in traditional multi-axis linkage detection. The system, through the non-contact optical path of the lower and upper spectral confocal probes, eliminates micro-scratches that could damage the precision optical coating surface from physical contact.

[0009] This invention integrates a precision displacement module, a connecting frame, and a sample carrying module. It also incorporates a multi-level dynamic height compensation module that includes a sample carrying module, a first lifting module, and a second lifting module. This ensures that the lens under test can still achieve extremely high positioning repeatability, axial depth of focus consistency, and sub-micron level dynamic calculation accuracy even in high-angle edge regions and under transparent multi-interface reflection interference. This is particularly in line with the high standards required for high-frequency online testing of precision optical components in intelligent production lines. Attached Figure Description

[0010] Figure 1 This is a three-dimensional schematic diagram of the present invention; Figure 2 for Figure 1 Rear view; Figure 3 for Figure 1 The right view; Figure 4 for Figure 2 Top view.

[0011] In the diagram: 100, Optical Measurement Module; 101, Lower Spectral Confocal Probe; 102, First Fixing Plate; 103, First Lifting Module; 104, Upper Spectral Confocal Probe; 105, Second Fixing Plate; 114, Mounting Base; 200, Precision Displacement Module; 210, Sliding Frame; 211, Slide Rail; 212, Precision Servo Motor; 308, Connecting Frame; 309, Second Lifting Module; 400, Sample Carrying Module; 406, V-Shaped Tray Frame; 407, Clamping Driver; 408, Lens Under Test; 513, Photoelectric Sensor; 514, Grating Ruler Feedback Unit. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] Example 1:

[0014] Please see Figure 1-4This invention provides a technical solution: a lens full-shape measurement system with spectral confocalization and precision position feedback coordination, including a mounting base 114. An optical measurement module 100 is fixedly connected to the upper surface of the mounting base 114. A precision displacement module 200 is fixedly connected to the upper surface of the mounting base 114 on the side of the optical measurement module 100. The precision displacement module 200 is used to drive a second lifting module 309 to move horizontally. A connecting frame 308 is fixedly connected to the second lifting module 309. A sample carrying module 400 is fixedly connected to the upper surface of the connecting frame 308. The sample carrying module 400 is used to clamp and position the lens 408 to be measured, thereby achieving the desired shape through the coordination of various modules. This system solves the problems of morphology reconstruction distortion and mapping coordinate misalignment caused by software-timed acquisition in traditional multi-axis linkage detection. The system completely eliminates micro-scratches and damage to the precision optical coating surface caused by physical contact through a through-beam non-contact optical path. At the same time, the system integrates the sample carrier module 400, the optical measurement module 100 and the second lifting module 309 into a multi-level dynamic height compensation module, which ensures that the lens under test can still obtain extremely high positioning repeatability, axial depth of focus consistency and sub-micron dynamic calculation accuracy in the high-angle edge region and under the interference of transparent multi-interface reflection. It is particularly in line with the high standard requirements of high-frequency online detection of precision optical components in intelligent production lines.

[0015] The optical measurement module 100 includes a first fixing plate 102 fixedly connected to the upper surface of the mounting base 114. A second fixing plate 105 is provided on the upper side of the first fixing plate 102. A first lifting module 103 is fixedly connected between the second fixing plate 105 and the first fixing plate 102. The first lifting module 103 is used to lift the second fixing plate 105 to adjust its height. A lower spectral confocal probe 101 is snapped onto the first fixing plate 102, and an upper spectral confocal probe 104 is snapped onto the second fixing plate 105. The upper spectral confocal probe 104 and the lower spectral confocal probe 101 are coaxially opposed. The lower spectral confocal probe 101 and the upper spectral confocal probe 104 are used to adjust the measurement depth of focus and physical working distance in the vertical axis. This is used to achieve the purpose of aligning the reference focus with lenses of different thicknesses and curvature radii. The precision displacement module 200 includes a slide rail 211 fixedly connected to the upper surface of the mounting base 114. The slide rail 211 is located on the side of the measurement position of the optical measurement module 100. A sliding frame 210 is slidably connected to the slide rail 211. A precision servo motor 212 is fixedly connected to the slide rail 211. The precision servo motor 212 is used to drive the sliding frame 210 to move horizontally. The sliding frame 210 is fixedly connected to the second lifting module 309. The second lifting module 309 is used to lift the connecting frame 308 and the sample carrier module 400 for height adjustment, thereby performing reciprocating motion of entering and exiting the detection range or resetting and exiting, thereby ensuring the straightness characteristics and positioning accuracy attributes of the dynamic scanning path, and realizing multi-level dynamic height compensation. The sample carrying module 400 includes a clamping driver 407 fixedly connected to the upper surface of the connecting frame 308. The clamping driver 407 is used to drive two symmetrical V-shaped tray frames 406 to clamp the lens under test 408. The V-shaped tray frames 406 are used for high-precision positioning and clamping. Together with the second lifting module 309 and the first lifting module 103, they form a multi-level vertical axis motion compensation architecture, which is used to dynamically adjust the vertical height of the lens tray and the infeed and outfeed paths during the scanning process. The V-shaped tray frames 406 use the inclined side walls on both sides to perform double-point contact non-destructive clamping on the outer edge of the lens under test, thereby performing automatic centering axis alignment operation on lenses with different outer diameter specifications. The upper surface of the mounting base 114 is fixedly connected to a photoelectric sensor 513 and a grating ruler feedback unit 514 located on the side of the precision displacement module 200. The photoelectric sensor 513 is installed at a specific starting node of the horizontal reciprocating scanning path. The grating ruler feedback unit 514 records the spatial displacement data of the precision displacement scanning module in the horizontal direction in real time and outputs a high-frequency position pulse trigger signal to the processing system in real time. The photoelectric sensor 513 is used to sense the spatial edge cutting state of the lens in real time and establish the zero point of the displacement reference coordinate. The processor is configured to determine the initial boundary based on the reference signal output by the photoelectric sensor 513 and follow the position pulse trigger signal output by the grating ruler feedback unit 514. In real time, the lower spectral confocal probe 101 and the upper spectral confocal probe 104 are synchronously driven to perform real-time synchronous data sampling of the spectral signal in a hardware circuit hard trigger mode. This aims to eliminate the sampling lag caused by software timing polling, so that the hardware-level synchronous mapping calculation of the horizontal spatial position coordinate and the two sets of vertical distance and thickness data can be achieved.

[0016] Working principle: First, install the lens under test 408 and place it between the V-shaped tray frame 406. Start the clamping driver 407, which drives 106 to clamp the lens under test 408. 506 positions the lens under test 408 with high precision to determine its position. Then, rotate the adjusting rods of the second lifting module 309 and the first lifting module 103 to adjust the height of the lens under test 408 and the height of the upper spectral confocal probe 104. Perform multi-level adjustments to adjust the lens under test 408 to a suitable height, which is located in the middle position between the lower spectral confocal probe 101 and the upper spectral confocal probe 104.

[0017] Under the condition that the lens under test 408 is placed in the self-centering positioning structure of the V-shaped tray frame 406, the precision servo motor 212 is triggered to start, and the motor drives the sliding frame 210 to slide horizontally. The sliding frame 210 drives the lens under test 408 to smoothly enter the optical beam detection range. During the dynamic scanning process, when the outer edge of the lens enters the axis of the lower spectral confocal probe 101 and the upper spectral confocal probe 104, the photoelectric sensor 513 installed at a specific node is triggered, and the system automatically locks the spatial point as the absolute zero point of the global three-dimensional coordinate system. Then, linear scanning is continuously performed, and the grating ruler feedback unit 514 generates orthogonal position pulses. When the horizontal displacement reaches the preset micron-level pulse increment, the pulse signal directly hard triggers the lower spectral confocal probe 101 to... The upper spectral confocal probe 104 performs instantaneous spectral sampling; the lower spectral confocal probe 101 and the upper spectral confocal probe 104 continuously emit broadband light sources and receive wavelength reflection signals from the upper and lower surfaces of the lens at high frequency, and analyze to obtain the absolute distance of the current measurement position. The processor calculates the absolute thickness of the lens based on the difference between the two sets of distances. Relying on this hardware-level synchronous linkage, the thickness data of each sampling point strictly corresponds to a unique horizontal position spatial coordinate during the multi-axis linkage scanning process, effectively eliminating the calculation mapping errors caused by mechanical transmission system backlash, shaft movement vibration, and time axis misalignment. Finally, the processor performs the corresponding surface profile and three-dimensional full-shape reconstruction processing steps based on the two-dimensional or three-dimensional displacement coordinate matrix and thickness difference data collected throughout the entire stroke.

[0018] It should be noted that, in this document, 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.

[0019] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lens full-shape measurement system that combines spectral confocal imaging and precise position feedback, characterized in that: The device includes a mounting base (114), on which an optical measurement module (100) is fixedly connected. The optical measurement module (100) has a precision displacement module (200) fixedly connected to the upper surface of the mounting base (114) on its side. The precision displacement module (200) is used to drive a second lifting module (309) to move horizontally. The second lifting module (309) is fixedly connected to a connecting frame (308). The upper surface of the connecting frame (308) is fixedly connected to a sample carrier module (400). The sample carrier module (400) is used to clamp and position the lens to be tested (408).

2. The lens full-shape measurement system with spectral confocalization and precise position feedback coordination according to claim 1, characterized in that: The optical measurement module (100) includes a first fixing plate (102) fixedly connected to the upper end face of the mounting base (114). A second fixing plate (105) is provided on the upper side of the first fixing plate (102). A first lifting module (103) is fixedly connected between the second fixing plate (105) and the first fixing plate (102). The first lifting module (103) is used to lift the second fixing plate (105) to adjust the height. The first fixing plate (102) is fitted with a lower spectral confocal probe (101), and the second fixing plate (105) is fitted with an upper spectral confocal probe (104). The upper spectral confocal probe (104) and the lower spectral confocal probe (101) are coaxially opposed. The lower spectral confocal probe (101) and the upper spectral confocal probe (104) are used to adjust the measurement depth of focus and physical working distance in the vertical axis.

3. The lens full-shape measurement system with spectral confocalization and precise position feedback coordination according to claim 1, characterized in that: The precision displacement module (200) includes a slide rail (211) fixedly connected to the upper surface of the mounting base (114). The slide rail (211) is located on the side of the measurement position of the optical measurement module (100). The slide rail (211) is slidably connected to a sliding frame (210). The slide rail (211) is fixedly connected to a precision servo motor (212). The precision servo motor (212) is used to drive the sliding frame (210) to move horizontally. The sliding frame (210) is fixedly connected to the second lifting module (309). The second lifting module (309) is used to lift the connecting frame (308) and the sample carrier module (400) for height adjustment.

4. The lens full-shape measurement system with spectral confocalization and precise position feedback coordination according to claim 1, characterized in that: The sample carrying module (400) includes a clamping driver (407) fixedly connected to the upper surface of the connecting frame (308). The clamping driver (407) is used to drive two symmetrical V-shaped tray frames (406) to clamp the lens to be tested (408). The V-shaped tray frames (406) are used for high-precision positioning and clamping. Together with the second lifting module (309) and the first lifting module (103), they form a multi-level vertical axis motion compensation architecture, which is used to dynamically adjust the vertical height of the lens tray and the infeed and outfeed paths during the scanning process. The V-shaped tray frames (406) perform double-point contact non-destructive clamping on the outer edge of the circumference of the lens to be tested through the inclined side walls on both sides.

5. The lens full-shape measurement system with spectral confocalization and precise position feedback coordination according to claim 1, characterized in that: The mounting base (114) is fixedly connected to a photoelectric sensor (513) and a grating ruler feedback unit (514) located on the side of the precision displacement module (200). The photoelectric sensor (513) is installed at a specific starting node of the horizontal reciprocating scanning path. The grating ruler feedback unit (514) is used to record the spatial displacement data of the precision displacement scanning module in the horizontal direction in real time and output a high-frequency position pulse trigger signal to the processing system in real time. The photoelectric sensor (513) is used to sense the spatial edge cutting state of the lens in real time and establish the zero point of the displacement reference coordinate.

Images