Optical path automatic calibration optical device and calibration method

Abstract

The present application relates to a kind of optical path automatic calibration optical device and calibration method, including light beam projection unit, optical path displacement promoting unit, optical path calibration unit and computer control display unit, light beam projection unit includes lamp bead and coaxially arranged on its top light-emitting round hole, for the light of no order directional projection to optical path calibration unit, optical path calibration unit includes reflector and displacement sensor, reflector is diffusely reflected to light output port by directional light, computer control display unit obtains the focal length f of reflector, reflectivity n, light-emitting round hole inner diameter d1 and the current position of displacement sensor detection, based on the first corresponding relation d=(d2d1) / ((1-n) × (d2-d1)) and the second corresponding relation calculation target optical path d2, according to determine displacement and control optical path displacement promoting unit drive reflector moves to target position to calibrate diffuse reflection light optical path, from physical layer, eliminate LED light spot in imaging image, realize optical path automatic accurate calibration.

Description

Technical Field

[0001] This invention relates to the field of optical testing equipment calibration technology, specifically to an automatic optical path calibration optical device and calibration method. Background Technology

[0002] In precision optical inspection equipment that uses CCD cameras for image acquisition, an illumination source is usually required inside the lens barrel to obtain clear and bright images. Currently, a common practice is to evenly arrange multiple LED beads along the circumference inside the lens barrel, with the beads directly illuminating the imaging area.

[0003] However, the above-mentioned lighting method has significant shortcomings in practical applications. Because the LED beads are arranged externally inside the lens barrel, the light emitted by the beads undergoes multiple planar reflections through the lower light-emitting port face and the upper reflector. Some of the reflected light travels back along the optical path to the imaging system, forming bright spots on the image captured by the photoelectric sensor corresponding to the positions of the LED beads. These bright spots, superimposed on the target image, cause localized distortion of the image information in that area, reducing the accuracy of subsequent image analysis.

[0004] To address the issue of light spot interference, the industry has attempted to improve the situation by optimizing the arrangement angle of LED chips and adding light-shielding structures. While these solutions can alleviate the light spot phenomenon under certain conditions, they cannot fundamentally eliminate the conditions that generate light spots, and they often come at the cost of sacrificing some lighting efficiency, resulting in limited improvement.

[0005] Another, more effective approach is to use a method where the light beam is directionally projected and then diffused through a surface to form the illumination path. Specifically, the LED light is directionally projected through a specific optical path structure onto a diffuse mirror, which then diffusely reflects the light onto the shooting area. Because the diffusely reflected light lacks regular directionality, the target area is uniformly illuminated, and the spot-like pattern corresponding to the original LED image is physically eliminated. However, the optical path length of the diffused light in this scheme is not an arbitrarily set parameter; it has a definite correspondence with the curvature of the diffuse mirror, its effective diameter, and the inner diameter of the light source's exit end. Only when these parameters are well-matched can the desired spot-free illumination effect be achieved.

[0006] In practical use, optical equipment inevitably experiences environmental vibrations, slow release of stress on mating surfaces, structural loosening, and material aging. The combined effect of these factors causes a slight shift in the actual spatial position of the diffuse reflector relative to its factory calibration position, leading to changes in the optical path of the diffuse reflection light. This disrupts the original parameter matching relationship and deteriorates the spotless illumination effect. In this case, the optical path must be recalibrated to restore the proper correspondence between parameters.

[0007] In existing technologies, the calibration of diffuse reflection optical path mainly relies on manual methods: operators manually adjust the installation position of the diffuse mirror and determine the appropriate calibration displacement based on experience and the degree of light spot reduction in the image. This method is not only cumbersome and time-consuming, but also susceptible to differences in operator experience, making it difficult to guarantee the consistency and repeatability of the calibration results.

[0008] More importantly, the compact internal space of the microscope tube and the limited operational range significantly restrict the precision and controllability of manual adjustments, making it difficult to meet the requirements for accurate optical path positioning in high-precision applications. Currently available optical path adjustable or mirror positioning solutions are mostly designed for applications such as long-path gas detection and photometer light source switching. Their working principles and control objectives are fundamentally different from the short-path precision calibration based on spotless effects within the confined space addressed in this application, and therefore cannot be directly applied.

[0009] In summary, under the limited space conditions inside the lens barrel, how to enable the equipment to automatically complete the precise calibration of the diffuse reflection optical path and maintain a spotless illumination state during long-term operation has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides an automatic optical path calibration device and calibration method, aiming to solve one or more of the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: an automatic optical path calibration optical device, comprising a beam projection unit, an optical path displacement actuation unit, an optical path calibration unit, and a computer control and display unit. The beam projection unit includes an LED and a light-emitting circular aperture, the light-emitting circular aperture being coaxially disposed directly above the light-emitting direction of the LED, for directionally projecting the disordered light emitted by the LED to the optical path calibration unit. The optical path calibration unit includes a reflector and a displacement sensor. The reflector has a known effective diameter d, and the reflector is used to diffusely reflect the directionally projected light to the light output port. The displacement sensor is used to detect the current position of the reflector in real time. The computer control and display unit is configured to: acquire the focal length of the reflector. f, reflectivity n, inner diameter d1 of the light-emitting end of the light-emitting aperture, and the current position detected by the displacement sensor; based on the acquired parameters, the target optical path d2 is calculated based on a first correspondence and a second correspondence, wherein the first correspondence is d = (d2d1) / ((1-n)×(d2-d1)), and the second correspondence is the relationship between the curvature parameter of the reflector and the effective diameter d: curvature parameter = arcsin(d / 4f); the target displacement is determined based on the current position and the target optical path d2; the optical path displacement actuation unit is controlled to drive the reflector to move to the target position based on the target displacement, and the optical path of the diffuse reflection light is calibrated when the reflector moves to the target position.

[0012] Furthermore, the light-emitting circular aperture is an independently formed stepped cylindrical light-shielding structure, which includes: The lower hole of the light-emitting circular hole is located near the end of the lamp bead and has a larger inner diameter, which is used to receive the large-angle diffused light emitted by the lamp bead. The upper hole of the light-emitting circular hole is located at the end furthest from the lamp bead, and its inner diameter is smaller than that of the lower hole of the light-emitting circular hole, in order to block stray light. The inner diameter d1 is the inner diameter of the upper hole of the light-emitting circular hole.

[0013] Furthermore, a circular ring structure is fixedly provided at the top opening of the upper hole of the light-emitting circular hole, which is used to further concentrate the emitted light beam and direct it to the central area of ​​the reflector.

[0014] Furthermore, the optical path displacement actuation unit includes a stepper motor, a roller guide rail, a guide block, and a slot. The guide block is fixedly connected to the outside of the slot, and the bracket of the reflector is fixedly connected to the inside. The stepper motor drives the guide block and the slot through the roller guide rail, thereby driving the reflector to move in a straight line.

[0015] Furthermore, the displacement sensor is an integrated laser displacement sensor, whose body is rigidly fixed on the bracket of the reflector, with the sensing end pointing vertically downward, and the fixed support surface of the device serving as the sole measurement reference surface.

[0016] Furthermore, it also includes a robotic arm equipped with a limit switch. When the optical path calibration unit moves to the limit position, the conductive end of the displacement sensor triggers the limit switch, causing the computer control and display unit to control the optical path displacement actuation unit to stop moving.

[0017] Furthermore, it also includes a light intensity feedback unit, which is used to adjust the light intensity of the lamp beads during the lighting operation. During the automatic optical path calibration process, the light intensity of the lamp beads remains constant.

[0018] It also includes an automatic optical path calibration method, applied to an optical device for automatic optical path calibration, comprising the following steps: The computer-controlled display unit acquires the focal length f, reflectivity n, inner diameter d1 of the light-emitting end of the light-emitting hole of the reflector, and the current position of the reflector detected in real time by the displacement sensor. The computer-controlled display unit calculates the target optical path d2 based on the acquired parameters and the first and second correspondences, wherein the first correspondence is d = (d2d1) / ((1-n)×(d2-d1)), and the second correspondence is the relationship between the curvature parameter of the reflector and the effective diameter d: curvature parameter = arcsin(d / 4f); The computer-controlled display unit determines the target displacement based on the current position and the target optical path d2; The computer-controlled display unit controls the optical path displacement actuation unit to drive the reflector to the target position according to the target displacement amount, so as to calibrate the optical path of diffuse reflection light.

[0019] Furthermore, the focal length f is a known fixed design parameter that has been determined after the mirror is processed, the reflectivity n is a known inherent parameter of the mirror coating material, and the inner diameter d1 is a known structural parameter of the light-emitting end of the light-emitting circular hole.

[0020] Furthermore, the effective diameter d of the reflector is a known parameter; The computer-controlled display unit calculates the target optical path d2 based on the acquired parameters, including: First, based on the second correspondence, the curvature parameter of the reflector is determined by the effective diameter d and the focal length f; Based on the first correspondence, the target optical path d2 is calculated from the effective diameter d, the inner diameter d1, and the reflectivity n.

[0021] The optical device and method for automatic optical path calibration described in this invention have the following advantages: By coaxially positioning the light-emitting circular aperture directly above the light-emitting direction of the LED bead, disordered light is directed onto the reflector and diffusely reflected to the light output port, thus physically eliminating LED light spots in the image and solving the problem of local image distortion caused by light spots. Simultaneously, the computer-controlled display unit accurately calculates the target optical path based on the effective diameter d, focal length f, reflectivity n, inner diameter d1 of the light-emitting circular aperture, and the current position detected in real time by the displacement sensor. This is done using a preset first and second correspondence relationship, and the optical path displacement actuator is used to drive the reflector to move into position in one go. This achieves automatic and accurate calibration of the diffuse reflection light path without manual intervention, significantly improving calibration efficiency and repeatability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the optical device for automatic optical path calibration of the present invention.

[0023] Explanation of reference numerals in the attached drawings: 1. Support rod; 11. Upper end of support frame; 12. Lower end of support frame; 2. Beam projection unit; 21. Projection cover; 22. Lamp bead; 23. Light emission hole; 231. Upper hole of light emission hole; 232. Lower hole of light emission hole; 233. Circular structural component; 24. Projection cover base; 3. Light intensity feedback unit; 31. Beam projection control unit; 32. Light intensity control unit; 4. Optical path displacement actuation unit; 41. Stepper motor ; 42. Guide rail base; 43. Roller guide rail; 44. Guide block; 45. Slot; 5. Optical path calibration unit; 51. Reflector; 52. Reflector bracket; 53. Displacement sensor; 531. Displacement sensor sensing end; 532. Displacement sensor transmission end; 6. Robotic arm; 61. Robotic arm body; 62. Robotic arm extension rod; 63. Limit switch; 7. Connecting rod; 8. Computer control display unit; 9. Power supply; 10. Optical output port. Detailed Implementation

[0024] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0025] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] To further illustrate the principles and structure of the present invention, preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] Please see Figure 1 This embodiment provides an automatic optical path calibration optical device, which includes a support rod 1, an upper end 11 of a support frame, a lower end 12 of a support frame, a beam projection unit 2, a light intensity feedback unit 3, an optical path displacement actuation unit 4, an optical path calibration unit 5, a robotic arm 6, a connecting rod 7, a computer control and display unit 8, a power supply 9, and a light output port 10. The support frame 1 is connected to the connecting rod 7 and has an upper end 11 and a lower end 12, which are used to support and fix the various functional units of the device, respectively.

[0028] Beam projection unit The beam projection unit 2 is fixed on the upper end 11 of the support frame and is the key structure for this device to separate the illumination light from the directional projection light.

[0029] The beam projection unit 2 includes a projection cover 21, an LED bead 22, and a light-emitting circular aperture 23. The projection cover 21 is a convex lens formed by coating a high-transmittance material onto a transmission mirror surface using a coating process, and it is fixed to the projection cover base 24. The projection cover base 24 is fixed to the upper end 11 of the support frame, is made of light-transmitting material, and is used to stably support the projection cover 21.

[0030] The LED bead 22 is located in the center of the upper surface of the projection cover 21, with its light-emitting surface facing upwards. The LED bead 22 is electrically connected to the light intensity control unit 32 and the power supply 9, which provides a regulated power supply to enable it to emit light. The LED bead 22 is a wide-angle light source, emitting light in multiple directions. Among them, the downward-emitting light directly illuminates the projection cover 21, and after transmission and refraction by the projection cover 21, it is transmitted to the light output port 10, forming a uniform and soft background illumination light.

[0031] The light-emitting circular aperture 23 is the core component for achieving directional light projection in this embodiment. The light-emitting circular aperture 23 is an independently formed stepped cylindrical light-shielding structure, coaxially arranged with the lamp bead 22, and positioned directly above the light-emitting direction of the lamp bead 22. For ease of description, the light-emitting circular aperture 23 is defined in this embodiment as follows: the end closer to the lamp bead 22 is the lower end, which has a lower light-emitting circular aperture 232; the end closer to the reflector 51 is the upper end, which has an upper light-emitting circular aperture 231.

[0032] The light-emitting circular aperture 23 includes a lower light-emitting aperture 232, an upper light-emitting aperture 231, and a circular ring structure 233. The lower light-emitting aperture 232 is located at the lower end, with its lower opening adjacent to the light-emitting surface of the LED bead 22 and completely covering the light-emitting area of ​​the LED bead 22. This is used to fully receive the disordered light emitted by the LED bead 22, which has a large divergence angle. The lower light-emitting aperture 232 has a large inner diameter, maximizing the collection of light energy emitted by the LED bead 22 and improving light energy utilization efficiency. The upper light-emitting aperture 231 is located at the upper end, with an inner diameter smaller than that of the lower light-emitting aperture 232, forming a stepped inner cavity structure that is smaller at the top and larger at the bottom. This stepped structure effectively blocks stray light with large angles from entering the upper light-emitting aperture 231, allowing only light with a propagation direction basically consistent with the axis to pass through, achieving initial shaping of the light. The circular structure 233 is fixedly installed at the top opening of the upper hole 231 of the light-emitting circular hole, and is used to further concentrate the light beam that has been initially shaped by the upper hole 231 of the light-emitting circular hole, so that the light is accurately directed and projected to the central area of ​​the reflector 51.

[0033] Thus, another part of the disordered radial light emitted by the lamp bead 22 is collected and received by the lower hole 232 of the light-emitting circular hole, blocked by the stray light of the upper hole 231 of the light-emitting circular hole, and shaped by the ring structure 233 to form a high-quality directional beam, which is then accurately projected onto the reflector 51 located above it.

[0034] Those skilled in the art will understand that the annular structure 233 is essentially a fixed aperture stop, which can be an independent thin-film annular component or integrally formed with the upper hole 231 of the light-emitting circular hole.

[0035] Light intensity feedback unit A light intensity feedback unit 3 is located at the lower end 12 of the support frame and includes a beam projection control unit 31 and a light intensity control unit 32. The beam projection control unit 31 is electrically connected to the light intensity control unit 32 and the computer control display unit 8, and is used to send a control electrical signal to the light intensity control unit 32 according to the illuminance requirements of the lamp beads 22 input from the external input port of the computer control display unit 8. The light intensity control unit 32 is electrically connected to the lamp beads 22 and the beam projection control unit 31, and is used to receive the control electrical signal and adjust the light intensity of the lamp beads 22 accordingly.

[0036] It should be noted that the light intensity feedback unit 3 is mainly used to maintain a constant illuminance of the lamp bead 22 during normal lighting operation. However, during the automatic optical path calibration process described later, the light intensity of the lamp bead 22 remains constant, and the light intensity feedback unit 3 does not participate in the control of the calibration process. Automatic optical path calibration and light intensity adjustment are two independent control functions.

[0037] Optical path displacement actuation unit The optical path displacement actuation unit 4 is an actuator that enables precise adjustment of the position of the reflector 51. The optical path displacement actuation unit 4 includes a stepper motor 41, a guide rail base 42, a roller guide rail 43, a guide block 44, and a slot 45.

[0038] A stepper motor 41 is mounted on the upper end 11 of the support frame and electrically connected to the power supply 9. One end of the guide rail base 42 is fixed to the stepper motor 41, and the other end is fixed to the roller guide rail 43. The roller guide rail 43 contains a rolling roller, and a guide block 44 is connected within the roller guide rail 43, enabling it to move linearly up and down along the rolling direction of the roller. The slot 45 is a concave slot, externally fixed to the guide block 44 and internally fixed to the reflector bracket 52. When the stepper motor 41 operates, its rotational motion is converted into linear motion through the roller guide rail 43. Through the transmission of the guide block 44 and the slot 45, it drives the reflector bracket 52 and the reflector 51 mounted on it to move precisely in a vertical direction. The movement of the stepper motor 41 is controlled by a computer control display unit 8, and its power supply is provided by the power supply 9.

[0039] Optical path calibration unit The optical path calibration unit 5 is the core unit of this device that works in conjunction with the optical path displacement actuation unit 4 to complete the automatic optical path calibration. The optical path calibration unit 5 includes a reflector 51, a reflector support 52, and a displacement sensor 53.

[0040] The reflector 51 is mounted on the reflector bracket 52, which is fixedly connected to the slot 45 and moves along with the linear up-and-down movement of the guide block 44. The reflector 51 is a high-reflectivity reflector formed by coating a high-reflectivity material onto its surface using a coating process. It has a known effective diameter d and a known focal length f. The focal length f is a fixed design parameter determined after the reflector 51 is manufactured and does not require further measurement or calibration. The coating material of the reflector 51 has a known reflectivity n. The reflector 51 receives light rays directionally projected from the light-emitting circular aperture 23 and diffusely reflects them to the light output port 10. Because the diffusely reflected light rays lack regular directionality, the light is uniformly scattered towards the light output port 10, thereby physically eliminating potential LED light spots in the image.

[0041] The displacement sensor 53 is an integrated non-contact laser displacement sensor, rigidly fixed to the reflector bracket 52, maintaining a strict relative position with the reflector 51, and moving linearly up and down with the reflector bracket 52. The displacement sensor 53 includes a sensing end 531 and a transmitting end 532. The sensing end 531 is vertically downward, facing the horizontal upper surface of the upper end 11 of the support frame. This horizontal upper surface is a finely machined flat metal surface, serving as the sole fixed reference surface for displacement measurement. The sensing end 531 emits a laser beam towards this reference surface and receives the reflected signal, accurately detecting the current position of the reflector 51 relative to this fixed reference surface in real time, and transmitting this position data to the computer control display unit 8 in real time through the transmitting end 532. A high-temperature resistant flexible shielded cable is used for this signal transmission to ensure transmission stability and anti-interference capabilities. It should be noted that the current position of the reflector 51 detected by the displacement sensor 53 is the measured value of the diffuse reflection optical path of the optical path displacement actuation unit 4.

[0042] robotic arm and limit protection structure The robotic arm 6 includes a robotic arm body 61, a robotic arm extension rod 62, and a limit switch 63. The robotic arm body 61 is welded to the connecting rod 7, and the robotic arm extension rod 62 is tenon-jointed to the robotic arm body 61. The limit switch 63 is fixedly installed on the lower surface of the robotic arm extension rod 62, and its position corresponds to the limit safety position of the upward movement of the optical path calibration unit 5.

[0043] When the optical path calibration unit 5 moves upward to its limit position under the drive of the optical path displacement actuation unit 4, the top surface of the displacement sensor transmission end 532 will directly touch the limit switch 63. After the limit switch 63 is triggered, it immediately sends an emergency stop electrical signal to the computer control display unit 8. After receiving the signal, the computer control display unit 8 immediately sends a stop rotation signal to the power supply 9, cutting off the power supply to the stepper motor 41, causing the optical path displacement actuation unit 4 to stop moving immediately, thereby preventing the reflector bracket 52 from overtravel and colliding, and playing a reliable limit protection role.

[0044] Computer-controlled display unit The computer control display unit 8 is the control core of this device, electrically connected to the beam projection control unit 31, the displacement sensor conduction end 532, the limit switch 63, and the power supply 9. The computer control display unit 8 undertakes two main functions: lighting control and automatic calibration control.

[0045] In terms of lighting control, the computer control display unit 8 generates a control electrical signal based on the externally input illuminance requirements, and transmits it to the light intensity control unit 32 via the beam projection control unit 31 to perform light intensity control on the lamp beads 22.

[0046] In terms of automatic calibration control, the computer control display unit 8 is configured to implement the following control logic: First, the computer control display unit 8 acquires multiple parameters required for calibration calculation, including: the known focal length f of the reflector 51, the known reflectivity n of the coating material of the reflector 51, the known inner diameter d1 of the upper hole 231 of the light-emitting circular hole, and the current position of the reflector 51 detected and transmitted in real time by the displacement sensor 53.

[0047] Subsequently, the computer control display unit 8 calculates the target optical path d2 based on the acquired parameters and the preset first and second correspondence relationships.

[0048] The first correspondence is the relationship between the effective diameter d of the reflector 51 and the optical path d2 of the diffuse reflection light: d=(d2d1) / ((1-n)×(d2-d1)) The second correspondence is the relationship between the curvature parameter of the reflector 51 and its effective diameter d: Curvature parameter = arcsin(d / 4f) During the calculation, since the effective diameter d is a known parameter of the reflector 51, the computer-controlled display unit 8 can first determine the current curvature parameter of the reflector 51 based on the second correspondence, using the effective diameter d and the focal length f, and then calculate the corresponding target optical path d2 based on the first correspondence, using the effective diameter d, the inner diameter d1 and the reflectivity n.

[0049] After obtaining the target optical path d2, the computer control display unit 8 compares the target optical path d2 with the current position of the reflector 51 detected by the displacement sensor 53, and calculates the displacement required for the reflector 51 to move from the current position to the position corresponding to the target optical path d2, i.e., the target displacement.

[0050] Finally, the computer control display unit 8 sends a stepper motor 41 operation control signal to the power supply 9 according to the determined target displacement. The power supply 9 supplies power to the stepper motor 41 to make it run, driving the optical path displacement actuator 4 to move the reflector 51 precisely to the target position, thus completing the automatic calibration of the optical path of diffuse reflection light.

[0051] After the above calibration process, the disordered radial light emitted by the LED 22 passes sequentially through the lower aperture 232 and the upper aperture 231 of the light-emitting circular aperture to the annular structure 233, forming a directional beam that is precisely projected onto the reflector 51. The reflector 51 diffusely reflects the directionally projected light to the light output port 10. Since the optical path of the diffusely reflected light is precisely matched with the curvature parameter, effective diameter, and inner diameter of the upper aperture 231 of the light-emitting circular aperture, the illumination light path is restored to a spotless state, and the light spots in the image are eliminated.

[0052] power supply Power supply 9 is electrically connected to LED 22, stepper motor 41, and computer control display unit 8. In illumination mode, power supply 9 provides regulated power to LED 22 to enable it to emit light. In automatic calibration mode, power supply 9 receives a control signal from computer control display unit 8 to operate stepper motor 41, supplying power to it to drive optical path calibration unit 5 in vertical linear motion, thus achieving automatic calibration of diffuse reflection optical path. Power supply 9 also receives a stop signal from computer control display unit 8, stopping power supply to stepper motor 41 and preventing optical path displacement actuation unit 4 from generating displacement actuation, ensuring calibration accuracy and system safety.

[0053] Calibration method workflow The automatic optical path calibration method of this embodiment will be described in detail below. The method includes the following steps: Step S1: The computer-controlled display unit 8 controls the power supply 9 to provide regulated power to the LED bead 22, causing the LED bead 22 to emit light. Part of the disordered radial light emitted by the LED bead 22 shines directly downward onto the projection cover 21, and after being transmitted through the projection cover 21, it is transmitted to the outside of the light output port 10 to provide background illumination; the other part of the light passes through the lower hole 232 of the light-emitting circular aperture, the upper hole 231 of the light-emitting circular aperture, and the annular structure 233 in sequence to form a directional beam, which is projected onto the reflector 51.

[0054] Step S2: The computer-controlled display unit 8 acquires the known focal length f, known reflectivity n, known inner diameter d1 of the upper hole 231 of the light-emitting circular hole of the reflector 51, and the current position of the reflector 51 detected in real time by the displacement sensor 53.

[0055] Step S3: The computer-controlled display unit 8 calculates the target optical path d2 based on the acquired parameters, the first correspondence d = (d2d1) / ((1-n)×(d2-d1)) and the second correspondence curvature parameter = arcsin(d / 4f). The specific calculation order is as follows: first, based on the second correspondence, the curvature parameter of the reflector 51 is determined from the effective diameter d and the focal length f; then, based on the first correspondence, the target optical path d2 is calculated from the effective diameter d, the inner diameter d1, and the reflectivity n.

[0056] Step S4: The computer control display unit 8 compares the target optical path d2 with the current position of the reflector 51 detected by the displacement sensor 53 to determine the target displacement.

[0057] Step S5: The computer control display unit 8 sends a running control signal to the power supply 9 according to the target displacement, and the power supply 9 supplies power to the stepper motor 41. The stepper motor 41 runs, and through the transmission of the roller guide rail 43, guide block 44 and slot 45, it drives the reflector 51 to move precisely to the target position in a straight line, completing the automatic calibration of the optical path of diffuse reflection light.

[0058] Step S6: After calibration, the curvature parameter of the reflector 51 and the optical path of the diffuse reflection light are restored to a precise matching state. The ordered directional beam emitted by the LED 22 is diffusely reflected by the reflector 51 and uniformly emitted to the light output port 10. No LED light spots appear in the image, and the image clarity and accuracy are guaranteed.

[0059] Step S7 (Limit Protection): During calibration, if the optical path calibration unit 5 moves upward to its limit position under the drive of the optical path displacement actuation unit 4, the top surface of the displacement sensor transmission end 532 contacts the limit switch 63, and the limit switch 63 sends an emergency stop electrical signal to the computer control display unit 8. The computer control display unit 8 then sends a stop rotation signal to the power supply 9, and the power supply 9 stops supplying power to the stepper motor 41. The optical path displacement actuation unit 4 immediately stops moving, ensuring system safety.

[0060] Technical Effect Description The optical path automatic calibration optical device and calibration method provided in this embodiment utilize the operation of the optical path displacement actuation unit to drive the optical path calibration unit to automatically complete the precise calibration of the optical path of diffuse reflection light, realizing the full automation of optical path calibration without manual intervention, and significantly improving calibration efficiency and accuracy.

[0061] By combining directional beam projection with diffuse reflection in the optical path design, the conditions for the generation of LED light spots in the image are eliminated from a physical level, solving the problem of local image distortion caused by light spots, which is beneficial to improving the accuracy of subsequent image processing and analysis.

[0062] By pre-setting the correspondence between the curvature parameters, effective diameter, inner diameter of the light-emitting circular aperture, and optical path of diffuse reflection light of the reflector in the form of mathematical formulas in the computer control and display unit, one-time accurate calculation and driving position based on physical model are realized. The calibration process is fast and reliable, without the need for complex image feedback hardware and iterative optimization algorithms. The system structure is simple and the cost is low, making it particularly suitable for applications with limited space, such as inside the mirror tube.

[0063] The accuracy of the calibration process and the safety of operation are ensured by the real-time position detection of the displacement sensor and the dual protection of the limit switch.

[0064] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An automatic optical path calibration optical device, comprising a beam projection unit, an optical path displacement actuation unit, an optical path calibration unit, and a computer control and display unit, characterized in that: The beam projection unit includes an LED and a light-emitting circular aperture. The light-emitting circular aperture is coaxially disposed directly above the light-emitting direction of the LED and is used to directionally project the disordered light emitted by the LED to the optical path calibration unit. The optical path calibration unit includes a reflector and a displacement sensor. The reflector has a known effective diameter d. The reflector is used to diffusely reflect the directionally projected light to the light output port. The displacement sensor is used to detect the current position of the reflector in real time. The computer control display unit is configured as follows: The focal length f, reflectivity n, inner diameter d1 of the light-emitting end of the light-emitting hole, and the current position detected by the displacement sensor are obtained from the reflector. Based on the acquired parameters, the target optical path d2 is calculated based on the first correspondence and the second correspondence, wherein the first correspondence is d = (d2d1) / ((1-n)×(d2-d1)), and the second correspondence is the relationship between the curvature parameter of the reflector and the effective diameter d: curvature parameter = arcsin(d / 4f); The target displacement is determined based on the current position and the target optical path d2; The optical path displacement actuator is controlled according to the target displacement to drive the reflector to move to the target position. When the reflector moves to the target position, the optical path of the diffuse reflection light is calibrated. The light-emitting circular aperture is an independently formed stepped cylindrical light-shielding structure, which includes: The lower hole of the light-emitting circular hole is located near the end of the lamp bead and has a larger inner diameter, which is used to receive the large-angle diffused light emitted by the lamp bead. The upper hole of the light-emitting circular hole is located at the end furthest from the lamp bead, and its inner diameter is smaller than that of the lower hole of the light-emitting circular hole, in order to block stray light. The inner diameter d1 is the inner diameter of the upper hole of the light-emitting circular hole; The displacement sensor is an integrated laser displacement sensor, whose body is rigidly fixed on the bracket of the reflector, with the sensing end pointing vertically downward, and the fixed support surface of the device serving as the sole measurement reference surface.

2. The optical device for automatic optical path calibration according to claim 1, characterized in that, A circular ring structure is fixedly installed at the top opening of the upper hole of the light-emitting circular hole, which is used to further concentrate the emitted light beam and direct it to the central area of ​​the reflector.

3. The optical device for automatic optical path calibration according to claim 1, characterized in that, The optical path displacement actuation unit includes a stepper motor, a roller guide rail, a guide block, and a slot. The guide block is fixedly connected to the outside of the slot, and the bracket of the reflector is fixedly connected to the inside. The stepper motor drives the guide block and the slot through the roller guide rail, thereby driving the reflector to move in a straight line.

4. The optical device for automatic optical path calibration according to claim 1, characterized in that, It also includes a robotic arm, which is equipped with a limit switch. When the optical path calibration unit moves to the limit position, the transmission end of the displacement sensor triggers the limit switch, causing the computer control and display unit to control the optical path displacement actuation unit to stop moving.

5. The optical device for automatic optical path calibration according to claim 1, characterized in that, It also includes a light intensity feedback unit, which is used to adjust the light intensity of the lamp beads during the lighting operation and keep the light intensity of the lamp beads constant during the automatic optical path calibration process.

6. An automatic optical path calibration method, applied to the automatic optical path calibration optical device according to any one of claims 1 to 5, characterized in that, Includes the following steps: The computer-controlled display unit acquires the focal length f, reflectivity n, inner diameter d1 of the light-emitting end of the light-emitting hole of the reflector, and the current position of the reflector detected in real time by the displacement sensor. The computer-controlled display unit calculates the target optical path d2 based on the acquired parameters and the first and second correspondences, wherein the first correspondence is d = (d2d1) / ((1-n)×(d2-d1)), and the second correspondence is the relationship between the curvature parameter of the reflector and the effective diameter d: curvature parameter = arcsin(d / 4f); The computer-controlled display unit determines the target displacement based on the current position and the target optical path d2; The computer-controlled display unit controls the optical path displacement actuation unit to drive the reflector to the target position according to the target displacement amount, so as to calibrate the optical path of diffuse reflection light.

7. The automatic optical path calibration method according to claim 6, characterized in that, The focal length f is a known fixed design parameter that has been determined after the mirror is processed. The reflectivity n is a known inherent parameter of the mirror coating material. The inner diameter d1 is a known structural parameter of the light-emitting end of the light-emitting circular hole.

8. The automatic optical path calibration method according to claim 6, characterized in that, The effective diameter d of the reflector is a known parameter; The computer-controlled display unit calculates the target optical path d2 based on the acquired parameters, including: First, based on the second correspondence, the curvature parameter of the reflector is determined by the effective diameter d and the focal length f; Based on the first correspondence, the target optical path d2 is calculated from the effective diameter d, the inner diameter d1, and the reflectivity n.

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