Beam quality measurement system and method and electronic device

Abstract

The application relates to a light beam quality measuring system and method and an electronic device. The system comprises a light beam emitting part, a light beam guiding part and a light beam information processing part arranged in sequence, wherein the light beam emitted by the light beam emitting part can generate a moving light spot on the first side of the light beam guiding part, the light spot is moved into and / or across a measuring field of view defined on the first side of the light beam guiding part by controlling the movement of the light beam emitting part relative to the light beam guiding part, meanwhile, the light beam information processing part continuously captures an image generated on the second side of the light beam guiding part falling into the measuring field of view, at least until complete light spot imaging information is acquired, so as to obtain the quality parameter of the light beam. According to the technical scheme provided by the application, accurate measurement of the light beam quality such as the large-angle light spot divergence angle can be realized.

Description

Technical Field

[0001] This invention relates to the field of wireless detection technology, and more specifically, to a beam quality measurement system and method, as well as an electronic device. Background Technology

[0002] Radar is an electronic device that uses electromagnetic waves to detect targets. Radar emits electromagnetic waves to illuminate a target and receives its echo, thereby obtaining information such as the distance from the target to the electromagnetic wave emission point, the rate of change of distance (radial velocity), azimuth, and altitude. Due to the many advantages of lasers, such as their high monochromaticity, high brightness, and strong directionality, lidar is receiving increasing attention.

[0003] The beam quality of a lidar light field typically includes three parameters: beam divergence angle, uniformity, and optical efficiency. These parameters are crucial indicators for evaluating the optical performance of the lidar transmitter lens and directly affect the overall performance of the lidar system. In the design and verification of lidar transmitter lenses, it is necessary to accurately detect the beam divergence angle, uniformity, and optical efficiency using light field testing equipment to ensure the quality of the transmitter lens product. Currently, the most common light field testing equipment is the beam quality analyzer.

[0004] However, the beam quality analyzer's test field of view is not large enough to directly and completely measure the divergence angle and uniformity of large-angle beams. To use a beam quality analyzer to measure large-angle divergence angles, the beam emitted from the transmitter must be projected onto a target, and the beam quality analyzer will indirectly measure the beam by photographing the beam on the target. Because the material and flatness of the target surface vary at different locations, the roughness of the surface can cause a halo effect when the beam hits the target, resulting in a large measurement error when measuring the beam size and thus inaccurate calculation of the divergence angle. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a beam quality measurement system and method, as well as an electronic device, which at least partially overcomes or compensates for the deficiencies of the prior art, and in particular allows for the accurate measurement of beam quality such as large-angle beam divergence angle.

[0006] According to a first aspect of the present invention, a beam quality measurement system is provided, comprising a beam emitting unit, a beam guiding unit, and a beam information processing unit arranged sequentially, wherein the beam emitted by the beam emitting unit can generate a moving spot on a first side of the beam guiding unit, and by controlling the movement of the beam emitting unit relative to the beam guiding unit, the spot moves into and / or sweeps across a measurement field of view defined on the first side of the beam guiding unit, while the beam information processing unit continuously captures images generated on a second side of the beam guiding unit that fall into the measurement field of view, at least until complete spot imaging information is obtained, thereby determining the quality parameters of the beam.

[0007] Accordingly, on the one hand, by projecting the light beam onto the imaging surface of the camera device to obtain a sampled light spot, and directly taking pictures of it for detection, the corresponding image can accurately reflect the characteristic information of the light beam, thereby achieving precise measurement; on the other hand, by using the method of segmented sampling of the light spot, continuous shooting, and comprehensive image processing, the size of the light beam being measured (or its light spot) is no longer limited by the size of the measurement field of view, so that theoretically, light beams of any cross-sectional size can be detected, and it is especially suitable for detecting light beams with large divergence angles.

[0008] In this invention, the quality parameters of the light beam can be the beam divergence angle, beam uniformity, optical efficiency, or a combination thereof.

[0009] Suitablely, when performing beam quality measurement, the light spot generated by the beam emitted by the beam emitting unit can move in at least one direction perpendicular to the direction of light propagation.

[0010] In some embodiments, the measurement field of view of the beam guide has a maximum field width W1 in the direction of beam spot movement. When the beam information processing unit continuously captures images, each frame of the image corresponds to a displacement W2 of the beam spot. The maximum field width W1 and the displacement W2 satisfy: W1 / W2≥1.

[0011] According to some specific embodiments of the present invention, the beam information processing unit includes a camera device and a computer device.

[0012] According to the present invention, it is advantageous that the computer device can analyze and process the captured images, and stitch multiple image segments together into a fused image containing complete spot imaging information.

[0013] Therefore, the computer device may include an image stitching algorithm module capable of executing a template matching algorithm to stitch image segments together.

[0014] Furthermore, the computer device includes a binarization calculation module for performing binarization processing on the stitched fused image.

[0015] Furthermore, the computer device includes a pixel accumulation algorithm module for calculating the geometric size of the light spot from the fused image.

[0016] Here, it is appropriate that the camera device continuously takes pictures of the light spot pattern projected onto the imaging surface of the second side of the beam guide during the process from when one edge of the light spot enters the measurement field of view to when the other edge of the light spot enters the measurement field of view, so as to obtain at least one set of static images carrying light spot imaging information.

[0017] A particular advantage is that the speed at which the camera takes continuous photos can be adapted to the moving speed of the light source device.

[0018] Specifically, according to some embodiments, the imaging device includes a CCD and / or an infrared imaging element, such as a CCD infrared camera.

[0019] In some embodiments, the beam guide includes an optical device with at least one lens.

[0020] Advantageously, the relative positions of the beam emitting part and the beam guiding part are set such that, along the optical axis of the lens, the distance LA between the light spot generated by the beam emitting part and the incident surface of the lens and the focal length F of the lens satisfy: LA / F≤0.35, preferably LA / F≤0.3.

[0021] Furthermore, the beam quality measurement system also includes a collimation module for ensuring that the beam emitted by the beam emitting unit is incident parallel to the lens of the beam guiding unit.

[0022] Specifically, according to some embodiments, the collimation module may be constructed as a TIR lens, a plano-convex lens, a spherical or aspherical lens, or a combination thereof.

[0023] In some embodiments, the beam emitting portion includes a carrier device and a light source device fixed to the carrier device.

[0024] Specifically, according to some embodiments, the supporting device includes a rotating platform, the light source device is detachably fixed on the rotating platform, and the rotating platform can drive the light source device to rotate so that the light beam emitted by the light source device generates a corresponding moving light spot on the first side of the light beam guide.

[0025] Here, it is preferable that the measurement field of view of the beam guide has a maximum field of view angle FV1, and when the beam information processing unit continuously captures images, each frame of the image corresponds to a rotation angle FV2 of the rotary table. The maximum field of view angle FV1 and the rotation angle FV2 satisfy: FV1 / FV2≥1, preferably FV1 / FV2≥1.5.

[0026] Specifically, according to some embodiments, the supporting device includes a lifting platform, and the rotating platform is supported on the lifting platform. The height of the rotating platform can be adjusted by the lifting platform so that the light beam emitted by the light source device is aligned with the measurement field of view on the first side of the beam guide.

[0027] In some embodiments, the light source device is an LD, LED, or halogen lamp, or a combination thereof. In principle, the beam quality measurement system proposed in this invention is applicable to beam quality measurement of various types of light sources. The light source device can be a laser emitter, such as an infrared laser emitter, and can be a pulsed laser or a continuous laser.

[0028] According to a second aspect of the present invention, a method for measuring beam quality is provided, comprising the following steps:

[0029] I. Provide a beam emitting section;

[0030] II. Provide a beam information processing unit;

[0031] III. Provides a beam guide;

[0032] IV. Arrange the beam emitting unit, beam guiding unit, and beam information processing unit in sequence and adjust their relative positions.

[0033] V. Perform beam quality measurement;

[0034] The present invention specifically proposes that, in step V, the beam emitted by the beam emitting unit is made to generate a moving light spot on the first side of the beam guiding unit, wherein the light spot is moved into and / or across the measurement field of view defined on the first side of the beam guiding unit, while the beam information processing unit continuously captures images generated on the second side of the beam guiding unit that fall into the measurement field of view, at least until complete light spot imaging information is obtained; then, the captured images are analyzed and processed to determine the quality parameters of the beam.

[0035] In step I, the light source device to be tested is typically detachably fixed to the carrier device to form the beam emitting part.

[0036] In some embodiments, specifically, in step V, the light source device is driven to move relative to the beam guide in at least one direction perpendicular to the light propagation direction, so that the light beam emitted by the light source device generates a correspondingly moving light spot on the first side of the beam guide.

[0037] In some embodiments, it is specifically specified that the movement of the light source device is rotation. That is, in step V, the light source device is driven to rotate so that the light beam emitted by the light source device generates a correspondingly moving light spot on the first side of the beam guide.

[0038] In some embodiments, it is proposed that: in step IV, the height position of the light source device is adjusted so that the light beam emitted by the light source device is aligned with the measurement field of view on the first side of the beam guide.

[0039] In some embodiments, it is proposed that, in step III, an optical device with at least one lens is provided to form the beam guide.

[0040] According to the present invention, it is advantageous that the stage of analyzing and processing the captured images using a computer device includes the following steps:

[0041] (a) stitching together multiple image segments captured by the camera device into a fused image containing complete spot imaging information;

[0042] (b-1) Binarize the stitched fused image;

[0043] (c-1) The geometric dimensions of the light spot are determined or calculated from the fused image;

[0044] (d-1) Calculate the divergence angle of the beam based on the geometric dimensions of the beam spot.

[0045] Appropriately, step (c-1) should further include:

[0046] (c-1-1) Based on the gray value function of the fused image, the width and height of the fused image, the total energy of the light spot, and the camera resolution of the imaging device in the horizontal and vertical directions, the centroid coordinates (X, Y) of the light spot are calculated.

[0047] (c-1-2) With the centroid of the light spot as the center, the pixel points of the light spot are accumulated in the horizontal and vertical directions respectively. The number of pixels after accumulation is counted, and the size of the light spot in the horizontal and vertical dimensions is calculated accordingly.

[0048] It should be understood that the technical solution proposed in this invention is not limited to beam quality detection solely based on the divergence angle. Evaluating beam uniformity and optical efficiency based on the captured image is also entirely feasible. Therefore, according to this invention, the stage of analyzing and processing the captured image using a computer device can include the following steps:

[0049] (a) stitching together multiple image segments captured by the camera device into a fused image containing complete spot imaging information;

[0050] (b-2) The uniformity and optical efficiency of the beam are analyzed based on the gray level and gray distribution of the fused image.

[0051] According to a third aspect of the present invention, an electronic device is provided, comprising:

[0052] A processor is used to execute instructions, and

[0053] A memory communicatively connected to the processor, the memory having at least one instruction;

[0054] The instructions are executed by the processor to perform beam quality measurement using the beam quality measurement method described above. Here, the beam quality parameter can be beam divergence angle, beam uniformity, optical efficiency, or a combination thereof.

[0055] The features and advantages of the beam quality measurement system provided in the first aspect of the present invention are also applicable to the beam quality measurement method provided in the second aspect of the present invention and the electronic device provided in the third aspect of the present invention. Attached Figure Description

[0056] Some exemplary embodiments of the invention are illustrated in the accompanying drawings. The embodiments and drawings disclosed herein should be considered illustrative rather than restrictive. It is also worth noting that, for clarity of illustration, some structural details in the drawings are not drawn to scale.

[0057] Figure 1 This is a schematic diagram of the beam quality measurement system;

[0058] Figure 2 This is a schematic diagram illustrating the working principle of a beam quality measurement system;

[0059] Figure 3 This is a schematic diagram of a light spot image captured by a camera.

[0060] Figure 4 This is a schematic diagram of a light spot image created using image stitching technology;

[0061] Figure 5 This is a schematic diagram of the optical path for one implementation of spot imaging.

[0062] Figure 6 This is a schematic diagram illustrating the principle of spot imaging and geometric calculation in one implementation form.

[0063] Figure 7 This is a flowchart of the beam quality measurement method;

[0064] Figure 8 This is a schematic diagram of one implementation of a beam quality measurement method. Detailed Implementation

[0065] The following description is used to illustrate the technical solutions of the present invention, so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art can conceive of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention. Furthermore, it is worth noting that the features, structures, or characteristics described in conjunction with a particular embodiment are not necessarily limited to that specific implementation, nor are they mutually exclusive with other embodiments. Within the capabilities of those skilled in the art, different combinations of features in different embodiments can be considered.

[0066] The terms "first," "second," etc., used in the specification and claims are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising," "including," and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses. In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not mean that the corresponding device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the invention. In addition, the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of a component can be one, while in another embodiment, the number of the component can be multiple. In other words, the term "a" should not be understood as a limitation on the quantity.

[0067] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art and may be interpreted in the context of their application in the relevant technical description.

[0068] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0069] This invention provides a beam quality measurement system, such as... Figure 1As shown, it includes a beam emitting unit A, a beam guiding unit B, and a beam information processing unit C arranged sequentially. According to the invention, the beam emitted by the beam emitting unit A can generate a moving light spot on a first side E1 of the beam guiding unit B. By controlling the movement of the beam emitting unit A relative to the beam guiding unit B, the light spot moves into and / or across the measurement field of view defined by the first side E1 of the beam guiding unit B. Simultaneously, the beam information processing unit C continuously captures images falling into the measurement field of view and generated on a second side E2 of the beam guiding unit B, at least until complete light spot imaging information is obtained, thereby determining the beam quality parameters. Here, the beam quality parameters can be beam divergence angle, beam uniformity, optical efficiency, or a combination thereof.

[0070] Figure 1 A schematic diagram of a beam quality measurement system according to an embodiment of the present invention is shown. The beam quality measurement system includes a beam emitting unit A, a beam guiding unit B, and a beam information processing unit C arranged sequentially. The beam emitting unit A includes a carrier device 11 and a light source device 12 fixed to the carrier device. The beam guiding unit B has a first side E1 near the beam emitting unit and a second side E2 near the beam information processing unit in the light propagation direction. The first side E1 defines a measurement field of view. The beam information processing unit C includes a camera device 14 and a computer device 15.

[0071] Suitablely, during beam quality measurement, the light spot generated by the beam emitted by the beam emitting unit A moves in at least one direction perpendicular to the light propagation direction. According to a specific embodiment of the invention, in order to generate the moving light spot, the supporting device 11 is equipped with an actuation mechanism 111 and configured to drive the light source device 12 to move relative to the beam guide in at least one direction perpendicular to the light propagation direction. Thus, the beam emitted by the light source device generates a correspondingly moving initial light spot on the first side E1 of the beam guide. During beam quality measurement, the actuation mechanism 111 controllably drives the light source device 12, causing the initial light spot to move into and / or across the measurement field of view. At least during the process from one edge of the initial light spot entering the measurement field of view to the other edge of the initial light spot entering the measurement field of view, the imaging device 14 continuously photographs the sampled light spot projected onto its imaging surface via the second side E2 of the beam guide. The computer device 15 analyzes and processes the captured images to determine the beam quality parameters.

[0072] Therefore, theoretically, regardless of whether the light spot emitted by the beam emitter is larger than the measurement field of view (corresponding to a large divergence angle) or smaller than the measurement field of view (corresponding to a small divergence angle), measurement can be performed using this system. The technical solution proposed in this invention is particularly suitable for measuring beams with large divergence angles.

[0073] like Figure 1 As shown, in this embodiment, the supporting device 11 includes a rotating platform 111b, the light source device 12 is detachably fixed on the rotating platform, and the actuation mechanism 111 is connected to the rotating platform and can drive the rotating platform to rotate, thereby causing the light source device to rotate, so that the light beam emitted by the light source device generates a correspondingly moving initial light spot on the first side E1 of the beam guide. According to the conventional arrangement of the system equipment, the light propagation direction is generally horizontal. In this case, the movement of the light source device (and thus the movement of the light spot) can be a movement perpendicular to the light propagation direction to the left or right. For example, in the illustrated embodiment, the rotating platform drives the light source device to rotate left or right in a horizontal plane. Of course, it is also conceivable that, depending on the arrangement orientation of the light source device and the specific shape of its beam, the movement of the light source device (and thus the movement of the light spot) can also be a movement perpendicular to the light propagation direction to the up or down. For example, the actuation mechanism can drive the light source device to pitch up or down in a vertical plane.

[0074] like Figure 1 As shown, the supporting device 11 also includes a lifting platform 111a, and the rotating platform 111b is supported on the lifting platform. The height of the rotating platform can be adjusted by the lifting platform so that the light beam emitted by the light source device 12 is aligned with the measurement field of view of the first side E1 of the beam guide.

[0075] The lifting platform 111a can be driven by the actuation mechanism 111 to perform lifting movements; alternatively, the lifting platform 111a can be separately configured with a drive device for realizing its lifting movements. The present invention is not limited in this respect.

[0076] To achieve comprehensive image analysis and processing to obtain the quality parameters of the tested beam (including spot divergence angle, uniformity, and optical efficiency), according to the present invention, the computer device 15 includes an image stitching algorithm module for stitching multiple image segments captured by the camera device into a fused image containing complete spot imaging information, thereby comprehensively and accurately reflecting the quality characteristics of the tested beam / spot. Preferably, the image stitching algorithm module is capable of executing a template matching algorithm to stitch the image segments.

[0077] Figure 2 This is a schematic diagram illustrating the working principle of a beam quality measurement system. As an example, Figure 3 A schematic diagram of a light spot image captured by a camera device is shown; Figure 4 This is a schematic diagram of a light spot image created using image stitching technology.

[0078] The imaging device 14 continuously captures images of the light spot pattern projected onto the imaging surface of the second side E2 of the beam guide unit B during the process from when one edge of the light spot enters the measurement field of view to when the other edge of the light spot enters the measurement field of view, so as to obtain at least one set of static images carrying light spot imaging information. Depending on actual needs and equipment conditions, the imaging device 14 may include a CCD and / or infrared imaging element, such as a CCD infrared camera.

[0079] In one advantageous embodiment, the continuous image capture speed of the camera device 14 can be adapted to the moving speed of the light source device 12. This adaptation avoids excessive redundant data acquisition and reduces overlap between image segments, facilitating subsequent processing, while ensuring complete beam / spot information is recorded. For example, during beam measurement by rotating the light source device, the image capture speed of the camera device can be adapted to the moving speed of the light source device such that the camera device captures and saves one frame for every degree the light source device rotates.

[0080] To acquire complete spot imaging information without omission or distortion, this invention further specifies that: the measurement field of view of the beam guiding unit B has a maximum field width W1 in the spot movement direction; when the beam information processing unit C continuously captures images, each frame corresponds to a displacement W2 of the spot; the maximum field width W1 and the displacement W2 satisfy: W1 / W2≥1. Specifically, for an embodiment where the light source device 12 is rotated using a rotating stage 111b, the measurement field of view of the beam guiding unit B has a maximum field angle FV1; when the beam information processing unit C continuously captures images, each frame corresponds to a rotation angle FV2 of the rotating stage 111b; the maximum field angle FV1 and the rotation angle FV2 satisfy: FV1 / FV2≥1, preferably FV1 / FV2≥1.5, for example, FV1 = 1-2 degrees, FV2 = 1-1.5 degrees. Because the rotation angle is smaller than the field of view of the measurement field of view, each captured light spot can have a certain length of overlap information. This overlap information can be used as a reference for stitching, thereby ensuring the efficiency, integrity, and accuracy of image stitching.

[0081] exist Figure 2 For clarity, the diagram is exaggerated to illustrate the following scenario: the rotary stage 111b rotates the light source device 12 by an angle ω (e.g., 1 degree), causing the light spot to move accordingly, that is, light spot M1 shifts to light spot M2, which correspond to the two captured images P1 and P2 respectively. The overlapping information area MR of the light spot corresponds to the overlapping area PR of the imaging data of images P1 and P2. Since there is an overlapping area between the acquired sequence of images, the overlapping area must be reduced before forming the fused image. As mentioned above, this overlapping area can be used as a alignment reference during image stitching processing.

[0082] Of particular advantage is that the computer device 15 includes a binarization calculation function module for binarizing the stitched fused image, thereby obtaining an image with clear boundaries, which facilitates the measurement or calculation of the geometric size of the light spot.

[0083] According to a particularly advantageous embodiment, the computer device 15 includes a pixel accumulation algorithm module for calculating the geometric size of the light spot from the fused image. Based on this, the divergence angle of the beam under test can be accurately calculated, as will be explained in detail below.

[0084] According to the technical solution of the present invention, after the light spot (or each light spot segment) generated by the light beam is guided and shaped by the light beam guide B, a corresponding real image should be obtained on the imaging surface of the imaging device 14, such as a reduced and inverted real image, so as to photosensitively record the optical data / information of the light spot (or each light spot segment).

[0085] The beam guiding section B is composed of a light guide assembly 13, which may include, for example, an optical device 131 with a lens. Therefore, based on the corresponding geometric optical model and the sampled light spot image directly captured by the photograph, the geometric parameters of the initial light spot (corresponding to the beam emitted by the light source device), especially the beam divergence angle (or "spot divergence angle"), can be calculated. Simultaneously, the uniformity and optical efficiency of the beam can be analyzed from the grayscale levels and grayscale distribution of the sampled light spot image. It is worth mentioning that using a suitable light guide assembly, especially a fixed-focal-length light guide assembly, can ensure image quality, so as to accurately reflect the characteristic information of the beam and achieve precise measurement. As an example, the optical device 131 can be constructed as a collimator, an optical lens, etc.

[0086] Figure 5 This is a schematic diagram of the optical path for a light spot imaging implementation. The light beam emitted by the light source device 12 is guided and shaped by the light guide assembly 13, and its light spot imaging information is recorded at the imaging device 14. The beam guide (or light guide assembly 13) includes an optical device with at least one lens S1.

[0087] Here, the relative positions of the beam emitting part A and the beam guiding part B can be set such that, along the optical axis of the lens S1, the distance LA between the light spot generated by the beam emitting part A and the incident surface of the lens and the focal length F of the lens satisfy: LA / F≤0.35, preferably LA / F≤0.3. This facilitates the effective portion of the light spot from the beam emitting part entering the beam guiding part, and the light spot rays enter the rear system as much as possible. According to a generally feasible embodiment, the values ​​of LA and F can be: LA=60-90mm, F=300-400mm. According to a specific embodiment, the light guide assembly 13 includes an optical device 131 and a support platform 132 for fixing and supporting the optical device (e.g., Figure 1 (As shown). Preferably, the relative position of the support platform and the support device 11 is adjustable so as to set the distance between the beam emitting part A and the beam guiding part B, and can be adapted to the measurement of different types and specifications of light source devices.

[0088] In this embodiment, the beam quality measurement system of this application may further include a collimation module, which is disposed between the beam emitting part A and the beam guiding part B, for making the beam emitted by the beam emitting part A incident parallel to the lens S1 of the beam guiding part B. The collimation module is constructed as a TIR lens, a plano-convex lens, a spherical or aspherical lens, or a combination thereof. Figure 5 Lens S2 is used to schematically represent the image.

[0089] As an alternative or additional solution, the beam guiding unit can be implemented based on the pinhole imaging principle. With the help of a properly designed light guide component 13, the light spots M (or various light spot segments) generated by the light beam emitted from the light source device 12 are projected onto the imaging surface of the imaging device 14. Based on the pinhole imaging principle, each point element of the light spot corresponds one-to-one with the point element of the image (real image) after passing through the pinhole, thus accurately reflecting the optical data / information of the light spot and can be used to obtain the quality parameters of the light beam. Figure 6 A schematic diagram illustrating the principle of spot imaging and geometric calculation in one embodiment is shown.

[0090] according to Figure 5 and Figure 6 The illustrated implementation, particularly the calculation of the spot size and divergence angle, can be achieved using a simple geometric optics model. For example, according to a very simple implementation, based on... Figure 5 As shown, the distance from the beam emitting unit A (specifically, the laser) to the collimation module (specifically, the lens S2) can be set to be equal to the focal length of the collimator (i.e., the optical device 131 with lens S1). This will be explained in detail below.

[0091] In principle, the beam quality measurement system proposed in this invention is applicable to beam quality measurement of various types of light sources. The light source device 12 can be an LD, LED, halogen lamp, or a combination thereof.

[0092] The present invention also provides a method for measuring beam quality.

[0093] Figure 7 A flowchart of a beam quality measurement method is shown. The method generally includes the following steps:

[0094] I. The light source device 12 to be tested is fixed to the carrier device 11 to form a beam emitting part A;

[0095] II. A beam information processing unit C, including a camera device 14 and a computer device 15;

[0096] III. A beam guiding section B is provided, the beam guiding section B having a first side E1 near the beam emitting section and a second side E2 near the beam information processing section in the light propagation direction, the first side E1 defining a measurement field of view;

[0097] IV. Arrange the beam emitting unit A, the beam guiding unit B, and the beam information processing unit C sequentially along the direction of light propagation, and adjust the relative positions of the three.

[0098] V. Perform beam quality measurement.

[0099] According to the technical solution proposed in this invention, in step V, the light source device 12 is driven to move relative to the beam guide in at least one direction perpendicular to the light propagation direction, so that the light beam emitted by the light source device generates a correspondingly moving initial light spot on the first side E1 of the beam guide. The initial light spot is moved into and / or across the measurement field of view. During the process from one edge of the initial light spot entering the measurement field of view to the other edge of the initial light spot entering the measurement field of view, the imaging device 14 continuously takes pictures of the sampling light spot projected onto the imaging surface of the second side E2 of the beam guide. Then, the computer device 15 analyzes and processes the captured images to determine the quality parameters of the light beam.

[0100] In some embodiments, it is specifically specified that the movement of the light source device is rotation. That is, in step V, the light source device is driven to rotate so that the light beam emitted by the light source device generates a correspondingly moving initial light spot on the first side E1 of the beam guide.

[0101] In some embodiments, it is proposed that: in step IV, the height position of the light source device 12 is adjusted so that the light beam emitted by the light source device is aligned with the measurement field of view of the first side E1 of the beam guide.

[0102] In some embodiments, it is proposed that, in step III, an optical device with at least one lens is provided to form the beam guide.

[0103] According to the present invention, it is advantageous that the stage of analyzing and processing the captured images using the computer device 15 includes the following steps:

[0104] (a) stitching together multiple image segments captured by the camera device into a fused image containing complete spot imaging information;

[0105] (b-1) Binarize the stitched fused image;

[0106] (c-1) The geometric dimensions of the light spot are determined or calculated from the fused image;

[0107] (d-1) Calculate the divergence angle of the beam based on the geometric dimensions of the beam spot.

[0108] In step (c-1), the following may be further included:

[0109] (c-1-1) Based on the gray value function of the fused image, the width and height of the fused image, the total energy of the light spot, and the camera resolution of the imaging device in the horizontal and vertical directions, the centroid coordinates (X, Y) of the light spot are calculated.

[0110] (c-1-2) With the centroid of the light spot as the center, the pixel points of the light spot are accumulated in the horizontal and vertical directions respectively. The number of pixels after accumulation is counted, and the size of the light spot in the horizontal and vertical dimensions is calculated accordingly.

[0111] It should be understood that the technical solution proposed in this invention is not limited to beam quality detection solely based on the divergence angle. Evaluating beam uniformity and optical efficiency based on the captured image is also entirely feasible. Therefore, according to this invention, the stage of analyzing and processing the captured image using the computer device 15 includes the following steps:

[0112] (a) stitching together multiple image segments captured by the camera device into a fused image containing complete spot imaging information;

[0113] (b-2) The uniformity and optical efficiency of the beam are analyzed based on the gray level and gray distribution of the fused image.

[0114] Specifically, the beam quality measurement method of the present invention can be implemented in the following manner:

[0115] - During the test, the laser under test emits laser light, which is incident on the optical device of the beam guide. The field of view of the optical device is 1.3°, and a 1.3° spot image is acquired in a single acquisition.

[0116] - Initialize the position of the electronically controlled rotary table, rotate the electronically controlled rotary table so that the edge of the light spot just enters the field of view of the optical device, and then use an infrared camera to capture the first image of the light spot;

[0117] Then, the electrically controlled rotary table is rotated multiple times at 1° intervals, and the infrared camera sequentially captures images of the light spot after the rotary table rotates. When the infrared camera acquires an image of the other edge of the light spot, the rotary table stops rotating, and the infrared camera stops capturing images.

[0118] Specifically, the present invention can realize a beam quality measurement system, which generally includes three parts: a beam emitting unit A, a beam guiding unit B, and a beam information processing unit C. The beam emitting unit A has a carrier device 11 and a light source device 12, the beam guiding unit B may include a light guide assembly 13, and the beam information processing unit may include a camera device 14 and a computer device 15.

[0119] The support device 11 is used to support the light source device 12, such as a laser emitter. Here, the support device 11 is equipped with an actuation mechanism 111, which can drive the light source device 12 mounted on the support device to move (e.g., rotate left or right or swing) to adjust the beam emission angle of the light source device 12. The actuation mechanism 111 is connected to a lifting platform 111a and a rotating platform 111b. Figure 1 Taking the conventional arrangement of the system equipment shown as an example, for ease of description, a spatial coordinate system can be defined here: the X-axis extends horizontally, consistent with the direction of light propagation; the Y-axis extends horizontally, perpendicular to the direction of light propagation; the Z-axis extends vertically, or in other words, in the height direction. Therefore, the lifting platform 111a can be used to move the light source device 12 in the Z-axis direction (i.e., the height direction), while the rotating platform 111b can be used to move or rotate the light source device 12 in the XY plane (or around the Z-axis), or in the ZX plane (or around the Y-axis). Here, the control mode of the actuation mechanism 111 can be automatic, manual, or a combination thereof.

[0120] The light source device 12 is disposed on the carrier device 11 for emitting a light beam. Here, the light source device 12 can be an infrared laser emitter that emits infrared laser light. Of course, within the framework of this invention, the light source device 12 can also be an LD (Laser Diode), an LED (Light Emitting Diode), a halogen lamp, or a combination thereof.

[0121] The light guide assembly 13 is arranged adjacent to the support device 11 and the light source device 12. The light guide assembly 13 includes an optical element (e.g., constructed as a collimator) 131 and a support platform 132. The support platform 132 supports the optical element 131, aligning or corresponding the optical element 131 in height (Z-axis direction) with or corresponding to the light source device 12. Here, the support platform 132 can be considered as a support component for the optical element 131. The imaging device 14 is disposed on one side of the optical element 131 to receive laser light emitted from the light source device 12. Specifically, the light source device 12 is located on a first side E1 of the optical element 131, and the imaging device 14 is disposed on a second side E2 of the optical element 131, wherein the second side E2 is opposite to the first side E1. Preferably, the length of the optical element 131 is ≤300mm, and the optical element 131 has a lens with a focal length F. According to one construction method, the lens of the optical device 131 can be designed to include two sub-lenses. The focal lengths of the two sub-lenses are adjusted to obtain the total focal length F mentioned above, and then the two sub-lenses are cemented together. The cross-section of the optical device can be circular, rectangular, polygonal, or a combination thereof.

[0122] Here, the camera device 14 can be a CCD (Charge-coupled Device) camera and / or an infrared camera.

[0123] See Figure 2 In the illustrated embodiment, the laser beam emitted by the light source device 12 enters the optical device 131 and is guided to the imaging surface of the imaging device 14 to acquire an image. An actuation mechanism 111, for example, drives a rotating stage 111b to rotate, causing the light source device 12 to rotate about the Y-axis (or Z-axis), generating a rotation angle ω. During measurement, the rotating stage 111b is adjusted or rotated so that the light spot of the light source device 12 with a divergence angle enters and / or passes over the field of view of the optical device 131. While the rotating stage 111b rotates, the imaging device 14 continuously takes pictures to acquire images of the light spot entering the field of view, particularly capturing multiple segmented light spot images, such as... Figure 3 As shown. Next, multiple light spot images are stitched together. For example, these captured images are transmitted to a computer device 15, where a pre-programmed light spot image algorithm is used to stitch the images together to form a uniform light spot, such as... Figure 4 As shown.

[0124] Specifically, according to this system, when performing beam quality measurement, the light source device 12 to be measured is first placed on the rotating stage 111b, and the height of the light source device 12 relative to the optical device 131 is adjusted to ensure alignment and equal height, so as to ensure that the light spot image is located in the center of the image. Next, the position of the rotating stage is initialized, and the rotating stage 111b drives the light source device 12 to rotate, so that one edge of the light spot with a divergence angle just enters the field of view of the optical device 131. Then, the rotating stage 111b continues to rotate, so that the entire light spot rotates from one edge to the other edge, until the other edge of the light spot just enters the field of view of the optical device 131, thereby ensuring accurate measurement of the light spot length. During the rotation of the light source device 12 driven by the rotating stage 111b, the imaging device 14 continuously takes pictures to capture images of the segmented light spot. Then, the images captured by the imaging device 14 are transmitted to the computer device 15 for analysis and processing. The captured multiple light spot images are stitched together using image stitching technology to form a fused image of a uniform light spot. The specific method involves using a template matching algorithm to extract common features from multiple captured light spot images and then fusing them (rather than merging images by hitting the light spots onto a target and marking them with the target). Suitable for this system, the light spot emitted by the light source device 12 is a long, strip-shaped light spot. The system photographs the long, strip-shaped light spots rotated to different angles and then performs the fusion process. As another example, the light spot shape can also be circular, square, triangular, polygonal, or a combination thereof.

[0125] Figure 8 This is a schematic diagram of one implementation of a beam quality measurement method, specifically illustrating the divergence angle algorithm flow. The stitched fused image is further binarized to perform binarization image processing on the light spot, thus making the light spot image boundary clearer and enabling more accurate determination or calculation of the light spot length. Here, the stitched image is pixel-extracted, with pixels greater than a threshold set to 255 (white) and pixels less than the threshold set to 0 (black), making the image a black and white image.

[0126] Next, the centroid of the light spot is calculated. After binarization, the light spot is a uniform strip-shaped light spot. According to the following formulas (1) and (2), the centroid of the entire light spot is calculated to obtain the centroid coordinates (X,Y) of this light spot:

[0127]

[0128]

[0129] Where f(i,j) represents the grayscale function of the image, m represents the image width, n represents the image height, E is the total energy of the light spot, θ1 is the camera resolution in the X direction, and θ2 is the camera resolution in the Y direction.

[0130] Next, pixel accumulation calculation is performed. Centered on the centroid (X,Y) of the light spot, the pixels of the light spot are accumulated in the X and Y directions respectively, and the number of pixels after accumulation is counted. The length or width of the light spot is calculated according to the following formula (3). For example, the length of the light spot can be calculated from this:

[0131] L=μ×N… (3)

[0132] Where μ is the camera pixel size, N is the number of pixels, and L is the spot length.

[0133] With the arrangement of the components in the system (including the beam emitting unit A, the beam guiding unit B, and the beam information processing unit C) determined, in the simplest embodiment, since the focal length of the lens of the optical device 131 is known, the horizontal and vertical divergence angles of the beam can be calculated according to the following formula (4):

[0134]

[0135] Where a is the beam divergence angle (or "spot divergence angle"), and f is the focal length of the lens of the optical device.

[0136] When L in formula (4) is the spot length in the X direction, the calculated divergence angle α is the horizontal divergence angle; when L is the spot length in the Y direction, the calculated divergence angle α is the vertical divergence angle. (See [reference needed]). Figure 6 The diagram shown illustrates the principle of calculating the beam divergence angle.

[0137] The aforementioned image-stitching optical field beam quality measurement system and method can measure the divergence angle of large-angle beams. By directly capturing beam images with a camera, the size of large-angle beams can be measured accurately, and the divergence angle can be calculated. Furthermore, by using image stitching technology to obtain a pixel distribution map of the beam, the overall beam uniformity can be determined. Moreover, unlike traditional methods that require pre-projecting the beam onto a target, the influence of external factors such as target material and flatness on the measurement of the divergence angle does not need to be considered. Compared to methods that project onto a target and cannot directly test light efficiency, this system and method provide a more direct and accurate measurement method, while simultaneously addressing the shortcomings of existing beam quality analyzers, such as insufficient test field of view and inability to completely measure large-angle beam divergence angles, uniformity, and optical efficiency.

[0138] While exemplary embodiments of the present invention have been described above, those skilled in the art should understand that various changes and modifications can be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the invention, and all such changes and modifications are included within the scope of protection of the present invention.

[0139] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A beam quality measurement system, comprising a beam emitting unit, a beam guiding unit, and a beam information processing unit arranged sequentially. Its features are, The beam emitted by the beam emitting unit can generate a moving spot on the first side of the beam guiding unit. By controlling the movement of the beam emitting unit relative to the beam guiding unit, the spot moves into and / or sweeps across the measurement field of view defined on the first side of the beam guiding unit. At the same time, the beam information processing unit continuously captures the image generated on the second side of the beam guiding unit that falls into the measurement field of view, at least until complete spot imaging information is obtained, so as to determine the quality parameters of the beam.

2. The beam quality measurement system according to claim 1, characterized in that, The quality parameters of the beam are beam divergence angle, beam uniformity, optical efficiency, or a combination thereof.

3. The beam quality measurement system according to claim 1, characterized in that, When performing beam quality measurement, the light spot generated by the beam emitted by the beam emitter moves in at least one direction perpendicular to the direction of light propagation.

4. The beam quality measurement system according to any one of claims 1 to 3, characterized in that, The measurement field of view of the beam guiding unit has a maximum field width W1 in the direction of beam spot movement. When the beam information processing unit continuously captures images, each frame of the image corresponds to a displacement W2 of the beam spot. The maximum field width W1 and the displacement W2 satisfy: W1 / W2≥1.

5. The beam quality measurement system according to any one of claims 1 to 3, characterized in that, The beam information processing unit includes a camera device and a computer device.

6. The beam quality measurement system according to claim 5, characterized in that, The computer device can analyze and process the captured images, stitching multiple image segments together into a fused image containing complete spot imaging information.

7. The beam quality measurement system according to claim 6, characterized in that, The computer device includes an image stitching algorithm module, which can execute a template matching algorithm to stitch image segments together.

8. The beam quality measurement system according to claim 6, characterized in that, The computer device includes a binarization calculation function module for performing binarization processing on the stitched fused image.

9. The beam quality measurement system according to claim 6, characterized in that, The computer device includes a pixel accumulation algorithm module for calculating the geometric size of the light spot from the fused image.

10. The beam quality measurement system according to claim 5, characterized in that, The camera device continuously takes pictures of the light spot pattern projected onto the imaging surface of the second side of the beam guide during the process from when one edge of the light spot enters the measurement field of view to when the other edge of the light spot enters the measurement field of view, so as to obtain at least one set of static images carrying light spot imaging information.

11. The beam quality measurement system according to claim 10, characterized in that, The camera device can continuously take pictures at a speed that is adapted to the movement speed of the light spot.

12. The beam quality measurement system according to claim 10, characterized in that, The camera device includes a CCD and / or an infrared imaging element.

13. The beam quality measurement system according to any one of claims 1 to 3, characterized in that, The beam guiding section includes an optical device with at least one lens.

14. The beam quality measurement system according to claim 13, characterized in that, The relative positions of the beam emitting part and the beam guiding part are set such that, along the optical axis of the lens, the distance LA between the light spot generated by the beam emitting part and the incident surface of the lens and the focal length F of the lens satisfy: LA / F≤0.

35.

15. The beam quality measurement system according to claim 13, characterized in that, The beam quality measurement system also includes a collimation module, which is used to make the beam emitted by the beam emitting unit incident parallel to the lens of the beam guiding unit.

16. The beam quality measurement system according to claim 15, characterized in that, The collimation module is constructed as a TIR lens, a plano-convex lens, a spherical or aspherical lens, or a combination thereof.

17. The beam quality measurement system according to any one of claims 1 to 3, characterized in that, The beam emitting part includes a carrier device and a light source device fixed to the carrier device.

18. The beam quality measurement system according to claim 17, characterized in that, The supporting device includes a rotating platform, and the light source device is detachably fixed on the rotating platform. The rotating platform can drive the light source device to rotate so that the light beam emitted by the light source device generates a corresponding moving light spot on the first side of the light beam guide.

19. The beam quality measurement system according to claim 18, characterized in that, The measurement field of view of the beam guiding unit has a maximum field of view angle FV1. When the beam information processing unit continuously captures images, each frame of the image corresponds to a rotation angle FV2 of the rotary table. The maximum field of view angle FV1 and the rotation angle FV2 satisfy: FV1 / FV2≥1.

20. The beam quality measurement system according to claim 18, characterized in that, The supporting device includes a lifting platform, and the rotating platform is supported on the lifting platform. The height of the rotating platform can be adjusted by the lifting platform so that the light beam emitted by the light source device is aligned with the measurement field of view on the first side of the beam guide.

21. The beam quality measurement system according to claim 17, characterized in that, The light source device is an LD, an LED, a halogen lamp, or a combination thereof.

22. A method for measuring beam quality, comprising the following steps: I. Provide a beam emitting section; II. Provide a beam information processing unit; III. Provides a beam guide; IV. Arrange the beam emitting unit, beam guiding unit, and beam information processing unit in sequence and adjust their relative positions. V. Perform beam quality measurement; Its features are, In step V, the beam emitted by the beam emitting unit is made to generate a moving spot on the first side of the beam guiding unit, wherein the spot is moved into and / or across the measurement field of view defined on the first side of the beam guiding unit, while the beam information processing unit continuously captures images generated on the second side of the beam guiding unit that fall into the measurement field of view, at least until complete spot imaging information is obtained; then, the captured images are analyzed and processed to determine the quality parameters of the beam.

23. The beam quality measurement method according to claim 22, characterized in that, In step I, the light source device to be tested is detachably fixed to the carrier device to form the beam emitting part.

24. The beam quality measurement method according to claim 23, characterized in that, In step V, the light source device is driven to move relative to the beam guide in at least one direction perpendicular to the light propagation direction, so that the light beam emitted by the light source device generates a correspondingly moving light spot on the first side of the beam guide.

25. The beam quality measurement method according to claim 23, characterized in that, In step V, the light source device is driven to rotate so that the light beam emitted by the light source device generates a correspondingly moving light spot on the first side of the beam guide.

26. The beam quality measurement method according to claim 23, characterized in that, In step IV, the height position of the light source device is adjusted so that the light beam emitted by the light source device is aligned with the measurement field of view on the first side of the beam guide.

27. The beam quality measurement method according to claim 22, characterized in that, In step III, an optical device with at least one lens is provided to form the beam guide.

28. The beam quality measurement method according to any one of claims 22 to 27, characterized in that, The analysis and processing of the captured images includes the following steps: (a) The captured image segments are stitched together into a fused image containing complete spot imaging information; (b-1) Binarize the stitched fused image; (c-1) The geometric dimensions of the light spot are determined or calculated from the fused image; (d-1) Calculate the divergence angle of the beam based on the geometric dimensions of the beam spot.

29. The beam quality measurement method according to claim 28, characterized in that, In step (c-1), the following is further included: (c-1-1) Based on the gray value function of the fused image, the width and height of the fused image, the total energy of the spot, and the imaging resolution in the horizontal and vertical directions, the centroid coordinates (X, Y) of the spot are calculated. (c-1-2) With the centroid of the light spot as the center, the pixel points of the light spot are accumulated in the horizontal and vertical directions respectively. The number of pixels after accumulation is counted, and the size of the light spot in the horizontal and vertical dimensions is calculated accordingly.

30. The beam quality measurement method according to any one of claims 22 to 27, characterized in that, The analysis and processing of the captured images includes the following steps: (a) The captured multiple image segments are stitched together into a fused image containing complete spot imaging information; (b-2) The uniformity and optical efficiency of the beam are analyzed based on the gray level and gray distribution of the fused image.

31. An electronic device, comprising: A processor is used to execute instructions, and A memory communicatively connected to the processor, the memory having at least one instruction; The instructions are executed by the processor to perform beam quality measurement using the beam quality measurement method according to any one of claims 22 to 30.

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