Point light source luminosity distribution measurement method and device, terminal and storage medium

Abstract

The invention discloses a point light source luminosity distribution measurement method and device, a terminal and a storage medium. Diffusing the light source signal through an optical diffuser, and outputting a diffused light source signal; re-imaging the diffused light source signal through an imaging lens, and outputting a target light signal; converting the target optical signal into a target array electric signal through a charge coupling module; and generating a luminosity distribution measurement result according to the target array electric signal, wherein the luminosity distribution measurement result comprises at least one of a luminosity distribution pseudo-color graph, a luminosity distribution contour map and a luminosity distribution uniformity index. The portable and low-cost measuring device is formed by the optical diffuser, the imaging lens and the charge coupling module. After an optical signal of the point light source is transmitted to the optical diffuser, receiving information of diffusion light beam distribution is extracted and calculated by the imaging lens and the charge coupling module, and the luminosity distribution uniformity of the point light source in a limited angle space range is evaluated, so that efficient and rapid measurement of luminosity distribution of the point light source is realized.

Description

Technical Field

[0001] The present invention relates to the field of optical technologies, and particularly to a method, device, terminal and storage medium for measuring the photometric distribution of a point light source. Background Art

[0002] Traditional measurement schemes for the spatial photometric distribution of light sources commonly use dynamic scanning methods. The instrument equipment is huge, complex, expensive and inconvenient to use. The application demands for light sources in various fields are increasing, and the performance requirements are also getting higher and higher, which requires higher requirements for the measurement accuracy and convenience of light sources. The semiconductor inspection link is an indispensable part in the integrated circuit manufacturing process. The inspection equipment can monitor, identify, locate and analyze process defects during production, and plays a crucial role in helping the wafer fab to detect problems in time, improve processes and increase the yield. With the continuous multi-layerization and complexity of integrated circuits, the importance of inspection equipment has become increasingly prominent. Optical inspection equipment occupies 70% of the market space of all inspection equipment. The light source is one of its key core components, which determines the final inspection performance of the equipment. Among the various indicators of the light source, the photometric distribution is extremely important for the application of the light source, especially in the field of semiconductor measurement. The uniformity of the light source distribution in each space affects the measurement accuracy of the measurement equipment and also visualizes the process nodes of the chip manufacturing process.

[0003] As Figure 2 shown, most current measurements of the photometric distribution of light sources use large-scale scanning measurements. The size of the measurement device is up to several meters, and the test time is in hours. It is difficult to evaluate the photometric distribution of the light source efficiently, conveniently and at low cost.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method, device, terminal and storage medium for measuring the photometric distribution of a point light source, aiming at solving the problem that most current measurements of the photometric distribution of light sources use large-scale scanning measurements, the size of the measurement device is large, and the test time is long, making it difficult to evaluate the photometric distribution of the light source efficiently, conveniently and at low cost.

[0006] The technical solution adopted by the present invention to solve the problem is as follows: In the first aspect, an embodiment of the present invention provides a method for measuring the photometric distribution of a point light source, the method comprising: Receiving the light source signal of the point light source to be measured through an optical diffuser, diffusing the light source signal, and outputting a diffused light source signal; Receiving the diffused light source signal through an imaging lens, re-imaging the diffused light source signal, and outputting a target optical signal; Receiving the target optical signal through a charge-coupled module and converting the target optical signal into a target array electrical signal; Generating a photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal; the photometric distribution measurement result includes at least one piece of information among a photometric distribution pseudocolor map, a photometric distribution contour map, and a photometric distribution uniformity index.

[0007] In one embodiment, the distance between the point light source to be measured and the optical diffuser is more than a preset multiple of the size of the point light source to be measured.

[0008] In one embodiment, the optical axis of the optical diffuser, the imaging lens, the charge-coupled module, and the point light source to be measured are coaxial.

[0009] In one embodiment, the charge-coupled module includes a plurality of charge-coupled elements in an array type, and the charge-coupled elements are equally spaced, and the array size is determined based on the imaging field angle of the imaging lens.

[0010] In one embodiment, converting the target optical signal into a target array electrical signal includes: Converting the target optical signal into an electrical signal to obtain an original array electrical signal; Preprocessing the original array electrical signal through median filtering and Gaussian filtering, and using the preprocessed signal as the target array electrical signal.

[0011] In one embodiment, generating the photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal includes: Identifying the coordinates of the normal projection of the point light source onto the optical diffuser to obtain the center coordinates; Based on the target array electrical signal, determining the light intensity values of each point on a circle with different radii centered on the center coordinates; Calculating the photometric distribution uniformity index according to the light intensity values of each point on each circle.

[0012] In one embodiment, before the method, it further includes: Based on the test array electrical signal obtained in the test session, determining the test light intensity values of each point on a circle with different radii centered on the center coordinates according to the test array electrical signal; Obtaining the photometric distribution data of the calibration point light source; For each circle, determining the correction coefficient corresponding to each point on the circle according to the photometric distribution data of the calibration point light source and the test light intensity values of each point on the circle to correct the systematic error.

[0013] In a second aspect, an embodiment of the present invention further provides a device for measuring the photometric distribution of a point light source, and the device includes: An optical diffuser for receiving a light source signal of a point light source to be measured, diffusing the light source signal, and outputting a diffused light source signal; An imaging lens for receiving the diffused light source signal, re-imaging the diffused light source signal, and outputting a target optical signal; A charge-coupled module for receiving the target optical signal and converting the target optical signal into a target array electrical signal; Generating a photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal; the photometric distribution measurement result includes at least one of the following information: a pseudo-color map of the photometric distribution, a contour map of the photometric distribution, and a uniformity index of the photometric distribution.

[0014] In a third aspect, an embodiment of the present invention further provides a terminal, which includes a memory and more than one processor; the memory stores more than one program; the program includes instructions for executing the point light source photometric distribution measurement method as described in any one of the above; the processor is used to execute the program.

[0015] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which multiple instructions are stored, and the instructions are suitable for being loaded and executed by a processor to implement the steps of the point light source photometric distribution measurement method as described in any one of the above.

[0016] Advantages of the present invention: The embodiment of the present invention forms a portable and low-cost measurement device through an optical diffuser, an imaging lens, and a charge-coupled module. After the light signal of the point light source is transmitted to the optical diffuser, the imaging lens and the charge-coupled module extract and calculate the received information of the diffused light beam distribution, and evaluate the uniformity of the photometric distribution of the point light source within a limited angular space range, realizing efficient and rapid measurement of the photometric distribution of the point light source. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic flowchart of the point light source photometric distribution measurement method provided by an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of the existing point light source photometric distribution measurement method provided by an embodiment of the present invention.

[0020] Figure 3It is a schematic diagram of a point light source photometric distribution measuring device provided by an embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the measurement result of the photometric distribution of a point light source provided by an embodiment of the present invention.

[0022] Figure 5 It is a principle block diagram of a terminal provided by an embodiment of the present invention. Detailed implementation manners

[0023] The present invention discloses a method, device, terminal and storage medium for measuring the photometric distribution of a point light source. To make the purpose, technical solution and effect of the present invention clearer and more definite, the following further describes the present invention in detail with reference to the accompanying drawings and by way of examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] Those skilled in the art of the present technology can understand that unless specifically stated otherwise, the singular forms "a", "an", "the" and "said" used herein may also include the plural forms. It should be further understood that the term "including" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any unit and all combinations of one or more of the associated listed items.

[0025] Those skilled in the art of the present technology can understand that unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as here.

[0026] In view of the above defects of the prior art, the present invention provides a method for measuring the photometric distribution of a point light source. The method receives the light source signal of the point light source to be measured through an optical diffuser, diffuses the light source signal, and outputs a diffused light source signal; receives the diffused light source signal through an imaging lens, re-images the diffused light source signal, and outputs a target light signal; receives the target light signal through a charge-coupled module, and converts the target light signal into a target array electrical signal; generates a photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal; the photometric distribution measurement result includes at least one of the following information: a photometric distribution pseudocolor map, a photometric distribution contour map, and a photometric distribution uniformity index. The present invention uses an optical diffuser, an imaging lens, and a charge-coupled module to form a portable and low-cost measurement device. After the light signal of the point light source is transmitted to the optical diffuser, the imaging lens and the charge-coupled module extract and calculate the received information of the diffused light beam distribution, and evaluate the photometric distribution uniformity of the point light source within a limited angular space range, realizing efficient and rapid measurement of the photometric distribution of the point light source.

[0027] As Figure 1 shown, the method specifically includes the following steps: Step S100: Receive the light source signal of the point light source to be measured through an optical diffuser, diffuse the light source signal, and output a diffused light source signal.

[0028] Specifically, the light intensity distribution projected by the point light source onto the diffuser conforms to the inverse square law. Taking the light intensity point projected normally by the point light source onto the optical diffuser as the center coordinate (i.e., the center of the circle), the concentric rings of the light intensity distribution are ideally of equal light intensity distribution. Therefore, the photometric distribution of the point light source can be analyzed based on the diffused light source signal. In an actual application scenario, the point light source to be measured can be any point light source that meets the preset conditions, and the point light source to be measured emits a light source signal. The optical diffuser is the component closest to the light source to be measured. It receives the light source signal, diffuses the light source signal, and outputs a diffused light source signal.

[0029] In one implementation, the types of output systems of the point light source to be measured include but are not limited to: plasma light-emitting light sources, traditional electroluminescent light sources, LED diode light sources, semiconductor laser light sources, fiber laser light sources, gas laser light sources, solid laser light sources, In one implementation, the types of optical diffusers include but are not limited to: transmissive diffusers, reflective diffusers, diffractive diffusers, array diffusers, etc. Classified by diffusion function, they include uniform diffusers, flat-top diffusers, and Gaussian diffusers. Secondly, the shapes of optical diffusers include but are not limited to: planar, spherical, aspherical, etc.

[0030] In one implementation, the distance between the point light source to be measured and the optical diffuser is more than a preset multiple of the size of the point light source to be measured.

[0031] Specifically, the method of this embodiment is mainly applied to the measurement scenario of far-field photometric distribution of light intensity. Therefore, the size of the point light source to be measured and the distance between the point light source to be measured and the optical diffuser need to meet the preset numerical relationship to use the method of this embodiment. In other words, the method of this embodiment is mainly applied to small-size point light sources, and the projection distance meets the far-field requirements of the point light source.

[0032] For example, when the distance between the optical diffuser and the point light source to be measured is more than 5 times the size of the point light source to be measured, it can be determined that the light intensity distribution is a far-field photometric distribution, meeting the usage conditions of the method of this embodiment. Preferably, the size of the point light source is less than 1 cm. It is applicable to the measurement of the photometric distribution of small light spots (<1 cm, limited by the space of the simple measurement system) in applications such as semiconductor measurement, industrial processing, and home lighting sources.

[0033] Step S200: Receive the diffused light source signal through an imaging lens, re-image the diffused light source signal, and output a target light signal.

[0034] Specifically, the light signal diffused by the optical diffuser is collected by an imaging lens (or called a diffused beam energy collector). The optical axis of the imaging lens vertically passes through the central coordinate of the optical diffuser, collects the diffused energy of the diffuser (i.e., the diffused light source signal), and re-images the light diffusion point information. The light signal obtained by re-imaging in this embodiment is defined as the target light signal.

[0035] In one implementation, the types of imaging lenses include but are not limited to: transmissive collectors, reflective collectors, etc.

[0036] Step S300: Receive the target light signal through a charge-coupled module, and convert the target light signal into a target array electrical signal.

[0037] Specifically, the target light signal obtained after re-imaging by the imaging lens is received by the charge-coupled module, and photoelectric conversion is performed within the charge-coupled module to obtain the corresponding target array electrical signal for subsequent data analysis and calculation. There is a certain mapping relationship between the target array electrical signal and the light signal on the optical diffuser. Therefore, the target array electrical signal can reflect the photometric distribution of the point light source to be measured.

[0038] In one implementation, the charge-coupled module (or called a light signal detector), classified according to the response band, includes but is not limited to: wide-spectrum response detectors, ultraviolet band-pass response detectors, visible light, near-infrared band-pass response detectors, etc.; classified according to the package type, includes but is not limited to: line array cameras, area array cameras, scanning line array cameras, etc.

[0039] In one implementation, the charge-coupled module includes a number of charge-coupled elements in an array form, and the charge-coupled elements are equally spaced. The size of the array is determined based on the imaging field of view angle of the imaging lens.

[0040] In this embodiment, an array-type charge-coupled module is adopted, which can better receive the target optical signal output by the imaging lens. As a signal receiver, the charge-coupled module can convert the received light intensity information into an array of electrical signals. Specifically, the charge-coupled module is composed of a plurality of charge-coupled elements (CCDs), and each charge-coupled element is equally spaced and has the same shape and response. Secondly, the array size of the charge-coupled module needs to meet the imaging field of view angle of the imaging lens.

[0041] In one implementation, converting the target optical signal into a target array of electrical signals includes: Converting the target optical signal into an electrical signal to obtain an original array of electrical signals; Preprocessing the original array of electrical signals through median filtering and Gaussian filtering, and using the preprocessed signal as the target array of electrical signals.

[0042] Specifically, in this embodiment, the original signal obtained after the charge-coupled module performs photoelectric conversion is defined as the original array signal. Median filtering and Gaussian filtering are used to preprocess the original array signal. Among them, median filtering sets the gray value of a certain pixel point to the median of all pixel points within the neighborhood window, thereby eliminating isolated noise points; Gaussian filtering is an effective low-pass filter in both the spatial domain and the frequency domain. For a projection image of photometric distribution measurement within a limited range, Gaussian filtering can retain the edge features of the image. In this embodiment, the signal obtained after preprocessing is defined as the target array signal. By preprocessing, the signal quality can be improved, and further the accuracy and reliability of subsequent data analysis and calculation can be improved.

[0043] Step S400: Generating a measurement result of the photometric distribution corresponding to the point light source to be measured according to the target array of electrical signals; the measurement result of the photometric distribution includes at least one piece of information among a pseudo-color map of the photometric distribution, a contour map of the photometric distribution, and an index of photometric distribution uniformity.

[0044] Specifically, the definition of the spatial uniformity of a point light source is the evaluation of the consistency of the energy distribution within a unit solid angle in the beam-emitting three-dimensional space. There is a certain mapping relationship between the target array electrical signal and the optical signal on the optical diffuser. Therefore, the target array electrical signal can reflect the photometric distribution of the point light source to be measured, and the photometric distribution measurement result corresponding to the point light source to be measured can be obtained quantitatively. In an actual application scenario, the electrical signal values of each array in the charge-coupled module are extracted and processed, and one or more photometric distribution measurement results are output. For example, the data type of the photometric distribution measurement result can be a pseudo-color map of the photometric distribution, a contour map of the photometric distribution, a photometric distribution uniformity index (such as Figure 4 shown). The pseudo-color map of the photometric distribution and the contour map of the photometric distribution visualize the photometric distribution; the roundness of the contour map of the photometric distribution directly reflects the uniformity of the photometric distribution; the photometric distribution uniformity index quantifies the photometric uniformity, including but not limited to: Na, the uniformity index at different azimuth angles; Nstd, the standard deviation; Npv, the percentage calculated from the peak-to-peak value. In this embodiment, through the light source diffusion transmission and lens imaging, the photometric energy distribution within the angular space range of the point light source can be quickly detected and its uniformity can be evaluated.

[0045] In one implementation, the optical axis of the optical diffuser, the imaging lens, the charge-coupled module, and the point light source to be measured are coaxial.

[0046] Specifically, in order to improve the accuracy of the photometric distribution measurement result, this embodiment defines that each component in the point light source photometric distribution measurement device needs to satisfy a certain positional relationship with the point light source to be measured, that is, the optical axis of the optical diffuser, the imaging lens, the charge-coupled module, and the point light source to be measured are coaxial. In other words, the planes of the optical diffuser, the imaging lens, and the charge-coupled module should be perpendicular to the optical axis.

[0047] In one implementation, generating the photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal includes: Identifying the coordinates of the normal projection of the point light source onto the optical diffuser to obtain the center coordinates; Based on the target array electrical signal, determining the light intensity values of each point on a circle with the center coordinates as the center and different radii; Calculating the photometric distribution uniformity index according to the light intensity values of each point on each circle.

[0048] Specifically, the measured result of the photometric distribution finally output by the system includes an index of photometric distribution uniformity. To calculate this index, it is first necessary to identify the central coordinates of the projected image, that is, the coordinates where the point light source is projected normally onto the diffuser plate. Then, with this coordinate point as the center, the optical signals on different radius rings of the optical diffuser corresponding to the charge-coupled module are extracted, and the energy distribution uniformity on different rings is calculated, that is, the light intensity distribution uniformity in different NA azimuths. The calculation method can use but is not limited to evaluating with the standard deviation coefficient of the statistical normal distribution.

[0049] In another implementation, the index of photometric distribution uniformity can be calculated based on the contour map and box dimension. The specific calculation method includes: Perform binarization processing on the photometric distribution contour map to obtain a binarized photometric distribution contour map; Cover a square grid with a grid size of the first value on the binarized photometric distribution contour map, and count the number of grids containing the contour line to obtain the number of covered boxes; Judge whether the stop condition is reached (for example, stop when the preset number of processing rounds is reached). If not, reduce the first value; Continue to cover a square grid with a grid size of the first value on the binarized photometric distribution contour map and count the number of grids containing the contour line to obtain the number of covered boxes until the stop condition is reached, obtaining multiple data pairs. Each data pair includes a grid size and the number of covered boxes corresponding to this grid size; Perform linear fitting based on all data pairs and take the absolute value of the slope as the box dimension; Evaluate the roundness level of the photometric distribution contour map according to the size of the box dimension, and calculate the index of photometric distribution uniformity according to the roundness level.

[0050] In this embodiment, from the perspective of box dimension, the shape and boundary of the closed contour lines in the photometric distribution contour map are analyzed to quantify the complexity of the contour lines, and then the roundness condition thereof is analyzed. Specifically, first, the contour map is binarized so that the contour region is the foreground (value is 1) and the background is 0. Then, a square grid with a grid size of the first value r is overlaid on the binarized photometric distribution contour map. The number of grid boxes containing the contour lines is counted to obtain the number of covered boxes N(r). The grid size (i.e., the first value r) is continuously decreased, and the above steps are repeated to obtain a series of numbers of covered boxes N(r) corresponding to different grid sizes. The box dimension D is calculated based on a series of r and N(r): a scatter plot of N(r) versus 1 / r can be plotted on a double logarithmic coordinate graph, and the estimated value D of the box dimension is obtained through linear regression. The larger D is, the higher the complexity of the photometric distribution contour map and the lower the roundness. The roundness index C can be defined as C = 1 / D. The box dimension D of an ideal circle is 1. The closer C is to 1, the higher the roundness of the photometric distribution contour map; the smaller C is, the lower the roundness of the photometric distribution contour map.

[0051] Furthermore, the binarized photometric distribution contour map can be split into binarized images of different contour lines; For each binarized image, taking this binarized image as the aforementioned binarized photometric distribution contour map, the box dimension corresponding to this binarized image is calculated; Based on the box dimensions corresponding to the respective binarized images, the average box dimension and the box dimension consistency are calculated; Based on the average box dimension and the box dimension consistency, the roundness grade of the photometric distribution contour map is evaluated, and the photometric distribution uniformity index is calculated according to the roundness grade.

[0052] In one implementation, before the method, it further includes: Based on the test array electrical signals obtained in the test session, the test light intensity values of each point on the concentric circles with different radii centered at the center coordinates are determined according to the test array electrical signals; The photometric distribution data of the calibration point light source is obtained; For each concentric circle, according to the photometric distribution data of the calibration point light source and the test light intensity values of each point on this concentric circle, the correction coefficient corresponding to each point on this concentric circle is determined to correct the systematic error.

[0053] This embodiment also adopts a dedicated software processing procedure to calibrate the correction coefficient to correct the system error. Specifically, the calibrated photometric distribution data of the point light source is used to calibrate the optical signals of different rings of the test system: theoretically, the photometric intensity / light intensity on the same ring is consistent. Therefore, with the aforementioned center coordinates as the center of the circle, combined with the calibrated photometric distribution data of the point light source, the correction coefficient of each point on each ring is determined, that is, different correction coefficients for radial compensation. The photometric intensity / light intensity of each point on each ring is numerically corrected through the correction coefficient. The corrected light intensity distribution can evaluate the photometric distribution within the entire solid cone angle.

[0054] Based on the above embodiment, the present invention also provides a device for measuring the photometric distribution of a point light source, as Figure 3 shown, the device includes: An optical diffuser 2, configured to receive the light source signal of the point light source to be measured, diffuse the light source signal, and output a diffused light source signal; An imaging lens 3, configured to receive the diffused light source signal, re-image the diffused light source signal, and output a target optical signal; A charge-coupled module 4, configured to receive the target optical signal and convert the target optical signal into a target array electrical signal; Generate the photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal; the photometric distribution measurement result includes at least one piece of information among a photometric distribution pseudocolor map, a photometric distribution contour map, and a photometric distribution uniformity index.

[0055] Based on the above embodiment, the present invention also provides a terminal, and its principle block diagram can be as Figure 5 shown. The terminal includes a processor, a memory, a network interface, and a display screen connected through a system bus. Among them, the processor of the terminal is used to provide computing and control capabilities. The memory of the terminal includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the terminal is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it realizes the method for measuring the photometric distribution of a point light source. The display screen of the terminal can be a liquid crystal display screen or an electronic ink display screen.

[0056] Those skilled in the art can understand that Figure 5 the principle block diagram shown in

[0057] In one implementation, one or more programs are stored in the memory of the terminal, and are configured to be executed by one or more processors. The one or more programs include instructions for performing a method for measuring the photometric distribution of a point light source.

[0058] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0059] In summary, the present invention discloses a method, device, terminal, and storage medium for measuring the photometric distribution of a point light source. The method receives the light source signal of the point light source to be measured through an optical diffuser, diffuses the light source signal, and outputs a diffused light source signal; receives the diffused light source signal through an imaging lens, re-images the diffused light source signal, and outputs a target optical signal; receives the target optical signal through a charge-coupling module, and converts the target optical signal into a target array electrical signal; generates a photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal; the photometric distribution measurement result includes at least one of the following information: a photometric distribution pseudocolor map, a photometric distribution contour map, and a photometric distribution uniformity index. The present invention uses an optical diffuser, an imaging lens, and a charge-coupling module to form a portable and low-cost measurement device. After the light signal of the point light source is transmitted to the optical diffuser, the imaging lens and the charge-coupling module extract and calculate the received information of the diffused light beam distribution, and evaluate the photometric distribution uniformity of the point light source within a limited angular space range, realizing efficient and rapid measurement of the photometric distribution of the point light source.

[0060] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or modifications can be made according to the above description, and all such improvements and modifications shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for measuring the luminosity distribution of a point light source, characterized in that: The method comprises: Receiving a light source signal of a point light source to be measured through an optical diffuser, diffusing the light source signal, and outputting a diffused light source signal; receiving the diffuse light source signal through an imaging lens, re-imaging the diffuse light source signal, and outputting a target light signal; Receive the target optical signal through a charge coupled module and convert the target optical signal into a target array electrical signal; A photometric distribution measurement result corresponding to the point light source to be measured is generated according to the target array electrical signal; the photometric distribution measurement result includes: a photometric distribution pseudo-color map, a photometric distribution contour map, and at least one of a photometric distribution uniformity index.

2. The method for measuring the luminosity distribution of a point light source according to claim 1, characterized in that: The distance between the point light source to be measured and the optical diffuser is greater than a preset multiple of the size of the point light source to be measured.

3. The method for measuring the luminosity distribution of a point light source according to claim 1, characterized in that: The optical diffuser, the imaging lens, the charge coupling module and the optical axis of the point light source to be measured are coaxial.

4. The method for measuring the luminosity distribution of a point light source according to claim 1, characterized in that: The charge coupling module comprises a plurality of charge coupling elements in an array type, each of the charge coupling elements is distributed at equal intervals, and the size of the array is determined based on the imaging field angle of the imaging lens.

5. The method for measuring the luminosity distribution of a point light source according to claim 1, characterized in that: Converting the target optical signal into a target array electrical signal comprises: Converting the target optical signal into an electrical signal to obtain an original array electrical signal; The original array electrical signal is preprocessed by median filtering and Gaussian filtering, and the preprocessed signal is used as the target array electrical signal.

6. The method for measuring the luminosity distribution of a point light source according to claim 1, characterized in that: Generating a photometric distribution measurement result corresponding to the point light source to be measured according to the target array electrical signal, including: Identify the coordinates of the normal projection of the point light source onto the optical diffuser to obtain the center coordinates; Determine the light intensity value of each point on a circle with different radii and with the central coordinate as the center based on the target array electrical signal; The luminosity distribution uniformity index is calculated based on the light intensity value of each point on each ring.

7. The method for measuring the luminosity distribution of a point light source according to claim 6, characterized in that: The method also includes: Based on the test array electrical signal obtained in the test phase, determine the test light intensity value of each point on a circle with different radii and with the central coordinate as the center according to the test array electrical signal; Obtain the luminosity distribution data of the calibration point light source; For each circular ring, the correction coefficients corresponding to the points on the circular ring are determined according to the luminous intensity distribution data of the calibration point light source and the test light intensity values ​​of the points on the circular ring, so as to correct the system error.

8. A point light source luminosity distribution measuring device, characterized in that: The device comprises: An optical diffuser, used for receiving a light source signal of a point light source to be measured, diffusing the light source signal, and outputting a diffused light source signal; An imaging lens, used for receiving the diffuse light source signal, re-imaging the diffuse light source signal, and outputting a target light signal; A charge coupling module, used for receiving the target optical signal and converting the target optical signal into a target array electrical signal; A photometric distribution measurement result corresponding to the point light source to be measured is generated according to the target array electrical signal; the photometric distribution measurement result includes: a photometric distribution pseudo-color map, a photometric distribution contour map, and at least one of a photometric distribution uniformity index.

9. A terminal, characterized in that: The terminal includes a memory and one or more processors; the memory stores one or more programs; the program contains instructions for executing the point light source luminosity distribution measurement method as described in any one of claims 1-7; and the processor is used to execute the program.

10. A computer-readable storage medium having a plurality of instructions stored thereon, characterized in that: The instructions are suitable for being loaded and executed by a processor to implement the steps of the method for measuring the photometric distribution of a point light source as described in any one of claims 1 to 7.

Images