A method for observing ink droplets, an electronic device, and a computer-readable storage medium.

Abstract

This application relates to the field of inkjet printing technology, specifically providing an ink droplet observation method, electronic device, and computer-readable storage medium. The method includes the following steps: obtaining a first dynamic blur distance based on a preset time interval, first ink droplet position information, second ink droplet position information, and a pre-acquired invalid pulse width; and removing dynamic blur from the corresponding first ink droplet image and second ink droplet image based on the first dynamic blur distance. The pre-acquisition process of the invalid pulse width is as follows: acquiring a calibration image of a uniformly moving calibration block, and obtaining the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image; the driving voltage when acquiring the calibration image is the same as the driving voltage when acquiring the first ink droplet image and the second ink droplet image. This method can effectively reduce the cost of ink droplet observation and reduce the error of the observation results.

Description

Technical Field

[0001] This application relates to the field of inkjet printing technology, and more specifically, to a method for observing ink droplets, an electronic device, and a computer-readable storage medium. Background Technology

[0002] In the field of inkjet printing technology, visual droplet observation technology is commonly used to observe ink droplets. The duty cycle of the light source driving waveform affects the image acquired by visual droplet observation technology. Specifically, if the duty cycle of the light source driving waveform is too small, the amount of light entering the camera will be insufficient, resulting in insufficient contrast in the acquired image. If the duty cycle of the light source driving waveform is too large, the ink droplets will experience dynamic blurring due to excessive exposure time, resulting in inaccurate boundaries of the ink droplets obtained from the image.

[0003] To avoid the impact of the above two situations on the final observation results, the relevant techniques need to increase the amount of light entering the eye under short exposure conditions or approximate the ink droplet as a sphere. However, these techniques have the problem that increasing the amount of light entering the eye under short exposure conditions requires high-quality light sources, making it impossible to use conventional light sources for ink droplet observation, thus increasing the cost of ink droplet observation. Due to the effect of air resistance, the shape of the ink droplet is not spherical, meaning that there is an error between the actual shape of the ink droplet and the spherical shape. The initial velocity of the ink droplet is positively correlated with the error, while the distance between the observation point and the nozzle is negatively correlated with the error. Therefore, the relevant techniques also have the problem that if the initial velocity of the ink droplet is too high and / or the distance between the observation point and the nozzle is too small, the observation results obtained by approximating the ink droplet as a sphere will have too large an error.

[0004] Currently, there is no effective technical solution to the above-mentioned problems. It should be noted that the information disclosed in this section is only for understanding the background of the present invention and therefore may include information that does not constitute prior art. Summary of the Invention

[0005] The purpose of this application is to provide an ink droplet observation method, electronic device, and computer-readable storage medium that can effectively solve the problems of the inability to use conventional light sources for ink droplet observation due to the high requirements of light source for increasing light intake under short exposure conditions, the increased cost of ink droplet observation, and the excessive error in the observation results obtained by approximating the ink droplet as a sphere due to excessive initial velocity of the ink droplet and / or excessive distance between the observation point and the nozzle.

[0006] Firstly, this application provides a method for observing ink droplets, which includes the following steps:

[0007] S1. Acquire the first and second ink droplet images of the same falling ink droplet based on a preset time interval;

[0008] S2. Obtain the position information of the first ink droplet based on the first ink droplet image, and obtain the position information of the second ink droplet based on the second ink droplet image;

[0009] S3. Obtain the first dynamic blur distance based on the preset time interval, the first ink drop position information, the second ink drop position information, and the pre-acquired invalid pulse width, and remove the dynamic blur in the corresponding first ink drop image and second ink drop image based on the first dynamic blur distance.

[0010] The process for pre-acquiring invalid pulse widths is as follows:

[0011] A1. Obtain the calibration image of the calibration block moving at a constant speed, and obtain the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. The driving voltage when obtaining the calibration image is the same as the driving voltage when obtaining the first ink droplet image and the second ink droplet image.

[0012] This application provides a method for observing ink droplets, which can improve the accuracy of ink droplet observation results by first obtaining a first dynamic blur distance and then removing the dynamic blur in the first ink droplet image and the second ink droplet image based on the first dynamic blur distance. That is, this application does not require increasing the amount of light entering the eye or approximating the ink droplet as a sphere under short exposure conditions. Therefore, this application can effectively solve the problems that increasing the amount of light entering the eye under short exposure conditions requires high requirements for the light source, which makes it impossible to use conventional light sources for ink droplet observation, increases the cost of ink droplet observation, and causes excessive error in the observation results obtained by approximating the ink droplet as a sphere due to excessive initial velocity of the ink droplet and / or excessive distance between the observation point and the nozzle.

[0013] Optionally, the calibration block is a circular ink droplet calibration block, and step A1 includes:

[0014] A11. Control the circular ink droplet calibration block to fall at a constant speed based on a preset falling speed, and acquire the calibration image during the uniform falling process of the circular ink droplet calibration block;

[0015] A12. Based on the preset falling speed, the difference between the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image, and the calibration pulse width, the invalid pulse width is obtained. The calibration pulse width is the pulse width of the light source when the calibration image is obtained.

[0016] Optionally, step A12 includes:

[0017] A121. Obtain the second dynamic blur distance based on the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image;

[0018] A122. Obtain the first effective pulse width based on the second dynamic blur distance and the preset falling speed;

[0019] A123. Obtain the invalid pulse width based on the calibrated pulse width and the first effective pulse width.

[0020] Optionally, the formula for calculating the second dynamic fuzzy distance is shown in equation (1):

[0021] (1);

[0022] Where S1 represents the second dynamic blur distance, L1 represents the height of the circular ink droplet calibration block in the calibration image along the falling direction, and D represents the diameter of the circular ink droplet calibration block;

[0023] The formula for calculating the first effective pulse width is shown in equation (2):

[0024] (2);

[0025] Among them, T k1 v1 represents the first effective pulse width, and v1 represents the preset falling speed.

[0026] The formula for calculating invalid pulse width is shown in equation (3):

[0027] (3);

[0028] Among them, T q Indicates invalid pulse width, T 标 This indicates the calibration pulse width.

[0029] Optionally, step S3 includes:

[0030] S31. Obtain the droplet falling speed based on the preset time interval, the position information of the first ink droplet, and the position information of the second ink droplet;

[0031] S32. Obtain the second effective pulse width based on the actual pulse width and the pre-acquired invalid pulse width. The actual pulse width is the pulse width of the light source when acquiring the first ink droplet image and the second ink droplet image.

[0032] S33. Obtain the first dynamic blur distance based on the second effective pulse width and the ink droplet falling speed, and convert the first dynamic blur distance into the number of blurred pixels;

[0033] S34. Obtain the first ink drop region based on the first ink drop image and the second ink drop region based on the second ink drop image, wherein the first ink drop region is the region where the ink drop is located in the first ink drop image, and the second ink drop region is the region where the ink drop is located in the second ink drop image;

[0034] S35. Remove the pixels located at the top of the first ink droplet region and the pixels located at the top of the second ink droplet region according to the number of blurred pixels, so as to remove the motion blur in the first ink droplet image and the second ink droplet image. The distance between the outer contour of the top of the first ink droplet region before and after the pixel removal and the distance between the outer contour of the top of the second ink droplet region before and after the pixel removal are both equal to the first motion blur distance.

[0035] Optionally, the ink droplet observation method also includes steps performed after step S3:

[0036] S4. Obtain the volume of the first ink droplet based on the first ink droplet image, and obtain the volume of the second ink droplet based on the second ink droplet image;

[0037] S5. Obtain the actual volume of the ink droplet based on the volume of the first ink droplet and the volume of the second ink droplet.

[0038] Because ink droplets decelerate due to air resistance during their descent, the falling speed of the ink droplets obtained by this technical solution based on a preset time interval, the position information of the first ink droplet, and the position information of the second ink droplet is essentially the average falling speed. This average speed may have an error compared to the actual falling speed of the ink droplets. This speed error will cause the size of the ink droplets in the first and second ink droplet images after removing motion blur to still have an error compared to the actual size of the ink droplets. This size error will lead to inaccurate calculation of the ink droplet volume. Therefore, this technical solution needs to reduce the error between the actual and calculated ink droplet volume caused by the error between the average falling speed and the actual falling speed of the ink droplets by first obtaining the volume of the first ink droplet and the volume of the second ink droplet, and then obtaining the actual volume of the ink droplets based on the volume of the first ink droplets and the volume of the second ink droplets, thereby effectively improving the accuracy of the calculation of the actual volume of the ink droplets.

[0039] Optionally, step S4 includes:

[0040] S41. Obtain the third ink drop region based on the first ink drop image, and obtain the fourth ink drop region based on the second ink drop image. The third ink drop region is the region where the ink drop is located in the first ink drop image after dynamic blur removal, and the fourth ink drop region is the region where the ink drop is located in the second ink drop image after dynamic blur removal.

[0041] S42. Divide the third ink droplet region horizontally into multiple first rectangles with a width equal to the number of first preset pixels, and divide the fourth ink droplet region horizontally into multiple second rectangles with a width equal to the number of second preset pixels.

[0042] S43. Calculate the volume of the cylinder corresponding to each first rectangle based on the length and width of the first rectangle, and calculate the volume of the cylinder corresponding to each second rectangle based on the length and width of the second rectangle;

[0043] S44. The sum of the volumes of all cylinders corresponding to the first rectangle is taken as the volume of the first ink droplet, and the sum of the volumes of all cylinders corresponding to the second rectangle is taken as the volume of the second ink droplet.

[0044] Optionally, step S5 includes:

[0045] S51. Take the average of the volumes of the first and second ink drops as the actual volume of the ink drop.

[0046] Secondly, this application provides an electronic device including a processor and a memory, the memory storing computer-readable instructions, which, when executed by the processor, perform the steps of the method provided in the first aspect above.

[0047] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the method provided in the first aspect above.

[0048] As can be seen from the above, the ink droplet observation method, electronic device, and computer-readable storage medium provided in this application can improve the accuracy of ink droplet observation results by first obtaining a first dynamic blur distance and then removing the dynamic blur in the first ink droplet image and the second ink droplet image based on the first dynamic blur distance. That is, this application does not require increasing the amount of light entering the eye or approximating the ink droplet as a sphere under short exposure conditions. Therefore, this application can effectively solve the problems of being unable to use conventional light sources for ink droplet observation due to the high requirements of the light source for increasing the amount of light entering the eye under short exposure conditions, the increased cost of ink droplet observation, and the excessive error in the observation results obtained by approximating the ink droplet as a sphere due to the excessive initial velocity of the ink droplet and / or the small distance between the observation point and the nozzle. Attached Figure Description

[0049] Figure 1 This is a flowchart of an ink droplet observation method provided in an embodiment of this application.

[0050] Figure 2 This is a schematic diagram of the driving waveform of the light source provided in an embodiment of this application.

[0051] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0052] Reference numerals: 101, processor; 102, memory; 103, communication bus. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0054] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0055] Firstly, such as Figure 1 and Figure 2 As shown, this application provides a method for observing ink droplets, which includes the following steps:

[0056] S1. Acquire the first and second ink droplet images of the same falling ink droplet based on a preset time interval;

[0057] S2. Obtain the position information of the first ink droplet based on the first ink droplet image, and obtain the position information of the second ink droplet based on the second ink droplet image;

[0058] S3. Obtain the first dynamic blur distance based on the preset time interval, the first ink drop position information, the second ink drop position information, and the pre-acquired invalid pulse width, and remove the dynamic blur in the corresponding first ink drop image and second ink drop image based on the first dynamic blur distance.

[0059] The process for pre-acquiring invalid pulse widths is as follows:

[0060] A1. Obtain the calibration image of the calibration block moving at a constant speed, and obtain the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. The driving voltage when obtaining the calibration image is the same as the driving voltage when obtaining the first ink droplet image and the second ink droplet image.

[0061] This application preferably obtains the dynamic blur distance by multiplying the droplet's falling velocity by time. Since this application requires intermittent illumination of the ink droplet using a light source when observing ink droplets with an ink droplet observer, and the pulse width of the light source's driving waveform is very small, both the rising and falling edges of the driving waveform cannot be ignored. Only for a portion of the rising and falling edges can a dynamic blur with a grayscale exceeding a threshold be left in the image (see reference). Figure 2 , Figure 2 In this context, 'a' represents the broken line corresponding to the driving waveform of the light source. Figure 2 In this context, b represents the line corresponding to the threshold. Figure 2 In this context, tk represents the pulse width that leaves a dynamic blur in the image with a grayscale exceeding a threshold. Figure 2 In this context, tq represents the pulse width at which a motion blur exceeding a threshold grayscale level cannot be left in the image during either the rising or falling edge. It should be understood that the invalid pulse width in this embodiment consists of the pulse widths at the rising and falling edges that fail to leave a motion blur exceeding the threshold grayscale level in the image. Therefore, the invalid pulse width in this embodiment is the sum of the pulse widths at the rising and falling edges that fail to leave a motion blur exceeding the threshold grayscale level in the image, i.e., the invalid pulse width T mentioned below. q=2tq), that is, the pulse width of the driving waveform of the light source includes the pulse width that can leave a dynamic blur in the image with a gray level exceeding the threshold and the pulse width that cannot leave a dynamic blur in the image with a gray level exceeding the threshold (equivalent to the light emission time of the light source including the effective time that can leave a dynamic blur and the ineffective time that cannot leave a dynamic blur). If the pulse width of the driving waveform of the light source is directly used to calculate the dynamic blur distance, it will cause an error between the calculated dynamic blur distance and the actual dynamic blur distance. Therefore, this application needs to remove the ineffective pulse width (equivalent to the ineffective time) in the pulse width of the driving waveform of the light source. Since the ineffective pulse width is only related to the driving voltage of the light source, and the driving voltage when acquiring the calibration image is the same as the driving voltage when acquiring the first ink drop image and the second ink drop image, this application can use step A1 to pre-acquire the ineffective pulse width. Since step A1 acquires the calibration image of the calibration block moving at a constant speed, the actual size of the calibration block can be measured in advance, i.e., the actual size of the calibration block is a known value. Therefore, the difference between the actual size of the calibration block and the size of the calibration block in the calibration image is equivalent to the size of the motion blur. Since the calibration block moves at a constant speed when acquiring the calibration image, i.e., the speed of the calibration block is a known value, the size of the motion blur is positively correlated with the pulse width that can leave motion blur in the image (the first effective pulse width mentioned below). Therefore, this embodiment can obtain the first effective pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. Furthermore, since the pulse width of the driving waveform of the light source when acquiring the calibration image is a known value, this embodiment can obtain the invalid pulse width based on the pulse width of the driving waveform of the light source and the effective pulse width when acquiring the calibration image, thereby realizing the acquisition of the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image.

[0062] Step S1 preferably uses an existing ink drop observation instrument to acquire a first ink drop image and a second ink drop image of the same falling ink drop based on a preset time interval. Both the first ink drop image and the second ink drop image are images containing ink droplets ejected from the nozzle (equivalent to falling ink droplets). The difference between the time node for acquiring the first ink drop image and the time node for acquiring the second ink drop image is the preset time interval. That is, the first ink drop image and the second ink drop image are equivalent to images of the same falling ink droplet at different time nodes.

[0063] Step S2 can utilize existing image processing algorithms or models to obtain the position information of the first ink droplet from the first ink droplet image and the position information of the second ink droplet from the second ink droplet image. Since the position of the ink droplet observer is pre-calibrated, its position will not change during ink droplet observation. Therefore, the first and second ink droplet position information in this embodiment are equivalent to the positions of the ink droplets relative to the ink droplet observer at different time points. It should be understood that since both the first and second ink droplet images contain dynamic blur, and this application needs to obtain the falling speed of the ink droplets based on the first and second ink droplet position information, in order to improve the accuracy of the falling speed, step S2 needs to obtain the first and second ink droplet position information based on the same reference, for example, taking the lowest point of the ink droplet in the image as the position of the ink droplet.

[0064] The specific process for obtaining the first dynamic blur distance in step S3 can be as follows: The falling speed of the ink droplets (mentioned below) is obtained based on a preset time interval, the position information of the first ink droplet, and the position information of the second ink droplet; the pulse width (mentioned below) of the driving waveform of the light source (mentioned below) and the invalid pulse width are used to obtain the pulse width that leaves a dynamic blur with a gray level exceeding a threshold in the first and second ink droplet images (mentioned below); the first dynamic blur distance is obtained based on the falling speed of the ink droplets and the pulse width that leaves a dynamic blur with a gray level exceeding the threshold in the first and second ink droplet images. The first dynamic blur distance obtained in step S3 can reflect the size of the dynamic blur of the ink droplets in the first and second ink droplet images. Therefore, step S3 can remove the dynamic blur in the first and second ink droplet images based on the first dynamic blur distance, so that the first and second ink droplet images can accurately reflect the actual size of the ink droplets, thereby effectively improving the accuracy of the ink droplet observation results. It should be understood that the pulse width of the driving waveform of the light source when acquiring the first and second ink droplet images can be different from the pulse width of the driving waveform of the light source when acquiring the calibration image. Since the invalid pulse width is only related to the driving voltage of the light source, and the driving voltage when acquiring the calibration image is the same as the driving voltage when acquiring the first and second ink droplet images, the effective pulse width in the pulse width of the driving waveform of the light source when acquiring the first and second ink droplet images can be different from the effective pulse width in the pulse width of the driving waveform of the light source when acquiring the calibration image. It should also be understood that since the first dynamic blur distance in this embodiment is determined based on the invalid pulse width, this embodiment can effectively improve the accuracy of the first dynamic blur distance, so that the first dynamic blur distance can accurately reflect the actual size of the dynamic blur of the ink droplet in the first and second ink droplet images. It should also be understood that the ink drop observation method first uses an ink drop observation instrument to acquire an image of a falling ink drop, and then uses the image to acquire parameters such as the volume and trajectory of the ink drop. Since step S3 only acquires the first and second ink drop images after removing the dynamic blur, this embodiment does not constitute a complete ink drop observation method. The first and second ink drop images after removing the dynamic blur can be used to calculate parameters such as the volume and trajectory of the ink drop.

[0065] This application provides a method for observing ink droplets. By first acquiring a first dynamic blur distance and then removing the dynamic blur from the corresponding first and second ink droplet images based on that distance, the accuracy of ink droplet observation results can be improved. This method eliminates the need to increase the light intake or approximate the ink droplet as a sphere under short exposure conditions. Therefore, it effectively solves the problems of high light requirements for light sources under short exposure conditions, which prevent the use of conventional light sources for ink droplet observation; increased cost of ink droplet observation; and excessive errors in observation results obtained by approximating the ink droplet as a sphere due to excessively high initial droplet velocity and / or excessively small distance between the observation point and the nozzle. Furthermore, since this application can remove dynamic blur using invalid pulse widths, it can utilize traditional light sources for ink droplet observation. The application also has low power requirements for the light source driver board, which effectively extends the lifespan of the light source. Therefore, this application can also effectively reduce the number of light source replacements and maintenance cycles.

[0066] In some preferred embodiments, the calibration block is a circular ink droplet calibration block, and step A1 includes:

[0067] A11. Control the circular ink droplet calibration block to fall at a constant speed based on a preset falling speed, and acquire the calibration image during the uniform falling process of the circular ink droplet calibration block;

[0068] A12. Based on the preset falling speed, the difference between the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image, and the calibration pulse width, the invalid pulse width is obtained. The calibration pulse width is the pulse width of the light source when the calibration image is obtained.

[0069] In this embodiment, the circular ink droplet calibration block is preferably a circular black dot printed on a glass substrate using a photolithography machine. Step A11, which controls the uniform descent of the circular ink droplet calibration block based on a preset falling speed, can be as follows: the glass substrate with the printed circular black dot is fixed on a motion stage; a lifting mechanism is used to drive the motion stage to descend at a preset falling speed, so that the circular ink droplet calibration block falls uniformly at the preset falling speed. Step A12 can utilize existing image processing technology to obtain the height of the circular ink droplet calibration block along the falling direction in the calibration image. Step A12 is equivalent to using the diameter of the circular ink droplet calibration block as the actual size of the calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image as the size of the calibration block in the calibration image.

[0070] In some preferred embodiments, step A12 includes:

[0071] A121. Obtain the second dynamic blur distance based on the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image;

[0072] A122. Obtain the first effective pulse width based on the second dynamic blur distance and the preset falling speed;

[0073] A123. Obtain the invalid pulse width based on the calibrated pulse width and the first effective pulse width.

[0074] The difference between the diameter of the circular ink droplet calibration block and its height along the falling direction in the calibration image in this embodiment is caused by the dynamic blur of the ink droplet in the calibration image. Therefore, the second dynamic blur distance obtained in step A121 can reflect the size of the dynamic blur of the ink droplet in the calibration image. Since the size of the dynamic blur is only related to the effective pulse width in the pulse width of the driving waveform of the light source when the falling speed is constant, step A122 can obtain the first effective pulse width based on the second dynamic blur distance and the preset falling speed. Since the calibration pulse width consists of the first effective pulse width and the invalid pulse width, step A123 can obtain the invalid pulse width by subtracting the first effective pulse width from the calibration pulse width.

[0075] In some preferred embodiments, the formula for calculating the second dynamic fuzzy distance is shown in equation (1):

[0076] (1);

[0077] Where S1 represents the second dynamic blur distance, L1 represents the height of the circular ink droplet calibration block in the calibration image along the falling direction, and D represents the diameter of the circular ink droplet calibration block;

[0078] The formula for calculating the first effective pulse width is shown in equation (2):

[0079] (2);

[0080] Among them, T k1 v1 represents the first effective pulse width, and v1 represents the preset falling speed.

[0081] The formula for calculating invalid pulse width is shown in equation (3):

[0082] (3);

[0083] Among them, T q Indicates invalid pulse width, T 标 This indicates the calibration pulse width.

[0084] In some preferred embodiments, step S3 includes:

[0085] S31. Obtain the droplet falling speed based on the preset time interval, the position information of the first ink droplet, and the position information of the second ink droplet;

[0086] S32. Obtain the second effective pulse width based on the actual pulse width and the pre-acquired invalid pulse width. The actual pulse width is the pulse width of the light source when acquiring the first ink droplet image and the second ink droplet image.

[0087] S33. Obtain the first dynamic blur distance based on the second effective pulse width and the ink droplet falling speed, and convert the first dynamic blur distance into the number of blurred pixels;

[0088] S34. Obtain the first ink drop region based on the first ink drop image and the second ink drop region based on the second ink drop image, wherein the first ink drop region is the region where the ink drop is located in the first ink drop image, and the second ink drop region is the region where the ink drop is located in the second ink drop image;

[0089] S35. Remove the pixels located at the top of the first ink droplet region and the pixels located at the top of the second ink droplet region according to the number of blurred pixels, so as to remove the motion blur in the first ink droplet image and the second ink droplet image. The distance between the outer contour of the top of the first ink droplet region before and after the pixel removal and the distance between the outer contour of the top of the second ink droplet region before and after the pixel removal are both equal to the first motion blur distance.

[0090] Since this application calibrates the ink droplet observer when acquiring the first and second ink droplet images, and after completing the calibration, this application can obtain the size of a single pixel in the image acquired by the ink droplet observer, step S33 can convert the first dynamic blur distance into the number of blurred pixels. This number of blurred pixels can reflect the number of pixels corresponding to the minimum distance between the outer contour of the dynamic blur and the outer contour of the ink droplet. Step S34 can use existing image processing techniques to acquire the first ink droplet region based on the first ink droplet image and the second ink droplet region based on the second ink droplet image. Both the first and second ink droplet regions are composed of ink droplets and dynamic blur. Since the shape of the outer contour of the dynamic blur is the same as the shape of the outer contour of the top of the ink droplet, and the outer contour of the dynamic blur and the outer contour of the top of the ink droplet are parallel, and the number of blurred pixels in this embodiment can reflect the number of pixels corresponding to the minimum distance between the outer contour of the dynamic blur and the outer contour of the ink droplet, this embodiment can remove the dynamic blur in the first and second ink droplet images by removing pixels located at the top of the first ink droplet region and pixels located at the top of the second ink droplet region based on the number of blurred pixels.

[0091] In some preferred embodiments, the ink droplet observation method further includes a step performed after step S3:

[0092] S4. Obtain the volume of the first ink droplet based on the first ink droplet image, and obtain the volume of the second ink droplet based on the second ink droplet image;

[0093] S5. Obtain the actual volume of the ink droplet based on the volume of the first ink droplet and the volume of the second ink droplet.

[0094] Because ink droplets decelerate due to air resistance during their descent, the falling speed of the ink droplets obtained in this embodiment based on a preset time interval, the position information of the first ink droplet, and the position information of the second ink droplet is essentially the average falling speed. This average speed may have an error compared to the actual falling speed of the ink droplets. This speed error will cause the size of the ink droplets in the first and second ink droplet images after removing motion blur to still differ from the actual size of the ink droplets. This size error will lead to inaccurate ink droplet volume calculation. Therefore, this embodiment needs to reduce the error between the actual and calculated ink droplet volume caused by the error between the average falling speed and the actual falling speed of the ink droplets by first obtaining the first and second ink droplet volumes and then obtaining the actual ink droplet volume based on the first and second ink droplet volumes, thereby effectively improving the accuracy of the actual ink droplet volume calculation. Step S4 can utilize existing ink droplet volume acquisition algorithms or models to obtain the first ink droplet volume based on the first ink droplet image and the second ink droplet volume based on the second ink droplet image.

[0095] In some preferred embodiments, step S4 includes:

[0096] S41. Obtain the third ink drop region based on the first ink drop image, and obtain the fourth ink drop region based on the second ink drop image. The third ink drop region is the region where the ink drop is located in the first ink drop image after dynamic blur removal, and the fourth ink drop region is the region where the ink drop is located in the second ink drop image after dynamic blur removal.

[0097] S42. Divide the third ink droplet region horizontally into multiple first rectangles with a width equal to the number of first preset pixels, and divide the fourth ink droplet region horizontally into multiple second rectangles with a width equal to the number of second preset pixels.

[0098] S43. Calculate the volume of the cylinder corresponding to each first rectangle based on the length and width of the first rectangle, and calculate the volume of the cylinder corresponding to each second rectangle based on the length and width of the second rectangle;

[0099] S44. The sum of the volumes of all cylinders corresponding to the first rectangle is taken as the volume of the first ink droplet, and the sum of the volumes of all cylinders corresponding to the second rectangle is taken as the volume of the second ink droplet.

[0100] In step S41, both the third and fourth ink droplet regions are two-dimensional data. Since the third and fourth ink droplet regions in this embodiment are equivalent to the cross-sectional shape of an ink droplet, and an ink droplet can be approximated as being composed of multiple cylinders, this embodiment can first divide the ink droplet region horizontally into multiple rectangles with a preset width (step S42). Each first rectangle and each second rectangle corresponds to a cylinder. All first rectangles constitute the third ink droplet region, and all second rectangles constitute the fourth ink droplet region. Then, the width of the rectangle is used as the height of its corresponding cylinder, and the length of the rectangle is used as the diameter of its corresponding cylinder. The diameter of the cylinder is calculated based on the height and diameter of the cylinder (step S43). Finally, the volume of the ink droplet is obtained by adding the volumes of all cylinders (step S44). In this embodiment, the width of both the first and second rectangles is preferably one pixel, that is, the number of the first preset pixels and the number of the second preset pixels are preferably both 1.

[0101] In some preferred embodiments, step S5 includes:

[0102] S51. Take the average of the volumes of the first and second ink drops as the actual volume of the ink drop.

[0103] As can be seen from the above, the ink droplet observation method provided in this application can improve the accuracy of ink droplet observation results by first obtaining the first dynamic blur distance and then removing the dynamic blur in the first ink droplet image and the second ink droplet image based on the first dynamic blur distance. That is, this application does not require increasing the amount of light entering the eye or approximating the ink droplet as a sphere under short exposure conditions. Therefore, this application can effectively solve the problems of being unable to use conventional light sources for ink droplet observation due to the high requirements of the light source for increasing the amount of light entering the eye under short exposure conditions, the increased cost of ink droplet observation, and the excessive error in the observation results obtained by approximating the ink droplet as a sphere due to the excessive initial velocity of the ink droplet and / or the excessively small distance between the observation point and the nozzle.

[0104] Please refer to Figure 3 , Figure 3This application provides a schematic diagram of the structure of an electronic device according to an embodiment of the present application. The electronic device includes a processor 101 and a memory 102. The processor 101 and the memory 102 are interconnected and communicate with each other via a communication bus 103 and / or other forms of connection mechanisms (not shown). The memory 102 stores computer-readable instructions executable by the processor 101. When the electronic device is running, the processor 101 executes these computer-readable instructions to perform the method in any optional implementation of the above embodiments, thereby achieving the following functions: Step S1, acquiring a first ink droplet image and a second ink droplet image of the same falling ink droplet based on a preset time interval; Step S2, based on... The first ink drop position information is obtained from the first ink drop image, and the second ink drop position information is obtained from the second ink drop image; Step S3: The first dynamic blur distance is obtained according to the preset time interval, the first ink drop position information, the second ink drop position information and the pre-acquired invalid pulse width, and the dynamic blur in the corresponding first ink drop image and second ink drop image is removed based on the first dynamic blur distance; The pre-acquisition process of invalid pulse width is as follows: Step A1: The calibration image of the calibration block moving at a constant speed is obtained, and the invalid pulse width is obtained according to the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. The driving voltage when acquiring the calibration image is the same as the driving voltage when acquiring the first ink drop image and the second ink drop image.

[0105] This application embodiment also provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it executes the method in any optional implementation of the above embodiments to achieve the following functions: Step S1: Acquire a first ink drop image and a second ink drop image of the same falling ink droplet based on a preset time interval; Step S2: Acquire the position information of the first ink droplet based on the first ink drop image, and acquire the position information of the second ink droplet based on the second ink drop image; Step S3: Acquire a first dynamic blur distance based on the preset time interval, the position information of the first ink droplet, the position information of the second ink droplet, and a pre-acquired invalid pulse width, and remove the dynamic blur in the corresponding first ink drop image and second ink drop image based on the first dynamic blur distance; The pre-acquisition process of the invalid pulse width is as follows: Step A1: Acquire a calibration image of a calibration block moving at a uniform speed, and acquire the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. The driving voltage when acquiring the calibration image is the same as the driving voltage when acquiring the first ink drop image and the second ink drop image. The computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0106] As can be seen from the above, the ink droplet observation method, electronic device, and computer-readable storage medium provided in this application can improve the accuracy of ink droplet observation results by first obtaining a first dynamic blur distance and then removing the dynamic blur in the first ink droplet image and the second ink droplet image based on the first dynamic blur distance. That is, this application does not require increasing the amount of light entering the eye or approximating the ink droplet as a sphere under short exposure conditions. Therefore, this application can effectively solve the problems of being unable to use conventional light sources for ink droplet observation due to the high requirements of the light source for increasing the amount of light entering the eye under short exposure conditions, the increased cost of ink droplet observation, and the excessive error in the observation results obtained by approximating the ink droplet as a sphere due to the excessive initial velocity of the ink droplet and / or the small distance between the observation point and the nozzle.

[0107] In the embodiments provided in this application, it should be understood that relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0108] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for observing ink droplets, characterized in that, The ink droplet observation method includes the following steps: S1. Acquire the first and second ink droplet images of the same falling ink droplet based on a preset time interval; S2. Obtain the position information of the first ink droplet based on the first ink droplet image, and obtain the position information of the second ink droplet based on the second ink droplet image; S3. Obtain a first dynamic blur distance based on the preset time interval, the first ink droplet position information, the second ink droplet position information, and the pre-acquired invalid pulse width, and remove the dynamic blur in the corresponding first ink droplet image and second ink droplet image based on the first dynamic blur distance. The process for pre-acquiring the invalid pulse width is as follows: A1. Obtain the calibration image of the calibration block moving at a constant speed, and obtain the invalid pulse width based on the difference between the actual size of the calibration block and the size of the calibration block in the calibration image. The driving voltage when obtaining the calibration image is the same as the driving voltage when obtaining the first ink droplet image and the second ink droplet image. Step S3 includes: S31. Obtain the droplet falling speed according to the preset time interval, the first droplet position information and the second droplet position information; S32. Obtain a second effective pulse width based on the actual pulse width and the pre-acquired invalid pulse width, wherein the actual pulse width is the pulse width of the light source when acquiring the first ink droplet image and the second ink droplet image; S33. Obtain the first dynamic blur distance based on the second effective pulse width and the droplet falling speed, and convert the first dynamic blur distance into the number of blurred pixels; S34. Obtain a first ink drop region based on the first ink drop image and a second ink drop region based on the second ink drop image, wherein the first ink drop region is the region where the ink drop is located in the first ink drop image, and the second ink drop region is the region where the ink drop is located in the second ink drop image; S35. Remove the pixels located at the top of the first ink droplet region and the pixels located at the top of the second ink droplet region according to the number of blurred pixels, so as to remove the motion blur in the first ink droplet image and the second ink droplet image. The distance between the outer contour of the top of the first ink droplet region before and after the pixel removal and the distance between the outer contour of the top of the second ink droplet region before and after the pixel removal are both equal to the first motion blur distance.

2. The ink droplet observation method according to claim 1, characterized in that, The calibration block is a circular ink droplet calibration block, and step A1 includes: A11. The circular ink droplet calibration block is controlled to fall at a constant speed based on a preset falling speed, and a calibration image is acquired during the process of the circular ink droplet calibration block falling at a constant speed. A12. Based on the preset falling speed, the difference between the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image, and the calibration pulse width, the invalid pulse width is obtained, where the calibration pulse width is the pulse width of the light source when the calibration image is obtained.

3. The ink droplet observation method according to claim 2, characterized in that, Step A12 includes: A121. Obtain the second dynamic blur distance based on the diameter of the circular ink droplet calibration block and the height of the circular ink droplet calibration block along the falling direction in the calibration image; A122. Obtain the first effective pulse width based on the second dynamic blur distance and the preset falling speed; A123. Obtain the invalid pulse width based on the calibrated pulse width and the first effective pulse width.

4. The ink droplet observation method according to claim 3, characterized in that, The formula for calculating the second dynamic fuzzy distance is as follows: ； Where S1 represents the second dynamic blur distance, L1 represents the height of the circular ink droplet calibration block in the calibration image along the falling direction, and D represents the diameter of the circular ink droplet calibration block; The formula for calculating the first effective pulse width is as follows: ； Among them, T k1 v1 represents the first effective pulse width, and v1 represents the preset falling speed. The formula for calculating the invalid pulse width is as follows: ； Among them, T q Indicates invalid pulse width, T 标 This indicates the calibration pulse width.

5. The ink droplet observation method according to claim 1, characterized in that, The ink droplet observation method also includes steps performed after step S3: S4. Obtain the volume of the first ink droplet based on the first ink droplet image, and obtain the volume of the second ink droplet based on the second ink droplet image; S5. Obtain the actual volume of the ink droplet based on the volume of the first ink droplet and the volume of the second ink droplet.

6. The ink droplet observation method according to claim 5, characterized in that, Step S4 includes: S41. Obtain a third ink drop region based on the first ink drop image, and obtain a fourth ink drop region based on the second ink drop image. The third ink drop region is the region where the ink drop is located in the first ink drop image after dynamic blur removal, and the fourth ink drop region is the region where the ink drop is located in the second ink drop image after dynamic blur removal. S42. Divide the third ink droplet region horizontally into multiple first rectangles with a width equal to the number of first preset pixels, and divide the fourth ink droplet region horizontally into multiple second rectangles with a width equal to the number of second preset pixels. S43. Calculate the volume of the cylinder corresponding to each of the first rectangles based on the length and width of the first rectangles, and calculate the volume of the cylinder corresponding to each of the second rectangles based on the length and width of the second rectangles; S44. The sum of the volumes of all cylinders corresponding to the first rectangle is taken as the first ink droplet volume, and the sum of the volumes of all cylinders corresponding to the second rectangle is taken as the second ink droplet volume.

7. The ink droplet observation method according to claim 5, characterized in that, Step S5 includes: S51. The average value of the first ink droplet volume and the second ink droplet volume is taken as the actual ink droplet volume.

8. An electronic device, characterized in that, It includes a processor and a memory, the memory storing computer-readable instructions that, when executed by the processor, perform the steps of the method as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it performs the steps of the method as described in any one of claims 1-7.

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