A method and system for measuring the deposition volume of real-time aerosol inkjet printing ink flow

Abstract

The present invention relates to a method and system for measuring the deposition volume of an aerosol inkjet printing ink flow in real time. The method includes: acquiring a real-time image of the aerosol inkjet printing ink flow; preprocessing the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow; calibrating the thickness of the ink flow in the preprocessed real-time image of the ink flow; using an edge detection algorithm to perform connected domain segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate; determining the width of the ink flow according to the boundary contour; and determining the deposition volume of the ink flow according to the width of the ink flow and the thickness of the ink flow. The present invention can calculate the deposition volume of the ink flow in real time and achieve the effect of real-time feedback.

Description

Technical Field

[0001] The present invention relates to the field of aerosol inkjet printing, and particularly to a method and system for measuring the deposition volume of an aerosol inkjet printing ink flow in real time. Background Art

[0002] The morphological characteristics of an aerosol inkjet printing ink flow, including ink width, ink thickness, ink uniformity, and overspray degree, are an important evaluation index in aerosol inkjet printing technology and have an obvious impact on the mechanical and electrical properties of the ink flow path. By accurately measuring the aerosol deposition amount during the inkjet printing process, the morphological characteristics of the aerosol ink flow can be effectively controlled. Currently, the measurement of the aerosol deposition amount in aerosol inkjet printing technology mainly relies on the measurement method of an inkwell, which requires manual input of the time to fill the inkwell, resulting in low efficiency, large randomness, and difficulty in providing real-time feedback on the deposited ink volume during the printing process. Another measurement method is to characterize the three-dimensional morphology of the ink flow using a 3D profilometer after the inkjet printing is completed, which can relatively accurately reflect the morphological characteristics but also has difficulty in achieving real-time feedback on the deposition volume of the aerosol ink flow during the printing process. Summary of the Invention

[0003] The object of the present invention is to provide a method and system for measuring the deposition volume of an aerosol inkjet printing ink flow in real time to solve the problem of difficulty in providing real-time feedback on the deposited ink volume during the printing process.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A method for measuring the deposition volume of an aerosol inkjet printing ink flow in real time includes:

[0006] Obtaining a real-time image of the aerosol inkjet printing ink flow;

[0007] Preprocessing the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow;

[0008] Calibrating the thickness of the ink flow in the preprocessed real-time image of the ink flow;

[0009] Using an edge detection algorithm to perform connected domain segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate;

[0010] Determining the ink flow width according to the boundary contour;

[0011] Determining the deposition volume of the ink flow according to the ink flow width and the ink flow thickness.

[0012] Optionally, the obtaining of the real-time image of the aerosol inkjet printing ink flow specifically includes:

[0013] A camera perpendicular to the printing substrate and with a resolution higher than the set threshold is used to capture the aerosol inkjet printing ink flow in real time, and a real-time image of the aerosol inkjet printing ink flow is obtained.

[0014] Optionally, preprocessing the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow, specifically including:

[0015] The real-time image of the aerosol inkjet printing ink flow is sequentially subjected to image grayscale conversion, filtering and denoising, and binarization processing to extract the key positions of the aerosol ink flow, and a preprocessed real-time image of the ink flow is generated.

[0016] Optionally, calibrating the thickness of the ink flow in the preprocessed real-time image of the ink flow, specifically including:

[0017] Using a calibration plate, the pixel size of the camera, and the lens magnification to calibrate the width of the ink flow line in the preprocessed real-time image of the ink flow; the width of the ink flow line is the width of the printed ink flow within the same time required to fill the ink well;

[0018] Adopting the measurement method of the ink well and calibrating the ink flow thickness by means of the width and printing length of the ink flow line.

[0019] Optionally, using an edge detection algorithm to perform connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate, specifically including:

[0020] Using an edge detection algorithm, using Performing connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate; where B i,j is a binary image, I i,j is the pixel at the i-th row and j-th column in the preprocessed real-time image of the ink flow; ξ is the selected pixel threshold.

[0021] Optionally, determining the ink flow width according to the boundary contour, specifically including:

[0022] Using the formula w=(y u -y d )p to determine the ink flow width; where w is the ink flow width, y u is the longitudinal coordinate of the horizontal line of the upper edge of the ink flow in the field of view, y d is the longitudinal coordinate of the horizontal line of the lower edge of the ink flow in the field of view, and p is the pixel size in the field of view.

[0023] Optionally, after determining the ink flow deposition volume according to the ink flow width and the ink flow thickness, it further includes:

[0024] Obtain the printing time;

[0025] Determine the ink flow deposition rate according to the printing time and the ink flow deposition volume.

[0026] A real-time aerosol inkjet printing ink flow deposition volume measurement system, comprising:

[0027] An ink flow real-time image acquisition module for acquiring a real-time image of an aerosol inkjet printing ink flow;

[0028] A preprocessing module for preprocessing the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow;

[0029] A calibration module for calibrating the thickness of the ink flow in the preprocessed real-time image of the ink flow;

[0030] A connected component segmentation module for performing connected component segmentation on the preprocessed real-time image of the ink flow by using an edge detection algorithm to determine the boundary contour between the ink flow and the printing substrate;

[0031] An ink flow width determination module for determining the width of the ink flow according to the boundary contour;

[0032] An ink flow deposition volume determination module for determining the ink flow deposition volume according to the width of the ink flow and the thickness of the ink flow.

[0033] Optionally, the ink flow real-time image acquisition module specifically includes:

[0034] An ink flow real-time image acquisition unit for using a camera perpendicular to the printing substrate and having a resolution higher than a set resolution threshold to capture a real-time image of an aerosol inkjet printing ink flow in real time to obtain a real-time image of the aerosol inkjet printing ink flow.

[0035] Optionally, the preprocessing module specifically includes:

[0036] A preprocessing unit for sequentially performing image grayscale conversion, filtering and denoising, and binarization processing on the real-time image of the aerosol inkjet printing ink flow, extracting the key positions of the aerosol ink flow, and generating a preprocessed real-time image of the ink flow.

[0037] According to the specific embodiments provided by the present invention, the following technical effects are disclosed: The present invention provides a method and system for measuring the deposition volume of an aerosol inkjet printing ink flow in real time. By obtaining real-time images of the aerosol inkjet printing ink flow, it has no impact on the aerosol inkjet printing process at all, and can measure the geometric morphology characteristics of the aerosol ink flow without damage, mainly including the width and thickness of the ink flow line. An edge detection algorithm is used to perform connected domain segmentation on the preprocessed real-time image of the ink flow, determine the boundary contour between the ink flow and the printing substrate, thereby calculating the deposition volume of the ink flow, and then being able to accurately and efficiently evaluate and analyze the morphology of the aerosol ink flow, achieving the effect of real-time feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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 embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 Schematic structural diagram of the device for measuring the deposition rate of an aerosol inkjet printing ink flow based on images provided by the present invention;

[0040] Figure 2 Flowchart of the method for measuring the deposition volume of an aerosol inkjet printing ink flow in real time provided by the present invention;

[0041] Figure 3 More detailed flowchart of the method for measuring the deposition volume of an aerosol inkjet printing ink flow in real time provided by the present invention;

[0042] Figure 4 Schematic diagram of the ink well measurement method provided by the present invention;

[0043] Figure 5 Schematic diagram of using an ink well to check the thickness of the ink flow provided by the present invention;

[0044] Figure 6 Gray level histogram of the aerosol ink flow image provided by the present invention;

[0045] Figure 7 Schematic diagram of the measurement results of the ink flow characteristics by the real-time analysis software of the aerosol ink flow morphology; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] The object of the present invention is to provide a method and system for measuring the deposition volume of an ink flow in real-time aerosol inkjet printing, which can calculate the deposition volume of the ink flow in real-time and achieve the effect of real-time feedback.

[0048] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0049] The image-based size measurement method has the characteristics of high precision, non-contact, high efficiency, etc., providing a real-time, fast, effective, and economical measurement approach for size measurement. The present invention discloses a method and system for measuring the deposition volume of an ink flow in real-time aerosol inkjet printing. Figure 1 The following is a schematic structural diagram of the device for measuring the deposition rate of an ink flow in real-time aerosol inkjet printing provided by the present invention, as Figure 1 shown. The entire experimental device consists of a desktop computer and a display, an aerosol inkjet printing system, a CCD camera and a telecentric lens, a ring light source, etc.

[0050] Figure 2 The following is a flowchart of the method for measuring the deposition volume of an ink flow in real-time aerosol inkjet printing provided by the present invention, as Figure 2 shown. A method for measuring the deposition volume of an ink flow in real-time aerosol inkjet printing includes:

[0051] Step 201: Obtain a real-time image of the aerosol inkjet printing ink flow.

[0052] In practical applications, step 201 specifically includes: using a camera perpendicular to the printing substrate and with a resolution higher than the set resolution threshold to capture the aerosol inkjet printing ink flow in real-time, and obtaining a real-time image of the aerosol inkjet printing ink flow.

[0053] Step 202: Preprocess the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow.

[0054] In practical applications, step 202 specifically includes: sequentially performing image grayscale conversion, filtering and denoising, and binarization processing on the real-time image of the aerosol inkjet printing ink flow, extracting the key positions of the aerosol ink flow, and generating a preprocessed real-time image of the ink flow.

[0055] Step 203: Calibrate the thickness of the ink flow in the preprocessed real-time ink flow image.

[0056] In practical applications, Step 203 specifically includes: calibrating the width of the ink flow line in the preprocessed real-time ink flow image using a calibration plate, the pixel size of the camera, and the lens magnification; the width of the ink flow line is the width of the printed ink flow within the same time required to fill the ink well; calibrating the ink flow thickness using the measurement method of the ink well and by means of the width and printing length of the ink flow line.

[0057] In practical applications, adjust the camera so that its field of view focuses on the aerosol ink flow, and calibrate the pixel size of the field of view using a calibration plate, the pixel size of the camera, the lens magnification, etc.

[0058] In practical applications, it is considered that the volume of aerosol ink deposited within the same time is the same. Obtain the time for the aerosol ink to fill the volume of a single ink well using the measurement method of the ink well, and calculate the thickness of the deposited ink flow in combination with the length and width of the printed ink flow line within the same time.

[0059]

[0060] Among them, h is the thickness of the deposited ink flow, V inkwell is the volume of a single ink well, L is the length of the printed ink flow within the same time required to fill the ink well, and w' is the width of the printed ink flow within the same time required to fill the ink well.

[0061] Step 204: Use an edge detection algorithm to perform connected component segmentation on the preprocessed real-time ink flow image to determine the boundary contour between the ink flow and the printing substrate.

[0062] In practical applications, Step 204 specifically includes: using an edge detection algorithm to perform connected component segmentation on the preprocessed real-time ink flow image to determine the boundary contour between the ink flow and the printing substrate; among them, B i,j is a binary image, I i,j is the pixel at the i-th row and j-th column in the preprocessed real-time ink flow image; ξ is the selected pixel threshold.

[0063] In practical applications, select an appropriate segmentation threshold ξ according to the optical properties of the ink material and the printing substrate, in combination with the thickness distribution characteristics of the aerosol inkjet printing ink flow image.

[0064] In practical applications, use an edge detection operator to segment the aerosol inkjet printing ink flow image and find all contours with gray values greater than the threshold ξ.

[0065] In practical applications, for all the contours found by edge detection, contours that are not of interest, such as overspray and parts with a relatively low edge thickness of the ink flow, are removed, and only the main contours of the ink flow deposition line required for deposition rate measurement are retained.

[0066] Step 205: Determine the ink flow width according to the demarcation contour.

[0067] In practical applications, the determination of the ink flow width according to the demarcation contour specifically includes:

[0068] Use the formula w = (y u - y d )p to determine the ink flow width; where w is the ink flow width, y u is the longitudinal coordinate of the horizontal line of the upper edge of the ink flow in the field of view, y d is the longitudinal coordinate of the horizontal line of the lower edge of the ink flow in the field of view, and p is the pixel size in the field of view.

[0069] In practical applications, process the main contour of the ink flow deposition line, obtain the pixel coordinates of all points on the aerosol contour boundary, and calculate the ink flow width based on the difference in the longitudinal coordinates of the upper and lower edge pixels and the pixel size of the field of view image.

[0070] Step 206: Determine the ink flow deposition volume according to the ink flow width and the ink flow thickness.

[0071] In practical applications, after step 206, it further includes: obtaining the printing time; determining the ink flow deposition rate according to the printing time and the ink flow deposition volume.

[0072] Figure 3 The following is a more detailed flowchart of the method for measuring the ink flow deposition volume in real-time aerosol inkjet printing provided by the present invention. As Figure 3 shown, it successively includes building a working platform, image acquisition, image preprocessing, calibration of width and thickness, segmentation of the ink flow connected domain, outputting the ink flow width, thickness, uniformity, and overspray degree, and finally completing the accurate measurement of the ink flow deposition volume per unit time, that is, the deposition rate. Among them, image preprocessing includes specific operations such as image grayscale conversion, filtering and denoising, image binarization, grayscale value inversion, and ignoring small areas; width dimension calibration is determined by using a dimension calibration plate, the pixel size of the camera, and the magnification ratio of the telecentric lens; thickness calibration is jointly calibrated by using the measurement method of the ink well (such as Figure 4 ) and the ink flow width. The specific implementation method is as follows:

[0073] Step 1: According to Figure 1Build a real-time aerosol inkjet printing ink flow deposition rate measurement device, and connect a CCD camera, a telecentric lens, an annular light source, and a computer measurement system. The annular light source is coaxially connected to the telecentric lens to ensure the illumination uniformity and intensity of the ink flow sample, and improve the imaging quality. Adjust the position of the camera to ensure that the camera field of view is focused on a short distance after the ink flow deposition, and turn on the computer measurement system and the camera to obtain real-time images of the aerosol ink flow.

[0074] Step 2: Perform preprocessing operations on the acquired images, such as image grayscale conversion, filtering and denoising, binarization, grayscale value inversion, and ignoring small areas, to retain the key features required for ink flow measurement. Figure 6 The grayscale histogram of the ink flow image is shown. It can be seen that the grayscale value distribution has obvious differences, the threshold selection range is large, and the threshold segmentation is less difficult.

[0075] Step 3: Use a size calibration plate and calibrate the width dimension with the pixel size of the CCD camera and the magnification of the telecentric lens; measure the time required for the volume of the deposited ink well in the measurement method of the ink well, as Figure 4 shown, measure the width and length of the deposited ink flow within the same time, calculate the thickness of the ink flow, and complete the calibration of the ink flow thickness. Calibrate the ink flow thickness with the ink well as Figure 5 , and the specific calculation formula is:

[0076]

[0077] where h is the thickness of the deposited ink flow, V inkwell is the volume of a single ink well, w' is the width of the printed ink flow within the same time required to fill the ink well, and L is the length of the printed ink flow within the same time required to fill the ink well. It can be considered that the volume of the ink filling the ink well is equal to the volume of the deposited ink flow line within the same printing time.

[0078] Step 4: Perform edge detection and extraction on the ink flow image, and use the computer measurement system to process it, and output data such as the width, thickness, uniformity, and overspray degree of the aerosol-deposited ink flow. Figure 7 It is a schematic diagram of the measurement results of the ink flow characteristics by the real-time analysis software of the aerosol ink flow morphology.

[0079] Step 5: Accurately measure the deposition volume of the ink flow per unit time, that is, the deposition rate of the ink flow, according to the data such as the width, thickness, and printing length of the ink flow.

[0080] The present invention also provides a real-time aerosol inkjet printing ink flow deposition volume measurement system, including:

[0081] An ink flow real-time image acquisition module for acquiring real-time images of the aerosol inkjet printing ink flow.

[0082] The real-time ink flow image acquisition module specifically includes: a real-time ink flow image acquisition unit, which is used to use a camera perpendicular to the printing substrate and with a resolution higher than the set resolution threshold to capture the aerosol inkjet printing ink flow in real time, and obtain the real-time image of the aerosol inkjet printing ink flow.

[0083] A preprocessing module, which is used to preprocess the real-time ink flow image to generate a preprocessed real-time ink flow image.

[0084] The preprocessing module specifically includes: a preprocessing unit, which is used to perform image grayscale conversion, filtering and denoising, and binarization processing on the real-time image of the aerosol inkjet printing ink flow in sequence, extract the key positions of the aerosol ink flow, and generate a preprocessed real-time ink flow image.

[0085] A calibration module, which is used to calibrate the ink flow thickness in the preprocessed real-time ink flow image.

[0086] A connected component segmentation module, which is used to perform connected component segmentation on the preprocessed real-time ink flow image by using an edge detection algorithm to determine the boundary contour between the ink flow and the printing substrate.

[0087] An ink flow width determination module, which is used to determine the ink flow width according to the boundary contour.

[0088] An ink flow deposition volume determination module, which is used to determine the ink flow deposition volume according to the ink flow width and the ink flow thickness.

[0089] The measurement method of the present invention is a non-contact measurement method, which has no influence on the aerosol inkjet printing process at all, and can measure the geometric morphology characteristics of the aerosol ink flow without damage, mainly including the ink flow width, thickness, uniformity and overspray degree.

[0090] The measurement method of the present invention is based on an image processing algorithm, and can accurately and efficiently evaluate and analyze the morphology of the aerosol ink flow, achieving the effect of real-time feedback.

[0091] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description in the method part.

[0092] In this article, specific examples are used to illustrate the principles and implementation modes of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation modes and application scopes. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for measuring the deposition volume of real-time aerosol inkjet printing ink flow, characterized in that, Including: Obtain a real-time image of the aerosol inkjet printing ink flow; Preprocess the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow; Calibrate the thickness of the ink flow in the preprocessed real-time image of the ink flow; Use an edge detection algorithm to perform connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate; Determine the width of the ink flow according to the boundary contour; Determine the deposition volume of the ink flow according to the width of the ink flow and the thickness of the ink flow.

2. The real-time aerosol inkjet printing ink flow deposition volume measurement method according to claim 1, wherein The obtaining of the real-time image of the aerosol inkjet printing ink flow specifically includes: Use a camera perpendicular to the printing substrate and with a resolution higher than the set resolution threshold to capture the aerosol inkjet printing ink flow in real time, and obtain a real-time image of the aerosol inkjet printing ink flow.

3. The method for measuring the deposition volume of the real-time aerosol inkjet printing ink flow according to claim 1, wherein The preprocessing of the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow specifically includes: Perform image grayscale conversion, filtering for noise reduction, and binarization processing on the real-time image of the aerosol inkjet printing ink flow in sequence, extract the key positions of the aerosol ink flow, and generate a preprocessed real-time image of the ink flow.

4. The real-time aerosol inkjet printing ink flow deposition volume measurement method according to claim 1, wherein The calibration of the thickness of the ink flow in the preprocessed real-time image of the ink flow specifically includes: Use a calibration plate, the pixel size of the camera, and the lens magnification to calibrate the width of the ink flow line in the preprocessed real-time image of the ink flow; the width of the ink flow line is the width of the printing ink flow within the same time required to fill the ink well; the width of the ink flow line is the width of the printing ink flow within the same time required to fill the ink well; Use the measurement method of the ink well and calibrate the ink flow thickness with the help of the width of the ink flow line and the printing length.

5. The real-time aerosol inkjet printing ink flow deposition volume measurement method according to claim 1, characterized in that, The use of the edge detection algorithm to perform connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate specifically includes: Using an edge detection algorithm, and using to perform connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate; where B i,j is a binary image, and I i,j is the pixel at the i-th row and j-th column in the preprocessed real-time image of the ink flow; ξ is the selected pixel threshold.

6. The method for measuring the deposition volume of the real-time aerosol inkjet printing ink flow according to claim 1, wherein The determination of the width of the ink flow according to the boundary contour specifically includes: Determine the ink flow width using the formula w = (y u - y d )p; where w is the ink flow width, y u is the longitudinal coordinate of the horizontal line at the upper edge of the ink flow in the field of view, y d is the longitudinal coordinate of the horizontal line at the lower edge of the ink flow in the field of view, and p is the pixel size in the field of view.

7. The method for measuring the deposition volume of a real-time aerosol inkjet printing ink flow according to claim 1, characterized in that, After determining the deposition volume of the ink flow according to the width of the ink flow and the thickness of the ink flow, it further includes: Obtain the printing time; Determine the deposition rate of the ink flow according to the printing time and the deposition volume of the ink flow.

8. A real-time aerosol inkjet printing ink flow deposition volume measurement system, characterized in that, Including: An ink flow real-time image acquisition module for acquiring a real-time image of the aerosol inkjet printing ink flow; A preprocessing module for preprocessing the real-time image of the ink flow to generate a preprocessed real-time image of the ink flow; A calibration module for calibrating the thickness of the ink flow in the preprocessed real-time image of the ink flow; A connected component segmentation module for using an edge detection algorithm to perform connected component segmentation on the preprocessed real-time image of the ink flow to determine the boundary contour between the ink flow and the printing substrate; An ink flow width determination module for determining the width of the ink flow according to the boundary contour; An ink flow deposition volume determination module for determining the deposition volume of the ink flow according to the width of the ink flow and the thickness of the ink flow.

9. The real-time aerosol inkjet printing ink flow deposition volume measurement system according to claim 8, characterized in that, The ink flow real-time image acquisition module specifically includes: An ink flow real-time image acquisition unit for using a camera perpendicular to the printing substrate and with a resolution higher than the set resolution threshold to capture the aerosol inkjet printing ink flow in real time, and obtain a real-time image of the aerosol inkjet printing ink flow.

10. The real-time aerosol inkjet printing ink flow deposition volume measurement system according to claim 8, wherein The preprocessing module specifically includes: A preprocessing unit is configured to perform image grayscaling, filtering for noise reduction, and binarization on the real-time image of the aerosol inkjet printing ink flow in sequence, extract the key positions of the aerosol ink flow, and generate a preprocessed real-time image of the ink flow.

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