Broken hole number detection method and device based on machine vision, equipment and storage medium

Abstract

The invention belongs to the technical field of printing, provides a broken hole number detection method and device based on machine vision, equipment and a storage medium, and solves the technical problem that the number of broken holes of a nozzle cannot be efficiently detected and counted in the prior art. The method comprises the steps that ink-jet printing is carried out according to an image to be printed and a corresponding color bar image, a printing image is obtained, and the printing image comprises a target printing image and a color bar printing image; the printing image is scanned, and whether a blank area exists in the color bar printing image or not is judged; when a blank area exists in the color bar printing image, the first size of the blank area is obtained; and obtaining the number of broken holes according to the first size, the size of the color bar printing image and the number of nozzles of a spray head. According to the invention, rapid automatic detection and maintenance of the nozzle are realized, the manual maintenance cost is reduced, and the stability and reliability of ink-jet printing equipment are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inkjet printing technology, and particularly relates to a broken nozzle quantity detection method and device based on machine vision, equipment and a storage medium. BACKGROUND

[0002] The inkjet printing technology refers to a technology of spraying ink drops on a printing medium through a nozzle on a nozzle head to obtain an image or text, and with the development of the technology, the application field thereof is also wider and wider, such as printing characters, color blocks and lines on a PCB.

[0003] However, after the nozzle head of the inkjet printer works for a long time, due to reasons such as ink path pollution, ink deposition, dust and water vapor, the nozzle state of the nozzle head is prone to be abnormal, such as blockage, oblique spraying, virtuality, insufficient ink and the like, thereby causing problems such as line pulling and blank in the printed image, which seriously affects the quality of the product.

[0004] When the nozzle state of the nozzle head is abnormal, the prior art is to clear, press ink and scrape to dredge the nozzle or use a compensation technology to compensate for the abnormal nozzle or replace the nozzle head, but how to know whether the nozzle is abnormal and the number of abnormalities, the method of the prior art is to print a test image set by a nozzle to be used before formal printing, and by printing the test image, it can be known whether the nozzle in the nozzle head is abnormal and the position of the abnormal nozzle. This method can only obtain the abnormal condition before printing and cannot obtain the abnormal condition in the printing process, and the test image is complex and low in efficiency, and the prior art cannot meet the demand of knowing whether there is a broken nozzle and the number of the broken nozzle for judging whether the nozzle needs to be cleaned or replaced. SUMMARY

[0005] Therefore, the present application provides a broken nozzle quantity detection method and device based on machine vision, equipment and a storage medium, to solve the technical problem that the prior art cannot efficiently detect and count the number of broken nozzles.

[0006] In a first aspect, the present application provides a broken nozzle quantity detection method based on machine vision, which comprises the following steps:

[0007] performing inkjet printing on the basis of a to-be-printed image and a corresponding color bar image to obtain a printed image, wherein the printed image comprises a target printed image and a color bar printed image;

[0008] scanning the printed image to determine whether the color bar printed image has a blank area;

[0009] when the color bar printed image has a blank area, obtaining a first size of the blank area;

[0010] According to the first size, the size of the color bar printed image and the number of nozzles of the printhead, the number of broken holes is obtained.

[0011] As an optional embodiment of the present application, the step of scanning the printed image and determining whether the color bar printed image has a blank area includes:

[0012] Image acquisition is performed on the printed image to obtain a digital printed image.

[0013] Image segmentation is performed on the digital printed image to obtain a digital color bar image.

[0014] The color bar printed image is subjected to grayscale processing to obtain a color bar grayscale image.

[0015] The color bar grayscale image is binarized according to a preset threshold to obtain a color bar black-and-white image.

[0016] According to the color bar black-and-white image, it is determined whether the color bar image has a blank area.

[0017] As an optional embodiment of the present application, when the color bar printed image has a blank area, the step of obtaining the first size of the blank area includes:

[0018] The distance between the upper boundary and the lower boundary of the blank area in the length direction of the color bar printed image is obtained as the first size.

[0019] As an optional embodiment of the present application, the size of the color bar printed image includes the length of the color bar printed image, and the step of obtaining the number of broken holes according to the first size, the size of the color bar printed image and the number of nozzles of the printhead includes:

[0020] A first coefficient is obtained according to the ratio of the first size to the length of the color bar image.

[0021] The number of broken holes is obtained according to the first coefficient and the number of nozzles.

[0022] As an optional embodiment of the present application, the step of performing inkjet printing according to the to-be-printed image and the corresponding color bar image to obtain a printed image includes:

[0023] The size of the color bar image is obtained according to the size of the to-be-printed image.

[0024] Color bar printing data is obtained according to the size of the color bar image, wherein the color bar printing data includes ink ejection data of all nozzles.

[0025] The to-be-printed image is subjected to rasterization processing to obtain target image printing data.

[0026] Inkjet printing is performed according to the target image printing data and the color bar printing data, to obtain a printed image.

[0027] As an optional embodiment of the present application, the color bar image includes a left color bar image or / and a right color bar image, the left color bar image is located at one side of a starting printing position of the printed image, the right color bar image is located at one side of an ending printing position of the printed image, and the color bar printing data includes left color bar printing data corresponding to the left color bar image or / and right color bar printing data corresponding to the right color bar image.

[0028] As an optional embodiment of the present application, the method further includes:

[0029] When the number of broken holes is greater than or equal to a first broken hole number threshold, a printhead cleaning reminder signal is sent out;

[0030] When the number of broken holes is greater than or equal to a second broken hole number threshold, a printhead replacement reminder signal is sent out.

[0031] In a second aspect, the present application further provides a broken hole number detection device based on machine vision, which includes:

[0032] An inkjet printing module is configured to perform inkjet printing according to a to-be-printed image and a corresponding color bar image, to obtain a printed image, wherein the printed image includes a target printed image and a color bar printed image.

[0033] An image scanning module is configured to scan the printed image, to determine whether the color bar printed image has a blank area.

[0034] A size acquisition module is configured to acquire a first size of the blank area when the color bar printed image has a blank area.

[0035] A broken hole number acquisition module is configured to acquire a number of broken holes according to the first size, a size of the color bar printed image, and a number of nozzles of a printhead.

[0036] In a third aspect, the present application further provides a broken hole number detection device based on machine vision, which includes at least one processor, at least one memory, and computer program instructions stored in the memory, when the computer program instructions are executed by the processor, the method of the first aspect is implemented.

[0037] In a fourth aspect, the present application further provides a storage medium having computer program instructions stored thereon, when the computer program instructions are executed by a processor, the method of the first aspect is implemented.

[0038] In summary, the present application has the following advantages:

[0039] The machine vision-based broken hole quantity detection method, device, equipment and storage medium of the present application, by printing the image to be printed and the corresponding color bar image on the printing medium, obtaining the printed image containing the target printed image and the color bar printed image, merging the image to be printed and the color bar image on a printed image, can judge whether the nozzle is abnormal through the color bar image in the process of printing the image to be printed; then, by scanning the printed image, the image data of the color bar printed image can be obtained, and whether there is a blank area can be detected, so that whether the color bar printed image exists abnormal condition can be quickly found; once it is found that the color bar printed image exists a blank area, according to the result of image processing, the first size of the blank area can be accurately obtained, the first size is the size of the blank area in the length direction, by obtaining the first size, whether the working state of the nozzle is normal can be known; finally, by the first size, the size of the color bar printed image and the number of nozzles of the nozzle, the number of broken holes in the color bar printed image can be calculated. The number of broken holes is another index of nozzle abnormality, which reflects the working state of the nozzle of the nozzle, through the analysis of the color bar printed image and the calculation of the number of broken holes, the automatic detection and maintenance of the nozzle can be realized, the artificial maintenance cost is reduced, and the stability and reliability of the inkjet printing equipment are improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. For those skilled in the art, without paying creative labor, other drawings can also be obtained according to these drawings, which are all within the protection scope of the present application.

[0041] Figure 1 The flowchart of the machine vision-based broken hole quantity detection method in the embodiments of the present application;

[0042] Figure 2 The schematic diagram of the color bar image blank area and the nozzle in the embodiments of the present application;

[0043] Figure 3 The structure schematic diagram of the machine vision-based broken hole quantity detection device provided by the embodiments of the present application

[0044] Figure 4 The structure block diagram of the machine vision-based broken hole quantity detection device of the present application DETAILED DESCRIPTION

[0045] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be noted that, in this document, relational terms such as first and second and the like are used only to differentiate one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as center, upper, lower, front, back, left, right, vertical, horizontal, top, bottom, inner, outer and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Moreover, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the elements defined by the statement "comprise" do not exclude the presence of other identical elements in the process, method, article or device that includes the elements. If there is no conflict, the various features in the embodiments and examples of the present application can be combined with each other, and all within the scope of protection of the present application.

[0046] Embodiment 1

[0047] Referring to Figure 1 The present application provides a machine vision-based hole number detection method, which comprises the following steps:

[0048] S1, inkjet printing according to the to-be-printed image and the corresponding color bar image to obtain a printed image, wherein the printed image comprises a target printed image and a color bar printed image;

[0049] First, the to-be-printed image and the color bar image are obtained, and the target image to be printed and the color bar image are synthesized into the same image to ensure that the position and size of the color bar image are consistent with those at the time of design, wherein the color bar image can be located on the left and / or right side of the to-be-printed image, and printing according to the synthesized image can obtain the printed image;

[0050] As an optional embodiment of the present application, the step of inkjet printing according to the to-be-printed image and the corresponding color bar image to obtain a printed image comprises:

[0051] S11, obtaining the size of the color bar image according to the size of the to-be-printed image;

[0052] Specifically, the print image size includes an image width in a main scanning direction and an image height perpendicular to the main scanning direction, and the color bar image size also includes a color bar width in the main scanning direction and a color bar height perpendicular to the main scanning direction. In order to ensure that all nozzles are inked once after each scanning of the print head during the printing of the entire image, so that the moisturizing effect of all nozzles is better, the color bar height is set to be equal to the image height, and at the same time, the color bar image printed once per scanning can be used to confirm whether there is a damaged nozzle in time, and when there is a damaged nozzle, a compensation function can be enabled, thereby avoiding reprinting of the entire image, improving printing efficiency and quality. Wherein, the color bar height can also be less than the image height, although the moisturizing effect of the nozzle is relatively poor, but it can also play a certain moisturizing effect. The color bar width is set according to the print medium width and the image width, and only needs to ensure that the color bar image and the print image do not coincide.

[0053] S12, acquiring color bar printing data according to the size of the color bar image, wherein the color bar printing data includes ink data of all nozzles;

[0054] After the size of the color bar image is acquired, the color bar printing data can be generated according to the size and the ink data.

[0055] S13, rasterizing the to-be-printed image to obtain target image printing data;

[0056] Specifically, rasterizing the to-be-printed image is to convert the image into a matrix composed of pixel points, and to convert the color value or gray value of each pixel point into printing data that can be understood by the printer. The target image printing data obtained in this way can be used to control the inkjet printer to ink according to the specified pixel point position and color value, so as to generate the final print image on the print medium.

[0057] S14, inkjet printing according to the target image printing data and the color bar printing data to obtain a print image;

[0058] After obtaining the target image printing data and the color bar printing data, the color bar printing data and the image printing data are spliced to obtain the inkjet printing data. Before splicing the color bar printing data and the inkjet printing data, a specific splicing mode needs to be determined according to color bar printing position determination data. In this embodiment, the color bar image includes a left color bar image or / and a right color bar image. The left color bar image is located at the side of the starting printing of the printing image in one-time scanning printing. The right color bar image is located at the side of the ending printing of the printing image in one-time scanning printing. Correspondingly, the color bar printing data includes left color bar printing data or / and right color bar printing data.

[0059] Specifically, the color bar can be printed on one side and can be located at the starting position of each reciprocating scanning printing or at the ending position. For single-pass inkjet printing, one color bar is printed for each 1 pass data. For reciprocating scanning printing, a color bar can be printed once every X reciprocating scanning intervals. X is the total number of reciprocating scanning.

[0060] In order to avoid the influence of the color bar image on the printing image, the printing position of the color bar image is generally spaced apart from the printing position of the printing image by a certain distance. In order to ensure the accuracy of each printing position, all data in the printing area need to be obtained. When the printing area includes a blank area, the blank area cannot be filled with ink data. This is convenient for data transmission and storage and will not cause chaos.

[0061] S2, scanning the printing image to determine whether the color bar printing image has a blank area.

[0062] The entire printing image (including the target printing image and the color bar printing image) is converted into a digital image using a scanner or a camera. It is ensured that the scanned image maintains high quality and appropriate resolution for subsequent image processing. Through image processing technology, the scanned printing image is divided into a target printing image and a color bar printing image. The color bar image is usually located on both sides of the printing image, and they have specific boundaries or marks when designed. Subsequently, image processing techniques such as edge detection and connected region analysis are used to detect and mark the blank area. The blank area refers to the area with white pixel values, which is a missing or more obvious part compared with other image information.

[0063] In another embodiment, an optical sensor can also be added to the printing device during the printing process to monitor the surface of the color bar printing image in real time and detect whether there is a blank area. The optical sensor can determine whether the image has a blank area according to light reflectivity or transmittance.

[0064] As an optional embodiment of the present application, the step of scanning the printed image and determining whether the color bar printed image has a blank area comprises:

[0065] S21, image acquisition of the printed image to obtain a digital printed image;

[0066] Specifically, first use an imaging device such as a scanner or camera to image the entire printed image and convert it into a digital image. This way the actual printed image is converted into a digital format that can be processed by a computer, facilitating subsequent image processing and analysis.

[0067] S22, image segmentation of the digital printed image to obtain a digital color bar image;

[0068] Segment the digital printed image using image processing techniques to extract the color bar printed image from the entire digital printed image. This way the focus is on the color bar part, facilitating subsequent color bar image processing and analysis;

[0069] Specifically, image segmentation of the digital printed image to obtain a digital color bar image comprises: edge detection of the digital printed image, edge detection algorithms can extract edge information in the image, which helps to find the boundary of the color bar image; based on the results of edge detection, use contour detection algorithms to find the outer contour of the digital color bar image, the digital color bar image usually has a clear boundary, and the overall shape of the color bar can be found by contour detection; use image segmentation algorithms to segment the color bar image from other parts in the digital printed image, common image segmentation methods include threshold segmentation, region growing, watershed algorithm, etc. These methods can segment the color bar image into an independent region according to the gray value or color information of the pixels; according to the segmentation results, extract the segmented color bar image from the digital printed image. In this way, the digital color bar image is obtained, which contains the complete information of the color bar.

[0070] S23, gray scale processing of the color bar printed image to obtain a color bar gray scale image;

[0071] Gray scale processing of the color bar printed image converts it into a gray scale image. The gray scale image only contains brightness information, which is more suitable for subsequent binary processing and blank area detection;

[0072] The color bar image is usually a color image composed of red, green, blue and other color channels. In the gray scale processing, the weighted average method or other methods can be used to convert the RGB color value of each pixel of the color bar image into a gray scale value. The following formula is usually used for gray scale processing:

[0073] Gray value = 0.299 * red value + 0.587 * green value + 0.114 * blue value

[0074] wherein the red value, the green value and the blue value are the RGB channel values of each pixel of the color bar image respectively;

[0075] Finally, the calculated gray value replaces the original RGB value of the color bar image, and the new image obtained is the color bar gray image.

[0076] S24, binarizing the color bar gray image according to a preset threshold value to obtain a color bar black and white image;

[0077] Each pixel of the color bar gray image is traversed, and the size of the pixel value is judged according to the threshold value. If the pixel value is greater than or equal to the preset threshold value, the pixel is set to white (usually represented by the maximum value), otherwise it is set to black (usually represented by the minimum value). After threshold processing, the pixel value in the gray image is converted into the pixel value in the black and white image, thereby obtaining the color bar black and white image, wherein the preset threshold value is set according to the specific application scenario and image characteristics;

[0078] In the binarized color bar black and white image, the pixel value is only black (usually represented by 0) and white (usually represented by 255), which correspond to different pixel brightness respectively. Through such binarization processing, the color bar black and white image is more convenient for detecting the blank area. The blank area in the black and white image will be displayed in black, and the other areas (areas with ink) will be displayed in white, so that it can be more easily distinguished whether there is a blank area in the color bar.

[0079] S25, judging whether the color bar image has a blank area according to the color bar black and white image.

[0080] Specifically, in an embodiment, whether the color bar image has a blank area can be realized by the following method: by vertically projecting the binarized color bar image, the sum of each column of pixel values can be calculated to obtain a vertical projection image. The vertical projection value of the blank area is small, and whether there is a blank area can be judged by a threshold value; or, similar to the vertical projection method, the binarized color bar image is horizontally projected, the sum of each row of pixel values is calculated, and a horizontal projection image is obtained. Similarly, the horizontal projection value of the blank area is small, and whether there is a blank area can be judged by a threshold value.

[0081] In another embodiment, whether the color bar image has a blank area can also be judged by performing connected region analysis on the color bar black and white image according to the analysis result. The connected region analysis is a technique for marking the continuous same pixel value region in the image as a single object. In the binarized image, the connected region analysis can be used to find the connected region of the blank area.

[0082] S3, when the color bar printed image has a blank area, obtaining a first size of the blank area;

[0083] Specifically, once the blank area is found, the position information of the blank area can be obtained, such as the starting position (upper left corner coordinate) and the ending position (lower right corner coordinate) of the blank area; according to the position information of the blank area, the width or length of the blank area can be calculated, depending on the direction of the color bar;

[0084] If the color bar is vertical, the width of the blank area can be calculated, that is, the column number of the ending position minus the column number of the starting position, and add 1 (because the index starts from 0).

[0085] If the color bar is horizontal, the length of the blank area can be calculated, that is, the row number of the ending position minus the row number of the starting position, and add 1.

[0086] As an optional embodiment of the present application, when the color bar printed image has a blank area, the step of obtaining the first size of the blank area comprises:

[0087] S31, obtaining the interval between the upper boundary and the lower boundary of the blank area in the length direction of the color bar printed image, denoted as the first size;

[0088] By obtaining the interval between the upper boundary and the lower boundary of the blank area in the length direction of the color bar image, that is, the first size, the ink jetting situation of the printhead can be evaluated. The color bar printed image is specially printed to test whether the printhead is working normally, which contains the color bar and the target printed image. The blank area on the color bar should not exist under normal circumstances. If there is a blank area on the color bar, it means that the printhead may have abnormal conditions, such as clogging, uneven or non-working nozzles, etc.

[0089] By obtaining the interval between the upper boundary and the lower boundary of the blank area in the length direction of the color bar image, the size of the blank area can be calculated. This size can be used to determine whether the printhead needs to be cleaned, maintained or replaced. If the blank area is small, only a simple cleaning operation may be needed, but if the blank area is large, more thorough maintenance measures may be needed.

[0090] S4, according to the first size, the size of the color bar printed image and the number of nozzles of the printhead, obtaining the number of broken holes.

[0091] As an optional embodiment of the present application, the size of the color bar printed image comprises the length of the color bar printed image, and the step of obtaining the number of broken holes according to the first size, the size of the color bar printed image and the number of nozzles of the printhead comprises:

[0092] S41, obtaining a first coefficient according to a ratio of the first size and a length of the color bar image;

[0093] S42, obtaining a number of broken holes according to the first coefficient and the number of nozzles.

[0094] Specifically, first, the first size is converted into an actual physical size, i.e. pixel size is converted into a length (in centimeters or inches) corresponding to an actual blank area; according to the size of the color bar printing image, the length of a complete color bar is found. The length of the complete color bar should be consistent with the actual size of the color bar image, and a proportion value is obtained by dividing the length of the actual blank area by the length of the complete color bar. The number of broken holes is obtained by multiplying the proportion value and the number of nozzles;

[0095] In a specific embodiment, as shown in FIG. 1, the length of the color bar is L, the width of the blank is S, the printhead includes two rows of nozzles, and each row includes 5 nozzles. The number of nozzles is 10, and the number of broken holes is calculated by the following formula: Figure 2

[0096] Number of broken holes = 10*S / L

[0097] As an optional embodiment of the present application, the method further comprises:

[0098] S5, issuing a printhead cleaning reminder signal when the number of broken holes is greater than or equal to a first broken hole number threshold;

[0099] S6, issuing a printhead replacement reminder signal when the number of broken holes is greater than or equal to a second broken hole number threshold.

[0100] Wherein, the first broken hole number threshold is less than the second broken hole number threshold;

[0101] Specifically, if the number of broken holes is greater than or equal to the first broken hole number threshold, it means that the printhead has a large number of broken holes, and the printhead may be clogged or the nozzles may not work. In this case, the printhead cleaning reminder signal is issued to timely handle the printhead abnormality and ensure the normal operation of the printhead;

[0102] If the number of broken holes is greater than or equal to the second broken hole number threshold, it means that the printhead abnormality has reached a serious level, which may have exceeded the cleaning capacity. In this case, the printhead replacement reminder signal is issued to prompt the user to replace the printhead in time to ensure the printing quality and prolong the service life of the printhead.

[0103] ​Through such a scheme, the inkjet printer can monitor and remind the state of the nozzle in real time, the user can handle the abnormal condition of the nozzle in time, and the printing quality is guaranteed and the reliability of the equipment is improved. In addition, according to the setting of the broken hole quantity threshold, the sensitivity of the reminder can be adjusted according to the actual demand, and the accuracy and timeliness of the reminder signal are ensured. Such an early warning system can reduce maintenance cost and avoid printing failure caused by abnormal nozzle.

[0104] Embodiment 2

[0105] Please refer to Figure 3 The application also provides a broken hole quantity detection device based on machine vision, which comprises:

[0106] An insulation layer printing module is configured to perform inkjet printing on the substrate according to insulation layer printing data and the first ink, so as to obtain an insulation layer, wherein the surface of the insulation layer has a vacancy position for accommodating a circuit layer;

[0107] A scanning module is configured to scan the insulation layer to obtain an insulation layer image;

[0108] A circuit layer information acquisition module is configured to acquire an actual position of the circuit layer and a circuit layer printing image according to the insulation layer image;

[0109] A circuit layer printing module is configured to perform inkjet printing on the insulation layer by using the second ink according to the actual position and the circuit layer printing image, so as to obtain the circuit layer.

[0110] It should be noted that the modules and units in the broken hole quantity detection device based on machine vision in the embodiment correspond to the steps in the broken hole quantity detection method based on machine vision in the foregoing embodiment one by one, and therefore, the specific embodiments of the embodiment can refer to the embodiments of the broken hole quantity detection method based on machine vision, which will not be described herein again.

[0111] Embodiment 3

[0112] In addition, in combination with Figure 1 The broken hole quantity detection method based on machine vision described in the embodiments of the application can be implemented by a broken hole quantity detection device based on machine vision. Figure 4 A hardware structure schematic diagram of the broken hole quantity detection device based on machine vision provided by the embodiments of the application is shown.

[0113] The broken hole quantity detection device based on machine vision can comprise a processor 401 and a memory 402 having computer program instructions stored therein.

[0114] In particular, the processor 401 can include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or can be configured to implement one or more integrated circuits that implement embodiments of the present application.

[0115] The memory 402 can include mass storage for data or instructions. By way of example, and not limitation, the memory 402 can include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disc (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a tape drive, a USB drive, or a combination of two or more of these. The memory 402 can be removable and / or non-removable (or fixed) as appropriate. The memory 402 can be internal or external as appropriate. In certain embodiments, the memory 402 is non-volatile solid-state memory. In certain embodiments, the memory 402 includes read-only memory (ROM). Where appropriate, this ROM can be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM), or flash memory, or a combination of two or more of these.

[0116] The processor 401 implements the data addressing method of any of the above embodiments by reading and executing computer program instructions stored in the memory 402.

[0117] The hole number detection device based on machine vision in one example can also include a communication interface 403 and a bus 410. As shown, the processor 401, the memory 402, and the communication interface 403 are connected through the bus 410 and complete communication with each other. Figure 4

[0118] The communication interface 403 is mainly used to realize the communication between the modules, devices, units and / or equipment in the embodiments of the present application.

[0119] ​Bus 410 includes a hardware, software, or both that couples components for fractional ink output to each other. By way of example, and not limitation, a bus can be an accelerated graphics port (AGP) or other graphics bus, a Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand (IB) interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or some other suitable bus or interconnect, or a combination of two or more of these. Bus 410 can include one or more buses, where appropriate. Although this disclosure describes and illustrates a particular bus, this disclosure contemplates any suitable bus or interconnect.

[0120] Embodiment 4

[0121] In addition, in combination with the machine vision-based broken hole quantity detection method in the above embodiments, an embodiment of the present application can provide a computer readable storage medium for implementation. The computer readable storage medium has computer program instructions stored thereon; the computer program instructions are executed by a processor to implement any of the machine vision-based broken hole quantity detection methods in the above embodiments.

[0122] In summary, the machine vision-based broken hole quantity detection device of the present application determines the initial printing position according to the printing medium position information and the preset white edge value, selects one or more combinations of the first, second and third inkjet heads to perform inkjet printing, adjusts the initial printing position to obtain the actual printing position according to the selected inkjet head, and starts inkjet printing at the actual printing position through the selected inkjet head. The actual printing position can be automatically obtained from the initial printing position according to the selected inkjet head for printing, ensuring the consistency of the initial printing position when different inkjet heads are switched for printing, and ensuring the image printing effect.

[0123] It is to be understood that the present application is not limited to the particular configurations and processes described and illustrated herein. Detailed descriptions of known methods are omitted so as not to obscure the description of the present application. In the above embodiments, several specific steps are described and illustrated in order to provide a thorough understanding of the present application. However, the process of the present application is not limited to the specific steps described and illustrated, and one skilled in the art can make various changes, modifications and additions, or change the order of the steps, after understanding the spirit of the present application.

[0124] The functional blocks shown in the structural block diagrams described above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, functional cards, and the like. When implemented in software, the elements of the present application are program or code segments that are used to perform the required tasks. The program or code segments can be stored in a machine-readable medium or transmitted through a data signal carried in a carrier wave over a transmission medium or communication link. A "machine-readable medium" includes any medium that can store or transport information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, and the like. The code segments can be downloaded via computer networks such as the Internet, intranets, and the like.

[0125] It should also be noted that the exemplary embodiments mentioned in the present application describe some methods or systems based on a series of steps or devices. However, the present application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in an order different from that in the embodiments, or several steps can be performed simultaneously.

[0126] The above description is merely a specific implementation of the present application. Those skilled in the art can clearly understand the specific working processes of the above-described system, modules and units for the convenience and brevity of description, which can refer to the corresponding processes in the foregoing method embodiments, which will not be described here. It should be understood that the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A method for detecting the number of broken holes based on machine vision, characterized in that, The method includes the following steps: Inkjet printing is performed based on the image to be printed and the corresponding color bar image to obtain a printed image, wherein the printed image includes the target printed image and the color bar printed image; The printed image is scanned to determine whether there are blank areas in the colored bar printed image; When the printed color bar image has blank areas, obtain the first size of the blank areas; The number of broken holes is obtained based on the first size, the size of the color bar printed image, and the number of nozzles in the printhead.

2. The method for detecting the number of broken holes based on machine vision according to claim 1, characterized in that, The step of scanning the printed image to determine whether there are blank areas in the colored bar printed image includes: The printed image is acquired to obtain a digital printed image; The digitally printed image is segmented to obtain a digital color bar image; The printed image of the color bars is converted to grayscale to obtain a grayscale image of the color bars; The grayscale image of the color bars is binarized according to a preset threshold to obtain a black and white image of the color bars. Based on the black and white image of the color bars, determine whether there are blank areas in the color bar image.

3. The method for detecting the number of broken holes based on machine vision according to claim 2, characterized in that, The step of obtaining the first size of the blank area when the printed color bar image has a blank area includes: The distance between the upper and lower boundaries of the blank area along the length of the printed color bar image is obtained and denoted as the first dimension.

4. The method for detecting the number of broken holes based on machine vision according to claim 3, characterized in that, The size of the printed color bar image includes the length of the printed color bar image. The step of obtaining the number of broken holes based on the first size, the size of the printed color bar image, and the number of nozzles of the printhead includes: The first coefficient is obtained based on the ratio of the first size to the length of the color bar image; The number of broken holes is obtained based on the first coefficient and the number of nozzles.

5. The method for detecting the number of broken holes based on machine vision according to claim 1, characterized in that, The step of inkjet printing based on the image to be printed and the corresponding color bar image to obtain the printed image includes: Based on the dimensions of the image to be printed, obtain the dimensions of the color bar image; Based on the size of the color bar image, obtain color bar printing data, wherein the color bar printing data includes ink output data of all nozzles; The image to be printed is rasterized to obtain the target image printing data; Inkjet printing is performed based on the target image printing data and color bar printing data to obtain the printed image.

6. The method for detecting the number of broken holes based on machine vision according to claim 5, characterized in that, The color bar image includes a left color bar image and / or a right color bar image. The left color bar image is located on one side of the starting printing position of the printed image, and the right color bar image is located on one side of the ending printing position of the printed image. The color bar printing data includes left color bar printing data corresponding to the left color bar image and / or right color bar printing data corresponding to the right color bar image.

7. The machine vision-based method for detecting the number of broken holes according to any one of claims 1-6, characterized in that, The method further includes: When the number of broken holes is greater than or equal to the first broken hole number threshold, a nozzle cleaning reminder signal is issued. When the number of broken holes is greater than or equal to the second broken hole number threshold, a nozzle replacement reminder signal is issued. Wherein, the first threshold for the number of broken holes is less than the second threshold for the number of broken holes.

8. A machine vision-based device for detecting the number of broken holes, characterized in that, The device includes: An inkjet printing module is used to perform inkjet printing based on an image to be printed and a corresponding color bar image to obtain a printed image, wherein the printed image includes a target printed image and a color bar printed image; An image scanning module is used to scan the printed image and determine whether there are blank areas in the colored bar printed image; The size acquisition module is used to acquire the first size of the blank area when there is a blank area in the printed color bar image; The broken hole number acquisition module is used to acquire the number of broken holes based on the first size, the size of the color bar printed image, and the number of nozzles of the printhead.

9. A machine vision-based device for detecting the number of broken holes, characterized in that, include: At least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement the method as described in any one of claims 1-7.

10. A storage medium storing computer program instructions thereon, characterized in that, The method as described in any one of claims 1-7 is implemented when the computer program instructions are executed by the processor.

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