Cleaning method and device of spray head for jet printing

Abstract

The invention relates to a cleaning method and device for a spray head for jet printing. The cleaning method comprises the following steps that the jet face of the spray head is imaged; calibrating the positions of all the spray holes and numbering all the spray holes; a cleaning solution is supplied to the spray head, and the spray head sprays the cleaning solution for a preset cleaning time; enabling the spray head to continuously spray the cleaning liquid, and sequentially and respectively performing imaging detection on the spraying states of all spray holes of the spray head; whether the spraying states of all the spraying holes are qualified or not is judged, the number of the unqualified spraying holes is counted, and the serial numbers of the unqualified spraying holes are recorded; and if the proportion of the unqualified spray holes does not exceed the standard proportion, cleaning of the spray head is completed. Whether cleaning is qualified or not is judged by enabling the nozzle to spray the cleaning liquid to clean the nozzle, imaging detection is carried out during spraying of the spraying holes, imaging detection is carried out on the spraying states of the spraying holes in sequence, the serial numbers of the unqualified spraying holes are recorded, the unqualified spraying holes can be conveniently and rapidly processed, and therefore the cleaning detection efficiency of the spraying holes is high, and the cleaning effect can be guaranteed; and the jet printing processing requirement is met.

Description

Technical Field

[0001] The present application relates to the field of inkjet printing technology, and in particular to a method and device for cleaning a printing nozzle. Background Art

[0002] As an additive manufacturing technology, inkjet printing technology has the advantages of non-contact, large area, no need for mask, rapid manufacturing, low cost of finished products, and the ability to directly manufacture patterns on flat / curved substrates. It is the main manufacturing technology for printed electronics that will replace the long photolithography / vacuum process (development, etching, exposure and cleaning, etc.), and is widely used in display, sensing, chip, energy, aerospace and other fields.

[0003] Inkjet printing generally uses a nozzle to spray the functional liquid onto the molding surface. Since the solute in the printed functional liquid may adhere to the flow channel or the nozzle hole wall of the nozzle, it will cause the nozzle hole to be blocked, thus affecting the printing quality. In order to ensure the printing quality, the nozzle needs to be cleaned regularly.

[0004] In the related art, a cleaning liquid is supplied to the nozzle, and the solute of the functional liquid in the nozzle flow channel and the nozzle hole wall is taken out by spraying the cleaning liquid to achieve the effect of cleaning the nozzle. After the nozzle is cleaned, before using the nozzle for printing, the nozzle is made to spray the functional liquid for printing, and the spraying effect of the nozzle is tested to determine whether the nozzle meets the printing requirements.

[0005] However, the method of spraying functional liquid during trial printing to detect the eligibility of the nozzle cleaning before printing will, on the one hand, cause waste of functional liquid and increase cost; on the other hand, the printing preparation time is long, which reduces the processing efficiency; on the third hand, if the trial printing detection nozzle is unqualified, the nozzle needs to be cleaned again, which seriously affects the printing processing progress. Summary of the invention

[0006] The embodiments of the present application provide a method and device for cleaning a printing nozzle to solve the technical problems in the related art that, on the one hand, functional liquid will be wasted, resulting in increased costs; on the other hand, the printing preparation time is long, reducing the processing efficiency; and on the third hand, if the trial printing detection nozzle fails, the nozzle needs to be cleaned again, which seriously affects the progress of the printing process.

[0007] In a first aspect, a method for cleaning a printing nozzle is provided, which comprises the following steps:

[0008] Imaging the spray surface of the nozzle;

[0009] Mark the positions of all nozzles and number them;

[0010] supplying cleaning fluid to the nozzle and causing the nozzle to spray the cleaning fluid for a preset cleaning time;

[0011] The nozzle continues to spray the cleaning liquid, and the spraying states of all the nozzle holes of the nozzle are imaged and detected in turn;

[0012] Determine whether the spraying status of all nozzles is qualified, count the number of unqualified nozzles and record the numbers of unqualified nozzles;

[0013] If the proportion of unqualified nozzle holes does not exceed the standard ratio, the nozzle cleaning is completed.

[0014] In some embodiments, if the proportion of unqualified nozzle holes exceeds the standard proportion, the nozzle is rewashed, and the nozzle rewashing includes:

[0015] The nozzle sprays the cleaning liquid for a preset rewashing time;

[0016] Then the nozzle continues to spray the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively;

[0017] Count the number of remaining unqualified nozzle holes and record the numbers of the remaining unqualified nozzle holes;

[0018] If the proportion of the remaining unqualified nozzle holes is still greater than the standard proportion, the nozzle is repeatedly caused to continue spraying the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively until the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

[0019] In some embodiments, the step of causing the nozzle to continue to spray the cleaning liquid and performing imaging detection on different unqualified nozzle holes respectively includes:

[0020] Locating the positions of the multiple unqualified nozzle holes according to the serial numbers of the multiple unqualified nozzle holes;

[0021] According to the positions of the multiple unqualified nozzle holes, imaging detection is performed on the multiple unqualified nozzle holes in sequence.

[0022] In some embodiments, after imaging the spraying surface of the nozzle, a preliminary screening nozzle is further included, and the preliminary screening nozzle includes:

[0023] According to the injection surface imaging results, the unqualified proportion of the total number of nozzles is known;

[0024] If the unqualified ratio is less than the preset replacement ratio, the positions of all the nozzles are calibrated and all the nozzles are numbered; otherwise,

[0025] Replace the nozzle.

[0026] In some embodiments, the step of calibrating the positions of all the nozzles and numbering all the nozzles includes:

[0027] Record the distance between all nozzles in the length direction of the nozzle, and record the position of the nozzles at the edge to know the position of all nozzles;

[0028] Each nozzle is numbered sequentially.

[0029] In some embodiments, the step of determining whether the spray state detection of all the spray holes is qualified includes:

[0030] Judging whether the nozzle hole is spraying according to the imaging result of the spraying state of the nozzle hole;

[0031] If the imaging result of the nozzle hole has the image of the jet flow, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0032] In some embodiments, the step of determining whether the spray state detection of all the spray holes is qualified includes:

[0033] According to the imaging result of the spray state of the spray hole, the diameter of the spray flow is measured;

[0034] If the jet flow diameter of the nozzle hole is within the preset standard diameter value range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0035] In some embodiments, the step of determining whether the spray state detection of all the spray holes is qualified includes:

[0036] According to the imaging result of the spray state of the spray hole, the deflection angle of the spray flow relative to the vertical direction is measured;

[0037] If the deflection angle of the jet flow of the nozzle hole is within the preset standard angle range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0038] In some embodiments, the standard ratio comprises 5%.

[0039] In some embodiments, the method for cleaning the printing nozzle further includes placing the nozzle in a cleaning environment for cleaning;

[0040] The cleaning environment includes an inert gas environment.

[0041] The beneficial effects of the technical solution provided by this application include:

[0042] The embodiment of the present application provides a method for cleaning a nozzle for inkjet printing. The cleaning method first determines the position of each nozzle hole by imaging the spraying surface of the nozzle, and then can conveniently and accurately image the spraying state of each nozzle hole in sequence. The nozzle holes are numbered to clearly identify the nozzle hole number corresponding to each position, so as to facilitate and quickly find the corresponding nozzle hole. When cleaning the nozzle, first make the nozzle spray the cleaning liquid for a preset cleaning time. At this time, the nozzle completes the first stage of cleaning, and the nozzle flow channel and nozzle hole are basically cleaned. Then continue to spray the nozzle, and while the nozzle is spraying, image and detect the spraying state of the nozzle hole in sequence. The detection efficiency of nozzle cleaning is high.

[0043] Furthermore, as multiple nozzles of the nozzle are detected in sequence, on the one hand, the nozzles at the rear of the detection sequence continue to be cleaned to improve the cleaning effect of the rear nozzles; on the other hand, the nozzles after the imaging detection continue to be cleaned subsequently. Therefore, even if the nozzle is found to be unqualified after cleaning after detection, as the rear nozzles are detected in sequence, the nozzles that failed the cleaning in the front continue to be cleaned and are easily changed from unqualified to qualified. Therefore, the actual effect of nozzle cleaning will be better than the detection effect of the nozzle, ensuring the cleaning quality of the nozzle and ensuring that the nozzle meets printing requirements.

[0044] In addition, since the nozzles are numbered, the positions and numbers of all unqualified nozzles can be known after the nozzle inspection, which is convenient for quickly locating the unqualified nozzles and re-cleaning and re-inspecting, thereby improving the inspection efficiency and repeated cleaning efficiency.

[0045] Compared with the prior art, this cleaning method does not waste functional liquid when testing the cleaning effect, thus saving costs. In addition, when cleaning the nozzle, it is convenient to quickly determine the nozzle holes that have failed to clean. After repeated cleaning, it is convenient to quickly locate and detect the unqualified nozzle holes, thereby improving the detection efficiency and shortening the preparation time required for printing processing. Moreover, cleaning and testing at the same time not only improves the detection efficiency, but also ensures the cleaning quality due to the cleaning effect obtained by the test, ensuring that the nozzle meets the printing requirements.

[0046] In a second aspect, a device for cleaning a printing nozzle is provided, comprising:

[0047] A mounting mechanism, the mounting mechanism is used to mount the nozzle;

[0048] A detection mechanism, the detection mechanism is used for imaging and detecting the spraying surface of the nozzle, and detecting the spraying flow ejected by the nozzle;

[0049] A motion mechanism, wherein the motion mechanism drives the detection mechanism to move relative to the length direction of the nozzle;

[0050] A control system, wherein the control system controls the mounting mechanism, the detection mechanism and the motion mechanism according to the cleaning method of the printing nozzle as described above.

[0051] Another embodiment of the present application provides a device for cleaning a printing nozzle. Since the device for cleaning a printing nozzle is controlled based on the above-mentioned method for cleaning a printing nozzle, the beneficial effects of the device for cleaning a printing nozzle are consistent with the beneficial effects of the above-mentioned method for cleaning a printing nozzle, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 A flow chart of a method for cleaning a printing nozzle provided in an embodiment of the present application;

[0054] Figure 2 A schematic diagram of the jet diameter and the standard diameter provided in the embodiment of the present application;

[0055] Figure 3 A schematic diagram of a jet flow provided in an embodiment of the present application having an angle with the vertical direction. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0057] The embodiment of the present application provides a method and device for cleaning a nozzle for inkjet printing. The cleaning method cleans the nozzle by spraying a cleaning liquid from the nozzle, and performs imaging detection when the nozzle orifice is sprayed to determine whether the cleaning is qualified. The spraying state of the nozzle orifice is imaged and detected in turn, and the number of the unqualified nozzle orifice is recorded to facilitate further rapid processing of the unqualified nozzle orifice. Therefore, the cleaning detection efficiency of the nozzle orifice is high, the printing preparation time is short, the cleaning effect can be guaranteed, and the printing processing requirements are met. The present application solves the technical problems in the related technology that, on the one hand, functional liquid will be wasted, resulting in increased costs; on the other hand, the printing preparation time is long, reducing the processing efficiency; and on the third hand, if the nozzle is unqualified in the trial printing detection, the nozzle needs to be cleaned again, which seriously affects the progress of the printing process.

[0058] Reference Figure 1 A method for cleaning a printing nozzle comprises the following steps:

[0059] S100, imaging the ejection surface of the nozzle.

[0060] S200, calibrate the positions of all the spray holes and number all the spray holes.

[0061] S300, supplying cleaning liquid to the nozzle and causing the nozzle to spray the cleaning liquid for a preset cleaning time.

[0062] S400, the nozzle continues to spray the cleaning liquid, and imaging detection is performed on the spraying status of all the nozzle holes of the nozzle in sequence.

[0063] S500: Determine whether the spraying states of all the nozzles are qualified, count the number of unqualified nozzles and record the numbers of the unqualified nozzles.

[0064] S600: Determine whether the proportion of unqualified nozzle holes does not exceed the standard proportion.

[0065] S700: If the proportion of unqualified nozzle holes does not exceed the standard proportion, the nozzle cleaning is completed.

[0066] S800: If the proportion of unqualified nozzle holes exceeds the standard proportion, a nozzle rewashing step is performed until the proportion of unqualified nozzle holes does not exceed the standard proportion.

[0067] With this arrangement, the position of each nozzle hole can be determined by imaging the spraying surface of the nozzle, and then the spraying status of each nozzle hole can be imaged in sequence and accurately. The nozzle holes are numbered to clearly identify the nozzle hole number corresponding to each position, so as to quickly find the corresponding nozzle hole. When cleaning the nozzle, first make the nozzle spray the cleaning liquid for a preset cleaning time. At this time, the nozzle completes the first stage of cleaning, and the nozzle flow channel and nozzle hole are basically cleaned. Then continue to spray the nozzle, and while the nozzle is spraying, image and detect the spraying status of the nozzle hole in sequence, so that the detection efficiency of nozzle cleaning is high.

[0068] Furthermore, as multiple nozzles of the nozzle are detected in sequence, on the one hand, the nozzles at the rear of the detection sequence continue to be cleaned to improve the cleaning effect of the rear nozzles; on the other hand, the nozzles after the imaging detection continue to be cleaned subsequently. Therefore, even if the nozzle is found to be unqualified after cleaning after detection, as the rear nozzles are detected in sequence, the nozzles that failed the cleaning in the front continue to be cleaned and are easily changed from unqualified to qualified. Therefore, the actual effect of nozzle cleaning will be better than the detection effect of the nozzle, ensuring the cleaning quality of the nozzle and ensuring that the nozzle meets printing requirements.

[0069] In addition, since the nozzles are numbered, the positions and numbers of all unqualified nozzles can be known after the nozzle inspection, which is convenient for quickly locating the unqualified nozzles and re-cleaning and re-inspecting, thereby improving the inspection efficiency and repeated cleaning efficiency.

[0070] Compared with the prior art, this cleaning method does not waste functional liquid when testing the cleaning effect, thus saving costs. In addition, when cleaning the nozzle, it is convenient to quickly determine the nozzle holes that have failed to clean. After repeated cleaning, it is convenient to quickly locate and detect the unqualified nozzle holes, thereby improving the detection efficiency and shortening the preparation time required for printing processing. Moreover, cleaning and testing at the same time not only improves the detection efficiency, but also ensures the cleaning quality due to the cleaning effect obtained by the test, ensuring that the nozzle meets the printing requirements.

[0071] In step S100, the spraying surface of the nozzle is imaged. Specifically:

[0072] The spray surface of the nozzle is scanned and imaged by using a high-power camera to know the state of the spray surface of the nozzle.

[0073] With this arrangement, the state of the spray surface of the nozzle and the state of each nozzle hole can be more clearly known using a high-power camera.

[0074] Wherein, step S200, calibrating the positions of all the nozzles and numbering all the nozzles, specifically includes step S210 and step S220.

[0075] S210, recording the distances between all the nozzles in the length direction of the nozzle, and recording the positions of the nozzles at the edge, so as to know the positions of all the nozzles.

[0076] S220, numbering each nozzle hole in sequence.

[0077] In this way, by calibrating the positions of all the nozzles, when the injection status of the nozzles is subsequently imaged and detected in sequence, since the positions of the nozzles are determined, different nozzles can be located quickly and accurately within the imaging field of view, thereby improving the detection efficiency and accuracy. In addition, by numbering all the nozzles, the numbers of the nozzles that have passed the cleaning and the numbers of the nozzles that have failed the cleaning can be known. In the subsequent re-cleaning of the nozzle head, it is convenient to directly locate the nozzles that have failed the cleaning for detection, thereby improving the cleaning detection efficiency.

[0078] In step S210, the distances between all the nozzles in the length direction of the nozzle are recorded, and the positions of the nozzles at the edge are recorded to obtain the positions of all the nozzles. Specifically:

[0079] When the high-power camera is used to image the spray surface of the nozzle, the distance between the nozzles can be known according to the moving distance of the high-power camera or the nozzle, and the position of each nozzle can be determined. The nozzle at the edge of the spray surface can be determined by moving the high-power camera relative to the nozzle in the length direction of the spray surface of the nozzle.

[0080] In this way, the position of each nozzle can be determined more easily and accurately by imaging, and the position of the edge nozzle can be determined. When the nozzles are subsequently inspected in sequence, the nozzles at the edge are taken as the first inspection nozzles in the length direction of the injection surface, and all nozzles are inspected in sequence, so as to reduce the possibility of missed inspections.

[0081] In step S220, each nozzle hole is numbered in sequence. Specifically:

[0082] According to the direction of sequentially detecting all the nozzles, the plurality of nozzles are numbered sequentially. That is, the nozzle at one edge of the length direction of the spraying surface is numbered 1, and the subsequent nozzles are numbered 2, 3, 4... In addition, the nozzles can also be numbered sequentially in a binary numbering mode to facilitate data transmission.

[0083] In this way, by numbering the nozzles, each nozzle can be matched with the corresponding qualified cleaning status when the nozzle cleaning status is subsequently detected. For example, nozzle No. 1 corresponds to a qualified cleaning status, marked as OK; nozzle No. 3 corresponds to an unqualified cleaning status, marked as NG. By numbering the NG nozzles, the positions of the unqualified nozzles can be quickly located, thereby speeding up the efficiency of nozzle rewashing.

[0084] In step S300, the cleaning liquid is supplied to the nozzle and the nozzle is made to spray the cleaning liquid for a preset cleaning time. Specifically:

[0085] After the cleaning liquid is supplied to the nozzle, the nozzle is operated continuously, and the flow channel inside the nozzle and the hole wall of the nozzle hole are flushed with the cleaning liquid to achieve cleaning of the nozzle. In this embodiment, the cleaning time ranges from 30 seconds to 5 minutes.

[0086] With this arrangement, the solute attached to the nozzle flow channel and the nozzle hole wall can be effectively flushed out by the flow of the cleaning liquid inside the nozzle and the spraying of the cleaning liquid.

[0087] In step S400, the nozzle continues to spray the cleaning liquid, and imaging detection is performed on the spraying status of all the nozzle holes of the nozzle in sequence. Specifically:

[0088] A high-power camera is used to image the jet flow from the nozzle, and the jet state of the nozzle is judged to be qualified based on the imaging result, so as to know whether the nozzle cleaning is qualified.

[0089] According to the position of each nozzle, the distance that the high-power camera needs to move each time can be known, and the spray state of the next nozzle can be accurately imaged and detected. The efficiency of detection and alignment is improved, and the nozzle is not easily missed.

[0090] With this arrangement, as the nozzle sprays the cleaning liquid, the spraying state of each nozzle hole is imaged and detected in sequence while cleaning, thereby improving the detection efficiency of the cleaning effect. In addition, as the multiple nozzle holes of the nozzle are detected in sequence, on the one hand, the nozzle holes at the rear of the detection sequence continue to be cleaned to improve the cleaning effect of the rear nozzle holes; on the other hand, the nozzle holes that have been imaged and detected continue to be cleaned subsequently. Therefore, even if the nozzle hole is found to be unqualified after cleaning after detection, as the rear nozzle holes are detected in sequence, the nozzle holes that have been unqualified in the front continue to be cleaned and can easily change from unqualified to qualified. Therefore, the actual effect of nozzle cleaning will be better than the detection effect of the nozzle, ensuring the cleaning quality of the nozzle and ensuring that the nozzle meets the printing requirements.

[0091] In other embodiments, when the cleaning effect of the nozzle is detected, the nozzle simulates the printing state during operation and sprays the cleaning liquid at intervals.

[0092] In this embodiment, the spraying states of the plurality of nozzles are detected in sequence, and during the spraying interval of the nozzle head, the spraying position of the next nozzle to be imaged and detected is moved into the imaging field of view.

[0093] This arrangement, on the one hand, simulates the spraying state of the nozzle when it is working, making the cleaning result more reliable. On the other hand, it switches to detect different nozzles within the spraying interval, realizing the interlaced switching detection position steps while spraying, thereby improving the detection efficiency.

[0094] In step S500, it is determined whether the spraying status of all the nozzles is qualified, and the number of unqualified nozzles is counted and the serial numbers of the unqualified nozzles are recorded. Specifically:

[0095] The spray state of the nozzle hole includes one or more of whether the nozzle hole is spraying, the diameter of the jet flow, and the deflection angle of the jet flow relative to the vertical direction. In this embodiment, the spray state of the nozzle head includes whether the nozzle hole is spraying, the diameter of the jet flow, and the deflection angle of the jet flow relative to the vertical direction, that is, the nozzle hole is judged to be qualified for cleaning only when all three requirements are met.

[0096] After judging whether the nozzle holes are qualified for cleaning, the numbers of the unqualified nozzle holes are recorded synchronously, and the total number of the unqualified nozzle holes is counted.

[0097] In this way, by counting the total number of unqualified nozzles, the proportion of unqualified nozzles can be known through the total number of unqualified nozzles and the total number of nozzles, which is convenient for subsequent judgment of whether the overall nozzle cleaning is qualified. By recording the numbers of unqualified nozzles, when the nozzle needs to be rewashed later, it is convenient to quickly locate the positions of unqualified nozzles according to the numbers of unqualified nozzles, so as to improve the detection efficiency.

[0098] Among them, judging whether the spraying status of all the spray holes is qualified includes:

[0099] According to the imaging result of the spraying state of the spraying hole, it is judged whether the spraying hole is spraying.

[0100] If the imaging result of the nozzle hole has the image of the jet flow, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0101] In this way, since the position of the nozzle is calibrated, it is possible to determine that the nozzle of the nozzle to be tested is moved to the imaging field of view. If the nozzle does not spray at this time, it indicates that the nozzle is blocked and has not been cleaned properly. Therefore, even if the nozzle does not spray, the cleaning effect of the nozzle will not be missed.

[0102] Reference Figure 2 , wherein judging whether the injection state detection of all the nozzles is qualified includes:

[0103] Based on the imaging result of the spray state of the spray hole, the diameter of the spray flow is measured.

[0104] If the deviation between the jet flow diameter of the nozzle hole and the standard diameter is within the preset standard diameter value deviation range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0105] Specifically, when the nozzle hole is in a normal state, the diameter of the jet flow is the standard diameter. The standard diameter of the jet flow can also be determined according to the standard parameters of the nozzle. The standard diameter can also be obtained by measuring the diameters of the jet flows of multiple nozzle holes in an unblocked state and taking the average value.

[0106] The calculation form of the deviation between the jet flow diameter of the nozzle hole and the standard diameter includes: the jet flow diameter is d, the standard diameter is D, and the deviation between the jet flow diameter of the nozzle hole and the standard diameter is a=(dD) / D*100%.

[0107] In this embodiment, the standard diameter value deviation range includes ±5%. That is, if the deviation between the jet flow diameter of the nozzle hole and the standard diameter is not within ±5%, the nozzle hole is unqualified. If the deviation between the jet flow diameter of the nozzle hole and the standard diameter is within ±5%, the nozzle hole is qualified.

[0108] This arrangement facilitates the measurement of the jet diameter by imaging the jet. If the jet diameter is too large, the nozzle hole may be damaged. If the jet diameter is too small, the nozzle hole may be partially blocked. By measuring the jet diameter, it is possible to detect whether the nozzle hole is partially blocked. This improves the accuracy of the nozzle cleaning detection.

[0109] Reference Figure 3 , wherein judging whether the injection state detection of all the nozzles is qualified includes:

[0110] Based on the imaging result of the spray state of the spray hole, the deflection angle of the spray flow relative to the vertical direction is measured.

[0111] If the deflection angle of the jet flow of the nozzle hole is within the preset standard angle range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

[0112] Specifically, by measuring the image of the jet stream ejected from the nozzle, the deviation angle between the center line of the jet stream and the vertical direction is obtained. In this embodiment, the standard angle range includes no more than 10 degrees. When the deviation angle between the center line of the jet stream and the vertical direction is greater than 10 degrees, the nozzle cleaning is unqualified. When the deviation angle between the center line of the jet stream and the vertical direction is less than or equal to 10 degrees, the nozzle cleaning is qualified.

[0113] With this arrangement, when the nozzle hole is partially blocked, the spray direction of the jet stream sprayed from the nozzle hole will change, so whether the nozzle hole has been cleaned properly can be judged based on the spray direction of the jet stream.

[0114] In this embodiment, the nozzle hole needs to spray out a jet flow, and the deviation between the nozzle hole's jet flow diameter and the standard diameter is within ±5%, and the deviation angle between the center line of the jet flow and the vertical direction is less than or equal to 10 degrees. In this case, the nozzle hole cleaning is qualified.

[0115] By such arrangement, imaging detection is performed on various spraying states of the nozzle holes to ensure that the nozzle holes are properly cleaned, thereby ensuring the quality of the nozzle head used for the printing process and ensuring the quality of the printing process.

[0116] In other embodiments, the nozzle hole may be cleaned properly if only one of the following conditions is met: the deviation between the nozzle hole's jet diameter and the standard diameter is within ±5% and the deviation angle between the nozzle centerline and the vertical direction is less than or equal to 10 degrees.

[0117] In step S600, it is determined whether the proportion of unqualified nozzle holes does not exceed the standard proportion. Specifically:

[0118] According to the total number of unqualified nozzles and the total number of nozzles, the proportion of unqualified nozzles can be known. In this embodiment, the standard proportion includes 5%. In other embodiments, the standard proportion may also include 1%, 2%, 3%, 4%, 6%, 7%, 8%, 9%, 10%...

[0119] In step S700, if the proportion of unqualified nozzle holes does not exceed the standard proportion, the nozzle cleaning is completed. Specifically:

[0120] When the proportion of unqualified nozzle holes is less than or equal to the standard proportion, the nozzle cleaning is qualified and the nozzle cleaning is completed. The nozzle after cleaning meets the requirements of printing processing.

[0121] In step S800, if the proportion of unqualified nozzle holes exceeds the standard proportion, the nozzle rewashing step is performed until the proportion of unqualified nozzle holes does not exceed the standard proportion. Specifically:

[0122] When the proportion of unqualified nozzle holes is greater than the standard proportion, the number of unqualified nozzle holes is too large, which may have an adverse effect on the printing process. At this time, the nozzle rewashing step is performed until the proportion of unqualified nozzle holes does not exceed the standard proportion.

[0123] Specifically: the nozzle rewashing step includes steps S810-S840.

[0124] S810, causing the nozzle to spray the cleaning liquid for a preset rewashing time.

[0125] S820, the nozzle continues to spray the cleaning liquid, and performs imaging detection on different unqualified nozzle holes respectively.

[0126] S830, counting the number of remaining unqualified nozzle holes and recording the numbers of the remaining unqualified nozzle holes.

[0127] S840, determining whether the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

[0128] By judging the proportion of unqualified nozzle holes, there are two situations.

[0129] 1. If the proportion of remaining unqualified nozzle holes does not exceed the standard proportion, the nozzle is cleaned.

[0130] 2. If the proportion of the remaining unqualified nozzle holes is still greater than the standard proportion, the nozzle is repeatedly made to continue spraying the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively until the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

[0131] In this way, the nozzle is rewashed to increase the cleaning time, and the nozzle flow channel and the nozzle hole wall are flushed to remove the solute adhering to the nozzle flow channel and the hole wall. After the nozzle is rewashed, since the number of the unqualified nozzle hole is known, the qualified nozzle hole can be directly skipped and the unqualified nozzle hole can be directly tested, thereby improving the detection efficiency.

[0132] In step S810, the nozzle sprays the cleaning liquid for a preset rewashing time. Specifically:

[0133] The rewashing time ranges from 30 seconds to 5 minutes. The nozzle spraying adopts continuous spraying or spot spraying.

[0134] In step S820, the nozzle continues to spray the cleaning liquid to perform imaging detection on different unqualified nozzle holes. Specifically:

[0135] The nozzle continues to spray the cleaning liquid, and uses a high-power camera to perform imaging inspection on the spraying status of the unqualified nozzle holes one by one. The imaging inspection of unqualified nozzle holes specifically includes:

[0136] Positions of the multiple unqualified nozzle holes are located according to the serial numbers of the multiple unqualified nozzle holes.

[0137] According to the positions of the multiple unqualified nozzle holes, imaging detection is performed on the multiple unqualified nozzle holes in sequence.

[0138] In this arrangement, since the position of each nozzle is calibrated and corresponds to the nozzle number, the position of the nozzle can be matched by the number, so as to quickly locate the position of the unqualified nozzle, and directly use a high-magnification camera to image the unqualified nozzle, so as to quickly and accurately image and detect the unqualified nozzle after rewashing, thereby improving the cleaning and detection efficiency.

[0139] In step S830, the number of remaining unqualified nozzles is counted and the serial numbers of the remaining unqualified nozzles are recorded. Specifically:

[0140] After the nozzle is rewashed and the unqualified nozzle holes are retested, the numbers of the remaining unqualified nozzle holes and the number of the remaining unqualified nozzle holes are recorded to determine whether the nozzle is cleaned properly after rewashing, and after recording the numbers of the unqualified nozzle holes, it is convenient to quickly locate and test the unqualified nozzle holes after the nozzle is rewashed.

[0141] In step S840, it is determined whether the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

[0142] Specifically, after comparing the proportion of the remaining unqualified nozzles with the standard proportion, there are two situations:

[0143] 1. If the proportion of remaining unqualified nozzle holes does not exceed the standard proportion, the nozzle is cleaned.

[0144] Therefore, the proportion of unqualified nozzle holes after rewashing to the total number of nozzle holes does not exceed the standard proportion. At this time, the nozzle cleaning is completed and the printing processing requirements are met.

[0145] 2. If the proportion of the remaining unqualified nozzle holes is still greater than the standard proportion, the nozzle is repeatedly made to continue spraying the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively until the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

[0146] Therefore, if the nozzle is still not fully cleaned after rewashing, it will be rewashed again. After each rewashing of the nozzle, the corresponding unqualified nozzle holes are tested, and the testing efficiency is high.

[0147] Optionally, the method for cleaning the printing nozzle further includes step S900, pre-screening the nozzle, and the pre-screening nozzle specifically includes:

[0148] According to the injection surface imaging results, the unqualified proportion of the total number of nozzles is known.

[0149] If the unqualified ratio is less than the preset replacement ratio, the positions of all the nozzles are calibrated and all the nozzles are numbered; otherwise,

[0150] Replace the nozzle.

[0151] In this way, when the nozzles are initially screened, if the total number of unqualified nozzle holes of the nozzles is too large, it indicates that the nozzles do not need to be cleaned to avoid wasting time required for cleaning.

[0152] Specifically, after a high-power camera images the spray surface of the nozzle, the blockage condition of the nozzle can be preliminarily known using the imaging results of the nozzle position. After all blocked nozzles are screened, the total number of unqualified nozzles can be obtained.

[0153] The replacement ratio includes 20%-60%. In this embodiment, the replacement ratio includes 30%.

[0154] When the total number of unqualified nozzle holes accounts for a proportion of the total number of nozzles that is greater than or equal to the replacement ratio, the nozzle cleaning is abandoned and other nozzles are replaced.

[0155] When the ratio of the total number of unqualified nozzle holes to the total number of nozzles is less than the replacement ratio, step S200 can be performed to calibrate the positions of all nozzle holes and number all nozzle holes.

[0156] The method for cleaning the printing nozzle further comprises placing the nozzle in a cleaning environment for cleaning. The cleaning environment comprises an inert gas environment. In this embodiment, the inert gas environment comprises a nitrogen environment.

[0157] This arrangement can control the cleaning environment to avoid contamination of the nozzle by the external environment. In addition, it can also prevent the functional liquid remaining in the nozzle from volatilizing and polluting the surrounding environment during cleaning.

[0158] The embodiment of the present application provides a method for cleaning a nozzle for inkjet printing. The cleaning method first determines the position of each nozzle hole by imaging the spraying surface of the nozzle, and then can conveniently and accurately image the spraying state of each nozzle hole in sequence. The nozzle holes are numbered to clearly identify the nozzle hole number corresponding to each position, so as to facilitate and quickly find the corresponding nozzle hole. When cleaning the nozzle, first make the nozzle spray the cleaning liquid for a preset cleaning time. At this time, the nozzle completes the first stage of cleaning, and the nozzle flow channel and nozzle hole are basically cleaned. Then continue to spray the nozzle, and while the nozzle is spraying, image and detect the spraying state of the nozzle hole in sequence. The detection efficiency of nozzle cleaning is high.

[0159] Furthermore, as multiple nozzles of the nozzle are detected in sequence, on the one hand, the nozzles at the rear of the detection sequence continue to be cleaned to improve the cleaning effect of the rear nozzles; on the other hand, the nozzles after the imaging detection continue to be cleaned subsequently. Therefore, even if the nozzle is found to be unqualified after cleaning after detection, as the rear nozzles are detected in sequence, the nozzles that failed the cleaning in the front continue to be cleaned and are easily changed from unqualified to qualified. Therefore, the actual effect of nozzle cleaning will be better than the detection effect of the nozzle, ensuring the cleaning quality of the nozzle and ensuring that the nozzle meets printing requirements.

[0160] In addition, since the nozzles are numbered, the positions and numbers of all unqualified nozzles can be known after the nozzle inspection, which is convenient for quickly locating the unqualified nozzles and re-cleaning and re-inspecting, thereby improving the inspection efficiency and repeated cleaning efficiency.

[0161] Compared with the prior art, this cleaning method does not waste functional liquid when testing the cleaning effect, thus saving costs. In addition, when cleaning the nozzle, it is convenient to quickly determine the nozzle holes that have failed to clean. After repeated cleaning, it is convenient to quickly locate and detect the unqualified nozzle holes, thereby improving the detection efficiency and shortening the preparation time required for printing processing. Moreover, cleaning and testing at the same time not only improves the detection efficiency, but also ensures the cleaning quality due to the cleaning effect obtained by the test, ensuring that the nozzle meets the printing requirements.

[0162] Another embodiment of the present application provides a device for cleaning a printing nozzle, comprising:

[0163] An installation mechanism, the installation mechanism is used to install the sprinkler head;

[0164] A detection mechanism, the detection mechanism is used for imaging and detecting the spray surface of the nozzle, and detecting the spray flow ejected by the nozzle;

[0165] A motion mechanism, wherein the motion mechanism drives the detection mechanism to move relative to the length direction of the nozzle;

[0166] The control system controls the installation mechanism, the detection mechanism and the motion mechanism according to the above-mentioned method for cleaning the printing nozzle.

[0167] Another embodiment of the present application provides a device for cleaning a printing nozzle. Since the device for cleaning a printing nozzle is controlled based on the above-mentioned method for cleaning a printing nozzle, the beneficial effects of the device for cleaning a printing nozzle are consistent with the beneficial effects of the above-mentioned method for cleaning a printing nozzle, which will not be repeated here.

[0168] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0169] It should be noted that, in this application, relational terms such as "first" and "second" are only used 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. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0170] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for cleaning a printing nozzle, characterized in that: It includes the following steps: Imaging the spray surface of the nozzle; Mark the positions of all nozzles and number them; supplying cleaning fluid to the nozzle and causing the nozzle to spray the cleaning fluid for a preset cleaning time; The nozzle continues to spray the cleaning liquid, and the spraying status of all the nozzle holes of the nozzle is imaged and detected in turn; Determine whether the spraying status of all nozzles is qualified, count the number of unqualified nozzles and record the numbers of unqualified nozzles; If the proportion of unqualified nozzle holes does not exceed the standard ratio, the nozzle cleaning is completed.

2. The method for cleaning a printing nozzle according to claim 1, characterized in that: If the proportion of unqualified nozzles exceeds the standard ratio, the nozzle is rewashed, and the nozzle rewashing includes: The nozzle sprays the cleaning liquid for a preset rewashing time; Then the nozzle continues to spray the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively; Count the number of remaining unqualified nozzle holes and record the numbers of the remaining unqualified nozzle holes; If the proportion of the remaining unqualified nozzle holes is still greater than the standard proportion, the nozzle is repeatedly caused to continue spraying the cleaning liquid, and imaging detection is performed on different unqualified nozzle holes respectively until the proportion of the remaining unqualified nozzle holes does not exceed the standard proportion.

3. The method for cleaning a printing nozzle according to claim 2, characterized in that: The nozzle is then allowed to continue spraying the cleaning liquid to perform imaging detection on different unqualified nozzle holes, including: Locating the positions of the multiple unqualified nozzle holes according to the serial numbers of the multiple unqualified nozzle holes; According to the positions of the multiple unqualified nozzle holes, imaging detection is performed on the multiple unqualified nozzle holes in sequence.

4. The method for cleaning a printing nozzle according to claim 1, characterized in that: After imaging the ejection surface of the nozzle, a preliminary screening nozzle is further included, and the preliminary screening nozzle includes: According to the injection surface imaging results, the unqualified proportion of the total number of nozzles is known; If the unqualified ratio is less than the preset replacement ratio, the positions of all the nozzles are calibrated and all the nozzles are numbered; otherwise, Replace the nozzle.

5. The method for cleaning a printing nozzle according to claim 1, characterized in that: The step of calibrating the positions of all the nozzles and numbering all the nozzles includes: Record the distance between all nozzles in the length direction of the nozzle, and record the position of the nozzles at the edge to know the position of all nozzles; Each nozzle is numbered sequentially.

6. The method for cleaning a printing nozzle according to claim 1, characterized in that: The step of judging whether the spray state detection of all the spray holes is qualified comprises: Judging whether the nozzle hole is spraying according to the imaging result of the spraying state of the nozzle hole; If the imaging result of the nozzle hole has the image of the jet flow, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

7. The method for cleaning a printing nozzle according to claim 6, characterized in that: The step of judging whether the spray state detection of all the spray holes is qualified comprises: According to the imaging result of the spray state of the spray hole, the diameter of the spray flow is measured; If the jet flow diameter of the nozzle hole is within the preset standard diameter value range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

8. The method for cleaning a printing nozzle according to claim 1, 6 or 7, characterized in that: The step of judging whether the spray state detection of all the spray holes is qualified comprises: According to the imaging result of the spray state of the spray hole, the deflection angle of the spray flow relative to the vertical direction is measured; If the deflection angle of the jet flow of the nozzle hole is within the preset standard angle range, the nozzle hole is qualified; otherwise, the nozzle hole is unqualified.

9. The method for cleaning a printing nozzle according to claim 1, characterized in that: The standard ratio includes 5%.

10. The method for cleaning a printing nozzle according to claim 1, characterized in that: It also includes placing the nozzle in a cleaning environment for cleaning; The cleaning environment includes an inert gas environment.

11. A cleaning device for a printing nozzle, characterized in that: include: A mounting mechanism, the mounting mechanism is used to mount the nozzle; A detection mechanism, the detection mechanism is used for imaging and detecting the spraying surface of the nozzle, and detecting the spraying flow ejected by the nozzle; A motion mechanism, wherein the motion mechanism drives the detection mechanism to move relative to the length direction of the nozzle; A control system, wherein the control system controls the mounting mechanism, the detection mechanism and the motion mechanism according to the method for cleaning a printing nozzle according to any one of claims 1 to 10.

Images