Nozzle control methods and inkjet printing equipment

Abstract

This application provides a nozzle control method and an inkjet printing device. The nozzle control method includes: controlling a plurality of first nozzles to perform a first droplet detection, and determining a plurality of second nozzles from the plurality of first nozzles; controlling the plurality of second nozzles to perform simulated printing; and controlling the plurality of second nozzles after the simulated printing to perform a second droplet detection, and determining a plurality of target nozzles from the plurality of second nozzles. The nozzle control method provided by this application can solve the technical problem of poor selection effect of existing nozzles.

Description

Technical Field

[0001] This application relates to the field of inkjet printing technology, and in particular to a nozzle control method and an inkjet printing device. Background Technology

[0002] The inkjet printing process is the main process for manufacturing OLED (Organic Light-Emitting Diode) or QLED (Quantum Dots Light Emitting Diode Display) displays in the future. This process involves using inkjet printing equipment to inject functional layer material ink into the pixel openings, thereby forming an organic light-emitting layer.

[0003] In inkjet printer nozzles can become malfunctioning due to ink deposits, dust, moisture, or other factors, leading to abnormal ink droplet output and affecting print quality. Therefore, to ensure print quality, the nozzles on the inkjet printer must be inspected and selected before each printing session to ensure only those that meet the printing requirements are used.

[0004] However, the existing nozzles are not effective at screening and need further improvement. Summary of the Invention

[0005] This application provides a nozzle control method and an inkjet printing device.

[0006] The nozzle control method proposed in this application includes:

[0007] Control multiple first nozzles to detect the first drop of ink, and determine multiple second nozzles from the multiple first nozzles;

[0008] Control multiple second nozzles to perform simulated printing;

[0009] The system controls multiple second nozzles after the simulated printing to perform a second droplet detection, and determines multiple target nozzles from the multiple second nozzles.

[0010] The step of controlling multiple first nozzles to perform first droplet detection and determining multiple second nozzles from the multiple first nozzles includes:

[0011] Control the plurality of first nozzles to drop a plurality of first ink droplets onto the detection substrate;

[0012] Obtain the first characteristic parameters of the first ink droplet;

[0013] Multiple second nozzles are selected from the plurality of first nozzles based on the first feature parameter.

[0014] Wherein, the first feature parameter includes a first actual position and a first actual area, and the step of selecting a plurality of second nozzles from the plurality of first nozzles based on the first feature parameter includes:

[0015] Obtain the first target position of the first ink droplet;

[0016] Determine the first offset of the first actual position relative to the first target position;

[0017] When the first offset is less than or equal to the first reference value and the first actual area is within the preset reference range, the corresponding first ink droplet is determined to be the first target ink droplet;

[0018] The first nozzle corresponding to the first target ink droplet is determined to be the second nozzle.

[0019] The detection substrate is provided with an alignment mark, and the step of obtaining the first target position of the first ink droplet includes:

[0020] The detection substrate is aligned into a preset virtual coordinate system according to the alignment mark;

[0021] Obtain the first virtual coordinates corresponding to the first nozzle in the virtual coordinate system;

[0022] The first virtual coordinates are determined to be the location of the first target.

[0023] The step of determining the first offset of the first actual position relative to the first target position includes:

[0024] Obtain the first actual coordinates corresponding to the first actual position in the virtual coordinate system;

[0025] The first offset is determined based on the first actual coordinates and the first virtual coordinates.

[0026] Wherein, the first offset includes a first longitudinal offset and a first lateral offset, and the first reference value includes a first longitudinal reference value and a first lateral reference value;

[0027] When the first vertical offset is less than or equal to the first vertical reference value, the first horizontal offset is less than or equal to the first horizontal reference value, and the first actual area is within a preset reference range, the corresponding first ink droplet is determined to be the first target ink droplet.

[0028] Wherein, the first longitudinal reference value is greater than or equal to 5 micrometers and less than or equal to 10 micrometers, and the first lateral reference value is greater than or equal to 8 micrometers and less than or equal to 12 micrometers; the lower limit of the preset reference range is greater than or equal to 1300 square micrometers and the upper limit is less than or equal to 1500 square micrometers.

[0029] The nozzle control method is performed before the actual inkjet printing, and the step of controlling multiple second nozzles to perform simulated printing includes:

[0030] Obtain the printing parameters for the actual inkjet printing;

[0031] Based on the printing parameters, multiple second nozzles are controlled to perform simulated printing on the detection substrate.

[0032] The step of controlling multiple second nozzles after the simulated printing to perform second ink droplet detection and determining multiple target nozzles from the multiple second nozzles includes:

[0033] Control multiple second nozzles to dispense multiple second ink droplets in the third region of the detection substrate;

[0034] Obtain the second characteristic parameters of the second ink droplet;

[0035] Multiple target nozzles are determined from the plurality of second nozzles based on the second characteristic parameter.

[0036] Wherein, the second feature parameter includes a second actual position and a second actual area, and the step of determining a plurality of target nozzles from the plurality of second nozzles based on the second feature parameter includes:

[0037] Obtain the second target position of the second ink droplet;

[0038] Determine the second offset of the second actual position relative to the second target position;

[0039] Calculate the offset difference between the first offset and the second offset, and the area difference between the first actual area and the second actual area;

[0040] When the offset difference is less than or equal to the second reference value and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet;

[0041] The second nozzle corresponding to the second target ink droplet is identified as the target nozzle.

[0042] The detection substrate is provided with an alignment mark, and the step of obtaining the second target position of the second ink droplet includes:

[0043] The detection substrate is aligned into a preset virtual coordinate system according to the alignment mark;

[0044] Obtain the second virtual coordinates corresponding to the first nozzle in the virtual coordinate system;

[0045] The second virtual coordinates are determined as the location of the second target.

[0046] The step of determining the second offset of the second actual position relative to the second target position includes:

[0047] Obtain the second actual coordinates corresponding to the second actual position within the virtual coordinate system;

[0048] The second offset is determined based on the second actual coordinates and the second virtual coordinates.

[0049] The offset difference includes a longitudinal offset difference and a lateral offset difference, and the second reference value includes a second longitudinal reference value and a second lateral reference value.

[0050] When the longitudinal offset difference is less than or equal to the second longitudinal reference value, the lateral offset difference is less than or equal to the second lateral reference value, and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet.

[0051] Wherein, the first offset includes a first longitudinal offset and a first lateral offset, and the second offset includes a second longitudinal offset and a second lateral offset;

[0052] The absolute value of the difference between the first longitudinal offset and the second longitudinal offset is determined to be the longitudinal offset difference.

[0053] The absolute value of the difference between the first lateral offset and the second lateral offset is determined to be the longitudinal offset difference.

[0054] Wherein, the second longitudinal reference value is greater than or equal to 1 micrometer and less than or equal to 5 micrometers, the second lateral reference value is greater than or equal to 3 micrometers and less than or equal to 7 micrometers, and the third reference value is greater than or equal to 100 square micrometers and less than or equal to 150 square micrometers.

[0055] Specifically, multiple first nozzles are controlled to perform first ink drop detection in a first region of the detection substrate, multiple second nozzles are controlled to perform simulated printing in a second region of the detection substrate, and multiple second nozzles are controlled to perform second ink drop detection in a third region of the detection substrate; wherein the surfaces of the first region and the third region are both planar, and the second region is provided with multiple pixel openings.

[0056] The detection substrate is provided with at least two first regions, and the step of controlling multiple first nozzles to perform first droplet detection in the first regions of the detection substrate includes:

[0057] Control each of the first nozzles to dispense a first ink droplet in each of the first regions, or control each of the first nozzles to dispense a first ink droplet at at least two different locations within the first region;

[0058] And / or, the step of controlling a plurality of second nozzles to perform second ink droplet detection within a third region of the detection substrate includes:

[0059] Control each of the second nozzles to dispense a second ink droplet in each of the third regions, or control each of the second nozzles to dispense a second ink droplet at at least two different locations within the third region;

[0060] And / or, the step of controlling the plurality of second nozzles to perform simulated printing in the second region of the detection substrate includes:

[0061] Obtain the printing parameters for inkjet printing;

[0062] The printing parameters are used to control multiple second nozzles to drip ink into the multiple pixel openings.

[0063] This application also discloses an inkjet printing apparatus, comprising a stage, an inkjet unit, a control unit, and a detection unit; the stage is used to support a detection substrate, the inkjet unit is provided with a plurality of nozzles, the control unit is used to control the plurality of nozzles to supply ink to the detection substrate to form ink droplets; the detection unit is used to detect the ink droplets on the detection substrate and output the detection result to the control unit; the control unit includes a screening module, which is used to screen nozzles according to the detection result.

[0064] The control device further establishes a virtual coordinate system, and the inkjet printing equipment also includes an alignment device for aligning the detection substrate and the nozzle onto the virtual coordinate system; and / or,

[0065] The detection substrate has a first region, a second region, and a third region. The surfaces of the first region and the third region are both planar, and the second region has multiple pixel openings.

[0066] The control device is at least used to control the plurality of nozzles to supply ink to the first region, the second region and the third region to form ink droplets;

[0067] The detection device is used to detect ink droplets on the first region and the third region.

[0068] The nozzle control method provided in this application includes two screening actions and simulated printing interspersed between the two screening actions. This allows for the timely detection of nozzles that do not exhibit abnormalities during the first screening but do so during the printing process, thereby improving the nozzle screening effect. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0070] Figure 1 This is a schematic diagram of the structure of an embodiment of the inkjet printing device of this application;

[0071] Figure 2 This is a schematic diagram of the structure of a detection substrate used in the nozzle control method of this application;

[0072] Figure 3 This is a schematic flowchart of the nozzle control method of this application;

[0073] Figure 4 For this Figure 3 A detailed flowchart of step S1 is shown below;

[0074] Figure 5 For this Figure 4 A detailed flowchart of step S13 is shown below;

[0075] Figure 6 For this Figure 3 A detailed flowchart of step S2 in the process;

[0076] Figure 7 For this Figure 3 A detailed flowchart of step S3 in the process;

[0077] Figure 8 For this Figure 7 The detailed flowchart of step S33 is shown below.

[0078] Explanation of reference numerals: 100, Inkjet printing equipment; 10, Platform; 20, Inkjet unit; 21, Print head; 30, Detection device; 40, Detection substrate; 41, First area; 42, Second area; 43, Third area; 44, Alignment mark;

[0079] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0080] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0081] This application provides a nozzle control method to solve the problem of poor screening effect of existing nozzles. The following description is in conjunction with the accompanying drawings.

[0082] First, the nozzle printing method of this application is implemented by an inkjet printing device 100, such as... Figure 1 As shown, the inkjet printing equipment 100 mainly includes a carrier stage 10, an inkjet unit 20, and a detection unit 30. The carrier stage 10 carries the glass substrate to be inkjet-printed (note: the glass substrate can be a detection substrate for testing or a printing substrate for inkjet printing), and the carrier stage 10 can move the glass substrate to the inkjet unit 20 and the detection unit 30. The inkjet unit 20 mainly includes an ink cartridge (not shown) for storing ink, a print head 21 connected to the ink cartridge, and multiple nozzles (not shown) disposed on the print head 21. During inkjet printing, ink flows into the print head, and the print head then sprays ink onto the glass substrate through the nozzles, thereby achieving the printing of the organic light-emitting layer. The detection device 30 is used to detect ink droplets on the glass substrate to obtain information about the printing of ink droplets on the glass substrate, such as the position, area, or volume of the ink droplets on the glass substrate. In addition, the detection device 30 can detect ink droplets on the glass substrate by means of laser reflection, camera shooting, etc. For example, in this application, the detection device 30 uses a camera to photograph the ink droplets on the glass substrate. This not only provides a good understanding of the printing of ink droplets, but also has low cost and is easy to obtain.

[0083] In the embodiments of this application, the inkjet printing device 100 based on the above structure is as follows: Figure 3 As shown, the nozzle control method includes:

[0084] Step S1: Control multiple first nozzles to perform first droplet detection, and determine multiple second nozzles from the multiple first nozzles.

[0085] Step S2: Control multiple second nozzles to perform simulated printing.

[0086] Step S3: Control the multiple second nozzles after the simulated printing to perform second ink drop detection, and determine multiple target nozzles from the multiple second nozzles.

[0087] In this embodiment, for step S1, as follows: Figure 2 As shown, step S1 specifically includes:

[0088] Step S11: Control multiple first nozzles to drop multiple first ink droplets onto the detection substrate 40. Specifically, before starting the screening, a detection substrate 40 needs to be provided, such as... Figure 2 As shown, the detection substrate 40 is divided into a first region 41, a second region 42 and a third region 43. The surfaces of the first region 41 and the third region 43 are planar to facilitate the observation of the position and area of ​​the ink droplets after the nozzle dispenses ink. The second region 42 is provided with thin-film transistors and multiple pixel openings to allow the nozzle to simulate actual inkjet printing within the second region 42.

[0089] In actual operation, first position the detection substrate 40 onto the support stage 10, such as... Figure 2 As shown, to facilitate accurate alignment of the nozzles with the first region 41, the second region 42, or the third region 43 on the detection substrate 40, alignment marks 44 are provided on the detection substrate 40. After the detection substrate 40 is mounted on the support stage 10, the control device of the inkjet printing equipment 100 can use the alignment marks 44 to align the detection substrate 40 with a preset virtual coordinate system. For example, the side of the detection substrate 40 is aligned with the Y-axis of the virtual coordinate system, and when the detection substrate 40 moves, the side of the detection substrate 40 moves along the Y-axis of the virtual coordinate system. At the same time, the control device of the inkjet printing equipment 100 also maps the position of each nozzle to the virtual coordinate system, thus effectively controlling the positional relationship between multiple nozzles and the detection substrate 40, and thereby controlling each nozzle to accurately correspond to different positions on the detection substrate 40.

[0090] After the detection substrate 40 is aligned, multiple first nozzles can be controlled to correspond to the first region 41 of the detection substrate 40, and the switches on the multiple first nozzles can be controlled to open, so that the multiple first nozzles can drip multiple first ink droplets in the first region 41. It should be noted that when controlling the multiple first nozzles to drip first ink droplets, each first nozzle can drip one ink droplet, which is the first ink droplet; or each first nozzle can drip two or more ink droplets at the same position, which form a first ink droplet. The specific number of ink droplets dripped by each first nozzle can be set according to the ink dripping situation of the nozzle during actual inkjet printing. For example, during actual inkjet printing, if the nozzle drips only one ink droplet each time it passes through a pixel opening, then the number of ink droplets dripped by the first nozzle at the same position in the first region 41 can be one droplet; if the nozzle drips two ink droplets each time it passes through a pixel opening, then the number of ink droplets dripped by the first nozzle at the same position in the first region 41 can also be two drops. This is understandable, as it allows the inkjet state of the first nozzle during screening to be closer to that during actual printing, thus improving the screening effect.

[0091] Step S12: Obtain the first feature parameters of the first ink droplet. Specifically, in this embodiment, the first feature parameters of the first ink droplet are mainly detected by a detection device 30. The detection device 30 includes a camera and a processing module. The camera can capture an image of the first ink droplet, and the processing module can process the image of the first ink droplet and output the first feature parameters of the first ink droplet. The first feature parameters of the first ink droplet mainly include the first actual position and the first actual area. The processing module can determine the first actual position of the first ink droplet by aligning the image with the first ink droplet onto the virtual coordinate system in the alignment device. Generally, the center of the first ink droplet can be used as the first actual position. As for the first actual area of ​​the first ink droplet, the boundary of the ink droplet can be determined by an image processing algorithm, and then the area of ​​the ink droplet can be calculated. The specific processing method can refer to the prior art, and will not be described in detail here.

[0092] It is understandable that the three most important parameters of ink droplets in inkjet printing are volume, velocity, and angle. The first actual area can reflect the volume of the first ink droplet, and thus determine whether the volume of the first ink droplet is too large, too small, or the right size. The first actual position can reflect the velocity and angle of the first ink droplet, and thus determine whether the velocity of the ink droplet is too fast or too slow, and whether it deviates from the target printing position when it falls.

[0093] Of course, in practical applications, the first characteristic parameter of the first ink droplet can also directly include the volume, velocity or angle of the ink droplet. In this case, the detection device 30 can be replaced with a device that can detect the volume, velocity and angle of the ink droplet.

[0094] After obtaining the first characteristic parameters of the first ink droplet, step S13 can be executed.

[0095] Step S13: Determine a plurality of second nozzles from the plurality of first nozzles based on the first feature parameter. Specifically, as shown below... Figure 5 As shown, step S13 includes:

[0096] Step S131: Obtain the first target position of the first ink droplet;

[0097] Step S132: Determine the first offset of the first actual position relative to the first target position;

[0098] Step S133: When the first offset is less than or equal to the first reference value and the first actual area is within the preset reference range, the corresponding first ink droplet is determined to be the first target ink droplet;

[0099] Step S134: Determine that the first nozzle corresponding to the first target ink droplet is the second nozzle.

[0100] In step S131, the first target position of the first ink droplet is the ideal position on the detection substrate 40 when the ink droplet falls from the first nozzle without any abnormalities. Generally, the first nozzle is located directly above the detection substrate 40, and the ink droplet falls onto the detection substrate 40 through free fall without any interference. Therefore, the first target position is generally located directly below the first nozzle. Thus, the first target position of the first ink droplet on the detection substrate 40 can actually be determined by the position of the corresponding first nozzle. Therefore, in this embodiment, step S131 includes:

[0101] Step S1311: Align the detection substrate 40 to a preset virtual coordinate system according to the alignment mark 44;

[0102] Step S1312: Obtain the first virtual coordinates corresponding to the first nozzle in the virtual coordinate system;

[0103] Step S1313: Determine the first virtual coordinates as the first target position.

[0104] Specifically, as mentioned above, the inkjet printing device 100 generally comes with an alignment device to ensure accurate alignment of each nozzle with different pixel openings. In this step, the entire detection substrate 40 can be aligned into a preset virtual coordinate system within the alignment device using the alignment mark 44 on the detection substrate 40. For example, the side of the detection substrate 40 can be aligned with the Y-axis of the virtual coordinate system, thus determining the positional relationship between the nozzle and the detection substrate 40. Then, the first virtual coordinates corresponding to the first nozzle in the virtual coordinate system are obtained, and these first virtual coordinates are determined as the first target position of the first ink droplet.

[0105] Step S132 specifically includes:

[0106] Step S1321: Obtain the first actual coordinates corresponding to the first actual position in the virtual coordinate system;

[0107] Step S1322: Determine the first offset based on the first actual coordinates and the first virtual coordinates.

[0108] Specifically, after the detection device 30 captures an image of the first ink droplet, it can output the image containing the first ink droplet to the control device. The control device then aligns the image containing the first ink droplet onto the virtual coordinate system to obtain the first actual coordinates corresponding to the first actual position. At this point, the difference between the first actual coordinates and the first virtual coordinates can be calculated to more easily determine the first offset of the first actual position relative to the first target position.

[0109] It should be noted that the first offset can be the straight-line distance between the first actual position and the first target position, or it can be broken down into offsets in the X-axis direction and offsets in the Y-axis direction. The specific data format can be flexibly selected according to the actual situation.

[0110] For steps S133 and S134, after determining the first offset and the first actual area of ​​the first ink droplet, the first offset can be compared with the first reference value, and it can be determined whether the first actual area is within the preset reference range. When the first offset is less than or equal to the first reference value, it indicates that the first ink droplet deviates from the first target position by a small margin, thus indicating that the first ink droplet is qualified at least in terms of speed and angle. When the first offset is greater than the first reference value, it indicates that the first ink droplet deviates from the first target position by a large margin, thus indicating that the first ink droplet is unqualified at least in terms of speed and angle. In this case, the first ink droplet can be judged as unqualified, and the corresponding nozzle is in an abnormal state. It is unqualified and should be shut down or rejected. Similarly, when the first actual area is within the preset reference range, it indicates that the area and volume of the first ink droplet meet the requirements. When the first actual area is outside the preset reference range, it indicates that the area and volume of the first ink droplet do not meet the requirements. In this case, the first ink droplet can be judged as unqualified, and the corresponding nozzle is in an abnormal state. It is unqualified and should be shut down or rejected.

[0111] Therefore, when the first offset is less than or equal to the first reference value and the first actual area is within the preset reference range, the corresponding first ink droplet can be determined as the first target ink droplet, and the first nozzle corresponding to the first target ink droplet can also be determined as the second nozzle.

[0112] It should be noted that, to reduce computational load, in one embodiment, the first offset includes a first longitudinal offset and a first lateral offset. In this embodiment, "longitudinal and lateral" can refer to either the Y-axis or the X-axis. Similarly, the first reference value also adaptively includes a first longitudinal reference value and a first lateral reference value. Therefore, when the first longitudinal offset is less than or equal to the first longitudinal reference value, the first lateral offset is less than or equal to the first lateral reference value, and the first actual area is within a preset reference range, the corresponding first ink droplet can be determined as the first target ink droplet, and the nozzle corresponding to the first target ink droplet is determined as the first nozzle. It can be understood that by directly comparing the first longitudinal offset and the first longitudinal reference value, and the first lateral offset and the first lateral reference value, the computational load can be reduced, thereby improving the processing efficiency of the inkjet printing device 100.

[0113] It should also be noted that the specific values ​​of the first reference value and the preset reference range can be set according to the actual nozzle size, the nozzle movement speed during inkjet printing, the ink type, etc. For example, in this application, the first vertical reference value is greater than or equal to 5 micrometers and less than or equal to 10 micrometers, that is, the specific value of the first vertical reference value can be 5 micrometers, 5.5 micrometers, 6 micrometers, 6.5 micrometers, 7 micrometers, 7.5 micrometers, 8 micrometers, 8.5 micrometers, 9 micrometers, 9.5 micrometers, 10 micrometers, etc. The first horizontal reference value is greater than or equal to 8 micrometers and less than or equal to 12 micrometers, that is, the specific value of the second vertical reference value can be 8 micrometers, 8.5 micrometers, 9 micrometers, 9.5 micrometers, 10 micrometers, 10.5 micrometers, 11 micrometers, 11.5 micrometers, 12 micrometers, etc. The lower limit of the preset reference range is greater than or equal to 1300 square micrometers, and the upper limit is less than or equal to 1500 square micrometers. The specific preset reference range can be 1300 square micrometers to 1500 square micrometers, 1300 square micrometers to 1450 square micrometers, 1300 square micrometers to 1400 square micrometers, 1300 square micrometers to 1350 square micrometers, 1350 square micrometers to 1500 square micrometers, 1350 square micrometers to 1450 square micrometers, 1350 square micrometers to 1400 square micrometers, 1400 square micrometers to 1500 square micrometers, 1400 square micrometers to 1450 square micrometers, etc.

[0114] More specifically, in one embodiment of this application, the first longitudinal reference value is specifically taken as 7.5 micrometers, the second longitudinal reference value is specifically taken as 10 micrometers, and the specific preset reference range is 1300 square micrometers to 1500 square micrometers. Therefore, when the first longitudinal offset is less than or equal to 7.5 micrometers, the first lateral offset is less than or equal to 10 micrometers, and the first actual area is between 1300 square micrometers and 1500 square micrometers, the corresponding first ink droplet can be determined as the first target ink droplet, and the first nozzle corresponding to the first target ink droplet is the second nozzle.

[0115] Thus, through the above steps S1, several second nozzles without abnormalities have been preliminarily screened from the multiple first nozzles, and then steps S2 to S3 can be continued.

[0116] Step S2: Control multiple second nozzles to perform simulated printing. For example... Figure 6 As shown, step S2 specifically includes:

[0117] Step S21: Obtain the printing parameters for inkjet printing;

[0118] Step S22: Control multiple second nozzles to perform simulated printing on the detection substrate according to the printing parameters.

[0119] Because staff preset the corresponding printing parameters on the inkjet printing equipment before each actual inkjet print, the printing parameters for the upcoming actual inkjet print can be obtained before controlling multiple second nozzles to perform simulated printing. The specific printing parameters include at least the droplet size, inkjet speed, inkjet pressure, inkjet path, the distance between the nozzle and the substrate, and the number of inkjet prints in each pixel opening, etc.

[0120] Furthermore, in order to more realistically simulate actual inkjet printing, the detection substrate 40 is provided with a second region 42 for simulating printing. The second region 42 is provided with thin-film transistors and multiple pixel openings. The arrangement of the thin-film transistors and pixel openings can be the same as that of the glass substrate during actual inkjet printing. When controlling multiple second nozzles to perform simulated printing in the second region 42 of the detection substrate 40, the printing parameters of inkjet printing can be obtained first, and then the multiple second nozzles can be controlled to drip ink into the multiple pixel openings of the second region 42 according to the printing parameters. This can simulate a more realistic inkjet printing process.

[0121] Of course, since the arrangement of thin-film transistors and pixel openings in the second region 42 can be the same as that of the glass substrate during actual printing, after the nozzle screening is completed, if the printing quality of the second region 42 meets the requirements, the first region 41 and the third region 43 of the detection substrate 40 can also be cut off. At this time, the detection substrate 40 can also be put into the warehouse as a substrate with qualified printing quality.

[0122] Thus, through step S2 above, the simulation printing of multiple second nozzles has been completed. After the simulation printing, the second nozzles that are unqualified or unstable but performed well in step S1 can be revealed. Then, step S3 can be continued for further screening.

[0123] Step S3: Control the multiple second nozzles after the simulated printing to perform second ink drop detection, and determine multiple target nozzles from the multiple second nozzles.

[0124] In this application, as Figure 7 As shown, step S3 specifically includes:

[0125] Step S31: Control the multiple second nozzles to dispense multiple second ink droplets onto the detection substrate 40. Specifically, this step S31 is basically similar to step S11. After the simulated printing is completed, the multiple second nozzles can be controlled to correspond to the third region 43 of the detection substrate 40, and the switches on the multiple second nozzles can be turned on to dispense multiple second ink droplets within the third region 43. Similarly, when controlling the multiple second nozzles to dispense second ink droplets, each second nozzle can dispense one ink droplet, which is the second ink droplet; or each second nozzle can dispense two or more ink droplets at the same position, which form a second ink droplet. The specific number of ink droplets dispensed by each second nozzle can be set based on the ink dispensing pattern during actual printing. For example, if the nozzle dispenses only one droplet each time it passes through a pixel opening, then the number of ink droplets dispensed by the second nozzle at the same position in the third region 43 can be one droplet. Conversely, if the first nozzle dispenses two drops each time it passes through a pixel opening, then the number of ink droplets dispensed by the second nozzle at the same position in the third region 43 can also be two drops. This allows the ink jetting pattern during screening to more closely resemble the ink jetting pattern during actual printing, thus improving the screening effect.

[0126] Step S32: Obtain the second characteristic parameters of the second ink droplet. Specifically, step S32 is basically similar to step S12, that is, the detection device 30 can capture an image of the second ink droplet through a camera, the processing module can process the image of the second ink droplet and output the second characteristic parameters of the second ink droplet. The second characteristic parameters of the second ink droplet include the second actual position and the second actual area. The method for determining the second actual position and the method for calculating the second actual area can be referred to the previous introduction about the first actual position and the first actual area, and will not be described in detail here.

[0127] Step S33: Determine a plurality of target nozzles from the plurality of second nozzles based on the second feature parameter. Specifically, such as... Figure 8 As shown, step S33 specifically includes:

[0128] Step S331: Obtain the second target position of the second ink droplet. Specifically, similar to step S131, in this step, the second virtual coordinates corresponding to the first nozzle in the virtual coordinate system can be obtained first, and then the second virtual coordinates can be determined as the second target position.

[0129] Step S332: Determine the second offset of the second actual position relative to the second target position. This step S332 is basically similar to step S132, and specifically includes:

[0130] Step S3321: Obtain the second actual coordinates corresponding to the second actual position in the virtual coordinate system;

[0131] Step S3322: Determine the second offset based on the second actual coordinates and the second virtual coordinates.

[0132] Specifically, after the detection device 30 captures an image of the second ink droplet, it can output the image containing the second ink droplet to the control device. The control device then aligns the image containing the second ink droplet onto the virtual coordinate system to obtain the second actual coordinates corresponding to the second actual position. At this point, the difference between the second actual coordinates and the second virtual coordinates can be calculated to more easily determine the second offset of the second actual position relative to the second target position.

[0133] It should be noted that the second offset can be the straight-line distance between the second actual position and the second target position, or it can be broken down into offsets in the X-axis direction and offsets in the Y-axis direction. The specific data format can be flexibly selected according to the actual situation.

[0134] Step S333: Calculate the offset difference between the first offset and the second offset, and the area difference between the first actual area and the second actual area.

[0135] Step S334: When the offset difference is less than or equal to the second reference value and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet.

[0136] Step S335: Determine the second nozzle corresponding to the second target ink droplet as the target nozzle.

[0137] Specifically, unlike steps S133 to S134, in steps S333 to S335, the first offset determined in step 13 and the first actual area determined in step S12 are first obtained. Then, the offset difference between the first offset and the second offset, and the area difference between the first actual area and the second actual area are calculated. Next, the offset difference is compared with the second reference value, and the area difference is compared with the third reference value. When the offset difference is less than or equal to the second reference value, and the area difference is less than or equal to the third reference value, the corresponding second ink droplet can be determined as the second target ink droplet, and the second nozzle corresponding to the second target ink droplet can be determined as the target nozzle.

[0138] It should be noted that the reason for calculating the offset difference and area difference is that the second nozzle used to print the second ink droplet is a second nozzle that has been selected from multiple nozzles. The second nozzle is selected from multiple nozzles based on the selection criteria of "offset less than the first reference value and first actual area within the preset range". If the second offset of the second ink droplet is still compared with the first reference value and the second actual area of ​​the second ink droplet is compared with the preset reference range, it may result in almost all the second nozzles being identified as the target nozzles for formal printing. This would not improve the selection effect.

[0139] By calculating the offset difference and area difference, the stability of the same second nozzle before and after simulating the actual inkjet printing can be determined. This allows for the timely detection and closure or rejection of unstable second nozzles, leaving only stable second nozzles as target nozzles for actual inkjet printing, thus effectively improving print quality.

[0140] To reduce computational load, in one embodiment, the offset difference includes a longitudinal offset difference and a lateral offset difference. The second reference value includes a second longitudinal reference value and a second lateral reference value. In this embodiment, "longitudinal and lateral" can refer to either the Y-axis or the X-axis. Similarly, the second reference value also adaptively includes both the second longitudinal and lateral reference values. Therefore, when the longitudinal offset difference is less than or equal to the second longitudinal reference value, the lateral offset difference is less than or equal to the second lateral reference value, and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet, and the second nozzle corresponding to the second target ink droplet is determined to be the target nozzle.

[0141] It should also be noted that the specific values ​​of the second and third reference values ​​can be set according to the actual nozzle size, nozzle movement speed during inkjet printing, ink type, etc. For example, in this application, the second vertical reference value is greater than or equal to 1 micrometer and less than or equal to 5 micrometers, that is, the specific value of the first vertical reference value can be 1 micrometer, 1.5 micrometers, 2 micrometers, 2.5 micrometers, 3 micrometers, 35 micrometers, 4 micrometers, 4.5 micrometers, 5 micrometers, etc. The first horizontal reference value is greater than or equal to 3 micrometers and less than or equal to 7 micrometers, that is, the specific value of the second vertical reference value can be 3 micrometers, 3.5 micrometers, 4 micrometers, 4.5 micrometers, 5 micrometers, 5.5 micrometers, 6 micrometers, 6.5 micrometers, 7 micrometers, etc.

[0142] The lower limit of the preset reference range is greater than or equal to 100 square micrometers, and the upper limit is less than or equal to 150 square micrometers. Specific preset reference ranges can be 100 square micrometers to 150 square micrometers, 100 square micrometers to 145 square micrometers, 100 square micrometers to 140 square micrometers, 100 square micrometers to 135 square micrometers, 100 square micrometers to 130 square micrometers, 100 square micrometers to 125 square micrometers, 100 square micrometers to 120 square micrometers, 100 square micrometers to 115 square micrometers, 100 square micrometers to 110 square micrometers, 115 square micrometers to 150 square micrometers, 115 square micrometers to 145 square micrometers, 115 square micrometers to 140 square micrometers, 115 square micrometers to 135 square micrometers, and 115 square micrometers to 130 square micrometers. Meters, 115 square micrometers to 125 square micrometers, 115 square micrometers to 120 square micrometers, 120 square micrometers to 150 square micrometers, 120 square micrometers to 145 square micrometers, 120 square micrometers to 140 square micrometers, 120 square micrometers to 135 square micrometers, 120 square micrometers to 130 square micrometers, 120 square micrometers to 125 square micrometers, 130 square micrometers to 150 square micrometers, 130 square micrometers to 145 square micrometers, 130 square micrometers to 140 square micrometers, 130 square micrometers to 135 square micrometers, 135 square micrometers to 150 square micrometers, 140 square micrometers to 145 square micrometers, etc.

[0143] More specifically, in one embodiment of this application, the first longitudinal reference value is specifically taken as 7.5 micrometers, the second longitudinal reference value is specifically taken as 10 micrometers, and the specific preset reference range is 1300 square micrometers to 1500 square micrometers. Therefore, when the longitudinal offset difference is less than or equal to 3 micrometers, the lateral offset difference is less than or equal to 5 micrometers, and the area difference is less than or equal to 150 square micrometers, the corresponding second ink droplet is determined to be the second target ink droplet, and the second nozzle corresponding to the second target ink droplet is determined to be the target nozzle.

[0144] In this embodiment, the second offset includes a second longitudinal offset and a second lateral offset. In this case, the absolute value of the difference between the first longitudinal offset and the second longitudinal offset can be determined as the longitudinal offset difference, and the absolute value of the difference between the first lateral offset and the second lateral offset can be determined as the longitudinal offset difference.

[0145] In summary, the nozzle control method provided in this application includes two screening actions and simulated printing interspersed between the two screening actions. It can be understood that by performing screening again after simulated printing, nozzles that did not show abnormalities in the first screening but showed abnormalities during the printing process can be identified in a timely manner. Then, the abnormal nozzles can be removed through the second screening, which improves the nozzle screening effect and thus better ensures the printing quality.

[0146] Thus, after screening through steps S1 to S3 above, the target nozzle that meets the requirements is determined. Then, according to the preset printing parameters, the target nozzle is controlled to perform inkjet printing on the substrate to be printed.

[0147] Optionally, in one embodiment, such as Figure 2 As shown, the detection substrate 40 is provided with at least two first regions 41. The step of controlling multiple first nozzles to drip multiple first ink droplets in the first regions 41 of the detection substrate 40 includes: controlling each first nozzle to drip the first ink droplet in each first region 41. That is, each first nozzle will drip ink at least twice at at least two different positions. Since each first ink droplet will be acquired with a first feature parameter, and each first feature parameter will be used to determine whether the corresponding first nozzle meets the requirements. In other words, because each first nozzle drips ink at least twice in at least two first regions 41, each first nozzle has undergone at least two ink drip detections before executing step S2 (i.e., controlling multiple second nozzles to perform simulated printing). This can avoid the situation where some nozzles with abnormal states do not show abnormalities during the first screening and are thus identified as first nozzles, thereby improving the screening effect.

[0148] Alternatively, in another embodiment, instead of having multiple first regions 41, if the area of ​​the first region 41 is sufficient, each first nozzle can be controlled to drop the first ink droplet at at least two different positions within the first region 41. This also ensures that each first nozzle undergoes at least two ink droplet detections before executing step S2 (i.e., controlling multiple second nozzles to perform simulated printing). This avoids situations where nozzles with abnormal states happen not to exhibit abnormalities during the initial screening and are thus identified as first nozzles, thereby improving the screening effect.

[0149] Optionally, in one embodiment, such as Figure 2As shown, the detection substrate 40 is provided with at least two third regions 43. The step of controlling multiple second nozzles to drip multiple second ink droplets in the third regions 43 of the detection substrate 40 includes: controlling each second nozzle to drip a second ink droplet in each third region 43. That is, each second nozzle will drip ink at least twice at at least two different positions. Since each second ink droplet will be acquired with a second feature parameter, and each second feature parameter will be used to determine whether the corresponding nozzle meets the requirements. In other words, because each second nozzle drips ink at least twice in at least two third regions 43, each second nozzle is tested for ink dripping at least twice before the target nozzle for formal inkjet printing is finally determined. This can avoid the situation where some second nozzles with abnormal conditions happen not to show abnormalities during only one screening and are thus identified as target nozzles, thereby improving the screening effect and ensuring the printing effect.

[0150] Alternatively, in another embodiment, instead of having multiple second regions 42, if the area of ​​the second region 42 is sufficient, each second nozzle can be controlled to drop the second ink droplet at at least two different positions within the third region 43. This also ensures that each second nozzle undergoes at least two ink droplet detections before the final target nozzle for inkjet printing is determined. This avoids situations where some second nozzles with abnormal conditions happen to not exhibit abnormalities during only one screening and are thus identified as target nozzles, thereby improving the screening effect and ensuring printing quality.

[0151] like Figure 1 As shown, this application also proposes an inkjet printing device 100, which includes a carrier stage 10, an inkjet device 20, a control device (not shown), and a detection device 30. The carrier stage 10 is used at least to detect a substrate 40, and is also used to support the substrate during actual inkjet printing. The inkjet device 20 is provided with a print head 21, which has multiple nozzles. The control device is used at least to control the multiple nozzles to provide ink to the substrate to form ink droplets for ink droplet detection and simulated printing. The detection device 30 is mainly a camera, which is used to detect the ink droplets on the substrate and output the detection results to the control device.

[0152] The control device also includes a screening module, which mainly consists of a nozzle controller. The nozzle controller can shut down unqualified nozzles based on the detection results, thereby selecting target nozzles for actual inkjet printing. The specific screening method is the nozzle screening direction described earlier, and the nozzle control method can be pre-stored in the control device's memory.

[0153] It should be noted that the specific structure, installation method, and positional relationship of the carrier platform 10, inkjet device 20, control device, and detection device 30 can be realized based on relevant existing technologies, as long as the corresponding functions described above can be achieved.

[0154] In addition, in one embodiment of this application, the control device also establishes a virtual coordinate system, and the inkjet printing equipment 100 further includes an alignment device, which is used to align the detection substrate 40 and the nozzle to the virtual coordinate system.

[0155] Specifically, when the detection substrate 40 is positioned on the support stage 10, the control device can detect the size and position of the entire detection substrate 40 through the detection device 30, and then establish a corresponding virtual coordinate system for the area where the detection substrate 40 is located. The virtual coordinate system can be two-dimensional or three-dimensional, and can be established according to the printing requirements.

[0156] The alignment device mainly consists of a series of sensors (such as photoelectric sensors, mechanical sensors, Hall sensors, etc.) to sense the actual position of the nozzle and the detection substrate 40, and align the detection substrate 40 and the nozzle to the virtual coordinate system according to the alignment mark 44 preset on the detection substrate 40. For example, the alignment mark 44 on the detection substrate 40 is first aligned to the origin of the virtual coordinate system, and then the other positions of the detection substrate 40 and the nozzle are aligned to the virtual coordinate system one by one according to the orientation of the other positions of the detection substrate 40 relative to the alignment mark 44 and the orientation of the nozzle relative to the alignment mark 44.

[0157] By aligning the detection substrate 40 and the nozzle into the virtual coordinate system using the alignment device, the control device can accurately control multiple nozzles to drop ink at precise positions for detection or simulated printing, and facilitate the calculation of ink droplet offset.

[0158] Optionally, in one embodiment, such as Figure 2 As shown, the detection substrate 40 has a first region 41, a second region 42, and a third region 43. The surfaces of the first region 41 and the third region 43 are planar, and the second region 42 has multiple pixel openings. A control device is used to control multiple nozzles to supply ink to the first region 41, the second region 42, and the third region 43 to form ink droplets. A detection device 30 is used to detect the ink droplets on the first region 41 and the third region 43.

[0159] The above provides a detailed description of a nozzle control method, storage medium, inkjet printing equipment, and control device provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A nozzle control method, characterized in that, include: Control multiple first nozzles to detect the first drop of ink, and determine multiple second nozzles from the multiple first nozzles; Control multiple second nozzles to perform simulated printing; The second nozzles after the simulated printing are controlled to perform a second drop of ink detection, and the target nozzle is determined from the multiple second nozzles; The step of controlling multiple first nozzles to perform first droplet detection and determining multiple second nozzles from the multiple first nozzles includes: Control the plurality of first nozzles to drop a plurality of first ink droplets onto the detection substrate; Obtain the first characteristic parameter of the first ink droplet; A plurality of second nozzles are determined from the plurality of first nozzles based on the first feature parameter; Wherein, the first feature parameter includes a first actual position and a first actual area, and the step of determining a plurality of second nozzles from the plurality of first nozzles based on the first feature parameter includes: Obtain the first target position of the first ink droplet; Determine the first offset of the first actual position relative to the first target position; When the first offset is less than or equal to the first reference value and the first actual area is within the preset reference range, the corresponding first ink droplet is determined to be the first target ink droplet; The first nozzle corresponding to the first target ink droplet is determined to be the second nozzle; The step of controlling multiple second nozzles after the simulated printing to perform second ink droplet detection and determining multiple target nozzles from the multiple second nozzles includes: Control multiple second nozzles to drop multiple second ink droplets onto the detection substrate; Obtain the second characteristic parameters of the second ink droplet; Multiple target nozzles are determined from the plurality of second nozzles based on the second characteristic parameter; Wherein, the second feature parameter includes a second actual position and a second actual area, and the step of determining a plurality of target nozzles from the plurality of second nozzles based on the second feature parameter includes: Obtain the second target position of the second ink droplet; Determine the second offset of the second actual position relative to the second target position; Calculate the offset difference between the first offset and the second offset, and the area difference between the first actual area and the second actual area; When the offset difference is less than or equal to the second reference value and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet; The second nozzle corresponding to the second target ink droplet is identified as the target nozzle.

2. The nozzle control method as described in claim 1, characterized in that, The detection substrate is provided with alignment marks, and the step of obtaining the first target position of the first ink droplet includes: The detection substrate is aligned into a preset virtual coordinate system according to the alignment mark; Obtain the first virtual coordinates corresponding to the first nozzle in the virtual coordinate system; The first virtual coordinates are determined to be the location of the first target. The step of determining the first offset of the first actual position relative to the first target position includes: Obtain the first actual coordinates corresponding to the first actual position in the virtual coordinate system; The first offset is determined based on the first actual coordinates and the first virtual coordinates.

3. The nozzle control method as described in claim 1, characterized in that, The first offset includes a first longitudinal offset and a first lateral offset, and the first reference value includes a first longitudinal reference value and a first lateral reference value; When the first vertical offset is less than or equal to the first vertical reference value, the first horizontal offset is less than or equal to the first horizontal reference value, and the first actual area is within a preset reference range, the corresponding first ink droplet is determined to be the first target ink droplet.

4. The nozzle control method as described in claim 3, characterized in that, The first longitudinal reference value is greater than or equal to 5 micrometers and less than or equal to 10 micrometers, and the first lateral reference value is greater than or equal to 8 micrometers and less than or equal to 12 micrometers; the lower limit of the preset reference range is greater than or equal to 1300 square micrometers, and the upper limit is less than or equal to 1500 square micrometers.

5. The nozzle control method as described in claim 1, characterized in that, The step of controlling the multiple second nozzles to perform simulated printing includes: Obtain the printing parameters for inkjet printing; Based on the printing parameters, multiple second nozzles are controlled to perform simulated printing on the detection substrate.

6. The nozzle control method as described in claim 1, characterized in that, The detection substrate is provided with alignment marks, and the step of obtaining the second target position of the second ink droplet includes: The detection substrate is aligned into a preset virtual coordinate system according to the alignment mark; Obtain the second virtual coordinates corresponding to the second nozzle in the virtual coordinate system; The second virtual coordinates are determined as the location of the second target. The step of determining the second offset of the second actual position relative to the second target position includes: Obtain the second actual coordinates corresponding to the second actual position within the virtual coordinate system; The second offset is determined based on the second actual coordinates and the second virtual coordinates.

7. The nozzle control method as described in claim 1, characterized in that, The offset difference includes a longitudinal offset difference and a lateral offset difference, and the second reference value includes a second longitudinal reference value and a second lateral reference value; When the longitudinal offset difference is less than or equal to the second longitudinal reference value, the lateral offset difference is less than or equal to the second lateral reference value, and the area difference is less than or equal to the third reference value, the corresponding second ink droplet is determined to be the second target ink droplet.

8. The nozzle control method as described in claim 7, characterized in that, The first offset includes a first vertical offset and a first horizontal offset, and the second offset includes a second vertical offset and a second horizontal offset; The absolute value of the difference between the first longitudinal offset and the second longitudinal offset is determined to be the longitudinal offset difference. The absolute value of the difference between the first lateral offset and the second lateral offset is determined to be the lateral offset difference.

9. The nozzle control method as described in claim 7, characterized in that, The second longitudinal reference value is greater than or equal to 1 micrometer and less than or equal to 5 micrometers, the second lateral reference value is greater than or equal to 3 micrometers and less than or equal to 7 micrometers, and the third reference value is greater than or equal to 100 square micrometers and less than or equal to 150 square micrometers.

10. The nozzle control method according to any one of claims 1 to 9, characterized in that, The system controls multiple first nozzles to perform first ink drop detection in a first region of the detection substrate, controls multiple second nozzles to perform simulated printing in a second region of the detection substrate, and controls multiple second nozzles to perform second ink drop detection in a third region of the detection substrate. The surfaces of the first region and the third region are both planar, and the second region has multiple pixel openings.

11. The nozzle control method as described in claim 10, characterized in that, The detection substrate is provided with at least two first regions, and the step of controlling multiple first nozzles to perform first droplet detection within the first regions of the detection substrate includes: Control each of the first nozzles to dispense a first ink droplet in each of the first regions, or control each of the first nozzles to dispense a first ink droplet at at least two different locations within the first region; And / or, the detection substrate is provided with at least two of the third regions, and the step of controlling the plurality of second nozzles to perform second ink droplet detection within the third regions of the detection substrate includes: Control each of the second nozzles to dispense a second ink droplet in each of the third regions, or control each of the second nozzles to dispense a second ink droplet at at least two different locations within the third region; And / or, the step of controlling the plurality of second nozzles to perform simulated printing in the second region of the detection substrate includes: Obtain the printing parameters for inkjet printing; According to the printing parameters, multiple second nozzles are controlled to drip ink into the multiple pixel openings; And / or, after determining the target nozzle, control the target nozzle to perform inkjet printing on the substrate to be printed.

12. An inkjet printing device, characterized in that, Inkjet printing is performed using the nozzle control method as described in any one of claims 1 to 11, wherein the inkjet printing apparatus comprises: The support platform is used to support at least the detection substrate; An inkjet device, wherein the inkjet device is provided with multiple nozzles; A control device, the control device being at least configured to control the plurality of nozzles to supply ink to the detection substrate to form ink droplets; and, A detection device, wherein the detection device is at least used to detect ink droplets on the detection substrate and output the detection result to the control device; The control device includes a screening module, which is used to screen nozzles based on the detection results.

13. The inkjet printing apparatus as described in claim 12, characterized in that, The control device also establishes a virtual coordinate system, and the inkjet printing equipment also includes an alignment device, which is used to align the detection substrate and the nozzle to the virtual coordinate system. and / or The detection substrate has a first region, a second region, and a third region. The surfaces of the first region and the third region are both planar, and the second region has multiple pixel openings. The control device is at least used to control the plurality of nozzles to supply ink to the first region, the second region and the third region to form ink droplets; The detection device is used to detect ink droplets on the first region and the third region.

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