Air pressure control method, device and equipment for ink droplet observation ink collection box and storage medium

Abstract

The invention discloses an air pressure control method, device and equipment for an ink droplet observation ink collection box, and a storage medium. The method comprises the following steps: determining spray hole data of a to-be-detected spray hole participating in spraying ink droplets into the ink collection box; wherein the spraying hole data comprises spraying hole types, spraying hole numbers, spraying frequencies and diameters of ink droplets sprayed by the spraying holes; calculating a first volume flow rate corresponding to the ink droplets sprayed into the ink collection box according to the spray hole data; obtaining the internal air pressure of the ink collection box and the external environment air pressure; according to the preset area of the top opening of the ink collecting box and the preset internal and external pressure difference of the ink collecting box, calculating a second volume flow required for maintaining the internal and external pressure difference; determining the outward air suction flow of an air suction pump arranged in the ink collection box at least according to the first volume flow and the second volume flow; and controlling the sucking pump to adjust the air pressure in the ink collecting box according to the outward sucking flow. The air flow inside the ink collection box is prevented from gushing out to interfere with flying ink droplets above, and the accuracy of observation data is improved.

Description

Technical Field

[0001] This application relates to the field of inkjet printing droplet observation technology, specifically to a method, device, equipment, and storage medium for air pressure control of an ink droplet observation ink collection cartridge. Background Technology

[0002] In the field of inkjet printing technology, especially in high-precision industrial printing, PCB manufacturing, and display panel manufacturing, printhead performance is directly related to print quality. To ensure the uniformity and consistency of printed patterns and avoid defects such as ink skipping and ink splatter, it is crucial to perform on-flight droplet observation of the printhead before printing or during maintenance. This process uses high-speed cameras and other equipment to capture and analyze the flight trajectory, speed, volume, and landing point of ink droplets, and is a key step in assessing printhead condition, calibrating jetting parameters, and ensuring printing accuracy. Especially in high-efficiency printing scenarios where multiple nozzles operate in parallel, simultaneously observing the jetting of a batch of nozzles has become an essential means to improve the overall efficiency of printing system debugging and maintenance.

[0003] To achieve droplet observation, the conventional technical solution is to place an ink collection box below the printhead to collect and hold the ink ejected during the observation phase, preventing it from contaminating the worktable. Since the ink used for observation is typically volatile, aerosols or waste liquid molecules produced by its evaporation, if released in large quantities, may adhere to the surface of the precision printhead or the lens of the observation camera, causing secondary contamination that is difficult to remove and affecting printhead lifespan and observation clarity. Therefore, current technologies typically design the opening of the ink collection box to be as small as possible, physically limiting the evaporation area and thus reducing the intensity and range of volatile substances diffusing outward. This is the current mainstream anti-contamination design approach.

[0004] However, in practical applications, especially when observing simultaneous spraying from multiple nozzles, the aforementioned small-aperture design presents a challenge. When multiple nozzles open simultaneously, forming a dense stream of ink droplets that enters the small-aperture ink collection cartridge, the air inside the cartridge is rapidly displaced. Due to the narrow opening, the gas cannot escape smoothly, causing a temporary increase in air pressure inside the cartridge. The pressurized gas eventually surges violently out of the same narrow opening, forming an unstable directional airflow. This outflow, located directly below or to the side of the ink droplet's flight path, exerts adsorption and disturbance forces on subsequent ink droplets, severely interfering with their original flight trajectory and speed. This interference, caused by the observation device itself, distorts the ink droplet images captured by the high-speed camera, significantly reduces the reliability of the observation data, and ultimately affects the accurate judgment of the printhead's condition and parameter calibration. Summary of the Invention

[0005] This application provides a method, apparatus, device, and storage medium for controlling the air pressure of an ink collection box for ink droplet observation, which can solve the problem in the prior art where unstable air pressure inside the ink collection box causes internal gas to surge out and affect the flight trajectory of ink droplets during ink droplet observation.

[0006] In a first aspect, embodiments of this application provide a method for controlling the air pressure of an ink droplet observation ink collection cartridge, employing the following technical solution: A method for controlling the air pressure of an ink droplet observation ink collection cartridge, the method being performed during the ink ejection process of the printhead under test above the ink collection cartridge, comprising: Determine the nozzle data of the nozzles to be tested that participate in ejecting ink droplets into the ink collection cartridge; wherein, the nozzle data includes the type of nozzles participating in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each type, and the diameter of the ink droplets ejected by each type. Based on the nozzle data, calculate the first volume flow rate corresponding to the ink droplet injected into the ink collection cartridge; Obtain the internal air pressure of the ink collection cartridge and the external ambient air pressure; Based on the pre-set area of ​​the top opening of the ink collection box and the pre-set pressure difference between the inside and outside of the ink collection box, calculate the second volume flow rate required to maintain the pre-set pressure difference between the inside and outside of the ink collection box. The outward air extraction flow rate of the air pump installed in the ink collection box is determined based at least on the first volume flow rate and the second volume flow rate. The air pump is controlled according to the outward air flow rate to adjust the air pressure inside the ink collection box.

[0007] In one embodiment, determining the nozzle data of the nozzle to be detected that participates in ejecting ink droplets into the ink collection cartridge includes the following steps: Acquire the relative position information of the printhead to be tested above the ink collection cartridge and the nozzle distribution data of the printhead to be tested; The number of nozzles to be detected is determined based on the relative position information and the nozzle distribution data on the nozzle head to be detected.

[0008] In one embodiment, the calculation of the first volumetric flow rate corresponding to the ink droplet injected into the ink collection cartridge based on the nozzle data is performed using the following formula: Q1=n1⋅f1⋅V1+n2⋅f2⋅V2+…+n x ⋅f x ⋅V x V x =πd x 3 / 6 In the formula, Q1 is the first volumetric flow rate, and n x f represents the number of nozzles of type x. x Let d be the injection frequency of the x-th nozzle. x Let be the volume of the ink droplet ejected from the x-th nozzle.

[0009] In one embodiment, the second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box is calculated based on the area of ​​the opening at the top of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box, using the following calculation formula:

[0010] In the formula, Cv: flow coefficient; A orifice Area of ​​the top opening; ρ air Air density; ΔP: The set target pressure difference.

[0011] In one embodiment, before determining the outward air extraction flow rate of the air pump disposed in the ink collection cartridge based at least on the first volumetric flow rate and the second volumetric flow rate, the following steps are included: Calculate the third volumetric flow rate formed when the ejected ink droplets move inside the ink collection box, based on the number of each type of nozzle, the diameter of the ink droplets ejected by each type of nozzle, and the height of the ink collection box. The step of determining the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first volumetric flow rate and the second volumetric flow rate will be based on the sum of the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate.

[0012] In one embodiment, the calculation of the third volumetric flow rate formed by the ejected ink droplets moving inside the ink collection box, based on the number of each type of nozzle, the diameter of the ink droplets ejected by each nozzle, and the height of the ink collection box, adopts the following calculation formula: Q3=n⋅f⋅(C d ⋅4πd 2 ⋅H) Cd: drag coefficient, representing the efficiency of the ink droplet in driving the airflow; d: Diameter of the ink droplets ejected from the nozzle; H: Height of the ink collection cartridge.

[0013] In one embodiment, determining the outward air extraction flow rate of the air pump disposed within the ink collection cartridge based at least on the first volumetric flow rate and the second volumetric flow rate includes the following steps: Based on the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate, determine the first suction flow rate of the suction pump installed in the ink collection cartridge; Based on the actual pressure difference between the internal air pressure and the ambient air pressure of the ink collection box and the preset ratio of the internal and external pressure difference of the ink collection box, the first air extraction flow rate is adjusted to determine the outward air extraction flow rate of the air pump installed in the ink collection box.

[0014] Secondly, this application provides a pressure control device for an ink droplet observation ink collection cartridge.

[0015] The air pressure control device for the ink droplet observation ink collection cartridge includes: The nozzle determination module is configured to determine the nozzle data of the nozzles to be detected that participate in ejecting ink droplets into the ink collection cartridge; wherein the nozzle data includes the type of nozzles participating in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each type of nozzle, and the diameter of the ink droplets ejected by each type of nozzle. The air extraction flow rate calculation module is configured to: calculate the first volumetric flow rate corresponding to the ink droplets injected into the ink collection box based on the nozzle data; obtain the internal air pressure and external ambient air pressure of the ink collection box; calculate the second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box based on the area of ​​the opening at the top of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box; and determine the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first volumetric flow rate and the second volumetric flow rate. An air pressure control module is configured to control the air pump to adjust the air pressure inside the ink collection cartridge based on the outward air flow rate.

[0016] Thirdly, embodiments of this application provide a pressure control device for an ink droplet observation and collection cartridge, employing the following technical solution: A pressure control device for an ink droplet observation collection cartridge includes a processor, a memory, and a pressure control program for the ink droplet observation collection cartridge stored in the memory and executable by the processor. When the pressure control program for the ink droplet observation collection cartridge is executed by the processor, it implements the steps of the pressure control method for the ink droplet observation collection cartridge as described above.

[0017] Fourthly, embodiments of this application provide a storage medium, employing the following technical solution: A storage medium storing a pressure control program for an ink droplet observation collection cartridge, wherein when the pressure control program for the ink droplet observation collection cartridge is executed by a processor, the steps of the pressure control method for the ink droplet observation collection cartridge as described above are implemented.

[0018] The air pressure control method, apparatus, equipment, and storage medium for the ink droplet observation and collection cartridge provided in this application have the following beneficial effects: The method, apparatus, equipment, and storage medium for controlling the air pressure of the ink droplet observation ink collection box provided in this application calculate the first volumetric flow rate corresponding to the ink droplets injected into the ink collection box by determining the nozzle data participating in the injection; acquiring the internal air pressure and external ambient air pressure of the ink collection box; calculating the second volumetric flow rate required to maintain the internal and external pressure difference based on the pre-set area of ​​the opening at the top of the ink collection box and the preset internal and external pressure difference of the ink collection box; and determining the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first and second volumetric flow rates; and finally controlling the air pump to adjust the air pressure inside the ink collection box according to the outward air extraction flow rate, thereby effectively preventing the airflow inside the ink collection box from rushing out and interfering with the flying ink droplets above, and improving the accuracy of the observation data. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall process of the air pressure control method for the ink droplet observation and collection cartridge in one embodiment of this application; Figure 2 This is a schematic diagram of the functional modules of the air pressure control device for the ink droplet observation and collection cartridge in one embodiment of this application; Figure 3 This is a schematic diagram of the hardware structure of the air pressure control device for the ink droplet observation and collection cartridge in one embodiment of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0022] In the field of inkjet printing technology, observation of flying ink droplets is a crucial step in assessing printhead condition and calibrating ejection parameters. Current technologies often design the ink collection cartridge opening to be relatively small to prevent contamination from ink volatiles. However, when observing simultaneous ejection from multiple nozzles, the flow of ink droplets into the small-opening ink collection cartridge causes an increase in internal pressure. This pressurized gas then escapes from the narrow opening, creating an unstable directional airflow that disturbs the flying ink droplets, interfering with their trajectory and speed. This reduces the reliability of the observation data and affects the accurate assessment of printhead condition.

[0023] To address this issue, this application proposes a method for controlling the air pressure of an ink droplet observation cartridge, which is executed during the ink ejection process of the printhead under test above the cartridge. This method involves determining the nozzle data involved in the ejection, calculating the first volumetric flow rate corresponding to the ink droplets ejected into the cartridge, acquiring the internal air pressure and external ambient air pressure of the cartridge, calculating the second volumetric flow rate required to maintain the internal and external pressure difference based on the pre-set area of ​​the top opening of the cartridge and the preset internal and external pressure difference, determining the outward air extraction flow rate of the pump installed inside the cartridge based at least on the first and second volumetric flow rates, and finally controlling the pump to adjust the internal air pressure of the cartridge based on the outward air extraction flow rate. This effectively prevents the airflow inside the cartridge from surging outwards and interfering with the flying ink droplets above, thus improving the accuracy of the observation data.

[0024] This embodiment provides a method for controlling the air pressure of an ink droplet observation ink collection box. The method aims to actively adjust the internal air pressure of the ink collection box to eliminate interference from the outward flow of air that may affect ink droplets during flight. It includes at least the following steps: S100, Determine the nozzle data of the nozzle to be tested that participates in ejecting ink droplets into the ink collection cartridge; First, it is necessary to determine the nozzle data of the nozzles to be tested that participate in ejecting ink droplets into the ink collection cartridge. This nozzle data can include the type of nozzles involved in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each nozzle, and the diameter of the ink droplets ejected by each nozzle. This data can be obtained, for example, by manually inputting the printhead model and nozzle configuration information, or by reading the specification table provided by the printhead manufacturer. This data provides the basis for subsequent calculations of the volumetric flow rate of ink droplets entering the ink collection cartridge.

[0025] S200. Calculate the first volume flow rate corresponding to the ink droplet injected into the ink collection box based on the nozzle data. Furthermore, based on the aforementioned nozzle data, the first volumetric flow rate corresponding to the ink droplets injected into the ink collection cartridge is calculated. This calculation can be estimated based on the average droplet volume and ejection frequency for each type of nozzle. For example, a table corresponding to droplet volume and nozzle diameter can be pre-established. Then, the corresponding droplet volume can be found in the table based on the nozzle data, and the total flow rate of ink droplets entering the ink collection cartridge can be obtained by combining the number of nozzles and the ejection frequency.

[0026] S300: Obtain the internal air pressure of the ink collection cartridge and the external ambient air pressure; In step S300, this can be achieved by installing a pressure sensor both inside and outside the ink collection cartridge. The pressure sensors monitor and output the air pressure value at their respective locations in real time, and this air pressure data will be used for subsequent differential pressure calculations and control of the air pump.

[0027] S400. Calculate the second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box based on the area of ​​the opening at the top of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box. This calculation can be simplified based on fluid dynamics principles, for example, by consulting pre-established empirical curves of flow rate versus pressure difference and opening area, or by using a simplified linear model. The preset internal and external pressure difference can be a slight negative pressure to ensure that gas inside the ink cartridge does not escape outwards.

[0028] S500: Determine the outward air extraction flow rate of the pump installed in the ink collection cartridge based at least on the first volumetric flow rate and the second volumetric flow rate. For example, the first volumetric flow rate and the second volumetric flow rate can be simply superimposed to obtain a preliminary air extraction flow rate requirement. This preliminary air extraction flow rate is intended to balance the volume increase caused by ink droplets entering the ink collection cartridge and the gas exchange volume required to maintain a preset pressure difference through the opening.

[0029] S600. The air pump is controlled to adjust the internal air pressure of the ink cartridge according to the determined outward air extraction flow rate. The air pump is a device used to extract gas from inside the ink cartridge and discharge it to the external environment. It controls the internal air pressure of the ink cartridge by adjusting the extraction flow rate. The air pump can be a variable frequency speed control pump, and its extraction flow rate can be adjusted in real time according to the control signal. For example, when the calculated outward air extraction flow rate increases, the speed of the air pump is increased, thereby increasing the extraction flow rate; conversely, when the outward air extraction flow rate decreases, the speed of the air pump is decreased to reduce the extraction flow rate. Thus, the internal air pressure of the ink cartridge is dynamically maintained within the target range, avoiding abnormal pressure fluctuations.

[0030] This method precisely calculates the first volumetric flow rate caused by ink droplets entering the ink collection cartridge and the second volumetric flow rate required to maintain a preset internal and external pressure difference. Based on this, it dynamically controls the outward airflow of the vacuum pump, achieving stable regulation of the internal air pressure of the ink collection cartridge. This effectively avoids interference from the outflowing airflow caused by increased air pressure inside the ink collection cartridge when observing simultaneous spraying from multiple nozzles. This ensures the stability of the ink droplet flight trajectory, significantly improves the accuracy of ink droplet images captured by the high-speed camera and the reliability of the observation data, thereby guaranteeing the accuracy of printhead condition assessment and parameter calibration.

[0031] In some embodiments described above, the method of determining nozzle data to calculate the volume of ink droplets injected into the ink collection cartridge is proposed. In some embodiments, the nozzle data may be obtained through direct external input, or through other methods. This application will further disclose the actual means by which the nozzle data participating in ink ejection above the ink collection cartridge is determined.

[0032] Step S100 includes the following steps: S110. Obtain the relative position information of the printhead to be tested above the ink collection cartridge and the nozzle distribution data of the printhead to be tested; S120. Determine the number of nozzles to be detected based on the relative position information and the nozzle distribution data on the nozzle head to be detected.

[0033] The purpose of obtaining the relative position information of the printhead to be tested above the ink collection cartridge is to clarify the spatial relationship between the printhead and the ink collection cartridge, so as to accurately determine which nozzles are within the receiving range of the ink collection cartridge. This can be achieved, but is not limited to: using a visual positioning system, such as a high-speed camera or a dedicated positioning camera, to capture images of the printhead and ink collection cartridge, and then calculating their relative coordinates using image processing algorithms (such as edge detection and feature matching); or using a mechanical encoder or displacement sensor mounted on a robotic arm or platform that controls the movement of the printhead or ink collection cartridge to obtain its precise X, Y, and Z axis coordinates in real time, thereby calculating the relative position of the printhead above the ink collection cartridge.

[0034] Acquiring the nozzle distribution data on the printhead under test aims to obtain the geometric arrangement and position information of all nozzles on the surface of the printhead under test, providing basic data for subsequent screening of the nozzles that actually participate in inkjet printing. This can be achieved, but is not limited to: directly reading detailed data such as the nozzle array layout, nozzle spacing, and nozzle size from the printhead manufacturer's technical specifications, CAD drawings, or database; or scanning the surface of the printhead under test using a high-resolution optical scanning or microscopic imaging system to generate a precise two-dimensional or three-dimensional distribution map of the nozzles, and extracting the center coordinates of each nozzle from it.

[0035] The determination of the number of nozzles to be detected based on the relative position information and the nozzle distribution data on the printhead to be tested aims to comprehensively utilize the acquired printhead position and nozzle layout information to accurately identify and count the number of nozzles actually located above the ink cartridge opening that can eject ink droplets into the ink cartridge. This can be achieved, but is not limited to: at the software level, projecting the opening area of ​​the ink cartridge onto the coordinate system of the printhead to be tested, then traversing all nozzles on the printhead, determining whether the center point of each nozzle falls within the projected area, thereby counting the number of nozzles that meet the conditions; or establishing a geometric model, inputting the geometric shape and relative position parameters of the printhead to be tested and the ink cartridge into the model, and automatically filtering and counting those nozzles whose ejection paths will enter the ink cartridge through computational geometry algorithms (such as point-within-polygon judgment, region intersection calculation).

[0036] Through the above technical solution, this application can accurately determine the nozzle data of the nozzles to be tested that participate in ejecting ink droplets into the ink collection cartridge. Specifically, by obtaining the relative position information of the printhead to be tested above the ink collection cartridge, the spatial correspondence between the printhead and the ink collection cartridge can be accurately grasped, avoiding the erroneous inclusion of nozzles not above the ink collection cartridge in the calculation range due to printhead offset or angular deviation. At the same time, obtaining the nozzle distribution data on the printhead to be tested provides detailed information on the printhead's own nozzle layout. Based on this, according to the relative position information and nozzle distribution data, the nozzles that are truly located above the ink collection cartridge and participate in ink ejection can be accurately screened through geometric calculations or logical judgments, and their number can be determined. This precise nozzle data acquisition method eliminates the estimation errors or uncertainties caused by fixed parameters that may exist in traditional methods, ensuring the accuracy of the subsequent calculation of the first volume flow rate corresponding to the ink droplets ejected into the ink collection cartridge. Given that the first volumetric flow rate is one of the key inputs for determining the outward air flow rate of the air pump located inside the ink collection cartridge, the implementation of this solution significantly improves the accuracy and stability of the air pressure control inside the ink collection cartridge, thereby effectively avoiding interference caused by air pressure fluctuations to the observation of flying ink droplets, ensuring the reliability of the observation data, and thus improving the accuracy of printhead status assessment and parameter calibration.

[0037] Furthermore, in some implementations, the first volumetric flow rate aims to accurately quantify the total amount of ink droplets entering the ink collection cartridge within a specific observation period, providing crucial and precise input for determining the outward airflow of the subsequent suction pump. This calculation can be achieved in various ways. For example, the ink droplet flow rate can be directly obtained or estimated by looking up a preset ink droplet parameter table and nozzle operating mode; alternatively, the ink droplet volumetric flow rate can be dynamically calculated by real-time monitoring of the nozzle's ejection state combined with ink droplet image analysis technology; or, the calculation can be performed based on calibration data of the ejection frequency and ink droplet volume, combined with the printhead drive signal.

[0038] In this embodiment, the following calculation formula will be used to calculate the first volumetric flow rate corresponding to the ink droplets injected into the ink collection cartridge: Q1=n1⋅f1⋅V1+n2⋅f2⋅V2+…+n x ⋅f x ⋅V x , Among them, V x =πdx 3 / 6.

[0039] In the formula, Q1 is the first volumetric flow rate, and n x f represents the number of nozzles of type x. x Let d be the injection frequency of the x-th nozzle. x Let be the volume of the ink droplet ejected from the x-th nozzle.

[0040] Specifically, the above formula can be automatically calculated in the control system through programming, or it can be rapidly calculated in parallel using various hardware accelerators such as FPGA or ASIC to meet real-time requirements.

[0041] The above technical solution, through a clear mathematical model and precise droplet volume calculation, avoids the inaccurate volumetric flow rate estimation problems that may arise from traditional estimation methods. In particular, by comprehensively considering and summing the number of different types of nozzles, jetting frequency, and droplet volume, it ensures that the total droplet volumetric flow rate entering the ink collection cartridge can be fully and accurately quantified in multi-nozzle parallel operation scenarios. This precise initial volumetric flow rate calculation provides a reliable and crucial input for determining the subsequent outward airflow of the suction pump, thereby enabling more precise control of the air pressure inside the ink collection cartridge. Ultimately, this effectively prevents airflow interference with droplet flight caused by inaccurate air pressure control, ensuring the authenticity of the droplet images captured by the high-speed camera and the reliability of the observation data, thus improving the accuracy of printhead status judgment and parameter calibration.

[0042] Furthermore, in some embodiments, step S400, based on the pre-set area of ​​the opening at the top of the ink collection box and the pre-set pressure difference between the inside and outside of the ink collection box, calculates the second volumetric flow rate required to maintain the pre-set pressure difference between the inside and outside of the ink collection box, using the following calculation formula:

[0043] In the formula, Cv: flow coefficient; Aorifice: Area of ​​the top opening; ρair: air density; ΔP: The set target pressure difference.

[0044] The pre-defined area (Aorifice) of the top opening of the ink collection cartridge refers to the area of ​​the physical channel above the ink collection cartridge used for ink droplet entry and gas exchange. This area is a key geometric parameter affecting the airflow dynamics inside the ink collection cartridge. It can be set in various ways. For example, the geometric dimensions of the top opening of the ink collection cartridge, such as the diameter of a circular opening or the length and width of a rectangular opening, can be accurately measured using CAD design software to calculate the area. Alternatively, physical measuring tools, such as calipers or laser rangefinders, can be used to measure the dimensions of the top opening of the actually manufactured ink collection cartridge and calculate its area based on the measurement results.

[0045] The preset pressure difference ΔP between the inside and outside of the ink collection cartridge refers to the target pressure difference that needs to be maintained between the inside of the ink collection cartridge and the external environment. This pressure difference is set to effectively control the escape of volatiles and avoid interfering with ink droplet flight. This pressure difference can be predetermined through experimental testing or simulation based on the specific requirements of the inkjet observation system and the volatile characteristics of the ink. For example, it can be set in the range of -5 Pa to -20 Pa to ensure effective air extraction and avoid excessive suction on ink droplet flight. Alternatively, it can be set by consulting technical specifications or empirical data based on factors such as printhead type, ink type, and ambient humidity. For example, for highly volatile inks, a larger negative pressure difference may be required.

[0046] The flow coefficient Cv is a dimensionless parameter used to describe the ratio of the actual flow rate to the theoretical flow rate of a fluid passing through an orifice. It reflects the efficiency of fluid flow and is typically 0.6 to 0.8. It is a correction factor for accurately calculating gas flow rate, ensuring that theoretical calculations match actual physical phenomena.

[0047] The air density ρair refers to the mass of air per unit volume, which is affected by factors such as ambient temperature, humidity, and air pressure. It is a fundamental physical parameter in gas flow rate calculation, directly affecting the conversion between mass flow rate and volumetric flow rate. Air density can be dynamically calculated by measuring the temperature, humidity, and air pressure of the external environment of the ink collector in real time, and then applying the ideal gas law or relevant air density calculation formulas; alternatively, it can be preset using the air density at standard atmospheric pressure and temperature under relatively stable observation conditions.

[0048] Through the above technical solution, this application solves the problem of inaccurate pressure difference calculation by introducing a precise calculation formula based on physical parameters, ensuring that the second volumetric flow rate required to maintain the pressure difference inside and outside the ink collection box is scientifically determined. This comprehensive parameter calculation method avoids random errors in empirical estimation and achieves high-precision determination of the second volumetric flow rate Q2. Based on this, combined with the first volumetric flow rate corresponding to the ink droplets injected into the ink collection box, the outward air extraction flow rate of the vacuum pump can be determined more accurately, thereby stabilizing the air pressure inside the ink collection box, effectively preventing gas outflow from interfering with ink droplet flight, and ensuring the accuracy and reliability of the flight ink droplet observation data.

[0049] In some of the solutions described above in this application, during the process of controlling the internal air pressure of the ink collection box by the outward air extraction flow rate calculated by the first volume flow rate and the second volume flow rate, the additional airflow formed when the ejected ink droplets move inside the ink collection box may cause inaccurate calculation of the air extraction flow rate, affecting the stability of the air pressure and the accuracy of ink droplet observation.

[0050] In response, this application further proposes a method for controlling the air pressure of an ink droplet observation and collection cartridge, which includes the following steps before step S500: S410. Calculate the third volumetric flow rate formed when the ejected ink droplets move inside the ink collection box, based on the number of each type of nozzle, the diameter of the ink droplets ejected by each type of nozzle, and the height of the ink collection box. Furthermore, when determining the outward air extraction flow rate of the air pump installed in the ink collection box in step S500, the outward air extraction flow rate of the air pump installed in the ink collection box will be determined based on the sum of the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate.

[0051] Specifically, the third volumetric flow rate aims to quantify the disturbance or driving effect of ink droplets on the surrounding air during their flight within the ink cartridge. When an ink droplet is ejected at high speed into the ink cartridge, it carries away some air, creating an additional airflow. This airflow has a significant impact on the overall air pressure balance within the ink cartridge. Several methods can be used to accurately calculate this effect. For example, a fluid dynamics model can be established, combining physical parameters such as the ink droplet's momentum, surface tension, and air viscosity, as well as the geometry of the ink cartridge and the droplet's flight distance, to accurately estimate the volume of airflow driven by the droplet's motion through numerical simulation or empirical formulas. Another approach is to use a simplified approximation method, treating the ink droplet as a tiny object moving in the air. The effective volume swept by the droplet per unit time or the volume of its wake is used as an approximation of the third volumetric flow rate. This may involve correcting for the product of the droplet's effective cross-sectional area, flight velocity, and ink cartridge height, and introducing an empirical drag coefficient to characterize the efficiency of the droplet's driving effect on the airflow.

[0052] Based on this, this embodiment determines the outward air extraction flow rate of the air pump located inside the ink collection cartridge by summing the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate. This comprehensively considers all factors affecting the internal air pressure of the ink collection cartridge to determine the precise operating flow rate of the air pump. The first volumetric flow rate represents the volume of ink injected into the ink collection cartridge, the second volumetric flow rate represents the air flow rate required to maintain the preset pressure difference inside and outside the ink collection cartridge, and the third volumetric flow rate supplements the additional air movement caused by the ink droplets. By summing these three flow rates, a more comprehensive and accurate total flow rate requirement can be obtained. For example, the air pump control system can directly receive these three flow rate values, perform an arithmetic summation, and use the result as the target air extraction flow rate setting value for the air pump. Alternatively, to cope with the complexity under different operating conditions, a weighted summation method can be used, assigning a weight coefficient to each volumetric flow rate component and then performing a weighted summation to achieve finer flow control.

[0053] Through the above technical solution, this application can more comprehensively consider the airflow changes inside the ink cartridge, including not only the volume of ink injected and the airflow required to maintain the pressure difference, but also accurately quantify the driving effect of ink droplets on the air during flight. This introduction and integration of the third volume flow rate makes the calculation of the outward airflow of the suction pump more accurate, thereby more effectively maintaining the stability of the internal air pressure of the ink cartridge. Stable internal air pressure can significantly reduce or eliminate turbulent airflow caused by air pressure fluctuations, preventing these airflows from adsorbing or disturbing ink droplets in flight, thus ensuring the authenticity of the ink droplet images captured by the high-speed camera and the reliability of the observation data. This is of great significance for accurately assessing the printhead status, calibrating ejection parameters, and improving the debugging and maintenance efficiency of the overall printing system, ultimately improving the accuracy and reliability of in-flight ink droplet observation.

[0054] In some of the embodiments described above in this application, a third volume flow rate is calculated to more comprehensively control the ink collection cartridge air pressure. Specifically, the following calculation formula is used in this embodiment: Q3=n⋅f⋅(Cd⋅4πd2⋅H) Where Cd is the drag coefficient; d is the diameter of the ink droplet ejected by the nozzle; and H is the height of the ink collection cartridge.

[0055] Specifically, the calculation of the third volumetric flow rate, generated by the ejected ink droplets moving within the ink cartridge, refers to the airflow effect created when the ink droplets interact with the surrounding air at high speed within the cartridge. This airflow pulls a portion of the air along with the droplets, forming a downward airflow. The volumetric flow rate of this airflow is the third volumetric flow rate. Accurately calculating this flow rate is crucial for precisely assessing changes in the total airflow within the ink cartridge and is one of the key factors in maintaining stable air pressure inside the cartridge. The above calculation formula, by comprehensively considering the dynamic characteristics of ink droplet ejection, the interaction between the ink droplets and air, and the geometric dimensions of the ink cartridge, achieves an accurate estimation of the third volumetric flow rate.

[0056] Here, n (the number of each type of nozzle) refers to the total number of nozzles that eject ink droplets into the ink collection cartridge within a specific observation period. In multi-nozzle parallel operation scenarios, the simultaneous ejection of ink from multiple nozzles generates a cumulative airflow effect. Accurately obtaining the number of nozzles, such as through the printhead control system or through image recognition technology, is fundamental to ensuring comprehensive calculations. f (the ejection frequency of each type of nozzle) refers to the number of times each nozzle ejects ink droplets per unit time. The higher the ejection frequency, the more ink droplets enter the ink collection cartridge per unit time, and the more significant the resulting airflow effect. This frequency is usually set by the printhead drive parameters and can be obtained directly from the printhead controller. d (the diameter of the ink droplets ejected by the nozzle) refers to the average diameter of a single ink droplet ejected from the nozzle. The size of the droplet diameter directly affects its contact area with air and its drag force. Typically, the droplet diameter can be measured and determined through printhead calibration data or by observing ink droplet images using a high-speed camera. H (the height of the ink collection cartridge) refers to the vertical distance from when the ink droplet is ejected from the nozzle until it falls to the bottom of the ink collection cartridge or is collected. The longer the distance an ink droplet travels inside the ink cartridge, the longer it interacts with the air, and the larger the volume of airflow it can generate. The cartridge height is an inherent physical parameter of the ink cartridge, obtainable through design drawings or actual measurements. Cd (drag coefficient) is a dimensionless parameter used to quantify the efficiency with which an ink droplet generates airflow. It reflects the influence of factors such as droplet shape, surface characteristics, and air viscosity on the airflow drag effect. The Cd value is an empirical constant, typically much less than 1 (e.g., 0.1~0.3), representing the efficiency with which the ink droplet generates airflow; specific values ​​can be obtained through experimental measurements, fluid dynamics simulations, or by consulting relevant literature.

[0057] Through the above technical solution, this application can accurately calculate the third volumetric flow rate formed when ink droplets move inside the ink collection cartridge. This accurate calculation avoids deviations in the overall air extraction flow rate caused by inaccurate estimation of the third volumetric flow rate, thereby ensuring the stability of the air pressure regulation inside the ink collection cartridge. When the outward air extraction flow rate of the air pump can accurately offset the airflow influence brought about by ink droplet ejection, the air pressure fluctuation inside the ink collection cartridge will be significantly reduced, effectively suppressing the interference of the outflowing airflow on the flying ink droplets. This allows the high-speed camera to capture clearer and more realistic ink droplet flight trajectories and states, greatly improving the reliability and accuracy of flying ink droplet observation data, and thus providing a solid foundation for accurate judgment of printhead status and parameter calibration.

[0058] In some embodiments of this application, it is proposed to determine the outward air flow rate of the air pump based at least on the first volume flow rate and the second volume flow rate, so as to more accurately control the internal air pressure of the ink collection cartridge and maintain the preset pressure difference. However, in its implementation, since the actual ink droplet volume ejected from the nozzle has a certain error relative to the theoretical value, the air flow rate calculated according to the theoretical value may not achieve the target effect during execution and cannot adapt to the dynamic changes in air pressure in real time, thereby affecting the observation stability of the ink droplet flight trajectory.

[0059] In response, this application further proposes a method for controlling the air pressure of an ink droplet observation ink collection cartridge, which specifically includes the following steps when performing step S500: First, the first suction flow rate of the pump installed in the ink collection cartridge is determined based on the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate. This first suction flow rate is the initial suction demand calculated based on a combination of factors, including ink droplet ejection, maintaining pressure difference, and the airflow driven by ink droplets. Specifically, the first suction flow rate can be determined in several ways. For example, it can be simply summed by the first, second, and third volumetric flow rates, i.e., the first suction flow rate equals the sum of these three, thus directly incorporating all known flow rate influencing factors. Alternatively, for more precise control, different weighting coefficients can be assigned to these three volumetric flow rates based on practical experience or experimental data, and the first suction flow rate can be determined by a weighted summation to reflect their different importance in influencing the internal air pressure of the ink collection cartridge.

[0060] Secondly, based on the ratio of the actual pressure difference between the internal air pressure and the ambient air pressure of the ink collection cartridge to the preset pressure difference between the inside and outside of the ink collection cartridge, the first suction flow rate is adjusted to determine the outward suction flow rate of the suction pump installed in the ink collection cartridge. By introducing a dynamic feedback mechanism, the suction flow rate is corrected in real time to address potential deviations during actual operation. Specifically, the adjustment method can be to use the ratio of the actual pressure difference to the preset pressure difference as an adjustment coefficient, multiplying this coefficient by the first suction flow rate to obtain the final outward suction flow rate. When the actual pressure difference is higher than the preset pressure difference, the adjustment coefficient will increase the suction flow rate accordingly to accelerate the reduction of internal air pressure; when the actual pressure difference is lower than the preset pressure difference, the suction flow rate will decrease accordingly. Alternatively, a more complex closed-loop control algorithm, such as a PID (Proportional-Integral-Derivative) controller, can be used. The difference between the actual pressure difference and the preset pressure difference is used as the controller input, and the controller outputs an adjustment amount, which is superimposed or multiplied by the first suction flow rate to determine the final outward suction flow rate. This approach allows for more precise handling of dynamic changes, reduces overshoot and oscillations, and improves the robustness of control.

[0061] Through the above technical solution, this application effectively solves the problem that the air extraction flow rate calculated based on the theoretical value cannot achieve the target effect and cannot adapt to dynamic changes in air pressure in real time due to the error between the actual ink droplet volume ejected from the nozzle and the theoretical value. Specifically, a basic first air extraction flow rate is determined by comprehensively considering the first, second, and third volume flow rates, providing a comprehensive initial setting for the operation of the air pump. On this basis, a dynamic adjustment mechanism based on the ratio of the actual pressure difference to the preset pressure difference is introduced, allowing the outward air extraction flow rate of the air pump to be accurately corrected according to the real-time state of the air pressure inside the ink collection box. This dynamic adjustment capability enables the system to quickly respond to and compensate for the deviation between the actual ink droplet ejection volume and the theoretical value, ensuring that the internal and external pressure difference inside the ink collection box remains stable within the preset target range. Thus, it effectively avoids the adsorption or disturbance force on flying ink droplets caused by air pressure fluctuations, ensuring the authenticity of the ink droplet images captured by the high-speed camera and the reliability of the observation data, and greatly improving the accuracy and stability of printhead status judgment and parameter calibration.

[0062] Secondly, embodiments of this application also provide an air pressure control for an ink droplet observation ink collection cartridge.

[0063] In one embodiment, reference is made to Figure 2 , Figure 2 This is a functional module diagram of an embodiment of the air pressure control device for the ink droplet observation and collection cartridge of this application. Figure 2 As shown, the air pressure control device for the ink droplet observation ink collection cartridge includes: The nozzle determination module is configured to determine the nozzle data of the nozzles to be detected that participate in ejecting ink droplets into the ink collection cartridge; wherein the nozzle data includes the type of nozzles participating in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each type of nozzle, and the diameter of the ink droplets ejected by each type of nozzle. The air extraction flow rate calculation module is configured to: calculate the first volumetric flow rate corresponding to the ink droplets injected into the ink collection box based on the nozzle data; obtain the internal air pressure and external ambient air pressure of the ink collection box; calculate the second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box based on the area of ​​the opening at the top of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box; and determine the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first volumetric flow rate and the second volumetric flow rate. An air pressure control module is configured to control the air pump to adjust the air pressure inside the ink collection cartridge based on the outward air flow rate.

[0064] The functions of each module in the air pressure control device of the above-mentioned ink droplet observation ink collection box correspond to the steps in the above-mentioned air pressure control method embodiment of the ink droplet observation ink collection box, and their functions and implementation processes will not be described in detail here.

[0065] Thirdly, embodiments of this application provide a pressure control device for an ink droplet observation ink collection box. The pressure control method, apparatus, equipment, and storage medium for the ink droplet observation ink collection box can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.

[0066] Reference Figure 3 , Figure 3 This is a schematic diagram of the hardware structure of the air pressure control method, apparatus, device, and storage medium for the ink droplet observation ink collection box involved in the embodiments of this application. In the embodiments of this application, the air pressure control method, apparatus, device, and storage medium for the ink droplet observation ink collection box may include a processor, a memory, a communication interface, and a communication bus.

[0067] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0068] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces. These interfaces are used for interconnecting devices within the ink droplet observation ink collector's pressure control method, device, equipment, and storage medium, as well as for interconnecting the ink droplet observation ink collector's pressure control method, device, equipment, and storage medium with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0069] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0070] The processor can be a general-purpose processor, which can call the air pressure control program of the ink droplet observation ink collection cartridge stored in the memory and execute the air pressure control method of the ink droplet observation ink collection cartridge provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the air pressure control program of the ink droplet observation ink collection cartridge is called can refer to the various embodiments of the air pressure control method of the ink droplet observation ink collection cartridge of this application, and will not be repeated here.

[0071] Those skilled in the art will understand that Figure 3 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0072] Fourthly, embodiments of this application also provide a storage medium.

[0073] The storage medium of this application stores a pressure control program for an ink droplet observation ink collection cartridge. When the pressure control program for the ink droplet observation ink collection cartridge is executed by a processor, it implements the steps of the pressure control method for the ink droplet observation ink collection cartridge as described above.

[0074] The method implemented when the air pressure control program of the ink droplet observation ink collection box is executed can be referred to in various embodiments of the air pressure control method of the ink droplet observation ink collection box of this application, and will not be repeated here.

[0075] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0076] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0077] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0078] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0079] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0080] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0081] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for controlling the air pressure of an ink droplet observation ink collection cartridge, characterized in that, The method is performed during the ink ejection process of the printhead under test above the ink collection cartridge, and includes the following steps: Determine the nozzle data of the nozzles to be tested that participate in ejecting ink droplets into the ink collection cartridge; wherein, the nozzle data includes the type of nozzles participating in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each type, and the diameter of the ink droplets ejected by each type. Based on the nozzle data, calculate the first volume flow rate corresponding to the ink droplet injected into the ink collection cartridge; Obtain the internal air pressure of the ink collection cartridge and the external ambient air pressure; Based on the pre-set area of ​​the top opening of the ink collection box and the pre-set pressure difference between the inside and outside of the ink collection box, calculate the second volume flow rate required to maintain the pre-set pressure difference between the inside and outside of the ink collection box. The outward air extraction flow rate of the air pump installed in the ink collection box is determined based at least on the first volume flow rate and the second volume flow rate. The air pump is controlled according to the outward air flow rate to adjust the air pressure inside the ink collection box.

2. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 1, characterized in that, The process of determining the nozzle data of the nozzles to be detected that participate in ejecting ink droplets into the ink collection cartridge includes the following steps: Acquire the relative position information of the printhead to be tested above the ink collection cartridge and the nozzle distribution data of the printhead to be tested; The number of nozzles to be detected is determined based on the relative position information and the nozzle distribution data on the nozzle head to be detected.

3. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 1, characterized in that, The first volumetric flow rate corresponding to the ink droplet injected into the ink collection cartridge is calculated based on the nozzle data using the following formula: Q1=n1f1V1+n2f2V2+…+n x f x V x V x =πd x 3 / 6 In the formula, Q1 is the first volumetric flow rate, and n x f represents the number of nozzles of type x. x Let d be the injection frequency of the x-th nozzle. x Let be the volume of the ink droplet ejected from the x-th nozzle.

4. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 1, characterized in that, The second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box is calculated based on the area of ​​the top opening of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box, using the following calculation formula: In the formula, Cv: flow coefficient; A orifice Area of ​​the top opening; ρ air Air density; ΔP: The set target pressure difference.

5. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 1, characterized in that, Before determining the outward air extraction flow rate of the air pump installed in the ink collection cartridge based at least on the first volumetric flow rate and the second volumetric flow rate, the following steps are included: Calculate the third volumetric flow rate formed when the ejected ink droplets move inside the ink collection box, based on the number of each type of nozzle, the diameter of the ink droplets ejected by each type of nozzle, and the height of the ink collection box. The step of determining the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first volumetric flow rate and the second volumetric flow rate will be based on the sum of the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate.

6. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 5, characterized in that, The third volumetric flow rate, formed by the ejected ink droplets moving inside the ink collection box, is calculated based on the number of each type of nozzle, the diameter of the ink droplets ejected by each nozzle, and the height of the ink collection box. The calculation formula is as follows: Q3=nf(C d 4πd 2 H) In the formula, C d : Drag coefficient, representing the efficiency of the airflow driven by the ink droplet; d: Diameter of the ink droplets ejected from the nozzle; H: Height of the ink collection cartridge.

7. The air pressure control method for the ink droplet observation and collection cartridge as described in claim 5, characterized in that, Determining the outward air extraction flow rate of the air pump installed in the ink collection cartridge based at least on the first volumetric flow rate and the second volumetric flow rate includes the following steps: Based on the first volumetric flow rate, the second volumetric flow rate, and the third volumetric flow rate, determine the first suction flow rate of the suction pump installed in the ink collection cartridge; Based on the actual pressure difference between the internal air pressure and the ambient air pressure of the ink collection box and the preset ratio of the internal and external pressure difference of the ink collection box, the first air extraction flow rate is adjusted to determine the outward air extraction flow rate of the air pump installed in the ink collection box.

8. A pressure control device for an ink droplet observation and collection cartridge, characterized in that, include: The nozzle determination module is configured to determine the nozzle data of the nozzles to be detected that participate in ejecting ink droplets into the ink collection cartridge; wherein the nozzle data includes the type of nozzles participating in ink ejection above the ink collection cartridge, the number of nozzles of each type, the ejection frequency of each type of nozzle, and the diameter of the ink droplets ejected by each type of nozzle. The air extraction flow rate calculation module is configured to: calculate the first volumetric flow rate corresponding to the ink droplets injected into the ink collection box based on the nozzle data; obtain the internal air pressure and external ambient air pressure of the ink collection box; calculate the second volumetric flow rate required to maintain the preset pressure difference between the inside and outside of the ink collection box based on the area of ​​the opening at the top of the ink collection box and the preset pressure difference between the inside and outside of the ink collection box; and determine the outward air extraction flow rate of the air pump installed in the ink collection box based at least on the first volumetric flow rate and the second volumetric flow rate. An air pressure control module is configured to control the air pump to adjust the air pressure inside the ink collection cartridge based on the outward air flow rate.

9. A pressure control device for an ink droplet observation and collection cartridge, characterized in that, The air pressure control device of the ink droplet observation ink collection cartridge includes a processor, a memory, and an air pressure control program for the ink droplet observation ink collection cartridge stored in the memory and executable by the processor, wherein when the air pressure control program for the ink droplet observation ink collection cartridge is executed by the processor, the steps of the air pressure control method for the ink droplet observation ink collection cartridge as described in any one of claims 1-7 are implemented.

10. A storage medium, characterized in that, The storage medium stores a pressure control program for the ink droplet observation collection cartridge, wherein when the processor executes the pressure control program for the ink droplet observation collection cartridge, it implements the steps of the pressure control method for the ink droplet observation collection cartridge as described in claims 1 to 7.

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