Printer ink path pressure adjusting system and method

Abstract

The invention provides a printer ink path pressure adjusting system and method, and belongs to the technical field of printers. The system comprises a plurality of independent pressure regulating units, a common negative pressure source, a plurality of isolating valves and a controller. Each pressure adjusting unit corresponds to one ink path channel and comprises an independent negative pressure cavity, a negative pressure sensor and a switching valve. The public negative pressure source is composed of a public negative pressure cavity, a negative pressure pump and a controlled air inlet device. And the isolating valve is arranged between the independent negative pressure cavity and the public negative pressure cavity. The controller controls the switching valve, the isolating valve, the positive pressure source, the negative pressure pump and the controlled air inlet device according to feedback of the negative pressure sensor, and independent closed-loop adjustment is carried out on the pressure of each ink path channel. Through an independent unit and common source architecture, parallel independent control of pressure of multiple ink paths is realized, the structure is simplified, the cost is reduced, and the stability of pressure regulation and the recovery speed after positive and negative pressure switching are optimized through the controlled air inlet device.

Description

Technical Field

[0001] This invention relates to the field of printer technology, and more particularly to a printer ink path pressure regulation system. Background Technology

[0002] To ensure print quality and printhead lifespan, printer inkjet systems require different air pressures applied to the ink path during different operating phases. For example, during printing or standby, a stable negative pressure is applied to the printhead to prevent ink from dripping and to keep the printhead moist; while when the printhead becomes clogged, positive pressure is applied for flushing.

[0003] In existing technologies, a common pressure regulation solution is to set up independent pressure control pipelines and valve groups for each color channel. Although this method can achieve independent control, each channel requires a complete set of positive and negative pressure control components, resulting in a complex system structure, a large number of components, and high costs.

[0004] Furthermore, existing technologies have shortcomings in pressure regulation. For example, when replenishing air to a negative pressure system to increase pressure (i.e., decrease the negative pressure value), directly connecting the pipeline to the atmosphere can easily lead to pressure overshoot and violent fluctuations due to excessively fast air intake, affecting the accuracy and stability of control. Simultaneously, after positive pressure flushing, residual positive pressure in the pipeline can hinder the system from quickly returning to the negative pressure state required for operation, reducing the printer's continuous operating efficiency and response speed.

[0005] Therefore, existing printer ink path pressure regulation systems generally suffer from drawbacks such as complex structure, unstable pressure regulation, and slow recovery after switching between positive and negative pressure modes. Summary of the Invention

[0006] The main objective of this invention is to provide a printer ink path pressure regulation system and method, which aims to solve the problems of complex structure, unstable pressure regulation, and slow recovery after switching between positive and negative pressure modes in the prior art.

[0007] To achieve the above objectives, the present invention provides a printer ink path pressure regulation system, comprising: multiple independent pressure regulation units, each pressure regulation unit being used for one ink path channel, each pressure regulation unit including: an independent negative pressure chamber; a negative pressure sensor communicating with the independent negative pressure chamber; a switching valve connected to a corresponding printer ink cartridge, a positive pressure source, and the independent negative pressure chamber, and used to selectively connect the ink cartridge to the positive pressure source or the independent negative pressure chamber; and a common negative pressure source, the common negative pressure source including a common negative pressure chamber and a... A negative pressure pump for evacuating the common negative pressure chamber, and a controlled air intake device for selectively introducing atmospheric air into the common negative pressure chamber; a plurality of isolation valves, each of the isolation valves being disposed between a corresponding independent negative pressure chamber and the common negative pressure chamber, for selectively connecting or isolating the two; and a controller electrically connected to the negative pressure sensor, the switching valve, the isolation valve, the positive pressure source, the negative pressure pump, and the controlled air intake device, for independently closed-loop regulating the pressure of each ink path channel based on feedback from the negative pressure sensor.

[0008] Optionally, in the above technical solution, the pressure regulating unit includes a negative pressure chamber and a negative pressure cover covering the negative pressure chamber; a plurality of independent negative pressure chambers are formed on the negative pressure chamber and sealed by the negative pressure cover; a common negative pressure chamber is formed in the negative pressure cover and its path extends above each of the independent negative pressure chambers, such that the isolation valve is installed between the common negative pressure chamber and the corresponding independent negative pressure chamber; the switching valve, the isolation valve, and the controlled air intake device are all installed on the negative pressure cover; a tee connector is connected to the pipeline between each negative pressure sensor and the corresponding switching valve, the tee connector is installed on the outer surface of the negative pressure cover and communicates with the corresponding independent negative pressure chamber; the positive pressure source and the negative pressure pump are installed at one end of the negative pressure chamber, and the positive pressure sensor and the negative pressure sensor are installed at the other end of the negative pressure chamber.

[0009] Optionally, in the above technical solution, the controlled air intake device includes an air intake solenoid valve and an air intake throttle valve connected in series with the air intake solenoid valve. The air intake solenoid valve is used to selectively guide atmospheric air to the common negative pressure chamber, and the air intake throttle valve is used to limit the air intake flow rate when it is opened.

[0010] Optionally, in the above technical solution, the system further includes an exhaust valve, which is installed on the pipeline connecting the switching valve and the positive pressure source, and is used to connect the pipeline to the atmosphere after the positive pressure flushing is completed, so as to release the residual positive pressure in the pipeline.

[0011] Furthermore, in a scheme including the exhaust valve, the controller is also configured to control the exhaust valve to connect the pipeline to the atmosphere after the positive pressure flushing mode has ended.

[0012] Optionally, in the above technical solution, the switching valve is a three-way solenoid valve.

[0013] Optionally, in the above technical solution, the isolation valve is a two-way solenoid valve.

[0014] Optionally, in the above technical solution, as an alternative implementation, the switching valve includes: a first two-way solenoid valve connected in series between the independent negative pressure chamber and the ink cartridge; and a second two-way solenoid valve connected in series between the positive pressure source and the ink cartridge.

[0015] Alternatively, in the above technical solution, as an alternative implementation, the positive pressure source and the negative pressure pump are implemented by a single reversible air pump.

[0016] This invention also provides a printer ink path pressure adjustment method, which is executed using any of the aforementioned systems and includes the following steps: In negative pressure maintenance mode, controlling the switching valve to connect the ink cartridge to the corresponding independent negative pressure chamber; monitoring the pressure in the independent negative pressure chamber through the negative pressure sensor; when the monitored pressure value deviates from a preset negative pressure range, controlling the isolation valve corresponding to the channel to open, so as to connect the independent negative pressure chamber to a common negative pressure chamber; and: when the monitored pressure value is higher than the preset negative pressure range, controlling the negative pressure pump to evacuate air from the common negative pressure chamber; when the monitored pressure value is lower than the preset negative pressure range, controlling the controlled air intake device to introduce atmospheric air into the common negative pressure chamber, so as to adjust the pressure in the independent negative pressure chamber to the preset negative pressure range; in positive pressure flushing mode, controlling the switching valve of the target channel to connect the ink cartridge to a positive pressure source, so as to apply positive pressure to the ink cartridge.

[0017] Optionally, in the above method, the step of controlling the controlled air intake device to introduce air into the common negative pressure chamber includes: limiting the flow rate of the air introduced into the common negative pressure chamber by means of an air intake throttle valve.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. Independent and Precise Control, Integrated Structure: By setting up an independent pressure regulation unit (including an independent negative pressure chamber and negative pressure sensor) for each ink path channel, and enabling these units to share a common negative pressure source, selective interconnection is achieved through isolation valves. This architecture realizes parallel and independent closed-loop control of the pressure of multiple ink paths. Pressure regulation in one channel does not affect other channels, ensuring the accuracy and stability of the negative pressure. Furthermore, compared to solutions that require setting up a complete independent air path for each channel, this invention significantly simplifies the system structure, reduces the number of components, and lowers costs.

[0019] 2. Smooth pressure regulation and avoidance of overshoot: By setting an intake throttle valve in the controlled intake device, when it is necessary to replenish air to the common negative pressure chamber to increase the pressure, the intake rate can be effectively limited, so as to achieve smooth and gradual pressure regulation, thereby avoiding pressure overshoot and oscillation caused by airflow impact, and improving the accuracy and stability of negative pressure control.

[0020] 3. Fully functional and quick recovery: By adding an exhaust valve, which is controlled by the controller to open after the positive pressure flushing is completed, the residual positive pressure in the pipeline can be released quickly, allowing the system to quickly return to atmospheric pressure. This greatly shortens the preparation time for the system to switch from positive pressure flushing mode back to negative pressure working mode, and improves the printer's continuous working capability and overall efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a first-view perspective perspective view of the printer ink path pressure adjustment system of the present invention.

[0023] Figure 2 This is a second-view perspective perspective view of the printer ink path pressure adjustment system of the present invention.

[0024] Figure 3 This is a top view of the printer ink path pressure adjustment system of the present invention.

[0025] Figure 4 This is an exploded view of the printer ink path pressure regulation system of the present invention.

[0026] Figure 5 This is a top view of the negative pressure cover of the printer ink path pressure adjustment system of the present invention.

[0027] Figure 6 This is a top view of the negative pressure chamber and negative pressure cover of the printer ink path pressure regulating system of the present invention.

[0028] Figure 7 This is a schematic flowchart of a pressure regulation method according to an embodiment of the present invention.

[0029] Figure 8 This is a control block diagram of a pressure regulation system according to an embodiment of the present invention.

[0030] In the diagram: 10, positive pressure pump; 20, negative pressure pump; 30, common negative pressure chamber; 40, independent negative pressure chamber; 41, negative pressure chamber; 42, negative pressure cover; 43, three-way connector; 50, three-way solenoid valve; 60, two-way solenoid valve; 70, intake throttle valve; 80, intake solenoid valve; 90, ink cartridge interface; 91, exhaust valve; 100, circuit board; 110, positive pressure sensor; 120, negative pressure sensor. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be considered as limitations on the invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Unless otherwise defined, all technical and scientific terms used in the embodiments of this invention have the same meaning as commonly understood by those skilled in the art. The terminology used in the embodiments of this invention is for the purpose of describing the embodiments of this invention only and is not intended to limit the invention. Before further detailed description of the embodiments of this invention, some nouns and terms involved in the embodiments of this invention are explained, and the nouns and terms involved in the embodiments of this invention are subject to the following interpretations.

[0032] (1) Switching valve: refers to a valve device that is connected to a corresponding printer cartridge, a positive pressure source, and an independent negative pressure chamber, and is used to selectively connect the cartridge to the positive pressure source or the independent negative pressure chamber. In a specific embodiment of the present invention, the switching valve can be a three-way solenoid valve, or a valve group consisting of a first two-way solenoid valve and a second two-way solenoid valve.

[0033] (2) Isolation valve: refers to a valve installed between a corresponding independent negative pressure chamber and a common negative pressure chamber, used to selectively connect or isolate the two. In a specific embodiment of the present invention, the isolation valve is preferably a two-way solenoid valve to facilitate precise electrical control by the controller.

[0034] (3) Controlled air intake device: refers to a device for selectively introducing atmospheric air into a common negative pressure chamber to increase the pressure inside the chamber (i.e., reduce the negative pressure value). In a preferred embodiment, the device includes an intake solenoid valve and an intake throttle valve for limiting the intake airflow rate to achieve smooth pressure regulation.

[0035] (4) Preset negative pressure range: This refers to the ideal negative pressure range that should be maintained in the ink path channel to ensure that the printhead does not leak ink or dry out when the printer is printing or in standby mode. This range is the target reference for the controller to perform closed-loop adjustment. For example, it can be set to -1.2kPa to -0.8kPa.

[0036] The following will refer to the appendix. Figure 1 To be continued Figure 4 This invention provides a detailed description of a printer ink path pressure regulation system and method according to embodiments of the present invention. This system aims to solve problems existing in prior art ink path pressure regulation systems, such as complex structure, unstable pressure regulation, and slow recovery after switching between positive and negative pressure modes.

[0037] like Figure 1 and Figure 4 As shown, this embodiment of the invention provides a printer ink path pressure regulation system. The system includes multiple independent pressure regulation units, a common negative pressure source shared by all pressure regulation units, multiple isolation valves, and a controller serving as the system control center. The system is designed to independently control the pressure of multiple ink path channels in the printer (e.g., ink paths corresponding to the four colors C, M, Y, and K).

[0038] Specifically, each ink path channel is equipped with an independent pressure regulating unit. Each pressure regulating unit includes an independent negative pressure chamber 40, a negative pressure sensor 120 communicating with the independent negative pressure chamber 40, and a switching valve (e.g., a three-way solenoid valve 50). One end of the switching valve is connected to the corresponding printer cartridge interface 90, and the other two ends are connected to a positive pressure source and an independent negative pressure chamber 40, respectively. The function of the switching valve is, under the command of the controller, to selectively connect the ink cartridge's air path to the positive pressure source for flushing, or to the independent negative pressure chamber 40 to maintain the negative pressure required for printing.

[0039] The common negative pressure source in the system, serving as a shared negative pressure generation and buffering mechanism for all independent pressure regulating units, includes a common negative pressure chamber 30, a negative pressure pump 20 for evacuating air from the common negative pressure chamber 30, and a controlled air intake device. The negative pressure pump 20 is responsible for generating the basic negative pressure of the entire system, while the controlled air intake device (e.g., an intake throttle valve 70 in conjunction with an intake solenoid valve 80) is used to introduce outside air into the common negative pressure chamber 30 when it is necessary to increase the pressure (i.e., reduce the absolute value of the negative pressure).

[0040] An isolation valve (e.g., a two-way solenoid valve 60) is installed between each independent negative pressure chamber 40 and the common negative pressure chamber 30. The function of this isolation valve is to selectively connect or disconnect the corresponding independent negative pressure chamber 40 from the common negative pressure chamber 30 according to the controller's instructions. When a channel needs negative pressure adjustment, its corresponding isolation valve opens, connecting the independent negative pressure chamber 40 of that channel to the common negative pressure source; when pressure adjustment is complete or no adjustment is needed, the isolation valve closes, isolating the negative pressure environment of that channel from the common negative pressure source and other channels, thereby ensuring the independence and stability of the pressure in each channel.

[0041] like Figure 8 As shown, the controller is the core of the entire system; it can be a microcontroller (MCU), a programmable logic controller (PLC), or a control circuit based on other processors. The controller's input terminals are connected to the negative pressure sensors 120 in each pressure regulating unit (in... Figure 8 The controller is electrically connected to a negative pressure sensor group and a positive pressure sensor 110 for monitoring the positive pressure source pressure, in order to acquire pressure feedback signals and positive pressure flushing pressure signals for each ink path in real time. The output of the controller is electrically connected to each actuator in the system, including the positive pressure source (e.g., positive pressure pump 10), the negative pressure pump 20, multiple switching valves (collected as a switching valve group), multiple isolation valves (collected as an isolation valve group), and the controlled air intake device. Through this connection, the controller can perform independent closed-loop regulation of the pressure of each ink path based on the real-time pressure data fed back by the sensors.

[0042] In a preferred implementation, such as Figures 4 to 6 As shown, the pressure regulating unit includes a negative pressure chamber 41 and a negative pressure cover 42. Four independent negative pressure chambers 40 are formed on the negative pressure chamber 41. The negative pressure cover 42 covers the chamber 41 to seal the four independent negative pressure chambers 40. A common negative pressure chamber 30 is formed inside the negative pressure cover 42. The path of the common negative pressure chamber 30 extends above each independent negative pressure chamber 40 to install an isolation valve between the common negative pressure chamber 30 and the independent negative pressure chambers 40. A switching valve, an isolation valve, and a controlled air intake device are all installed on the negative pressure cover 42. A tee connector 43 is connected to the pipeline connecting each set of negative pressure sensors 120 and the switching valve. The tee connector 43 is installed on the outer surface of the negative pressure cover 42 and communicates with the corresponding independent negative pressure chamber 40. A positive pressure source and a negative pressure pump 20 are installed at one end of the negative pressure chamber 41, and a positive pressure sensor 110 and a negative pressure sensor 120 are installed at the other end of the chamber 41.

[0043] The pressure regulating unit employing the above-described structural design offers the following advantages in terms of integration, reliability, and ease of manufacturing: I. Highly Integrated Structure and Compact Layout: By integrating four independent negative pressure chambers 40 onto the negative pressure housing 41 and forming the common negative pressure chamber 30 within the negative pressure cover 42, a modular design for the negative pressure chambers is achieved. The path of the common negative pressure chamber 30 extends above each independent negative pressure chamber 40, allowing the isolation valve to be directly installed between them, resulting in a short and compact air path. The switching valve, isolation valve, and controlled air intake device are all integrated and installed on the negative pressure cover 42, further reducing the connection of external pipelines, lowering the risk of leakage, and improving the system's integration and reliability.

[0044] II. Optimized Sensor Layout and Precise Signal Acquisition: The T-connector 43, which connects to the negative pressure sensor 120, is installed on the outer surface of the negative pressure cover 42 and communicates with the corresponding independent negative pressure chamber 40. This ensures a direct air path connection between the sensor and the chamber, improving the real-time performance and accuracy of pressure detection, and also facilitates sensor installation and maintenance. The positive pressure sensor 110 and the negative pressure sensor 120 are centrally located at the other end of the negative pressure housing 41, separated from the positive pressure source and negative pressure pump 20. This achieves physical isolation between electrical components and air path actuators, reducing the impact of electrical faults on the air path system, avoiding interference from pump vibration on sensor signals, improving the stability and anti-interference capability of the control system, and also facilitating wiring and centralized calibration and maintenance of sensors, enhancing the overall safety and maintainability of the system.

[0045] III. Modular Design Facilitates Expansion and Maintenance: The positive pressure source and negative pressure pump 20 are centrally installed at one end of the negative pressure housing 41, while the sensor group is centrally located at the other end, forming a clear "front pump, rear sensor" layout structure, which facilitates air circuit zoning management and fault diagnosis. Each pressure regulating unit is independently grouped, with a high degree of modularity, allowing for flexible expansion based on the number of channels, adapting to the development needs of different printer models, and reducing development cycle and manufacturing costs.

[0046] This invention also provides a method for adjusting the ink path pressure of a printer. This method is executed by the aforementioned system, and its workflow can be referred to [reference needed]. Figure 7 As shown. This method mainly includes two working states: negative pressure maintenance mode and positive pressure flushing mode.

[0047] In negative pressure maintenance mode, such as when the printer is in standby or during normal printing, the controller controls the switching valves of all channels to connect the respective ink cartridge interfaces 90 to the corresponding independent negative pressure chambers 40. The controller continuously monitors the pressure value within each independent negative pressure chamber 40 via the negative pressure sensor 120.

[0048] During monitoring, the controller compares the real-time pressure values ​​with a preset negative pressure range. If the pressure value of a channel is within the preset negative pressure range, it indicates that the pressure of that channel is normal, and the controller continues monitoring. If the monitored pressure value deviates from the preset negative pressure range, the controller will initiate a pressure adjustment procedure for that channel.

[0049] During adjustment, the controller first opens the isolation valve corresponding to the channel, connecting the independent negative pressure chamber 40 of that channel to the common negative pressure chamber 30. If the monitored pressure value is higher than the preset negative pressure range (i.e., insufficient negative pressure), the controller starts the negative pressure pump 20 to evacuate the common negative pressure chamber 30, thereby indirectly reducing the pressure in the independent negative pressure chamber 40 until it falls back to the preset negative pressure range. If the monitored pressure value is lower than the preset negative pressure range (i.e., excessive negative pressure), the controller starts the controlled air intake device to introduce an appropriate amount of atmospheric air into the common negative pressure chamber 30, thereby indirectly increasing the pressure in the independent negative pressure chamber 40 until it rises back to the preset negative pressure range. After adjustment, the controller closes the isolation valve of that channel, allowing the channel to re-enter an independent and stable negative pressure maintenance state.

[0050] When the isolation valve of a certain channel is opened, the independent negative pressure chamber 40 of that channel forms a communicating air chamber with the common negative pressure chamber 30. Since the volume of the common negative pressure chamber 30 is much smaller than the sum of the volumes of all the independent negative pressure chambers 40 (for example, the volume of the common negative pressure chamber does not exceed 1.5 times the volume of a single independent negative pressure chamber), and the inner diameter of the connecting pipe is large enough (for example, ≥2mm), the pressure change in the common negative pressure chamber 30 can be synchronized to the independent negative pressure chamber 40 within 100ms, thereby achieving rapid and accurate pressure regulation. The controller ensures that at any given time, only one channel's isolation valve is in the open state to avoid pressure coupling between multiple channels.

[0051] When the printer needs to flush a clogged printhead, the system switches to positive pressure flushing mode. For example, when the controller receives a positive pressure flushing command for a target channel, it controls the switching valve of that target channel to disconnect the corresponding ink cartridge interface 90 from the independent negative pressure chamber 40 and connect it to the positive pressure source. At the same time, the controller activates the positive pressure source (e.g., positive pressure pump 10) to apply positive pressure to the ink path channel to dislodge the blockage.

[0052] By combining the above structure and method, this embodiment of the invention utilizes an "independent unit + common source" architecture to achieve parallel and independent closed-loop control of pressure on multiple ink paths, avoiding mutual interference between channels, simplifying the system structure, and reducing hardware costs. Compared to a solution that configures a complete set of positive and negative pressure control components for each channel, this solution has higher integration and more flexible control.

[0053] In a preferred embodiment, to achieve smoother pressure regulation and avoid pressure overshoot during the gas replenishment and pressurization process, such as... Figure 1 and Figure 3 As shown, the controlled air intake device may include an intake throttle valve 70 and an intake solenoid valve 80. The intake solenoid valve 80 and the intake throttle valve 70 are connected in series in a pipeline that introduces atmospheric air into the common negative pressure chamber 30.

[0054] The controlled air intake device consists of an intake solenoid valve 80 and an intake throttle valve 70 connected in series. The controller selectively introduces air by controlling the opening and closing state of the intake solenoid valve 80, while the intake throttle valve 70 always limits the maximum intake flow rate to ensure a steady increase in pressure.

[0055] In this implementation, when executing Figure 7 During the replenishment and pressurization process, the controller opens the intake valve. The atmosphere does not flow directly into the common negative pressure chamber 30, but must first pass through the intake throttle valve 70. The throttling effect of the intake throttle valve 70 limits the intake flow rate per unit time, so that the pressure in the common negative pressure chamber 30 and the independent negative pressure chamber 40 connected to it rises slowly and gradually, rather than abruptly.

[0056] The technical effect of the above settings is that by limiting the airflow velocity, pressure overshoot and oscillation caused by airflow impact are effectively suppressed. This makes the negative pressure adjustment process more delicate and controllable, and ultimately enables the pressure to be stabilized more precisely within the boundaries of the preset negative pressure range. This improves the accuracy and stability of the entire system's negative pressure control, which is particularly important for ensuring high-quality printing.

[0057] Furthermore, to address the issue of slow system recovery after positive pressure flushing, in another preferred embodiment of the present invention, such as... Figure 1 and Figure 3 As shown, it also includes an exhaust valve 91. The exhaust valve 91 is located on the pipeline connecting the switching valve and the positive pressure pump 10. One end of the exhaust valve 91 is connected to the pipeline, and the other end is open to the atmosphere.

[0058] Accordingly, the controller's functionality has been expanded. After completing the positive pressure flushing process and before switching back to the negative pressure maintenance mode, the controller performs a rapid venting process. In this process, the controller controls the vent valve 91 to open, directly and quickly releasing the high-pressure gas remaining in the flushing pipeline into the atmosphere.

[0059] The significant improvement in this technology is a substantial reduction in system recovery time. In designs without the vent valve 91, residual positive pressure needs to be slowly removed by the negative pressure pump through minor leaks within the system itself or after switching back to the negative pressure side, a process that is time-consuming. However, by actively and rapidly venting, the pipeline pressure can be restored to atmospheric pressure in a very short time (e.g., within 1 second), creating conditions for the system to quickly rebuild a stable working negative pressure, thereby greatly improving the printer's continuous operating capability and overall operational efficiency.

[0060] In a specific hardware implementation, the switching valve can preferably be a three-way solenoid valve 50. For example... Figure 1 As shown, the three-way solenoid valve 50 has one common port and two selectively energized ports. Its common port is connected to the ink cartridge interface 90, one selective port is connected to a positive pressure source (such as a positive pressure pump 10), and the other selective port is connected to a corresponding independent negative pressure chamber 40. By switching the electronic control state of a single three-way solenoid valve 50, the connection between the ink path and the positive and negative pressure air sources can be switched.

[0061] The advantage of using a three-way solenoid valve 50 as a switching valve lies in its highly integrated structure. Compared to using two separate valve combinations, a single three-way solenoid valve 50 not only occupies less physical space, but also simplifies the pneumatic connection and electrical control circuitry, reducing system complexity and potential failure points, thereby improving system reliability and compactness.

[0062] Optionally, to achieve precise automated control of each channel, the isolation valve can preferably be a two-way solenoid valve 60. For example... Figure 1 As shown, each independent negative pressure chamber 40 is connected to the common negative pressure chamber 30 via a two-way solenoid valve 60. This valve can be rapidly opened and closed by an electrical signal applied by a controller.

[0063] The use of a two-way solenoid valve 60 as an isolation valve is key to achieving the independent closed-loop control described in this invention. Its rapid response characteristics enable the controller to promptly connect or disconnect a channel from the common negative pressure source based on rapidly changing pressure feedback, allowing for precise pressure regulation. This is essential for achieving high-precision, high-stability pressure control.

[0064] In an alternative implementation, the function of the switching valve can also be achieved by a valve assembly instead of a single three-way solenoid valve. Specifically, the valve assembly may include a first two-way solenoid valve connected in series between the independent negative pressure chamber 40 and the cartridge interface 90, and a second two-way solenoid valve connected in series between the positive pressure source and the cartridge interface 90.

[0065] In this configuration, the controller achieves mode switching by complementary opening and closing of the two two-way solenoid valves. In negative pressure maintenance mode, the controller opens the first two-way solenoid valve and closes the second two-way solenoid valve, thereby connecting the ink cartridge to the independent negative pressure chamber 40. In positive pressure flushing mode, the controller closes the first two-way solenoid valve and opens the second two-way solenoid valve, thereby connecting the ink cartridge to the positive pressure source.

[0066] The technical advantage of this implementation is that it provides an alternative solution equivalent to the function of a three-way solenoid valve. This indicates that the core switching function of the present invention is not limited to a specific valve type; any structure capable of selectively connecting the ink path between the positive pressure source and the negative pressure chamber falls within the scope of the present invention, thus providing a broader basis for its implementation.

[0067] In an alternative implementation, the pressure source in the system can also be integrated. Specifically, the positive pressure source (such as positive pressure pump 10) and the negative pressure pump 20 can be implemented by a single reversible air pump. A reversible air pump is a pump that can switch its intake and exhaust port functions by changing the direction of the motor.

[0068] When a reversible air pump is used, the controller controls the pump's rotation direction based on the desired operating mode (negative pressure regulation or positive pressure flushing). When negative pressure is needed, the controller rotates the pump forward, connecting its intake port to the common negative pressure chamber 30 for evacuation. When positive pressure is needed, the controller reverses the pump, turning the original intake port into an exhaust port, connecting it to the positive pressure line supplying the switching valve to provide the necessary positive pressure for flushing. This solution may require an additional reversing valve to ensure proper airflow guidance.

[0069] The implementation using a single reversible air pump offers the technical advantage of further optimizing the system's hardware layout. By replacing two pumps with one, the entire pressure regulation system can be made more compact, potentially reducing hardware costs to some extent. This also demonstrates that the core control architecture of this invention can be flexibly adapted to different types of pressure sources.

[0070] The following describes a specific embodiment based on real product parameters. For example, this embodiment can be applied to an industrial-grade high-speed textile printer equipped with four color channels: C, M, Y, and K.

[0071] In this product, the controller uses an ARM Cortex-M4 core microcontroller with a high clock speed, providing powerful data processing and real-time control capabilities. The entire control program and parameters are stored in the microcontroller's built-in flash memory.

[0072] In the sensing section, each independent negative pressure chamber 40 is equipped with a differential pressure sensor as a negative pressure sensor 120, with a measurement range of -2kPa to +2kPa. It has high accuracy and fast response, and can meet the requirements for accurate monitoring of the preset negative pressure range (-1.2kPa to -0.8kPa). The positive pressure sensor 110 used to monitor the positive pressure flushing pressure is a model with a range of 0 to 10kPa to accommodate a flushing pressure setting of approximately 5kPa.

[0073] In the actuator section, the system uses four miniature three-way solenoid valves as three-way solenoid valves 50 for the switching valve, and four miniature two-way solenoid valves as two-way solenoid valves 60 for the isolation valve. These valves are small in size, have low power consumption, and have a response time in the millisecond range. The exhaust valve 91 also uses the same type of two-way solenoid valve.

[0074] For the pressure source, the negative pressure pump 20 is a small-sized diaphragm pump, which features long life, low noise, and stable pumping performance to help maintain stable negative pressure. The positive pressure pump 10 is a slightly larger model from the same series. The intake throttle valve 70 on the intake pipeline is an adjustable precision needle valve, which is precisely calibrated at the factory to obtain the optimal replenishment pressure rise curve.

[0075] All electrical connections for the sensors and valves are centralized on a custom circuit board 100, which also houses the controller and its peripheral circuitry. The sensors communicate with the controller via I2C or SPI bus, while the valves and pumps are controlled by the controller's GPIO pins through MOSFET drive circuitry.

[0076] In actual operation, printers equipped with this system have verified the feasibility of the present invention. The negative pressure of each color channel can be stably maintained within the range of -1.0 kPa ± 0.2 kPa over a long period of time. Even when one channel undergoes frequent pressure adjustments or positive pressure rinsing, the pressure of other channels remains almost unaffected. Compared with solutions lacking rapid venting capabilities, the system's recovery efficiency is significantly improved; for example, recovery time can be reduced by approximately 60% or more.

[0077] To more clearly demonstrate the best practice of this invention, the following describes an embodiment with the most specific scope of protection that integrates the above-described preferred technical features. The structure of this embodiment is as follows: Figure 1 and Figure 2 As shown, its control logic and workflow are as follows: Figure 7 and Figure 8 As shown.

[0078] The system in this embodiment is a four-channel (C, M, Y, K) pressure regulation system. Each channel is equipped with an independent pressure regulation unit, the core switching component of which is a three-way solenoid valve 50, used to switch between connection to the positive pressure pump 10 and connection to the independent negative pressure chamber 40. Each independent negative pressure chamber 40 is connected to a common negative pressure chamber 30 via a two-way solenoid valve 60. A high-precision negative pressure sensor 120 is installed in each independent negative pressure chamber 40.

[0079] The system's common negative pressure source section includes a controlled air intake device comprising an intake solenoid valve controlled by a controller and an intake throttle valve 70 for smoothing pressure. Furthermore, a controller-controlled exhaust valve 91 is connected in parallel to the main pipeline connecting all three-way solenoid valves 50 to their positive pressure input terminals for rapid pressure relief after flushing.

[0080] As the core of the system, the controller integrates closed-loop control functions for all the aforementioned components. It not only executes basic negative pressure maintenance and positive pressure flushing logic, but is also specifically configured to actively open the exhaust valve 91 after positive pressure flushing to achieve rapid recovery.

[0081] The following example, using a complete work cycle, illustrates the working process of this highly integrated embodiment: Step 1: System Initialization and Standby. After the printer is powered on, the controller starts. All three-way solenoid valves 50 are in the state of connecting the ink cartridge interface 90 to the independent negative pressure chamber 40. The controller checks the pressure of each of the four channels (C channel, M channel, Y channel, K channel). By alternately controlling the negative pressure pump 20 and the controlled air intake device with the air intake throttle valve 70, and coordinating the opening and closing of the corresponding two-way solenoid valves 60, the pressure of all four channels is precisely adjusted and stabilized near the center value of -1.0 kPa.

[0082] Step 2: Dynamic Independent Adjustment. During prolonged standby or printing, assume the negative pressure of the M channel rises to -0.7 kPa (above the upper limit of -0.8 kPa) due to ambient temperature changes. The controller's monitoring program detects this deviation. It immediately opens the isolation valve of the M channel (two-way solenoid valve 60) and starts the negative pressure pump 20. The pressure in the common negative pressure chamber 30 and the independent negative pressure chamber 40 of the M channel begins to decrease. When the reading of the negative pressure sensor 120 reaches -1.0 kPa, the controller closes the two-way solenoid valve 60 and stops the negative pressure pump 20. During this period, the isolation valves of the C, Y, and K channels remain closed, and their internal pressures remain stable, unaffected by the adjustment process of the M channel.

[0083] Step 3: Positive Pressure Flushing and Rapid Recovery. The printer detects a blockage in the Y-channel printhead, and the user issues a flushing command. The controller immediately changes the state of the Y-channel three-way solenoid valve 50, connecting the Y-cartridge interface 90 to the positive pressure pump 10. The positive pressure pump 10 then starts, applying 5 kPa of positive pressure to the Y-channel for flushing. After a preset 3 seconds of flushing, the controller stops the positive pressure pump 10. Crucially, simultaneously with stopping the positive pressure pump, the controller immediately opens the exhaust valve 91, instantly releasing the remaining 5 kPa of positive pressure in the pipeline to the atmosphere. Once the pressure approaches atmospheric pressure, the three-way solenoid valve 50 is switched back to the negative pressure connection state. Subsequently, the system can perform negative pressure reconstruction on the Y-channel; the entire process is short and the switching is smooth.

[0084] This embodiment achieves excellent overall technical results by synergistically combining an independent closed-loop control architecture, integrated switching of a three-way solenoid valve, precise isolation of a two-way solenoid valve, smooth adjustment of the intake throttle valve, and rapid recovery function of the exhaust valve.

[0085] First, compared to the aforementioned basic solution, the system's pressure control accuracy and stability are significantly improved. The introduction of the intake throttle valve 70 reduces the pressure overshoot during the air replenishment process from potentially exceeding 20% ​​to less than 2%, ensuring that the pressure is always within a preset range that is beneficial for protecting the printhead and stabilizing inkjet printing.

[0086] Secondly, the system's operating efficiency has been significantly improved. The addition of the exhaust valve 91 and its control logic reduces the system recovery time after positive pressure flushing from more than 30 seconds to less than 5 seconds, reducing the waiting time for printing tasks and helping to improve production efficiency in industrial applications.

[0087] Furthermore, the synergistic effect of various technical features produces unexpected technical results. For example, the compact structure of the three-way solenoid valve 50 combined with the rapid response of the two-way solenoid valve 60 makes the switching between positive and negative pressure modes both reliable and rapid. All of this is coordinated by a central controller, achieving a high degree of automation and intelligent pressure management.

[0088] In summary, the solution presented in this embodiment, through the organic combination of various preferred technical features, not only helps to solve the related problems mentioned in the background art, but also achieves performance improvement in multiple dimensions such as control accuracy, operating efficiency, system stability and structural integration, and is a preferred embodiment of the present invention.

[0089] The printer ink path pressure regulation system and method provided by this invention are applicable to a variety of inkjet printing devices that require precise pressure control. They are primarily suitable for various inkjet printing devices with stringent requirements for print quality and stability.

[0090] A typical application scenario is large-format advertising inkjet printers or industrial label printers. These devices typically require long-term continuous operation and use multiple colors of ink. The multi-channel independent control capability of this invention ensures that the ink supply pressure of each color channel remains highly stable during the printing of large images or a large number of labels, thereby guaranteeing color accuracy and consistency and avoiding color differences or printing defects caused by pressure fluctuations. Simultaneously, its efficient positive pressure flushing and rapid recovery function can quickly resolve printhead blockages, helping to reduce downtime and ensure production efficiency.

[0091] Another important application area is digital textile printing machines. Textile printing demands high precision in ink droplet control; even minute pressure changes can lead to blurred patterns or uneven color penetration. The high-precision, high-stability closed-loop pressure control provided by this invention offers a stable and reliable ink supply foundation for textile printing. Furthermore, textile printing inks are prone to drying, making positive pressure rinsing a necessary part of routine maintenance. The rapid recovery feature of this invention significantly improves equipment maintainability and uptime.

[0092] Furthermore, the ideas of this invention can be extended to other fields requiring precise pressure control of multiple fluid streams. For example, in the field of 3D printing, some devices employing material jetting technology require precise control of the jetting of various build and support materials. The system architecture of this invention can be used as a reference for independent pressure management of the supply lines for these materials.

[0093] In the biomedical field, high-precision multi-channel liquid dispensing systems are commonly used for drug screening or gene sequencing. These systems also face the challenges of preventing liquid leakage (requiring negative pressure) and clearing tubing blockages (requiring positive pressure). The independent closed-loop control and rapid mode switching architecture of this invention provides a reliable and efficient solution for such applications.

[0094] The system of this invention is scalable. Although the embodiment uses a four-channel (C, M, Y, K) system as an example, its modular design can be extended to six-channel (adding light cyan Lc and light magenta Lm), eight-channel (adding white W and varnish V), or even more channels in printing systems. Only independent pressure adjustment units and expanded controller I / O interfaces need to be added accordingly. Its core "independent unit + common source" architecture remains unchanged, demonstrating good flexibility and adaptability.

Claims

1. A printer ink path pressure regulating system, characterized in that, include: Multiple independent pressure regulating units, each pressure regulating unit for one ink path channel, the pressure regulating unit comprising: An independent negative pressure chamber; A negative pressure sensor connected to the independent negative pressure chamber; A switching valve is connected to a corresponding printer cartridge, a positive pressure source, and the independent negative pressure chamber, and is used to selectively connect the cartridge to the positive pressure source or the independent negative pressure chamber; A common negative pressure source, the common negative pressure source including a common negative pressure chamber, a negative pressure pump for evacuating the common negative pressure chamber, and a controlled air intake device for selectively introducing atmosphere into the common negative pressure chamber; Multiple isolation valves, each of which is disposed between a corresponding independent negative pressure chamber and a common negative pressure chamber, for selectively connecting or isolating the two; A controller is electrically connected to the negative pressure sensor, the switching valve, the isolation valve, the positive pressure source, the negative pressure pump, and the controlled air intake device, respectively, for independently closed-loop adjustment of the pressure of each ink path channel based on the feedback of the negative pressure sensor.

2. The system according to claim 1, characterized in that, The pressure regulating unit includes a negative pressure chamber and a negative pressure cover covering the negative pressure chamber; multiple independent negative pressure chambers are formed on the negative pressure chamber and sealed by the negative pressure cover; a common negative pressure chamber is formed in the negative pressure cover and its path extends above each of the independent negative pressure chambers, such that an isolation valve is installed between the common negative pressure chamber and the corresponding independent negative pressure chamber; the switching valve, the isolation valve, and the controlled air intake device are all installed on the negative pressure cover; a tee connector is connected to the pipeline between each negative pressure sensor and the corresponding switching valve, the tee connector is installed on the outer surface of the negative pressure cover and communicates with the corresponding independent negative pressure chamber; the positive pressure source and the negative pressure pump are installed at one end of the negative pressure chamber, and the positive pressure sensor and the negative pressure sensor are installed at the other end of the negative pressure chamber.

3. The system according to claim 1, characterized in that, The controlled air intake device includes an intake solenoid valve and an intake throttle valve connected in series with the intake solenoid valve. The intake solenoid valve is used to selectively allow atmospheric air to flow into the common negative pressure chamber, and the intake throttle valve is used to limit the intake airflow rate when it is open.

4. The system according to claim 1, characterized in that, It also includes an exhaust valve, which is located on the pipeline connecting the switching valve and the positive pressure source, and is used to connect the pipeline to the atmosphere after the positive pressure flushing is completed, so as to release the residual positive pressure in the pipeline.

5. The system according to claim 4, characterized in that, The controller is also used to control the exhaust valve to connect the pipeline to the atmosphere after the positive pressure flushing mode ends.

6. The system according to claim 1, characterized in that, The switching valve is a three-way solenoid valve.

7. The system according to claim 1, characterized in that, The isolation valve is a two-way solenoid valve.

8. The system according to claim 1, characterized in that, The switching valve includes: A first two-way solenoid valve connected in series between the independent negative pressure chamber and the ink cartridge; And a second two-way solenoid valve connected in series between the positive pressure source and the ink cartridge.

9. A method for adjusting the ink path pressure of a printer, wherein the method is executed using the system described in claim 1, characterized in that, Includes the following steps: In negative pressure maintenance mode, the switching valve is controlled to connect the ink cartridge to the corresponding independent negative pressure chamber; The pressure within the independent negative pressure chamber is monitored by the negative pressure sensor. When the monitored pressure value deviates from a preset negative pressure range, the isolation valve corresponding to that channel is opened to connect the independent negative pressure chamber to the common negative pressure chamber, and: When the monitored pressure value is higher than the preset negative pressure range, the negative pressure pump is controlled to evacuate the common negative pressure chamber. When the monitored pressure value is lower than the preset negative pressure range, the controlled air intake device is controlled to introduce atmospheric air into the common negative pressure chamber in order to adjust the pressure in the independent negative pressure chamber to the preset negative pressure range. In positive pressure flushing mode, the switching valve controlling the target channel connects the ink cartridge to the positive pressure source to apply positive pressure to the ink cartridge.

10. The method according to claim 9, characterized in that, The step of controlling the controlled air intake device to introduce atmospheric air into the common negative pressure chamber includes: An intake throttle valve is used to limit the flow rate of air introduced into the common negative pressure chamber.

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