Liquid supply system for a jet printing device, liquid supply method, and jet printing device

Abstract

The present disclosure relates to a liquid supply system for a jet printing apparatus, a liquid supply method, and a jet printing apparatus. The liquid supply system includes a pump assembly (50), a controller (56), a first liquid inlet flow path (12), a second liquid inlet flow path (14), and a liquid outlet flow path. A first valve (62) is provided on the first liquid inlet flow path (12) and a second valve (64) is provided on the first section (13) to create a first fluid environment for fluid going in and out of the first syringe pump (52) via the first valve (62) and the second valve (64); a third valve (66) is provided on the second liquid inlet flow path (14) and a fourth valve (68) is provided on the second section (15) to create a second fluid environment for fluid going in and out of the second syringe pump (54) via the third valve (66) and the fourth valve (68).

Description

Technical Field

[0001] This invention relates generally to digital inkjet printing, and more particularly to a liquid supply system for an inkjet printing apparatus. Background Technology

[0002] Printing apparatuses utilize digital inkjet printing technology to print onto substrates. The apparatus includes a printhead assembly with an array of nozzles, and ink cartridges for supplying liquids such as pretreatment solutions and ink to the nozzle array. The nozzle array can be actuated by a piezoelectric actuator, such as a piezoelectric ceramic. Ink printing is achieved by applying voltage to the electrodes of the piezoelectric actuator, causing the printhead to vibrate.

[0003] The liquid ejection volume of a printhead assembly's nozzle array is affected not only by the voltage applied to the piezoelectric actuator but also by multiple factors such as temperature and flow resistance. Traditional nozzle arrays are typically connected to an ink cartridge, which contains a height gauge. This height gauge allows adjustment of the pressure at the horizontal position of the nozzle array within the cartridge, thereby regulating the flow resistance. However, the complex cartridge structure of such printhead assemblies results in a large printhead assembly size, hindering miniaturization and increasing equipment cost. Further improvements in the performance of inkjet printing devices are anticipated. Summary of the Invention

[0004] Embodiments of this disclosure provide a liquid supply system, liquid supply method, and printing apparatus for a printing device, aimed at solving one or more of the above-described problems and other potential problems.

[0005] According to a first aspect of this disclosure, a liquid supply system for a printing apparatus is provided. The liquid supply system includes: a pump assembly including a first injection pump and a second injection pump; a controller configured to control the operation of the first injection pump and the second injection pump; a first inlet flow path configured to connect a liquid source to a pump chamber interface of the first injection pump; a second inlet flow path configured to connect the liquid source to a pump chamber interface of the second injection pump; and an outlet flow path including a first section communicating with the first injection pump, a second section communicating with the second injection pump, and a third section extending from the junction of the first section and the second section to a printhead chamber of the printing apparatus, wherein the nozzle of the printing apparatus is disposed in the printhead chamber; wherein a first valve is provided in the first inlet flow path and a second valve is provided in the first section to create a first fluid environment for fluid entering and exiting the first injection pump via the first valve and the second valve; a third valve is provided in the second inlet flow path and a fourth valve is provided in the second section to create a second fluid environment for fluid entering and exiting the second injection pump via the third valve and the fourth valve. According to this disclosure, by creating a first fluid environment for the first injection pump, a second fluid environment isolated from the first fluid environment for the second injection pump, and a third fluid environment for the nozzle assembly isolated from the first and second fluid environments respectively, fluctuations in fluid pressure and / or flow rate caused by the independent operation of the first and second injection pumps are effectively prevented.

[0006] In some embodiments, at least one of the first valve, the second valve, the third valve, and the fourth valve is a passive valve, which is configured to automatically open or close based on the pressure magnitude in the corresponding fluid environment.

[0007] In some embodiments, the first valve is a check valve that allows liquid to flow from the liquid source to the first injection pump; the second valve is a check valve that allows liquid to flow from the first injection pump to the third section; the third valve is a check valve that allows liquid to flow from the liquid source to the second injection pump; and the fourth valve is a check valve that allows liquid to flow from the second injection pump to the third section.

[0008] In some embodiments, the fluid supply system further includes at least one hydraulic sensor adapted to sense the liquid state of the first fluid environment and / or the second fluid environment, wherein the controller is configured to control the movement of the first injection pump and / or the second injection pump based on signals from the at least one hydraulic sensor.

[0009] In some embodiments, at least one of the first valve, the second valve, the third valve, and the fourth valve is an active valve, which is configured to open or close in response to a command from the controller.

[0010] In some embodiments, the fluid supply system further includes a hydraulic sensor disposed in the third section, wherein the controller is configured to control the movement parameters of the first injection pump and / or the second injection pump based on signals from the hydraulic sensor.

[0011] In some embodiments, the movement parameters include at least one of speed, acceleration, distance, and time.

[0012] In some embodiments, the controller is configured to independently control the first injection pump and the second injection pump based on signals from the hydraulic sensor, such that the first fluid environment and the second fluid environment are controlled in a decoupled manner from each other.

[0013] In some embodiments, the pump assembly is configured to operate the first injection pump and the second injection pump in a first operating mode, wherein the first operating mode includes a constant flow mode, in which the controller is configured to drive the respective pistons of the first injection pump and the second injection pump to move such that the liquid flow rate in the third section is constant.

[0014] In some embodiments, the constant flow mode includes at least one cycle, each cycle including a first phase and a second phase, the controller being configured to: acquire the flow rate of the liquid to be supplied; and, based on the liquid flow rate, determine a first moving speed of the piston of the first injection pump and a second moving speed of the piston of the second injection pump; during the first phase, the piston of the first injection pump is driven to move along a first direction at the first moving speed, and the piston of the second injection pump is driven to move along a second direction opposite to the first direction at the second moving speed; during the second phase, the piston of the first injection pump is driven to move along the second direction at the first moving speed, and the piston of the second injection pump is driven to move along the first direction at the second moving speed.

[0015] In some embodiments, each cycle further includes a transition phase between the first phase and the second phase; during the transition phase, the controller is configured to: acquire a sensed liquid pressure at the third segment; and based on the liquid pressure, determine a first acceleration of the piston of the first injection pump and a second acceleration of the piston of the second injection pump during the transition phase.

[0016] In some embodiments, the first acceleration and the second acceleration are determined to keep the liquid pressure constant.

[0017] In some embodiments, the controller is configured to determine the first acceleration and the second acceleration based on a PID algorithm.

[0018] In some embodiments, each cycle further includes a transition phase between the first phase and the second phase; wherein during the transition phase, the piston of the first injection pump is driven to gradually decelerate from the first moving speed to zero in the first direction and gradually increase from zero to the first moving speed in the second direction, and the piston of the second injection pump is driven to gradually decelerate from the second moving speed to zero in the second direction and gradually increase from zero to the second moving speed in the first direction with the second acceleration.

[0019] In some embodiments, the pump assembly is configured to operate the first and second injection pumps in a second operating mode, the second operating mode including a constant pressure mode, wherein in the constant pressure mode, the controller is configured to: acquire a fluid pressure sensed at the third segment; and determine a first motion parameter of the piston of the first injection pump and a second motion parameter of the piston of the second injection pump based on changes in the fluid pressure; wherein the first motion parameter and the second motion parameter are determined such that the fluid pressure sensed at the third segment is constant.

[0020] In some embodiments, the controller is configured to determine the first motion parameter and the second motion parameter based on a PID algorithm.

[0021] In some embodiments, the pump assembly is configured to operate the first injection pump and the second injection pump in a third operating mode, the third operating mode including a constant density mode, wherein in the constant density mode, the controller is configured to: acquire the moving speed of the substrate to be printed by the printing apparatus; acquire the flow rate of the liquid to be supplied; and determine a first motion parameter of the piston of the first injection pump and a second motion parameter of the piston of the second injection pump based on the moving speed and the liquid flow rate.

[0022] In some embodiments, the constant density mode includes at least one cycle, each cycle including a first phase, a second phase, and a transition phase between the first phase and the second phase; the controller is configured to: during the first phase, drive the piston of the first injection pump to move along a first direction at a first moving speed, and drive the piston of the second injection pump to move along a second direction opposite to the first direction at a second moving speed; during the second phase, drive the piston of the first injection pump to move along the second direction at the first moving speed, and drive the piston of the second injection pump to move along the first direction at the second moving speed; during the transition phase, acquire the fluid pressure sensed at the third segment, and determine, based on the fluid pressure, a first acceleration of the piston of the first injection pump and a second acceleration of the piston of the second injection pump during the transition phase.

[0023] In some embodiments, the controller is configured to determine the first acceleration and the second acceleration based on a PID algorithm to keep the liquid pressure constant.

[0024] In some embodiments, the liquid supply system further includes a first user interface for receiving instructions from a user to select an operating mode for the pump assembly.

[0025] In some embodiments, the liquid supply system further includes a second user interface for receiving instructions from a user to set the flow rate of the liquid to be supplied.

[0026] In some embodiments, the fluid supply system further includes a damper disposed in the third section.

[0027] According to a second aspect of this disclosure, a printing apparatus is provided, characterized in that it includes a liquid supply system according to any one of the first aspects.

[0028] According to a third aspect of this disclosure, a liquid supply method is provided for a liquid supply system of a printing apparatus, the liquid supply system comprising: a pump assembly including a first injection pump, a second injection pump, and a controller for controlling the first injection pump and the second injection pump; a first inlet flow path configured to connect a liquid source to a pump chamber interface of the first injection pump; a second inlet flow path configured to connect the liquid source to a pump chamber interface of the second injection pump; and an outlet flow path including a first section communicating with the first injection pump, a second section communicating with the second injection pump, and a third section extending from the junction of the first section and the second section to a printhead chamber of the printing apparatus, wherein the nozzle of the printing apparatus is disposed in the printhead chamber; wherein a first valve is provided in the first inlet flow path and a second valve is provided in the first section to create a first fluid environment for fluid entering and exiting the first injection pump via the first valve and the second valve; a third valve is provided in the second inlet flow path and a fourth valve is provided in the second section to create a second fluid environment for fluid entering and exiting the second injection pump via the third valve and the fourth valve. The method includes: acquiring a fluid pressure sensed at the third section; and determining, based on the fluid pressure, a first motion parameter of the piston of the first injection pump and a second motion parameter of the piston of the second injection pump. Attached Figure Description

[0029] The above and other objects, features, and advantages of embodiments of the present disclosure will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the present disclosure are illustrated in the drawings by way of example and not limitation.

[0030] Figure 1 A schematic diagram of a printing system according to an embodiment of the present invention is shown.

[0031] Figure 2 A schematic diagram of a printhead assembly of a printing system according to an embodiment of the present invention is shown.

[0032] Figure 3 It shows Figure 2 A partial cross-sectional schematic diagram of the nozzle assembly shown.

[0033] Figure 4 A schematic diagram of a liquid supply system according to an embodiment of the present invention is shown.

[0034] Figure 5 A schematic diagram of a liquid supply system according to another embodiment of the present invention is shown.

[0035] Figure 6 A flowchart of a liquid supply method according to an embodiment of the present disclosure is shown.

[0036] Figure 7A block diagram of an apparatus capable of implementing several embodiments of the present disclosure is shown.

[0037] In the various figures, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0038] Preferred embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0039] The term "comprising" and its variations as used herein signify an open-ended inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". Terms such as "upper", "lower", "front", and "rear", indicating placement or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are used only for the purpose of describing the principles of this disclosure, and are not intended to indicate or imply that the elements referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as limiting this disclosure.

[0040] Figure 1 A schematic diagram of a printing system 1 according to an embodiment of the present invention is shown. Figure 1 As shown, the inkjet printing system 1 includes a liquid source 30, a pump assembly 50, and a printhead assembly 20. The liquid source 30 can be a container for ink to be printed or various processing liquids. Ink can be printed onto a substrate 40 to form a predetermined pattern. In addition to ink, various processing liquids can also be printed onto the substrate 40 via the printhead assembly 20. The printhead assembly 20 can include a printhead cavity. Through the operation of the pump assembly 50, liquid in the liquid source 30 is supplied to the printhead cavity of the printhead assembly 20, creating a pressure environment within the printhead cavity. Multiple nozzles are disposed within the printhead cavity, one end of each nozzle communicating with the printhead cavity, and the other end open and exposed to ambient air. Under the pressure within the printhead cavity, liquid is printed onto the substrate 40 located below the nozzles via the nozzles.

[0041] Digital inkjet printing equipment requires uniform printing of patterns using printheads. Therefore, it is necessary to ensure that each nozzle in the printhead array achieves uniform printing, avoiding uneven printing problems. The amount of ink sprayed by the nozzle array is affected not only by the voltage applied to the piezoelectric actuator but also by multiple factors such as temperature and flow resistance. According to this disclosure, a liquid supply system is provided, comprising at least two pumps decoupled from each other, replacing an altitude gauge, and achieving cartridge pressure control through independent control of the two pumps. This reduces equipment costs and improves the uniform printing performance of the inkjet printing equipment.

[0042] Figure 2 and Figure 3 Structural details of a printhead assembly 20 according to an embodiment of the present disclosure are shown. The printhead assembly 1 may include a housing and an ink cartridge 21 mounted to the housing. In the illustrated embodiment, the housing may include a base plate 26 and a cover plate 24. Specifically, as shown... Figure 3 As shown, substrate 26 includes two opposing surfaces. Ink cartridge 21 can be mounted to one surface of substrate 26, and the other surface of substrate 26 is adapted to mount a nozzle assembly. The nozzle assembly may include a nozzle array 34, an actuator 26 (e.g., a piezoelectric actuator) adapted to drive the nozzle array, and corresponding control circuitry for operating the actuator. Cover plate 24 may cover substrate 26 to form an enclosed space. According to embodiments of this disclosure, by laterally arranging the ink cartridge, the nozzle assembly extends substantially parallel to the surface of substrate 26, thereby significantly improving the space efficiency of the entire device. In the illustrated embodiment, only the main components related to the liquid supply system are shown, while other components unrelated to the liquid supply are omitted.

[0043] like Figure 2 and Figure 3 As shown, the ink cartridge 21 includes a base and a cover. The base includes a first surface and a second surface opposite to the first surface. The first surface is at least partially recessed toward the second surface, thereby forming a chamber 25 for containing liquid. The cover covers the chamber 25 at the first surface to enclose the chamber 25 and form a closed space. In some embodiments, the cover may include a recess that communicates with the chamber 25 to further increase the volume of the chamber 25. The base also includes a flow path for liquid to enter the chamber 25, communicating with the chamber 25. With this arrangement, the size of the chamber 25, and further the size of the ink cartridge, can be significantly miniaturized because it eliminates the need for liquid pressure regulating devices such as level gauges in the chamber.

[0044] In some embodiments, such as Figure 2As shown, a flow path connector 23 is illustrated at the location of the flow path. The flow path connector 23 can be connected to a pipe, thereby supplying liquids such as pretreatment fluid or ink to the chamber 25. In some embodiments, the flow path has internal threads within its channels, suitable for connection to the connector. This allows for connection to other piping components via threaded connections. In some embodiments, the chamber 25 can be connected to the pump assembly 50 via the connector 23. Before performing the printing operation, the pump assembly 50 can be operated to fill the chamber 25 with liquid. This can be achieved, for example, by opening the inlet flow path and closing the outlet flow path. This allows for a constant pressure distribution within the chamber 25 through the operation of a constant-flow pump. This is beneficial for ensuring flow resistance at the nozzle and contributes to achieving uniform and constant liquid spraying from the nozzle.

[0045] In some embodiments, such as Figure 2 and Figure 3 As shown, the substrate includes a plurality of fluid through-holes extending from the chamber 25 through the substrate to the second surface. A corresponding single needle 22 of the nozzle array can be arranged in each fluid through-hole. Figure 3 The diagram shows multiple single needles 22 inserted into a fluid through-hole. One end of each single needle 22 is connected to a chamber, and the other end is open. A single needle 342 can be actuated by an actuator 26 for actuating the single needle 22, causing the fluid inside the single needle to flow out of the chamber 25 by vibration and then be sprayed onto the surface of the substrate.

[0046] Figure 4 A schematic diagram of a liquid supply system 10 according to an embodiment of the present invention is shown. Figure 4As shown, the liquid supply system 10 includes a pump assembly 50, a first inlet flow path 12, a second inlet flow path 14, and an outlet flow path. The pump assembly 50 includes at least two injection pumps. Each injection pump may include components such as a motor (e.g., a stepper motor), a driver (e.g., a lead screw module), and a piston. Commands can be sent to the motor to drive the piston to move linearly within the piston cylinder. When the piston compresses the piston chamber within the piston cylinder, the liquid contained within the piston cylinder flows out, corresponding to the injection stroke of the injection pump; when the piston expands the piston chamber within the piston cylinder, external liquid enters the piston cylinder, corresponding to the suction stroke of the injection pump. The reciprocating movement of the piston within the piston cylinder enables the pumping of liquid into the nozzle chamber. In the illustrated embodiment, the pump assembly includes two injection pumps, namely a first injection pump 52 and a second injection pump 54. It should be understood that the illustrated embodiment is merely exemplary, and the pump assembly may include three or more injection pumps. The liquid supply system 10 also includes a controller 56, which is communicatively connected to the pump assembly 50 and adapted to control the operation of the first injection pump 52 and the second injection pump 54. Considering the application scenario of the printing device, decoupling the control of the first injection pump 52 and the second injection pump 54 from each other helps to prevent crosstalk between the first injection pump 52 and the second injection pump 54.

[0047] One end of the first inlet flow path 12 is connected to the liquid source 30, and the other end is connected to the piston chamber of the first injection pump 52. Similarly, one end of the second inlet flow path 14 is connected to the liquid source 30, and the other end is connected to the piston chamber of the second injection pump 54. The outlet flow path connects the first injection pump 52 and the second injection pump 54 together to the chamber 25 of the nozzle assembly 20. The outlet flow path may include multiple sections 13, 15, and 16. The first section 13 is the section connecting from the outlet of the first injection pump 52 to the confluence point Q; the second section 15 is the section connecting from the outlet of the second injection pump 54 to the confluence point Q. The first section 13 and the second section 15 converge at the confluence point Q and communicate with the chamber 25 of the nozzle assembly 10 via the third section 16.

[0048] By creating a first fluid environment for the first injection pump 52, a second fluid environment isolated from the first fluid environment for the second injection pump 54, and a third fluid environment for the printhead assembly 20 that is also isolated from the first and second fluid environments, fluctuations in fluid pressure and / or flow rate caused by the independent operation of the first injection pump 52 and the second injection pump 54 are effectively prevented. Creating these three isolated fluid environments is important for uniform inkjet printing in the printing apparatus.

[0049] A first valve 62 is provided on the first inlet flow path 12, and a second valve 64 is provided on the first section 13. This creates a first fluid environment for the fluid entering and exiting the first syringe pump 52 via the first valve 62 and the second valve 64. Similarly, a third valve 66 is provided on the second inlet flow path 14, and a fourth valve 68 is provided on the second section 15. This creates a second fluid environment for the fluid entering and exiting the second syringe pump 54 via the third valve 66 and the fourth valve 68. By providing four valves, the flow environments of the first syringe pump 52 and the second syringe pump 54 are decoupled from each other. Therefore, desired fluid parameters (e.g., flow rate and / or pressure) at the third section 16 can be controlled by decoupling the first syringe pump 52 and the second syringe pump 54 from each other.

[0050] In some embodiments, one or more of the first valve 62, second valve 64, third valve 66, and fourth valve 68 are active valves, such as solenoid valves. The opening and closing of the first inlet flow path 12 and the second inlet flow path 14 can be controlled by opening or closing the solenoid valves via instructions from the controller 56. In some embodiments, a sensor adapted to sense the liquid state within the first syringe pump 52 may also be provided in the first section 12. The controller 56 may be configured to control the movement of the first syringe pump 52 based on signals from the sensor. Similarly, a sensor adapted to sense the liquid state within the second syringe pump 54 may also be provided in the second section 14. The controller 56 may be configured to control the movement of the second syringe pump 54 based on signals from the sensor.

[0051] In some embodiments, at least one of the first valve 62, the second valve 64, the third valve 66, and the fourth valve 68 is a passive valve, such as a check valve. Passive valves are configured to automatically open or close based on the pressure magnitude in the corresponding fluid environment. Passive valves offer the advantage of low cost and better time responsiveness. In some embodiments, the second valve 64 and the fourth valve 68 are implemented as check valves, while the first valve 62 and the second valve 64 are implemented as solenoid valves.

[0052] In some embodiments, the liquid supply system may further include a damper disposed at the third section 16. As an example, the damper may be located downstream of the sensor. The damper further reduces liquid fluctuations in the pipeline.

[0053] In some embodiments, the first valve 62, the second valve 64, the third valve 66, and the fourth valve 68 are all implemented as passive valves. Figure 5 An example of this situation is shown. For example... Figure 5As shown, the first valve 62 is a check valve that allows liquid to flow from the liquid source to the first injection pump 52; the second valve 64 is a check valve that allows liquid to flow from the first injection pump 52 to the third section 16; the third valve 66 is a check valve that allows liquid to flow from the liquid source to the second injection pump 54; and the fourth valve 68 is a check valve that allows liquid to flow from the second injection pump 54 to the third section 16. Considering the specific application of the printing device, the environmental differences between the first fluid environment, the second fluid environment, and the third fluid environment are not significant. By utilizing check valves, the cost of the equipment can be further reduced and the time responsiveness of the liquid supply system can be improved.

[0054] In some embodiments, such as Figure 5 As shown, the liquid supply system 10 may include a hydraulic sensor 17 disposed in the third section 16. For uniform printing, the state of the liquid in the third section 16 has a direct impact on the printing performance. Therefore, the liquid state can be obtained through the hydraulic sensor 17 in the third section 16, and the movement parameters of each injection pump can be controlled based on the hydraulic sensor 17. In some embodiments, the movement parameters may include one or more of speed, acceleration, distance, time, etc.

[0055] The liquid supply system 10 according to embodiments of this disclosure may include one or more liquid supply modes. As an example, the liquid supply system 10 may include a user interface. A user can select the operating mode of the liquid supply system 10 via the user interface.

[0056] In some embodiments, the liquid supply system 10 may include a constant flow mode. In constant flow mode, the controller 56 is configured to control the first injection pump 52 and the second injection pump 54 such that the liquid flow rate supplied from the liquid supply system to the printhead assembly 20 is constant. As an example, the constant flow mode may correspond to the constant flow printing mode of a printing apparatus. Because the liquid flow rate supplied to the printhead assembly 20 is constant, the liquid environment within the chamber 25 of the printhead assembly 20 is uniform, thereby resulting in uniform liquid ejection from the plurality of nozzles 22. In some embodiments, a user may configure the liquid flow rate to be supplied via a user interface, receiving instructions from the user. The controller may control the first injection pump 52 and the second injection pump 54 based on the set liquid flow rate. In some embodiments, the liquid supply system may be set to a default liquid supply flow rate. In this case, user setting may be omitted.

[0057] According to embodiments of this disclosure, a first injection pump 52 and a second injection pump 54 are configured to reciprocate to achieve fluid supply. The constant flow mode includes one or more cycles, each cycle including a first phase and a second phase. During the first phase, the piston of the first injection pump 52 is driven to move at a first speed along a first direction, and the piston of the second injection pump 54 is driven to move at a second speed along a second direction opposite to the first direction; during the second phase, the piston of the first injection pump 52 is driven to move at the first speed along the second direction, and the piston of the second injection pump 54 is driven to move at the second speed along the first direction. In some embodiments, the first speed and the second speed are different. Through the reciprocating motion of the pistons of the first injection pump 52 and the second injection pump 54 in opposite directions, a continuous fluid supply can be achieved.

[0058] In some embodiments, each cycle also includes a transition phase between the first and second phases. During the transition phase, the controller 56 is configured to gradually convert the motion of the first injection pump 52 and / or the second injection pump 54 in one direction into motion in the opposite direction. By gradually switching the first injection pump 52 and / or the second injection pump 54, flow rate fluctuations in the third segment 16 can be further prevented.

[0059] In some embodiments, the sensed liquid pressure at the third segment 16 may be acquired. Based on the sensed liquid pressure, a first acceleration of the piston of the first injection pump 52 during the transition phase and a second acceleration of the piston of the second injection pump 54 during the transition phase are determined. In some embodiments, the first and second accelerations are determined to keep the liquid pressure constant. In some embodiments, the first and second accelerations may be determined based on a PID algorithm. It should be understood that other algorithms may also be used to determine the first and second accelerations.

[0060] Instead of using acceleration to control the piston movement of the injection pump, in some embodiments, the piston movement of the injection pump can be controlled based on speed and time. As an example, the piston of the first injection pump 52 is driven to gradually decelerate from a first movement speed to zero in a first direction and gradually increase from zero to the first movement speed in a second direction. Similarly, the piston of the second injection pump 54 is driven to gradually decelerate from a second movement speed to zero in the second direction and gradually increase from zero to the second movement speed in the first direction with a second acceleration.

[0061] In some embodiments, the liquid supply system 10 may include a constant pressure mode. In constant pressure mode, the controller 56 is configured to control the first injection pump 52 and the second injection pump 54 to maintain a constant pressure supplied from the liquid supply system to the printhead assembly 20. In some embodiments, the constant pressure may be a higher pressure than that used during substrate printing. As an example, a constant flow mode may correspond to a cleaning mode of the printing equipment. Increasing the pressure to spray liquid from the nozzles can clean the nozzles and prevent liquid from clogging them. In some embodiments, the liquid pressure can be set via a user interface, receiving instructions from the user to set the liquid pressure. The controller can control the first injection pump 52 and the second injection pump 54 based on the set liquid pressure. In some embodiments, the liquid supply system may have a default cleaning pressure. In this case, user setting may be omitted.

[0062] During the execution of the constant pressure mode, the controller 56 is configured to acquire the fluid pressure sensed at the third segment 16. Based on the change in fluid pressure, a first motion parameter of the piston of the first injection pump 52 and a second motion parameter of the piston of the second injection pump 54 are determined. The first and second motion parameters are determined to keep the fluid pressure sensed at the third segment 16 constant. In some embodiments, the controller 56 is configured to determine the first and second motion parameters based on a PID algorithm.

[0063] In some embodiments, the liquid supply system 10 may include a constant density mode. In the constant density mode, the controller 56 is configured to control the first injection pump 52 and the second injection pump 54 such that the flow rate supplied from the liquid supply system to the printhead assembly 20 follows the moving speed of the substrate. Thus, adaptive adjustment of the flow rate can be achieved even if the substrate moves. In the constant density mode, the controller 56 is configured to: acquire the moving speed of the substrate to be printed in the printing assembly; acquire the liquid flow rate to be supplied; and determine a first motion parameter of the piston of the first injection pump 52 and a second motion parameter of the piston of the second injection pump 54 based on the moving speed and the liquid flow rate.

[0064] In some embodiments, the constant density mode includes at least one cycle, each cycle including a first phase, a second phase, and a transition phase between the first and second phases; the controller 56 is configured to: during the first phase, drive the piston of the first injection pump 52 to move along a first direction at a first moving speed, and drive the piston of the second injection pump 54 to move along a second direction opposite to the first direction at a second moving speed; during the second phase, drive the piston of the first injection pump 52 to move along the second direction at the first moving speed, and drive the piston of the second injection pump 54 to move along the first direction at the second moving speed; during the transition phase, acquire the fluid pressure sensed at the third segment 16, and based on the fluid pressure, determine a first acceleration of the piston of the first injection pump 52 and a second acceleration of the piston of the second injection pump 54 during the transition phase. Thus, a constant flow rate supply corresponding to the moving speed of the substrate can be achieved. In some embodiments, the controller 56 is configured to determine the first and second accelerations based on a PID algorithm.

[0065] This disclosure provides a liquid supply method. Figure 5 A flow chart of a liquid supply method 100 according to an embodiment of the present disclosure is shown. Method 100 is specifically designed for motion control of a first injection pump 52 and a second injection pump 54 during a change in direction of movement. During the change, the direction of movement of the first injection pump 52 and the second injection pump 54 changes, which will cause flow rate and / or pressure fluctuations in the flow path. By employing decoupled control for the first injection pump 52 and the second injection pump 54 according to the liquid supply method of the present disclosure, flow rate and / or pressure fluctuations in the flow path (particularly at the outlet) can be reduced. At 102, the liquid pressure sensed at the third segment 16 is acquired. At 104, based on the liquid pressure, a first motion parameter of the piston of the first injection pump 52 and a second motion parameter of the piston of the second injection pump 54 are determined. The pistons of the corresponding first injection pump 52 and the second injection pump 54 are driven based on the determined first and second motion parameters.

[0066] It is worth noting that although the embodiments of this disclosure are illustrated using a printing device as an example, this is merely exemplary, and this disclosure is also applicable to other fields that require a continuous and precise liquid supply system, such as pharmaceuticals or other liquids or fluids.

[0067] According to embodiments of this disclosure, this disclosure also provides an electronic device, a computer-readable storage medium, and a computer program product.

[0068] Figure 6A block diagram of a computing device 600 capable of implementing various embodiments of the present disclosure is shown. As shown, the device 600 includes a central processing unit (CPU) 601, which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) 602 or loaded from storage unit 608 into random access memory (RAM) 603. Various programs and data required for the operation of the device 600 may also be stored in RAM 603. The CPU 601, ROM 602, and RAM 603 are interconnected via bus 604. An input / output (I / O) interface 605 is also connected to bus 604.

[0069] Multiple components in device 600 are connected to I / O interface 605, including: input unit 606, such as keyboard, mouse, etc.; output unit 607, such as various types of monitors, speakers, etc.; storage unit 608, such as disk, optical disk, etc.; and communication unit 609, such as network card, modem, wireless transceiver, etc. Communication unit 609 allows device 600 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0070] Processing unit 601 executes the various methods and processes described above, such as processes 300 and 600. For example, in some embodiments, process 100 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 608. In some embodiments, part or all of the computer program may be loaded and / or installed on device 600 via ROM 602 and / or communication unit 609. When the computer program is loaded into RAM 603 and executed by CPU 601, one or more steps of process 100 described above may be performed. Alternatively, in other embodiments, CPU 601 may be configured to execute process 100 by any other suitable means (e.g., by means of firmware).

[0071] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload programmable logic devices (CPLDs), and so on.

[0072] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0073] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0074] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0075] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with embodiments of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0076] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other.

[0077] Furthermore, although the operations are depicted in a specific order, this should be understood as requiring that such operations be performed in the specific order shown or in sequential order, or requiring that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0078] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A liquid supply system for a printing apparatus, characterized in that, include: The pump assembly (50) includes a first injection pump (52) and a second injection pump (54); The controller (56) is configured to control the operation of the first injection pump (52) and the second injection pump (54); The first liquid inlet path (12) is configured to connect the liquid source (30) to the pump chamber interface of the first injection pump (52); The second liquid inlet path (14) is configured to connect the liquid source (30) to the pump chamber interface of the second injection pump (54); as well as The liquid outlet path includes a first section (13) connected to the first injection pump (52), a second section (15) connected to the second injection pump (54), and a third section (16) extending from the junction of the first section (13) and the second section (15) to the print head cavity of the printing device, wherein the nozzle (22) of the printing device is disposed in the print head cavity; A first valve (62) is provided on the first inlet flow path (12) and a second valve (64) is provided on the first section (13) to create a first fluid environment for the fluid entering and leaving the first injection pump (52) via the first valve (62) and the second valve (64); A third valve (66) is provided on the second inlet flow path (14) and a fourth valve (68) is provided on the second section (15) to create a second fluid environment for the fluid entering and leaving the second injection pump (54) via the third valve (66) and the fourth valve (68).

2. The liquid supply system according to claim 1, characterized in that, At least one of the first valve (62), the second valve (64), the third valve (66) and the fourth valve (68) is a passive valve, which is configured to open or close automatically based on the pressure in the corresponding fluid environment.

3. The liquid supply system according to claim 2, characterized in that, The first valve (62) is a check valve that allows liquid to flow from the liquid source (30) to the first injection pump (52); the second valve (64) is a check valve that allows liquid to flow from the first injection pump (52) to the third section (16); the third valve (66) is a check valve that allows liquid to flow from the liquid source (30) to the second injection pump (54); and the fourth valve (68) is a check valve that allows liquid to flow from the second injection pump (54) to the third section (16).

4. The liquid supply system according to claim 1, characterized in that, It also includes a hydraulic sensor (17) disposed in the third section (16), wherein the controller (56) is configured to independently control the movement parameters of the first injection pump (52) and / or the second injection pump (54) based on signals from the hydraulic sensor, such that the first fluid environment and the second fluid environment are controlled in a decoupled manner from each other; the movement parameters include at least one of speed, acceleration, distance, and time.

5. The liquid supply system according to any one of claims 1-4, characterized in that, The pump assembly (50) is configured to operate the first injection pump (52) and the second injection pump (54) in a first operating mode. The first operating mode includes a constant flow mode, in which the controller (56) is configured to drive the respective pistons of the first injection pump (52) and the second injection pump (54) to move such that the liquid flow rate in the third section (16) is constant.

6. The liquid supply system according to claim 5, characterized in that, The constant current mode includes at least one cycle, and each cycle includes a first stage and a second stage. The controller (56) is configured to: Obtain the flow rate of the liquid to be supplied; and Based on the liquid flow rate, determine the first moving speed of the piston of the first injection pump (52) and the second moving speed of the piston of the second injection pump (54); During the first phase, the piston of the first injection pump (52) is driven to move along a first direction at a first moving speed, and the piston of the second injection pump (54) is driven to move along a second direction opposite to the first direction at a second moving speed. During the second phase, the piston of the first injection pump (52) is driven to move along the second direction at the first moving speed, and the piston of the second injection pump (54) is driven to move along the first direction at the second moving speed.

7. The liquid supply system according to claim 6, characterized in that, Each cycle also includes a transition phase between the first phase and the second phase; During the transition phase, the controller (56) is configured to: Acquire the fluid pressure sensed at the third section (16); and Based on the liquid pressure, a first acceleration of the piston of the first injection pump (52) during the conversion phase and a second acceleration of the piston of the second injection pump (54) during the conversion phase are determined.

8. The liquid supply system according to claim 7, characterized in that, The first acceleration and the second acceleration are determined to keep the liquid pressure constant.

9. The liquid supply system according to claim 7, characterized in that, The controller (56) is configured to determine the first acceleration and the second acceleration based on a PID algorithm.

10. The liquid supply system according to claim 7, characterized in that, Each cycle also includes a transition phase between the first phase and the second phase; wherein during the transition phase, the piston of the first injection pump (52) is driven to gradually decelerate from the first moving speed to zero in the first direction and gradually increase from zero to the first moving speed in the second direction, and the piston of the second injection pump (54) is driven to gradually decelerate from the second moving speed to zero in the second direction and gradually increase from zero to the second moving speed in the first direction with the second acceleration.

11. The liquid supply system according to any one of claims 1-4 and 6-10, characterized in that, The pump assembly (50) is configured to operate the first syringe pump (52) and the second syringe pump (54) in a second operating mode, the second operating mode including a constant pressure mode. In the constant pressure mode, the controller (56) is configured as follows: Acquire the fluid pressure sensed at the third section (16); and Based on the change in liquid pressure, the first motion parameters of the piston of the first injection pump (52) and the second motion parameters of the piston of the second injection pump (54) are determined. The first motion parameter and the second motion parameter are determined such that the liquid pressure sensed at the third segment (16) is constant.

12. The liquid supply system according to claim 11, characterized in that, The controller (56) is configured to determine the first motion parameter and the second motion parameter based on a PID algorithm.

13. The liquid supply system according to any one of claims 1-4 and 6-10, characterized in that, The pump assembly (50) is configured to operate the first syringe pump (52) and the second syringe pump (54) in a third operating mode, the third operating mode including a constant density mode. In the constant density mode, the controller (56) is configured as follows: The moving speed of the substrate to be printed by the printing device is obtained; Obtain the flow rate of the liquid to be supplied; and Based on the moving speed and the liquid flow rate, the first motion parameters of the piston of the first injection pump (52) and the second motion parameters of the piston of the second injection pump (54) are determined.

14. The liquid supply system of claim 13, wherein the constant density mode comprises at least one cycle, each cycle comprising a first phase, a second phase, and a transition phase between the first phase and the second phase; The controller (56) is configured to: During the first phase, the piston of the first injection pump (52) is driven to move along a first direction at a first moving speed, and the piston of the second injection pump (54) is driven to move along a second direction opposite to the first direction at a second moving speed. During the second phase, the piston of the first injection pump (52) is driven to move along the second direction at the first moving speed, and the piston of the second injection pump (54) is driven to move along the first direction at the second moving speed; During the transition phase, the fluid pressure sensed at the third segment (16) is acquired, and based on the fluid pressure, a first acceleration of the piston of the first injection pump (52) and a second acceleration of the piston of the second injection pump (54) during the transition phase are determined.

15. The liquid supply system according to claim 14, characterized in that, The controller (56) is configured to determine the first acceleration and the second acceleration based on a PID algorithm so that the liquid pressure remains constant.

16. The liquid supply system according to any one of claims 4, 6-10, characterized in that, It also includes a first user interface for receiving instructions from a user to select the operating mode of the pump assembly (50).

17. The liquid supply system according to claim 15, characterized in that, It also includes a second user interface for receiving instructions from the user to set the flow rate of the liquid to be supplied.

18. The liquid supply system according to any one of claims 1-4, 6-10, and 14-15, characterized in that, It also includes a damper located in the third section (16).

19. A printing apparatus, characterized in that, Includes the liquid supply system according to any one of claims 1-18.

20. A liquid supply method for a liquid supply system of a printing apparatus, the liquid supply system comprising: The pump assembly (50) includes a first injection pump (52), a second injection pump (54), and a controller (56) for controlling the first injection pump (52) and the second injection pump (54). The first liquid inlet path (12) is configured to connect the liquid source (30) to the pump chamber interface of the first injection pump (52); The second liquid inlet path (14) is configured to connect the liquid source (30) to the pump chamber interface of the second injection pump (54); as well as The liquid outlet path includes a first section (13) connected to the first injection pump (52), a second section (15) connected to the second injection pump (54), and a third section (16) extending from the junction of the first section (13) and the second section (15) to the print head cavity of the printing device, wherein the nozzle (22) of the printing device is disposed in the print head cavity; A first valve (62) is provided on the first inlet flow path (12) and a second valve (64) is provided on the first section (13) to create a first fluid environment for the fluid entering and leaving the first injection pump (52) via the first valve (62) and the second valve (64); A third valve (66) is provided on the second inlet flow path (14) and a fourth valve (68) is provided on the second section (15) to create a second fluid environment for the fluid entering and leaving the second injection pump (54) via the third valve (66) and the fourth valve (68); The method includes: Acquire the fluid pressure sensed at the third section (16); as well as Based on the liquid pressure, the first motion parameters of the piston of the first injection pump (52) and the second motion parameters of the piston of the second injection pump (54) are determined.

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