An ink-jet printer, a piston control method and device thereof, and a storage medium

Abstract

This invention discloses an inkjet printer and its piston control method, device, and storage medium. The method includes: acquiring a first pressure value V1 detected by a pressure sensor on the inkjet printer; controlling a stepper motor to drive the piston to move at a preset step angle SetA; wherein the preset step angle SetA is the minimum step angle under the premise of satisfying the detection accuracy of the pressure sensor; acquiring a second pressure value V2 detected by the pressure sensor, and calculating a first pressure change value Vd based on the first pressure value V1 and the second pressure value V2; wherein Vd = V2 – V1; if the first pressure change value Vd is less than a preset minimum deviation value Vdmm, it is determined that the piston has reached the bottom; controlling the stepper motor to move a fixed angle to pull the piston back to the initial position. This invention utilizes the pressure sensor of the inkjet printer itself to minimize the stall angle of the stepper motor, which can minimize the wear and tear on the structure and motor without increasing other costs, and extend the service life of the pump body.

Description

Technical Field

[0001] This invention relates to the field of inkjet printer technology, and in particular to an inkjet printer and its piston control method, device, and storage medium. Background Technology

[0002] Inkjet printers require a pump to draw ink and spray it into the ink chamber to maintain a certain pressure within the chamber. During the coding process, the pump starts working when the pressure reaches a certain threshold and stops working when the pressure reaches a certain level. To accurately control the amount of ink pumped out, the pump is powered by a stepper motor.

[0003] Because the position of the pump piston within the ink chamber is difficult to detect using sensors, most inkjet printers do not provide piston position detection functionality within the ink chamber. This means that if the power is cut off while the pump is operating, it cannot return to its initial position. Upon restarting, if the piston is at the bottom, any subsequent piston movement will prevent normal reciprocating motion. To solve this problem, the usual practice is to push the piston to its lowest point or maximum stroke when starting the printer, and then pull it back to its initial position.

[0004] While the above solution can resolve the initial piston position issue, if the motor shuts down while the piston is working, it will cause the piston to touch the bottom during the final stroke, leading to motor stall. This stalling process will cause a sudden increase in circuit current, affecting the motor's lifespan. Furthermore, the downward force applied to the pump body will be resisted, turning into a force applied to the gear shaft on the structural components. Over time, this will cause the teeth on the gear shaft to wear out, eventually leading to slippage and the pump becoming ineffective. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an inkjet printer and its piston control method, device and storage medium to improve the above-mentioned problems.

[0006] This invention provides a piston control method for an inkjet printer, comprising:

[0007] S1, acquire the first pressure value V1 detected by the pressure sensor on the inkjet printer;

[0008] S2, control the stepper motor to drive the piston to move at a preset step angle SetA; the preset step angle SetA is the minimum step angle that meets the detection accuracy requirements of the pressure sensor.

[0009] S3, acquire the second pressure value V2 detected by the pressure sensor, and calculate the first pressure change value Vd based on the first pressure value V1 and the second pressure value V2; where Vd = V2 – V1;

[0010] S4, if the first pressure change value Vd is less than the preset minimum deviation value Vdmm, then it is determined that the piston has reached the bottom; the minimum deviation value Vdmm is the pressure deviation value corresponding to the preset step angle SetA;

[0011] S5, control the stepper motor to move at a fixed angle to pull the piston back to its initial position.

[0012] Preferably, it further includes:

[0013] S6, if the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm, then obtain the current cycle number N;

[0014] S7, determine whether MaxA = N*SetA is true. If true, control the stepper motor to move a fixed angle to pull the piston back to the initial position; otherwise, return to S1 and update the loop count N. Wherein, MaxA is the maximum movement angle of the stepper motor set according to the maximum stroke value of the piston.

[0015] Preferably, the preset step angle SetA and the minimum deviation value Vdmm are obtained through the following steps:

[0016] Obtain the third pressure value V3 measured by the pressure sensor when the piston is in its original position;

[0017] Control the stepper motor to move to the minimum step angle MinA with the set acceleration, and obtain the fourth pressure value V4 detected by the pressure sensor;

[0018] The second pressure change value of the pressure sensor, V5 = V4 - V3, is calculated based on the third pressure value V3 and the fourth pressure value V4.

[0019] If the second pressure change value V5 is greater than the error range of the pressure sensor, then the step angle is a valid value, it is marked as the preset step angle SetA, and the corresponding second pressure change value is recorded; otherwise, the step angle is determined to be invalid, and the step angle is increased until a valid step angle is obtained.

[0020] The minimum deviation value Vdmm is generated based on the recorded second pressure change value.

[0021] Preferably, the minimum deviation value Vdmm is generated based on the recorded second pressure change value as follows:

[0022] After obtaining a preset step angle SetA, the second pressure change value is obtained multiple times by moving at the preset step angle SetA, and the minimum second pressure change value is taken as the minimum deviation value Vdmm.

[0023] This invention also provides a piston control device for an inkjet printer, comprising:

[0024] The first pressure value acquisition unit is used to acquire the first pressure value V1 detected by the pressure sensor on the inkjet printer.

[0025] The stepper control unit is used to control the stepper motor to drive the piston to move at a preset step angle SetA; the preset step angle SetA is the minimum step angle that meets the detection accuracy requirements of the pressure sensor.

[0026] The first pressure change value calculation unit is used to obtain the second pressure value V2 detected by the pressure sensor, and calculate the first pressure change value Vd based on the first pressure value V1 and the second pressure value V2; where Vd = V2 – V1;

[0027] The determination unit is used to determine that the piston has reached the bottom when the first pressure change value Vd is less than the preset minimum deviation value Vdmm; the minimum deviation value Vdmm is the pressure deviation value corresponding to the preset step angle SetA.

[0028] The pull-back unit is used to control the stepper motor to move at a fixed angle to pull the piston back to its initial position.

[0029] Preferably, it further includes:

[0030] The cycle count acquisition unit is used to acquire the current cycle count N when the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm;

[0031] The determination unit is used to determine whether MaxA = N * SetA is true. If it is true, the stepper motor is controlled to move by a fixed angle to pull the piston back to the initial position; otherwise, the first pressure value acquisition unit is notified and the cycle number N is updated. Wherein, MaxA is the maximum movement angle of the stepper motor set according to the maximum stroke value of the piston.

[0032] Preferably, the preset step angle SetA and the minimum deviation value Vdmm are obtained through the following steps:

[0033] Obtain the third pressure value V3 measured by the pressure sensor when the piston is in its original position;

[0034] Control the stepper motor to move to the minimum step angle MinA with the set acceleration, and obtain the fourth pressure value V4 detected by the pressure sensor;

[0035] The second pressure change value of the pressure sensor, V5 = V4 - V3, is calculated based on the third pressure value V3 and the fourth pressure value V4.

[0036] If the second pressure change value V5 is greater than the error range of the pressure sensor, then the step angle is a valid value, it is marked as the preset step angle SetA, and the corresponding second pressure change value is recorded; otherwise, the step angle is determined to be invalid, and the step angle is increased until a valid step angle is obtained.

[0037] The minimum deviation value Vdmm is generated based on the recorded second pressure change value.

[0038] Preferably, the minimum deviation value Vdmm is generated based on the recorded second pressure change value as follows:

[0039] After obtaining a preset step angle SetA, the second pressure change value is obtained multiple times by moving at the preset step angle SetA, and the minimum second pressure change value is taken as the minimum deviation value Vdmm.

[0040] This invention also provides an inkjet printer, which includes a memory and a processor. The memory stores a computer program that can be executed by the processor to implement the piston control method described above.

[0041] This invention also provides a computer-readable storage medium storing a computer program that can be executed by a processor of the device in which the computer-readable storage medium is located, to implement the piston control method described above.

[0042] In summary, in this embodiment, by acquiring the preset step angle SetA corresponding to the pressure sensor, and then controlling the stepper motor to step at the preset step angle SetA to detect changes in the pressure value, the piston can be determined to have reached the bottom based on the changes in the pressure value. This minimizes the stall angle of the stepper motor, thereby maximizing the reduction of wear and tear on the structure and motor without increasing other costs, and extending the service life of the pump body. Attached Figure Description

[0043] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0044] Figure 1 This is a schematic flowchart of the piston control method provided in the first embodiment of the present invention.

[0045] Figure 2 This is a schematic diagram of the piston control device provided in the second embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0048] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0049] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0050] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0051] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0052] The terms "first" and "second" used in the embodiments are merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" can be interchanged in a specific order or sequence where permissible. It should be understood that the objects distinguished by "first" and "second" can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein.

[0053] Please see Figure 1 The first embodiment of the present invention provides a printing control method, which is applied to a battery-powered printer and includes the following steps:

[0054] This invention provides a piston control method for an inkjet printer, comprising:

[0055] S1, acquire the first pressure value V1 detected by the pressure sensor on the inkjet printer.

[0056] In this embodiment, the inkjet printer needs to use a pump to draw ink and spray it into the ink chamber to maintain a certain pressure within the chamber. During the inkjet printing process, the pump starts working when the pressure in the chamber reaches a certain threshold and stops working when the pressure reaches a certain level. The first pressure value V1 can be detected by a pressure sensor on the inkjet printer.

[0057] S2, control the stepper motor to drive the piston to move at a preset step angle SetA; the preset step angle SetA is the minimum step angle that meets the detection accuracy of the pressure sensor.

[0058] In this embodiment, as described above, since the position of the piston of the pump in the ink chamber cannot be known, after the inkjet printer is powered on and started, it is necessary to control the stepper motor piston to move to the bottom or the maximum stroke value first, and then pull it back to the initial position.

[0059] In order to determine whether the piston has moved to the bottom or the maximum stroke value, this embodiment first controls the stepper motor to drive the piston to move with a preset step angle SetA.

[0060] The preset step angle SetA here is obtained through the following steps:

[0061] First, obtain the third pressure value V3 measured by the pressure sensor when the piston is in its original position;

[0062] Then, control the stepper motor to move to the minimum step angle MinA with the set acceleration, and obtain the fourth pressure value V4 detected by the pressure sensor;

[0063] Next, based on the third pressure value V3 and the fourth pressure value V4, the second pressure change value V5 of the pressure sensor is calculated as V4 = V4 - V3;

[0064] Finally, if the second pressure change value V5 is greater than the error range of the pressure sensor, the step angle is a valid value, it is marked as the preset step angle SetA, and the corresponding second pressure change value is recorded; otherwise, the step angle is determined to be invalid, the step angle is increased, and a valid step angle is obtained.

[0065] In this embodiment, if the second pressure change value V5 is less than or equal to the error range of the pressure sensor, it indicates that the current step angle is too small, and the resulting pressure change cannot be detected by the pressure sensor. Therefore, the step angle is determined to be invalid, and the step angle is increased further. The second pressure change value V5 is then calculated again until it exceeds the error range of the pressure sensor. The step angle at this point is the minimum step angle that the pressure sensor can detect, i.e., the preset step angle Set.

[0066] In this embodiment, after obtaining the preset step angle Set, the minimum deviation value Vdmm can be further obtained.

[0067] In one implementation, a preset step angle SetA is obtained, and the device moves multiple times at the preset step angle SetA to obtain the second pressure change value multiple times. The minimum second pressure change value is then taken as the minimum deviation value Vdmm.

[0068] S3, obtain the second pressure value V2 detected by the pressure sensor, and calculate the first pressure change value Vd based on the first pressure value V1 and the second pressure value V2; where Vd = V2 – V1.

[0069] S4. If the first pressure change value Vd is less than the preset minimum deviation value Vdmm, then it is determined that the piston has reached the bottom. The minimum deviation value Vdmm is the pressure deviation value corresponding to the preset step angle SetA.

[0070] S5, control the stepper motor to move at a fixed angle to pull the piston back to its initial position.

[0071] In this embodiment, if the first pressure change value Vd is less than the preset minimum deviation value Vdmm, it indicates that the piston's displacement stroke is less than the displacement stroke corresponding to the preset step angle SetA. At this time, it means that the piston has reached the bottom or has reached the maximum stroke value. Since the maximum stroke value is known, its corresponding angle is also known. Therefore, the piston can be pulled back to the initial position by controlling the stepper motor to move a fixed angle (set as MaxA).

[0072] In this embodiment, if the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm, the current cycle number N is obtained; and it is determined whether MaxA = N * SetA is true. If it is true, the stepper motor is controlled to move at a fixed angle to pull the piston back to the initial position; otherwise, return to S1 and update the cycle number N; where MaxA is the maximum movement angle of the stepper motor set according to the maximum stroke value of the piston.

[0073] If the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm, it means that the piston's displacement stroke is greater than or equal to the displacement stroke corresponding to the preset step angle SetA, meaning the piston can still move freely. At this point, it is first determined whether MaxA = N * SetA is true. If it is true, it means the stepper motor has reached its maximum angle, indicating the piston has reached the bottom. If it is not true, it means the piston has not yet reached the bottom, and the stepper motor needs to continue stepping the preset step angle SetA.

[0074] In summary, in this embodiment, by acquiring the preset step angle SetA corresponding to the pressure sensor, and then controlling the stepper motor to step at the preset step angle SetA to detect changes in the pressure value, the piston can be determined to have reached the bottom based on the changes in the pressure value. This minimizes the stall angle of the stepper motor, thereby maximizing the reduction of wear and tear on the structure and motor without increasing other costs, and extending the service life of the pump body.

[0075] Please see Figure 2 The second embodiment of the present invention also provides a piston control device for an inkjet printer, comprising:

[0076] The first pressure value acquisition unit 210 is used to acquire the first pressure value V1 detected by the pressure sensor on the inkjet printer.

[0077] The stepper control unit 220 is used to control the stepper motor to drive the piston to move at a preset step angle SetA.

[0078] The first pressure change value calculation unit 230 is used to obtain the second pressure value V2 detected by the pressure sensor, and calculate the first pressure change value Vd based on the first pressure value V1 and the second pressure value V2; wherein, Vd=V2-V1;

[0079] The determination unit 240 is used to determine that the piston has reached the bottom when the first pressure change value Vd is less than the preset minimum deviation value Vdmm.

[0080] The pull-back unit 250 is used to control the stepper motor to move at a fixed angle to pull the piston back to its initial position.

[0081] Preferably, it further includes:

[0082] The cycle count acquisition unit is used to acquire the current cycle count N when the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm;

[0083] The determination unit is used to determine whether MaxA = N * SetA is true. If it is true, the stepper motor is controlled to move by a fixed angle to pull the piston back to the initial position; otherwise, the first pressure value acquisition unit is notified and the cycle number N is updated. Wherein, MaxA is the maximum movement angle of the stepper motor set according to the maximum stroke value of the piston.

[0084] Preferably, the preset step angle SetA and the minimum deviation value Vdmm are obtained through the following steps:

[0085] Obtain the third pressure value V3 measured by the pressure sensor when the piston is in its original position;

[0086] Control the stepper motor to move to the minimum step angle MinA with the set acceleration, and obtain the fourth pressure value V4 detected by the pressure sensor;

[0087] The second pressure change value of the pressure sensor, V5 = V4 - V3, is calculated based on the third pressure value V3 and the fourth pressure value V4.

[0088] If the second pressure change value V5 is greater than the error range of the pressure sensor, then the step angle is a valid value, it is marked as the preset step angle SetA, and the corresponding second pressure change value is recorded; otherwise, the step angle is determined to be invalid, and the step angle is increased until a valid step angle is obtained.

[0089] The minimum deviation value Vdmm is generated based on the recorded second pressure change value.

[0090] Preferably, the minimum deviation value Vdmm is generated based on the recorded second pressure change value as follows:

[0091] After obtaining a preset step angle SetA, the second pressure change value is obtained multiple times by moving at the preset step angle SetA, and the minimum second pressure change value is taken as the minimum deviation value Vdmm.

[0092] This invention also provides an inkjet printer, which includes a memory and a processor. The memory stores a computer program that can be executed by the processor to implement the piston control method described above.

[0093] This invention also provides a computer-readable storage medium storing a computer program that can be executed by a processor of the device in which the computer-readable storage medium is located, to implement the piston control method described above.

[0094] For example, the various devices and process steps described above can be implemented by a computer program, which can be divided into one or more units, which are stored in the memory and executed by the processor to complete the present invention.

[0095] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0096] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the present invention by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0097] If the unit integrated into the electronic device or printer is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0098] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0099] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A piston control method of an inkjet printer, characterized by, The method comprises the following steps: S1, acquiring a first pressure value V1 detected by a pressure sensor on the inkjet printer; S2, controlling a stepping motor to drive a piston to move by a preset stepping angle SetA; the preset stepping angle SetA is a minimum stepping angle under the premise of meeting the detection accuracy of the pressure sensor; S3, acquiring a second pressure value V2 detected by the pressure sensor, and calculating a first pressure change value Vd according to the first pressure value V1 and the second pressure value V2; wherein, Vd = V2 - V1; S4, if the first pressure change value Vd is less than a preset minimum deviation value Vdmm, it is determined that the piston has reached the bottommost position; the minimum deviation value Vdmm is a pressure deviation value corresponding to the preset stepping angle SetA; wherein, the preset stepping angle SetA and the minimum deviation value Vdmm are obtained by the following steps: acquiring a third pressure value V3 detected by the pressure sensor when the piston is at an original position; controlling the stepping motor to move to a minimum stepping angle MinA at a set acceleration, and acquiring a fourth pressure value V4 detected by the pressure sensor; calculating a second pressure change value V5 = V4 - V3 of the pressure sensor according to the third pressure value V3 and the fourth pressure value V4; if the second pressure change value V5 is greater than an error range of the pressure sensor, the stepping angle is a valid value, which is marked as the preset stepping angle SetA, and the corresponding second pressure change value is recorded; otherwise, it is determined that the stepping angle is an invalid value, and the stepping angle is increased until a valid stepping angle is obtained; generating the minimum deviation value Vdmm according to the recorded second pressure change value; specifically, the minimum deviation value Vdmm is generated according to the recorded second pressure change value: acquiring the second pressure change value multiple times by moving multiple times at the preset stepping angle SetA, and taking the minimum second pressure change value as the minimum deviation value Vdmm; S5, controlling the stepping motor to move by a fixed angle to pull the piston back to the initial position.

2. The piston control method of an inkjet printer according to claim 1, characterized by, Further comprising: S6, if the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm, acquiring a current cycle number N; S7, determining whether MaxA = N * SetA is established, if yes, controlling the stepping motor to move by a fixed angle to pull the piston back to the initial position; otherwise, returning to S1 and updating the cycle number N; wherein, MaxA is a maximum movement angle of the stepping motor set according to the maximum stroke of the piston.

3. A piston control device for an inkjet printer, characterized by The method comprises the following steps: a first pressure value acquisition unit, configured to acquire a first pressure value V1 detected by a pressure sensor on the inkjet printer; a stepping control unit, configured to control a stepping motor to drive a piston to move by a preset stepping angle SetA; the preset stepping angle SetA is a minimum stepping angle under the premise of meeting the detection accuracy of the pressure sensor; a first pressure change value calculation unit, configured to acquire a second pressure value V2 detected by the pressure sensor, and calculate a first pressure change value Vd according to the first pressure value V1 and the second pressure value V2; wherein, Vd = V2 - V1; The determination unit is configured to determine that the piston has reached the bottom position when the first pressure change value Vd is less than a preset minimum deviation value Vdmm, the minimum deviation value Vdmm being a pressure deviation value corresponding to a preset step angle SetA, wherein the preset step angle SetA and the minimum deviation value Vdmm are obtained by the following steps: obtaining a third pressure value V3 measured by the pressure sensor when the piston is at an original position; controlling the stepper motor to move to a minimum step angle MinA at a set acceleration, and obtaining a fourth pressure value V4 detected by the pressure sensor; calculating a second pressure change value V5 = V4-V3 of the pressure sensor according to the third pressure value V3 and the fourth pressure value V4; if the second pressure change value V5 is greater than an error range of the pressure sensor, the step angle is a valid value, which is marked as the preset step angle SetA, and the corresponding second pressure change value is recorded; otherwise, the step angle is determined to be an invalid value, and the step angle is increased until a valid step angle is obtained; and generating the minimum deviation value Vdmm according to the recorded second pressure change value, specifically, obtaining the preset step angle SetA, moving multiple times at the preset step angle SetA to obtain multiple second pressure change values, and taking the minimum second pressure change value as the minimum deviation value Vdmm. The pulling-back unit is configured to control the stepper motor to move a fixed angle to pull back the piston to the original position.

4. The piston control device for an inkjet printer according to claim 3, wherein Further comprising: The cycle number obtaining unit is configured to obtain a current cycle number N when the first pressure change value Vd is greater than or equal to the preset minimum deviation value Vdmm. The determination unit is configured to determine whether MaxA = N * SetA is true, if true, control the stepper motor to move a fixed angle to pull back the piston to the original position, otherwise, notify the first pressure value obtaining unit and update the cycle number N, wherein MaxA is a maximum movement angle of the stepper motor set according to a maximum stroke of the piston.

5. An inkjet printer characterized by comprising: The memory stores a computer program, and the computer program can be executed by the processor to implement the piston control method of any one of claims 1-2.

6. A computer-readable storage medium, characterized in that, The computer program can be executed by the processor of the device to implement the piston control method of any one of claims 1-2.

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