Power failure protection circuit and ink-jet printing equipment

Abstract

The utility model discloses a power-down protection circuit and ink-jet printing equipment, and relates to the technical field of ink-jet printing equipment, the ink-jet printing equipment comprises a main power supply circuit and a load, and the main power supply circuit is used for outputting power supply voltage to a power supply end of the load. The power failure protection circuit comprises an auxiliary power supply module, a sampling circuit and a control circuit. The output end of the auxiliary power supply module is connected with a load; the sampling end of the sampling circuit is connected with the main power supply circuit and is used for detecting external voltage and outputting corresponding voltage or current acquisition signals through the signal output end; the control circuit is respectively connected with the signal output end and the auxiliary power supply module; and the control circuit is used for controlling the auxiliary power supply module to output the auxiliary voltage to the power supply end of the load when determining that the power supply voltage is smaller than the first voltage according to the voltage acquisition signal. The power failure protection circuit provided by the utility model aims to reduce the situation of low reliability of the ink-jet printing equipment caused by power failure.

Description

Power-off protection circuit and inkjet printing equipment Technical Field

[0001] This utility model relates to the technical field of inkjet printing equipment, and in particular to a power-off protection circuit and an inkjet printing device. Background Technology

[0002] Inkjet printers have a main power circuit that draws power from an external power source. Once powered, the printer can control the printhead movement and perform the corresponding printing task. However, during the use of inkjet printers, there may be sudden power outages or accidental power failures. If the printhead is in the printing process and there is a sudden power loss, the printhead may remain in the working area, causing ink to solidify and potentially leading to printhead clogging. Therefore, traditional inkjet printers suffer from low reliability. Summary of the Invention

[0003] The main purpose of this invention is to propose a power-off protection circuit and an inkjet printing device, aiming to improve the reliability of the inkjet printing device.

[0004] To achieve the above objectives, this utility model proposes a power-down protection circuit for an inkjet printer. The inkjet printer includes a main power supply circuit and a load. The input terminal of the main power supply circuit is used to connect to an external voltage, and the output terminal of the main power supply circuit is connected to the power supply terminal of the load. The main power supply circuit processes the external voltage and outputs a supply voltage to the power supply terminal of the load. The power-down protection circuit includes:

[0005] An auxiliary power supply module, the output terminal of which is connected to the power supply terminal of the load;

[0006] A sampling circuit is provided, which has a sampling terminal and a signal output terminal. The sampling terminal is connected to the output terminal of the main power supply circuit. The sampling circuit is used to detect the external voltage and output a corresponding voltage acquisition signal or current acquisition signal through the signal output terminal.

[0007] A control circuit is connected to both the signal output terminal and the auxiliary power supply module. The control circuit is used to control the auxiliary power supply module to output an auxiliary voltage to the power supply terminal of the load when the supply voltage is less than a first voltage, based on the voltage acquisition signal.

[0008] In one embodiment, the sampling circuit includes a first resistor and a second resistor, a first end of the first resistor is connected to the main power supply circuit, a second end of the first resistor is connected to the first end of the second resistor, and a second end of the second resistor is grounded.

[0009] In one embodiment, the auxiliary power module includes an auxiliary power supply and a first switching circuit, wherein the input terminal of the first switching circuit is connected to the auxiliary power supply, the output terminal of the first switching circuit is connected to the load, and the controlled terminal of the first switching circuit is connected to the control circuit.

[0010] The control circuit is used to control the first switching circuit to be turned on or off according to the voltage acquisition signal, so as to control the connection or disconnection between the auxiliary power supply and the load.

[0011] In one embodiment, the first switching circuit includes: a first switching transistor, a third resistor, and a fourth resistor;

[0012] The first terminal of the first switching transistor is connected to the auxiliary power supply and the first terminal of the third resistor, the second terminal of the first switching transistor is connected to the load, and the controlled terminal of the first switching transistor is connected to the driving circuit through the fourth resistor.

[0013] In one embodiment, the first switching circuit further includes a backflow prevention circuit, which is connected in series in the path between the first switching transistor and the load. One end of the backflow prevention circuit is connected to the load, and the other end of the backflow prevention circuit is connected to the second end of the first switching transistor.

[0014] In one embodiment, the power-down protection circuit further includes a driving circuit, which is connected to the output terminal of the control circuit and the controlled terminal of the first switching circuit, respectively. The driving circuit is used to drive the first switching circuit to turn on or off according to the control command output by the control circuit.

[0015] In one embodiment, the driving circuit includes: a second switching transistor, a fifth resistor, and a sixth resistor;

[0016] The first terminal of the second switching transistor is connected to the first switching circuit, the second terminal of the second switching transistor is connected to one end of the fifth resistor and grounded, the controlled terminal of the second switching transistor is connected to the other end of the fifth resistor and one end of the sixth resistor, and the other end of the sixth resistor is connected to the control circuit.

[0017] In one embodiment, the power failure protection circuit further includes a charging circuit. The input terminal of the charging circuit is used to connect to the main power supply circuit, and the output terminal of the charging circuit is connected to the input terminal of the auxiliary power module. The charging circuit is used to output the electrical energy output by the main power supply circuit to the auxiliary power module to charge the auxiliary power module.

[0018] In one embodiment, the load of the inkjet printing device includes a main controller, a drive assembly, and a printhead, wherein the main controller is used to control the drive assembly to drive the printhead to move.

[0019] The control circuit of the power failure protection circuit is connected to the main controller. The control circuit is used to output a reset signal when the auxiliary power module supplies power to the load, so that the main controller controls the drive component to drive the print head to reset to the initial position according to the reset signal.

[0020] This utility model also provides an inkjet printing device, the inkjet printing device comprising:

[0021] Printing platform;

[0022] The print head is positioned above the printing platform and can move relative to the printing platform;

[0023] The main controller is connected to the drive assembly of the print head and is used to control the drive assembly to drive the print head to move.

[0024] The main power supply circuit is electrically connected to the main controller and is used to draw power from an external power source to supply power to the main controller.

[0025] The power-off protection circuit described in any of the above descriptions is electrically connected to the main controller and is used to supply power to the main controller in the event of a power failure in the main power circuit.

[0026] In one embodiment, the inkjet printing device further includes an ink stack assembly disposed on the movement path of the inkjet printing device corresponding to the printhead, the ink stack assembly being used to clean and / or moisturize the printhead when the printhead is located in the ink stack assembly;

[0027] The driving assembly includes a first driving assembly and a second driving assembly. The first driving assembly is used to drive the print head to reciprocate on a first plane so that the print head moves above the ink stack assembly. The second driving assembly is used to drive the print head to reciprocate on a second plane so that the print head moves toward a position opposite to the ink stack assembly.

[0028] The main controller is used to control the first driving component to drive the print head to reset above the ink stack component according to the reset signal output by the power failure protection circuit; and to control the second driving component to drive the print head to reset into the ink stack component.

[0029] In one embodiment, the ink stack assembly includes a peristaltic pump for moisturizing the printhead;

[0030] The main controller is electrically connected to the peristaltic pump and is also used to control the peristaltic pump to operate according to the reset signal in order to keep the printhead moist.

[0031] This utility model provides a power-down protection circuit designed to prevent inkjet printers from experiencing low reliability due to power outages. The power-down protection circuit includes an auxiliary power module, a sampling circuit, and a control circuit. The sampling circuit continuously collects the supply voltage from the external power source and converts the collected voltage value into a corresponding voltage acquisition signal output. When the voltage value corresponding to the voltage acquisition signal drops below a first voltage, the control circuit identifies it as a power-down state. At this time, the auxiliary power module immediately activates, providing power support to the inkjet printer. This ensures that the device can continue to operate and perform critical safety operations, such as moving the printhead to a safe position, performing cleaning procedures, or completing ongoing printing jobs. It prevents the printhead from becoming stuck in the working area due to sudden power loss, causing ink to solidify and clog. Thus, this auxiliary power module improves the overall reliability of the inkjet printer. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 is a schematic diagram of the first embodiment of the power-off protection circuit provided by this utility model;

[0034] Figure 2 is a circuit diagram of an embodiment of the sampling circuit provided by this utility model;

[0035] Figure 3 is a schematic diagram of the second embodiment of the power-off protection circuit provided by this utility model;

[0036] Figure 4 is a schematic diagram of the third embodiment of the power-off protection circuit provided by this utility model;

[0037] Figure 5 is a circuit diagram of an embodiment of the first switching circuit and driving circuit provided by this utility model;

[0038] Figure 6 is a schematic diagram of the fourth embodiment of the power-off protection circuit provided by this utility model;

[0039] Figure 7 is a schematic diagram of an embodiment of the inkjet printing device provided by this utility model.

[0040] Explanation of icon numbers:

[0041] 10. Power-off protection circuit; 100. Auxiliary power supply module; 110. Auxiliary power supply; 120. First switching circuit; 130. Drive circuit; 200. Sampling circuit; 300. Control circuit; 400. Second switching circuit; 500. Storage circuit; 600. Reset circuit; 20. Inkjet printer; 700. Load; 710. Main controller; 720. Drive assembly; 730. Printhead; 740. Ink stack assembly; 741. Peristaltic pump; 800. Main power supply circuit; 900. Charging circuit;

[0042] R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; ADC, analog-to-digital converter; Q1, first switching transistor; Q2, second switching transistor; D1, first diode.

[0043] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0045] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0046] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0047] Inkjet printing equipment is a common type of printing equipment. The inkjet printing equipment described in this application can be a thermal inkjet printer, a piezoelectric inkjet printer, a digital heat transfer printer (“Direct to Film”, DTF printer), a direct-to-garment printer (“Direct to Garment”, DTG printer), etc., as long as it is a device used for printing operations by jetting ink. Inkjet printing equipment forms text or images by precisely jetting tiny ink droplets onto paper or other media. Inkjet printing equipment may include ink cartridges for storing and dispensing ink, a piping system for delivering ink from the cartridges to the printhead, and a mechanical structure for controlling the movement of the printhead in the X and Z axes to achieve precise printing. Furthermore, the inkjet printer is equipped with a main power supply circuit, which obtains power from an external power source to provide energy support for the entire printing process.

[0048] In actual use, external power failures or human error may occur, leading to sudden power outages during printing. In such cases, the inkjet printer immediately loses power, preventing the printhead from returning to its safe stopping position. If any ink remains inside the printhead that is not fully dried, it will gradually solidify due to prolonged exposure to air, potentially causing a series of negative effects. Specifically, firstly, it directly leads to a decline in print quality, such as streaks, uneven coloring, or complete ink ejection. Secondly, resolving printhead clogging often requires significant time and resources, including multiple cleaning attempts and even replacing the printhead, increasing maintenance costs for users. More seriously, frequent printhead clogging can shorten the printer's lifespan, reduce its efficiency, and cause inconvenience to users. Therefore, existing inkjet printing equipment suffers from low reliability.

[0049] In one embodiment, the inkjet printing device includes a main power supply circuit and a load. The input terminal of the main power supply circuit is used to connect to an external voltage, and the output terminal of the main power supply circuit is connected to the power supply terminal of the load. The main power supply circuit processes the external voltage and outputs a supply voltage to the power supply terminal of the load. It is understood that the input terminal of the main power supply circuit is used to connect to an external voltage (typically 100-240V AC mains power), and the output terminal of the main power supply circuit is connected to the power supply terminal of the load to ensure a stable and suitable power supply.

[0050] Optionally, the main power supply circuit includes one or more of the following components: transformer, rectifier, filter, and voltage regulator. The transformer adjusts the input voltage to the required level; the rectifier converts alternating current to direct current; the filter removes ripple from the current, ensuring current stability; and the voltage regulator further ensures the stability of the output voltage, maintaining a constant output even when the input voltage fluctuates. The specific form of the main power supply circuit is not limited here; the key point is that it draws external voltage from an external power source to power the load of the inkjet printer.

[0051] Optionally, the load consists of multiple electronic modules within the inkjet printer, such as the main controller, printhead drive circuit, motor control system, control panel, and other auxiliary function modules. For example, the main controller connects to other components, such as the drive circuit, and controls their operation; the printhead drive circuit controls the ink volume and timing for high-quality printing; the motor control system controls printhead movement; and the control panel provides a user interface for configuring print settings and monitoring printer status. Powered by the main power circuit, these loads ensure the normal operation of the inkjet printer.

[0052] In one embodiment, as shown in FIG1, in order to reduce the reduced lifespan of the printhead 730 due to power failure in the inkjet printing device 20, the present invention proposes a power failure protection circuit 10 for the inkjet printing device 20. The power failure protection circuit 10 includes an auxiliary power supply module 100, a sampling circuit 200 and a control circuit 300.

[0053] In this embodiment, the output terminal of the auxiliary power module 100 is connected to the power supply terminal of the load 700. It is understood that the auxiliary power module 100 is used to provide temporary power support to the inkjet printing device 20 when the main power supply fails. The auxiliary power module 100 may consist of energy storage elements (such as supercapacitors or small batteries), capable of storing sufficient energy for a short period to maintain critical printer operations. Optionally, the energy storage portion of the auxiliary power module 100 may be a non-rechargeable alkaline battery pack or a rechargeable lithium battery pack.

[0054] In some embodiments, the sampling circuit 200 has a sampling terminal and a signal output terminal, the sampling terminal being connected to the output terminal of the main power supply circuit 800; the sampling circuit 200 is used to detect the external voltage and output a corresponding voltage acquisition signal or current acquisition signal through the signal output terminal. In one feasible embodiment, the sampling circuit 200 acquires voltage or current data of the main power supply circuit 800 and transmits the detected voltage and current data to the control circuit 300 in the form of a voltage acquisition signal or a current acquisition signal through the signal output terminal. In this process, the sampling circuit 200 can accurately capture any voltage drop trend and issue a timely warning signal, thus reacting before the main power supply malfunctions, thereby avoiding printing interruptions or other failures caused by sudden voltage drops.

[0055] It should be noted that the sampling circuit 200 can collect the voltage and / or current values ​​of the electrical energy output from the main power supply circuit 800 to the load 700.

[0056] In some embodiments, the control circuit 300 is connected to the signal output terminal and the auxiliary power module 100 respectively; the control circuit 300 is used to control the auxiliary power module 100 to output auxiliary voltage to the power supply terminal of the load 700 when the supply voltage is less than a preset first voltage according to the voltage acquisition signal.

[0057] Understandably, the control circuit 300 processes data from the sampling circuit 200 and makes corresponding decisions. The control circuit 300 is connected to both the signal output terminal of the sampling circuit 200 and the auxiliary power module 100, forming a complete monitoring and response mechanism. The control circuit 300 determines whether the supply voltage is lower than a preset first voltage based on the voltage acquisition signal. If the supply voltage is detected to be lower than the preset first voltage, it determines that the main power circuit 800 is experiencing a power outage. The control circuit 300 then activates the auxiliary power module 100, causing it to output auxiliary voltage to the load 700, and controls the inkjet printer 20 to pause operation and return the print head 730 of the inkjet printer 20 to its initial position for moisturizing. Furthermore, the control circuit 300 can perform other functions, such as recording power outage events and optimizing the power switching process, further improving the system's reliability and intelligence. Thus, through precise voltage management and a rapid response mechanism, the control circuit 300 effectively prevents hardware damage and print quality issues caused by unexpected power outages.

[0058] It should be noted that the control circuit 300 of the power failure protection circuit 10 can be integrated into the main controller 710 of the inkjet printing device 20. When a power failure occurs, the control circuit 300 allows the auxiliary power module 100 to supply power, so that the main controller 710 can directly draw power from the auxiliary power module 100.

[0059] In one feasible implementation, the power failure protection circuit 10 can also save the current printing status progress when the power fails, so as to remind the user whether to continue the last unfinished printing when the main power circuit 800 is powered on again. If no selection is made within 10 seconds, the printing will continue by default according to the last unfinished task.

[0060] Optionally, in addition to shutting down the main power circuit 800 and turning on the auxiliary power module 100 when a power failure is detected, the control circuit 300 may also include controlling the operating status of each load 700 of the inkjet printing device 20.

[0061] Optionally, if the sampling circuit 200 outputs a signal indicating that the supply voltage of the main power circuit 800 has dropped below a second voltage (the second voltage is lower than the first voltage), then the main power circuit 800 is determined to be open-circuited. This could be due to two scenarios: either the main power circuit 800 is manually turned off, or it is turned off externally. Therefore, the power-down protection circuit 10 may further include a selection circuit to receive a user input command when the supply voltage drops below the second voltage, and determine whether the inkjet printer 20 needs to be shut down based on the input command. When the input command indicates that the inkjet printer 20 needs to be shut down, the printhead 730 can be controlled to return to its initial position and perform moisturizing operations via an auxiliary voltage; when the input command indicates that the inkjet printer 20 does not need to be shut down, printing can continue via an auxiliary voltage (in this case, the auxiliary power supply 110 needs to be an energy storage module with a large amount of electrical energy to maintain printing operations for long or short periods).

[0062] Optionally, if the sampling signal output by the sampling circuit 200 indicates that the supply voltage of the main power supply circuit 800 has dropped below a first voltage, then the main power supply circuit 800 is determined to be powered down. The power-down protection circuit 10 may further include a selection circuit, used to receive a user input command when the supply voltage drops below the first voltage, and determine whether the inkjet printer 20 needs to be shut down based on the input command. If the input command indicates that the inkjet printer 20 needs to be shut down, the printhead 730 can be controlled to return to its initial position and perform moisturizing operations via an auxiliary voltage; if the input command indicates that the inkjet printer 20 does not need to be shut down, printing can continue via an auxiliary voltage. This is applicable to situations where the auxiliary power module 100 has limited power and cannot sustain long-term printing, allowing the user to continue printing when the printing job is almost finished, enhancing the user experience and efficiency.

[0063] Optionally, after the main power circuit 800 is turned off, if printing is required via the auxiliary power module 100 (regardless of whether printing needs to continue), the control circuit 300 can prioritize shutting down non-critical loads 700 (such as the display screen, user interface, etc.) to reduce overall power consumption. This can alleviate the operating time of the auxiliary power module 100 to some extent.

[0064] It should be noted that the first and second voltages mentioned above are the system's preset voltages, and the actual corresponding voltage values ​​are not limited here.

[0065] In summary, the power-down protection circuit 10 provided by this invention aims to reduce the reliability issues of the inkjet printing device 20 due to power outages. The power-down protection circuit 10 includes an auxiliary power supply module 100, a sampling circuit 200, and a control circuit 300. The sampling circuit 200 collects the supply voltage provided by the external power supply in real time and converts the collected voltage value into a corresponding voltage acquisition signal output. When the voltage value corresponding to the voltage acquisition signal drops below a first voltage, the control circuit 300 identifies it as a power-down state. At this time, the auxiliary power supply module 100 immediately starts, providing power support to the inkjet printing device 20. This ensures that the device can continue to operate and perform critical safety operations, such as moving the printhead 730 to a safe position, performing cleaning procedures, or completing ongoing printing jobs, thereby preventing the printhead 730 from remaining in the working area due to sudden power loss and causing ink solidification and clogging, thus improving the reliability of the inkjet printing device.

[0066] In one embodiment, as shown in FIG2, the sampling circuit 200 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the main power supply circuit 800, and the second end of the first resistor R1 is connected to the first end of the second resistor R2. The second end of the second resistor R2 is grounded. Thus, the first resistor R1 and the second resistor R2 form a voltage divider. Assuming the input voltage is VCC, a proportional output voltage Vout can be obtained at the lower end of the second resistor R2 through the voltage division of the first resistor R1 and the second resistor R2.

[0067] In this embodiment, as shown in Figure 2, a digital-to-analog converter (DAC) can also be used for sampling. Optionally, the sampling circuit 200 includes a first resistor R1, a second resistor R2, and an ADC. The first end of the first resistor R1 is connected to the main power supply circuit 800, the second end of the first resistor R1 is connected to the input terminal of the ADC and the first end of the second resistor R2, the second end of the second resistor R2 is grounded, and the output terminal of the ADC is used as the signal output terminal and connected to the control circuit 300. Thus, the first resistor R1 and the second resistor R2 form a voltage divider. Assuming the input voltage is VCC, a proportional output voltage Vout can be obtained at the lower end of the second resistor R2 through the voltage division of the first resistor R1 and the second resistor R2. This output voltage Vout is connected to the ADC, and the analog voltage signal of Vout is converted into a digital signal and input to the control circuit 300. The control circuit 300 determines whether the current supply voltage is lower than a preset first voltage based on the digital signal converted by the ADC.

[0068] In one embodiment, as shown in FIG3, the auxiliary power supply module 100 includes an auxiliary power supply 110 and a first switching circuit 120. The input terminal of the first switching circuit 120 is connected to the auxiliary power supply 110, the output terminal of the first switching circuit 120 is connected to the load 700, and the controlled terminal of the first switching circuit 120 is connected to the control circuit 300. The control circuit 300 is used to control the first switching circuit 120 to be turned on or off according to the voltage acquisition signal, so as to control the connection or disconnection of the path between the auxiliary power supply 110 and the load 700.

[0069] Optionally, the input terminal of the first switching circuit 120 is connected to the auxiliary power supply 110, and the output terminal is connected to the load 700, while its controlled terminal is connected to the control circuit 300. The control circuit 300 determines the current external power supply status based on the voltage acquisition signal and controls the on or off state of the first switching circuit 120 accordingly. When the supply voltage is detected to be lower than a preset threshold, the control circuit 300 activates the first switching circuit 120, turning it on to establish a current path between the auxiliary power supply 110 and the load 700, ensuring that the load 700 can continue to receive the necessary power supply. Conversely, if the external power supply voltage returns to normal, the control circuit 300 commands the first switching circuit 120 to turn off, disconnecting the auxiliary power supply 110 from the load 700 and restoring the normal power supply mode. In this way, damage to the equipment caused by sudden power failure is effectively avoided, and the reliability and stability of the entire printing system are also improved.

[0070] In one embodiment, as shown in FIG5, the first switching circuit 120 includes: a first switching transistor Q1, a third resistor R3 and a fourth resistor R4; the first terminal of the first switching transistor Q1 is connected to the auxiliary power supply 110 and the first terminal of the third resistor R3, the second terminal of the first switching transistor Q1 is connected to the load 700, and the controlled terminal of the first switching transistor Q1 is connected to the control circuit 300 through the fourth resistor R4.

[0071] Understandably, the control circuit 300 outputs a conduction signal to the controlled terminal of the first switching transistor Q1, causing Q1 to conduct. This connects the auxiliary power supply 110 and the load 700, allowing the auxiliary power supply 110 to output an auxiliary voltage to the load 700. The third resistor R3 and the fourth resistor R4 are both current-limiting resistors.

[0072] In this embodiment, the first switching circuit 120 further includes an anti-backflow circuit, which is connected in series in the path between the first switching transistor Q1 and the load 700. One end of the anti-backflow circuit is connected to the load 700, and the other end of the anti-backflow circuit is connected to the second end of the first switching transistor Q1.

[0073] Optionally, as shown in Figure 5, the backflow prevention circuit includes a first diode D1, which is connected in series in the path between the first switch Q1 and the load 700. The cathode of the first diode D1 is connected to the load 700, and the anode of the first diode D1 is connected to the second terminal of the first switch Q1. It is understood that the first diode D1 is used to prevent backflow, ensuring the stability of the entire circuit and thus improving the reliability of the inkjet printer 20.

[0074] In other embodiments, the backflow prevention circuit can also be other types of circuits, not limited to those implemented using diodes.

[0075] In one embodiment, as shown in FIG4, the power failure protection circuit 10 further includes a drive circuit 130, which is connected to the output terminal of the control circuit 300 and the controlled terminal of the first switch circuit 120 respectively. The drive circuit 130 is used to drive the first switch circuit 120 to be turned on or off according to the control command output by the control circuit 300.

[0076] Understandably, the drive circuit 130 receives low-power control commands from the control circuit 300 and converts them into signals of sufficient strength to directly operate the first switching circuit 120. Firstly, the drive circuit 130 provides sufficient current and voltage gain to ensure that the control signal can be accurately identified and responded to by the first switching transistor Q1 even during long-distance transmission or in high-noise environments, enhancing the system's anti-interference capability. Secondly, by using the drive circuit 130, the control circuit 300 and the first switching circuit 120 can be effectively isolated, avoiding the impact of voltage fluctuations that might occur due to direct connection on the sensitive control circuit 300, thus improving the overall system stability and reliability.

[0077] In some embodiments, as shown in FIG5, the driving circuit 130 includes: a second switch Q2, a fifth resistor R5, and a sixth resistor R6; the first end of the second switch Q2 is connected to the first switching circuit 120, the second end of the second switch Q2 is connected to one end of the fifth resistor R5 and grounded, the controlled end of the second switch Q2 is connected to the other end of the fifth resistor R5 and one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the control circuit 300.

[0078] Understandably, the drive circuit 130 enhances the transmission efficiency and stability of the control signal through the combination of the second switch Q2, the fifth resistor R5, and the sixth resistor R6. Specifically, the signal from the control circuit 300 is connected to the controlled terminal of the second switch Q2 via the sixth resistor R6, while the first terminal of the second switch Q2 is connected to the first switching circuit 120 to control its on or off state. One end of the fifth resistor R5 is grounded, and the other end is connected between the second terminal and the controlled terminal of the second switch Q2. The sixth resistor R6 limits current, and the fifth resistor R5 acts as a pull-down resistor to ensure that the circuit remains stable when there is no signal input. In one feasible embodiment, when the control circuit 300 sends a high-level signal, the second switch Q2 is turned on, causing the first switching circuit 120 to receive the corresponding command and change its state; conversely, a low-level signal will turn off the second switch Q2, restoring it to its initial state.

[0079] Combining the first switching circuit 120 and the driving circuit 130 described above, as shown in Figure 5, the circuit has the following characteristics: the first terminal of the first switching transistor Q1 is connected to the auxiliary power supply and the first terminal of the third resistor R3; the second terminal of the first switching transistor Q1 is connected to the load 700 through the first diode D1; the controlled terminal of the first switching transistor Q1 is connected to the first terminal of the second switching transistor Q2 through the fourth resistor R4; the second terminal of the second switching transistor Q2 is connected to one end of the fifth resistor R5 and grounded; the controlled terminal of the second switching transistor Q2 is connected to the other end of the fifth resistor R5 and one end of the sixth resistor R6; and the other end of the sixth resistor R6 is connected to the control circuit 300. In one feasible embodiment, when the control circuit 300 detects that the power supply voltage drops below a first voltage, it generates a control signal, which is amplified or converted into a signal suitable for driving the MOSFET by the driving circuit 130. After this signal is sent to the gate of the first switching transistor Q1, the first switching transistor Q1 is turned on. This ensures that the control signal can accurately control the state of the first switching circuit 120, thereby achieving the power-down protection function.

[0080] In one embodiment, as shown in FIG6, the power failure protection circuit 10 further includes a charging circuit 900. The input terminal of the charging circuit 900 is used to connect to an external power source, and the output terminal of the charging circuit 900 is connected to the input terminal of the auxiliary power supply 110 module 100. The charging circuit 900 is used to transfer electrical energy from the external power source to the auxiliary power supply 110 module 100 to charge the auxiliary power supply 110 module 100.

[0081] Understandably, the charging circuit 900 ensures that the auxiliary power supply module 100 can provide stable power support when needed. Specifically, the input of the charging circuit 900 is connected to an external power source, such as AC mains or other DC power, and its output is connected to the input of the auxiliary power supply module 100. It is used to transfer the electrical energy provided by the external power source to the auxiliary power supply module 100, charge it, and maintain its power reserve.

[0082] Optionally, by incorporating a built-in control and regulation mechanism, the charging circuit 900 can optimize the charging process, preventing overcharging, over-discharging, and excessive current, thereby extending the service life of the auxiliary power supply module 100 and ensuring it is always in optimal working condition. Furthermore, the charging circuit 900 is optionally equipped with voltage and current monitoring functions, allowing for real-time adjustment of charging parameters to adapt to different load requirements and environmental changes, further enhancing system reliability and stability.

[0083] Optionally, the charging circuit 900 can draw power from the main power circuit 800 and charge the auxiliary power supply module 110. In this way, when the inkjet printer 20 is operating normally, the charging circuit 900 can charge the auxiliary power supply module 110, ensuring that when the main power circuit 800 loses power or is disconnected, the auxiliary power supply module 110 has enough power to supply the load 700.

[0084] In one embodiment, as shown in FIG6, the power failure protection circuit 10 further includes a second switching circuit 400. The input terminal of the second switching circuit 400 is connected to the output terminal of the main power supply circuit 800, the output terminal of the second switching circuit 400 is connected to the load 700, and the controlled terminal of the second switching circuit 400 is connected to the output terminal of the control circuit 300. The control circuit 300 is further configured to control the second switching circuit 400 to turn off after controlling the first switching circuit 120 to turn on according to the voltage acquisition signal, and to control the second switching circuit 400 to turn on after controlling the first switching circuit 120 to turn off according to the voltage acquisition signal.

[0085] In one feasible implementation, when the supply voltage is detected to drop below a first voltage, the control circuit 300 first commands the first switching circuit 120 to turn on, allowing the auxiliary power supply 110 to supply power to the load 700. Immediately afterwards, the control circuit 300 sends a command to the second switching circuit 400 to turn off, thereby disconnecting the main power supply from the load 700 and preventing damage to the device due to voltage instability. Conversely, once the external power supply voltage returns to normal, the control circuit 300 first commands the first switching circuit 120 to turn off, disconnecting the auxiliary power supply 110, and then commands the second switching circuit 400 to turn on again, restoring the state of supplying power to the load 700 from the main power supply. Thus, the second switching circuit 400 and the first switching circuit 120 work together to ensure a continuous and stable power supply to the load 700, while also ensuring a smooth and safe switching process from the main power supply to the auxiliary power supply 110 and vice versa, effectively protecting the inkjet printing equipment 20 from voltage fluctuations.

[0086] In one embodiment, as shown in FIG7, the load 700 of the inkjet printing device 20 includes a main controller 710, a drive assembly 720, and a printhead 730. The main controller 710 is used to control the drive assembly 720 to drive the printhead 730 to move. It is understood that the main controller 710, as the core of the entire system, is used to parse the received printing task and generate corresponding control commands. These control commands are then transmitted to the drive assembly 720, which adjusts its output according to the control commands to ensure that the printhead 730 can move in the X and Z axis directions. Optionally, the drive assembly 720 includes an actuator such as a stepper motor or a servo motor, which can respond to signals from the main controller 710 and drive the printhead 730 to adjust its position so as to accurately spray ink droplets onto designated positions on the paper.

[0087] In some embodiments, the control circuit 300 of the power failure protection circuit 10 is connected to the main controller 710. The control circuit 300 is used to output a reset signal when controlling the auxiliary power supply 110 module 100 to supply power to the load 700. The main controller 710 controls the drive component 720 to drive the print head 730 to reset to the initial position according to the reset signal.

[0088] Understandably, when a power failure or interruption is detected in the main power circuit 800 and a switch to auxiliary power module 110 100 is needed to power the load 700, the control circuit 300 will not only activate the first switching circuit 120 to enable the auxiliary power supply 110, but will also simultaneously output a reset signal to the main controller 710. This reset signal indicates that critical components such as the printhead 730 need to be reset to their initial positions to avoid equipment damage caused by a sudden power outage. Therefore, the main controller 710 will control the printhead 730 to return to its initial position via the drive component 720. This effectively prevents data loss or hardware failure due to unexpected power outages, greatly improving the reliability of the entire system and the user experience.

[0089] Optionally, as shown in Figure 7, the control circuit 300 is integrated into the main controller 710. It is understood that integrating the control circuit 300 into the main controller 710 simplifies the hardware architecture of the inkjet printing device 20 and improves the system's integration and efficiency. The main controller 710, as the core of the entire system, is used to parse printing tasks, generate control commands, and manage all operations related to the drive component 720, printhead 730, and ink stack component 740. By integrating the functions of the control circuit 300 into the main controller 710, the number of external connections and interfaces can be reduced, signal transmission delay can be lowered, and the overall system response speed can be improved.

[0090] Optionally, as shown in FIG7, the power failure protection circuit 10 further includes a storage circuit 500 and a reset circuit 600. The power supply terminal of the storage circuit 500 is connected to the auxiliary power module 100, and the signal acquisition terminal of the storage circuit 500 is connected to the main controller 710. The storage circuit 500 is used to store the control commands output by the main controller 710 to the drive component 720. The power supply terminal of the reset circuit 600 is connected to the auxiliary power module 100, and the signal input terminal of the reset circuit 600 is connected to the signal output terminal of the storage circuit 500. The signal output terminal of the reset circuit 600 is connected to the main controller 710. The reset circuit 600 is used to output a corresponding reset command to the main controller 710 according to the control commands stored in the storage circuit 500 when the supply voltage of the main power circuit 800 is less than a first voltage, so as to reset the printhead 730. This ensures that the printhead 730 can return to its initial position after a power outage, preventing the printhead 730 from remaining stuck in the current printing position and causing the ink in the printhead 730 to solidify. This extends the lifespan of the printhead 730 and also improves the reliability of the device.

[0091] Optionally, not shown in the figures, the power-down protection circuit 10 only includes a reset circuit. This reset circuit has a preset initial position. When the supply voltage is not less than a first voltage, the load 700 of the inkjet printer 20 operates normally. When the supply voltage is less than the first voltage, the reset circuit outputs a reset command to the main controller 710, so that the main controller 710 controls the drive assembly 720 to drive the print head 730 back to the preset initial position for easy moisturizing. In this simplified design, the power-down protection circuit 10 only includes a reset circuit. This reset circuit has built-in preset initial position information. When the supply voltage drops below the first voltage, the reset circuit is automatically triggered and sends a reset command to the main controller 710. Upon receiving the command, the main controller 710 controls the drive assembly 720 to return the print head 730 to the preset initial position. This ensures that in the event of an unexpected power failure, the print head 730 can quickly and safely return to its original position, protecting the equipment and facilitating subsequent operation and maintenance, thus ensuring the service life of the inkjet printer 20.

[0092] This utility model also proposes an inkjet printing device 20, which includes a main power supply circuit 800 and a power failure protection circuit 10. The specific structure of the power failure protection circuit 10 is as described in the above embodiments. Since this inkjet printing device 20 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0093] In this embodiment, the inkjet printing device 20 includes a printing platform, a printhead 730, and a main controller 710. The printhead 730 is positioned above the printing platform and is movable relative to the printing platform. The main controller 710 is controlled and connected to the drive assembly 720 of the printhead 730, and is used to control the drive assembly 720 to drive the printhead 730 to move. Optionally, the printhead 730 is driven by the drive assembly 720 to move above the printing platform; optionally, the main controller 710 can control the drive assembly 720 to drive the printhead 730.

[0094] The main power supply circuit 800 draws power from an external power source to power the main controller 710 of the inkjet printing device 20; the power output terminal of the power failure protection circuit 10 is connected to the main controller 710 of the inkjet printing device 20. The power failure protection circuit 10 not only protects the inkjet printing device 20 from voltage fluctuations when the main power supply circuit 800 is interrupted, but also has reset and moisturizing functions.

[0095] In one embodiment, the load 700 of the inkjet printing device 20 further includes an ink stack assembly 740, which is disposed on the movement path of the inkjet printing device 20 corresponding to the printhead 730. The ink stack assembly 740 is used to clean and / or moisturize the printhead 730 when the printhead 730 is located in the ink stack assembly 740.

[0096] In some embodiments, the driving component 720 includes a first driving component and a second driving component. The first driving component drives the print head 730 to reciprocate on a first plane, so that the print head 730 moves above the ink stack assembly 740. The second driving component drives the print head 730 to reciprocate on a second plane, so that the print head 730 moves toward a position opposite to the ink stack assembly 740. It should be noted that the first driving component drives the print head 730 to reciprocate in a direction parallel to the first plane (which can be the X-axis), allowing the print head 730 to move freely above the ink stack assembly 740. The second driving component drives the print head 730 to move along the second plane (which can be the Z-axis), enabling the print head 730 to accurately reach the position of the ink stack assembly 740. This allows the print head 730 to move flexibly in two dimensions, ensuring both high efficiency in the printing process and convenient maintenance of the print head 730.

[0097] In some embodiments, the main controller 710 controls the first drive component 720 to determine that the printhead 730 is reset above the ink stack component 740 according to the reset signal; and the main controller 710 controls the second drive component 720 to drive the printhead 730 back into the ink stack component 740 according to the reset signal. It is understood that when the main controller 710 receives a reset signal from the control circuit 300, the main controller 710 will control the first drive component 720 to position the printhead 730 above the ink stack component 740 according to this signal, and further precisely reset the printhead 730 into the ink stack component 740 through the second drive component 720. This ensures that even in the event of a sudden power outage, the printhead 730 can safely return and remain inside the ink stack component 740, thereby effectively preventing clogging problems caused by drying and improving system reliability and maintenance efficiency.

[0098] Optionally, the reset circuit 600 includes a first reset circuit 600 and a second reset circuit 600. The first reset circuit 600 is used to output a first reset command to the main controller 710, so that the first drive component controls the printhead 730 to return to the position above the ink stack assembly 740. The second reset circuit 600 is used to output a second reset command to the main controller 710 after the first drive component is reset, so that the second drive component controls the printhead 730 to return to the position inside the ink stack assembly 740. In one embodiment, the first reset circuit 600 is used to send a first reset command to the control circuit 300 when it detects that the power supply voltage has dropped to a first voltage, so as to trigger the first drive component to act, so that the printhead 730 returns to the position above the ink stack assembly 740, ready to enter the maintenance state. Once the first drive component completes the reset, the second reset circuit 600 will issue a second reset command to the control circuit 300. According to the second reset command, the second drive component moves the printhead 730 into the ink stack assembly 740 for moisturizing, ensuring that the printhead 730 is properly protected even in the event of a power outage.

[0099] In one embodiment, the ink stack assembly 740 includes a peristaltic pump 741, and the main controller 710 is further configured to control the peristaltic pump 741 to perform moisturizing operations on the printhead 730. The peristaltic pump 741 is a device that delivers liquid by squeezing a flexible tube; in this application scenario, it can be used to precisely control the amount of moisturizing liquid delivered to the printhead 730. The control circuit 300 can send commands to the peristaltic pump 741 as needed to ensure that the printhead 730 is moisturized under appropriate time and conditions. This effectively prevents the printhead 730 from drying out and clogging due to prolonged inactivity, extends the lifespan of the printhead 730, and improves equipment reliability.

[0100] Therefore, the inkjet printing device 20 includes the power-down protection circuit 10. Compared with inkjet printing devices in the prior art, the inkjet printing device 20 can reduce the low reliability caused by power failure through the power-down protection circuit 10. The power-down protection circuit 10 can exist independently or be integrated into the main controller 710 of the inkjet printing device 20.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A power-off protection circuit, characterized in that, The power failure protection circuit is used in an inkjet printing device. The inkjet printing device includes a main power supply circuit and a load. The input terminal of the main power supply circuit is used to connect to an external voltage. The output terminal of the main power supply circuit is connected to the power supply terminal of the load. The main power supply circuit is used to process the external voltage and output a supply voltage to the power supply terminal of the load. The power failure protection circuit includes: an auxiliary power supply module, the output terminal of which is connected to the power supply terminal of the load; A sampling circuit, having a sampling terminal and a signal output terminal, wherein the sampling terminal is connected to the output terminal of the main power supply circuit; the sampling circuit is used to detect the external voltage and output a corresponding voltage acquisition signal or current acquisition signal through the signal output terminal; a control circuit, connected to the signal output terminal and the auxiliary power supply module respectively; the control circuit is used to control the auxiliary power supply module to output an auxiliary voltage to the power supply terminal of the load when determining, based on the voltage acquisition signal, that the supply voltage is less than a first voltage.

2. The power-off protection circuit as described in claim 1, characterized in that, The sampling circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the main power supply circuit, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded.

3. The power-off protection circuit as described in claim 1, characterized in that, The auxiliary power supply module includes an auxiliary power supply and a first switching circuit. The input terminal of the first switching circuit is connected to the auxiliary power supply, the output terminal of the first switching circuit is connected to the load, and the controlled terminal of the first switching circuit is connected to the control circuit. The control circuit is used to control the first switching circuit to be turned on or off according to the voltage acquisition signal, so as to control the connection or disconnection between the auxiliary power supply and the load.

4. The power-off protection circuit as described in claim 3, characterized in that, The first switching circuit includes: a first switching transistor, a third resistor, and a fourth resistor; the first terminal of the first switching transistor is connected to the auxiliary power supply and the first terminal of the third resistor, the second terminal of the first switching transistor is connected to the load, and the controlled terminal of the first switching transistor is connected to the control circuit through the fourth resistor.

5. The power-off protection circuit as described in claim 4, characterized in that, The first switching circuit further includes an anti-backflow circuit, which is connected in series in the path between the first switching transistor and the load. One end of the anti-backflow circuit is connected to the load, and the other end of the anti-backflow circuit is connected to the second end of the first switching transistor.

6. The power-off protection circuit as described in claim 3, characterized in that, The power failure protection circuit further includes a drive circuit, which is connected to the output terminal of the control circuit and the controlled terminal of the first switching circuit, respectively. The drive circuit is used to drive the first switching circuit to turn on or off according to the control command output by the control circuit.

7. The power-off protection circuit as described in claim 6, characterized in that, The driving circuit includes: a second switching transistor, a fifth resistor, and a sixth resistor; the first end of the second switching transistor is connected to the first switching circuit, the second end of the second switching transistor is connected to one end of the fifth resistor and grounded, the controlled end of the second switching transistor is connected to the other end of the fifth resistor and one end of the sixth resistor, and the other end of the sixth resistor is connected to the control circuit.

8. The power-off protection circuit as described in any one of claims 1 to 7, characterized in that, The power failure protection circuit also includes a charging circuit. The input terminal of the charging circuit is used to connect to the main power supply circuit, and the output terminal of the charging circuit is connected to the input terminal of the auxiliary power module. The charging circuit is used to output the electrical energy output by the main power supply circuit to the auxiliary power module to charge the auxiliary power module.

9. The power-off protection circuit as described in any one of claims 1 to 7, characterized in that, The load of the inkjet printing equipment includes a main controller, a drive assembly, and a printhead. The main controller is used to control the drive assembly to drive the printhead to move. The control circuit of the power failure protection circuit is connected to the main controller. The control circuit is used to output a reset signal when the auxiliary power module supplies power to the load, so that the main controller controls the drive assembly to drive the printhead to reset to the initial position according to the reset signal.

10. An inkjet printing device, characterized in that, The inkjet printing device includes: a printing platform; a printhead disposed above the printing platform and movable relative to the printing platform; a drive assembly connected to the printhead for driving the printhead to move; a main controller connected to the drive assembly for controlling the drive assembly to drive the printhead to move; a main power circuit electrically connected to the main controller, the main power circuit being used to draw power from a power source to supply power to the main controller; and a power-off protection circuit as described in any one of claims 1 to 9, wherein the power-off protection circuit is electrically connected to the main controller for supplying power to the main controller in the event of a power failure of the main power circuit.

11. The inkjet printing apparatus as described in claim 10, characterized in that, The inkjet printing device further includes an ink stack assembly disposed on the movement path of the printhead. The ink stack assembly is used to clean and / or moisturize the printhead when it is located in the ink stack assembly. The driving assembly includes a first driving assembly and a second driving assembly. The first driving assembly is used to drive the printhead to reciprocate on a first plane so that the printhead moves above the ink stack assembly. The second driving assembly is used to drive the printhead to reciprocate on a second plane so that the printhead moves toward a position opposite to the ink stack assembly. The main controller is used to control the first driving assembly to drive the printhead to return to its position above the ink stack assembly according to the reset signal output by the power failure protection circuit; and to control the second driving assembly to drive the printhead to return to its position within the ink stack assembly.

12. The inkjet printing apparatus as described in claim 11, characterized in that, The ink stack assembly includes a peristaltic pump for moisturizing the printhead; the main controller is electrically connected to the peristaltic pump and is also used to control the peristaltic pump to moisturize the printhead according to the reset signal.

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