KR20210087731A - Pressure controlling apparatus for ink-jet printer - Google Patents

Abstract

The present invention relates to a pressure control apparatus for an inkjet printer. The apparatus is connected to a storage unit for head supply supplying ink to an inkjet head with a plurality of nozzles discharging ink to control pressure, and comprises: a negative pressure generator to apply a negative pressure to the storage unit for head supply; a positive pressure generator to apply a positive pressure to the storage unit for head supply; an output tube outputting the negative pressure or the positive pressure generated by the negative pressure generator or the positive pressure generator to the outside; a first valve installed between the negative pressure generator and the output tube; a second valve which is a three-way valve installed between the positive pressure generator and the output tube; and a buffer unit connected to the second valve. The buffer unit is a sealed space filled with gas. The present invention applies the buffer unit connected to the positive pressure generator through the three-way valve to open the valve to the buffer unit while closing a port of the positive pressure generator to reduce a difference from a control target volume set for pressure control. The present invention switches a control direction through the three-way valve to reduce the difference from the control target volume. Therefore, a state in which the pressure is stable when closing the port of the positive pressure generator can be maintained, and the time taken to reach the control pressure when opening the port of the positive pressure generator can be reduced.

Description

PRESSURE CONTROLLING APPARATUS FOR INK-JET PRINTER}

The present invention relates to a pressure control device for controlling the pressure of an inkjet head, and more particularly, to a device connected to an ink storage unit for supplying ink to an inkjet head of an inkjet printer used in an industrial field to control the pressure.

In general, the inkjet method of spraying liquid ink on the surface of a medium in the form of droplets according to a shape signal is used not only as printing for creating documents or flyers, but also in solution processes in semiconductor or display fields.

The application range of inkjet printing, which can form a pattern of a complex shape on a substrate or precisely eject ink only at a specific location, is expanding. Small inkjet printers for document creation have a form of storing ink in an inkjet head that ejects ink droplets, but large-sized document printers or industrial inkjet printers use a large amount of ink. A structure in which the storage unit and the inkjet head are separated is applied.

12 is a schematic diagram for explaining the structure of a general industrial inkjet printer.

A typical industrial inkjet printer includes an inkjet head 10 , a head supply storage unit 20 , a pressure control device 30 , a buffer storage unit 40 , and an ink storage tank 50 .

The inkjet head 10 includes a nozzle for discharging ink, and performs printing by selectively discharging ink to a required position. The head supply storage unit 20 is a space for storing ink in order to supply ink to the inkjet head 10 , and the ink is continuously supplied through the supply passage 11 connected to the head supply storage unit 20 . . Ink may be supplied only in one direction from the head supply storage unit 20 toward the inkjet head 10 , but the ink remaining in the inkjet head 10 may be stored back in the head supply storage unit 20 to accurately control the discharge amount. ), it is common in industrial inkjet printers to have a recovery passage 12 for returning them. The pressure control device 30 is configured to adjust the pressure of the inkjet head 10 and the storage unit 20 for supplying the ink for accurate ejection of ink, and the pressure control tube 31 includes the storage unit for supplying the head 20 . is connected to Inkjet printers used for industrial purposes have to continuously supply ink to the storage unit 20 for supplying the head because the amount of ink used is very large, but instead of adding ink directly to the storage unit 20 for supplying the head, the buffer storage unit It is common to additionally input the ink stored in the ink storage tank 50 located outside through step (40). At this time, the additionally added ink moves from the ink storage tank 50 toward the buffer storage unit 40 in one direction.

In order to eject an accurate amount of ink in the inkjet printing process, the ink in the inkjet head in a state of preparation for ejection must maintain a meniscus state, which is a curved state in which the ink is indented inward by a capillary phenomenon with respect to the nozzle inlet. To this end, the position of the head supply storage unit is positioned higher than that of the inkjet head, and instead, the inside of the head supply storage unit is maintained in a vacuum to generate negative pressure in the head supply storage unit, thereby preventing ink from flowing down from the inkjet head. Thus, it is common to maintain the meniscus state. However, if the storage unit for supplying the head is maintained in a vacuum, the evaporation of the solvent constituting the ink is accelerated and the properties of the ink are changed, and the most problematic among them is that the viscosity of the ink increases as time goes by. As the viscosity of the ink increases, it becomes difficult to effectively eject the ink from the inkjet head.

In addition, as the field of application of the inkjet printer is diversified, the case of using the ink in which the metal particles are dispersed, such as the case of applying the ink in which the metal particles are dispersed, is increasing for the electrode pattern. In particular, as the use of quantum dot materials increases in the field of OLED displays, attempts have been made to apply inkjet printing in the process of applying quantum dot materials only to predetermined patterns or predetermined positions. However, the situation is that inkjet printing cannot be applied due to a problem in which dispersibility is lowered, such as metal particles or quantum dot materials sink due to their own weight in a state stored in the storage unit for supplying the head.

On the other hand, a pressure control device used in an inkjet printer includes a negative pressure generator that generates a negative pressure to maintain a meniscus state and a positive pressure generator that generates a positive pressure in the case of ink ejection, and uses a plurality of valves to provide positive and negative pressure is converting

Various technologies have been developed to minimize overshooting or undershooting that occurs when converting from negative pressure to positive pressure or from positive pressure to negative pressure in such a pressure control device and to precisely control the pressure. However, the problem that the control pressure becomes unstable in the process of closing the port of the positive pressure generator that generates the positive pressure continues to occur, and when the port connected to the positive pressure generator is opened again, the time to reach the control pressure is delayed.

Republic of Korea Patent Registration 10-1694278

An object of the present invention is to provide a pressure control device for an inkjet printer capable of reducing the instability of the control pressure and shortening the time for the positive pressure generator to reach the control pressure again.

A pressure control device for an inkjet printer according to the present invention for achieving the above object is a device connected to a head supply storage for supplying ink to an inkjet head having a plurality of nozzles for discharging ink to control the pressure, a negative pressure generator for applying negative pressure to the storage unit for supplying the head; a positive pressure generator for applying positive pressure to the storage unit for supplying the head; an output pipe through which the negative pressure or positive pressure generated by the negative pressure generator or the positive pressure generator is output to the outside; a first valve installed between the sound pressure generator and the output pipe; a second valve which is a three-way valve installed between the positive pressure generator and the output pipe; and a buffer part connected to the second valve, wherein the buffer part is an enclosed space filled with gas.

The present invention can reduce the difference with the control target volume set for pressure control by adding a buffer, and reduce pressure hunting and time to reach the control pressure.

It is preferable that the volume of the buffer part is set to be controlled by the positive pressure generator to be at least 10% of the volume to be controlled.

When the volume of the buffer part is 50% or more of the volume to be controlled by the volume set to be controlled by the positive pressure generator, the pressure hunting and the time to reach the control pressure can be sufficiently reduced.

When the volume of the buffer is set to be controlled by the positive pressure generator and is in the range of 90 to 100% of the control target volume, pressure hunting and time to reach the control pressure can be minimized.

The buffer unit may be a reservoir in the form of a pocket or a case connected by a tube.

The buffer unit may be in the form of a tube having a predetermined length or longer, and when the tube is formed in a rolled form, the space for installing the tube is reduced, thereby improving space utilization.

A pressure sensor for measuring pressure information and a temperature sensor for measuring temperature information are installed in the output tube, and it is preferable to perform temperature correction with respect to the pressure information measured by the pressure sensor based on the temperature measured by the temperature sensor.

In addition, two or more pressure sensors may be installed, and a temperature sensor may be provided for each of the plurality of pressure sensors.

The present invention configured as described above applies the positive pressure generator and the buffer connected to the 3-way valve, thereby closing the port of the positive pressure generator and opening the valve with the buffer, thereby reducing the difference from the control target volume set for pressure control. there is

Since the present invention reduces the difference with the control target volume by changing the control direction through the 3-way valve, the pressure can be maintained in a stable state when the port of the positive pressure generator is closed, and the control pressure is reached when the port of the positive pressure generator is opened. time can be reduced.

Finally, since the pressure control is stable and the time to reach the control pressure is reduced, the precision and work efficiency of the inkjet printer are improved.

1 is a schematic diagram for explaining the configuration of a pressure control device according to an embodiment of the present invention.
2 is a schematic diagram for explaining a conventional pressure control device for comparison with the present invention.
3 is a schematic diagram for explaining the operation of the second valve in the pressure control device according to the embodiment of the present invention.
4 is a view for explaining one form of the buffer used in the pressure control device according to the embodiment of the present invention.
5 is a graph showing the pressure measurement results according to the length of the buffer tube used in the pressure control device according to the embodiment of the present invention.
FIG. 6 is a view for explaining the shape of the buffer part measured by the second graph of FIG. 5 .
FIG. 7 is a view for explaining the shape of the buffer part measured by the third graph of FIG. 5 .
8 is a graph comparing the pressure measured by the pressure sensor installed inside the pressure control device and the actual pressure measured from the outside.
9 is a graph in which a temperature change is added to the graph of FIG. 8 .
10 is a temperature compensation table prepared for correction of a pressure sensor in the pressure control device.
11 is a graph comparing an output pressure of a correction sensor reflecting the temperature compensation of the pressure control device according to an embodiment of the present invention and an actual pressure measured from the outside.
12 is a schematic diagram for explaining the structure of a general industrial inkjet printer.

An embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Since the description of the disclosed technology is only an embodiment for structural or functional description, the scope of the disclosed technology should not be construed as being limited by the embodiment described in the text. That is, since the embodiment may have various changes and may have various forms, it should be understood that the scope of the disclosed technology includes equivalents capable of realizing the technical idea.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

Terms such as “first” and “second” are for distinguishing one component from other components, and the scope of rights should not be limited by these terms. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component.

Figure 1 is a schematic diagram for explaining the configuration of a pressure control device according to an embodiment of the present invention, Figure 2 is a schematic diagram for explaining a conventional pressure control device for comparison with the present invention, Figure 3 is a diagram of the present invention It is a schematic diagram for explaining the operation of the second valve in the pressure control device according to the embodiment.

The pressure control apparatus of this embodiment includes a negative pressure generator 1000 , a positive pressure generator 2000 , a first valve 1100 , a second valve 2200 , a buffer unit 3000 , and an output pipe 4000 .

The negative pressure generator 1000 generates negative pressure, the positive pressure generator 2000 generates a positive pressure, and the negative pressure or positive pressure generated by the negative pressure generator 1000 and the positive pressure generator 2000 is stored for head supply through the output tube 4000 . The pressure of the part 200 is adjusted.

The output pipe 4000 is branched into two pipes, each of the branched pipes is connected to the negative pressure generator 1000 and the positive pressure generator 2000 , and the first valve 1100 is located in the middle connected to the negative pressure generator 1000 and positive pressure A second valve 2200 is positioned in the middle connected to the generator 2000 . By controlling the operation of the first valve 1100 , the amount of air sucked from the ink storage unit may be adjusted by the negative pressure generated by the negative pressure generator 1000 . By controlling the operation of the second valve 2200 , it is possible to adjust the amount of air injected into the ink storage unit by the positive pressure generated by the positive pressure generator 2000 .

A control unit (not shown) controls the first valve 1100 and the second valve 2200 to adjust the pressure of the head supply storage unit 200 connected through the output pipe 4000 . Specifically, the internal pressure of the head supply storage unit 200 is set to a specific value at which the inkjet head can maintain a meniscus state, and the first valve 1100 and The second valve 2200 is controlled. In order to maintain the meniscus state, it may be considered that only the negative pressure generator 1000 is necessary because the inside of the storage unit 200 for supplying the head must be maintained in a negative pressure state. Since there is a case where it is necessary to apply pressure, a general inkjet printer includes a negative pressure generator 1000 and a positive pressure generator 2000 together.

However, in the illustrated embodiment, a configuration in which one valve is installed in each of the negative pressure generator and the positive pressure generator has been illustrated and described based on this, but the present invention is not limited thereto. For more precise control, an additional valve and a negative pressure generator or a positive pressure generator may be further provided. can For example, more precise pressure control may be performed by installing a plurality of valves in a pipe connected to the negative pressure generator and individually controlling them, or a plurality of negative pressure generators may be installed and a control valve may be installed in each negative pressure generator. .

At this time, as shown in FIG. 3 , in the prior art, the valve for controlling the port connected to the positive pressure generator 2000 was a 2-way valve 2100 performing an on/off function, but in this embodiment, as shown in FIG. A 3-way valve 2200 capable of changing the direction was applied. Among the three directions connected to the second valve 2200 of this embodiment, two are the positive pressure generator 2000 and the output pipe 4000 as in the prior art, and the other one is connected to the buffer unit 3000 newly added in this embodiment. do.

The buffer unit 3000 is an enclosed space having a predetermined volume filled with gas, and when the direction of the second valve 2200 is switched, the positive pressure of the positive pressure generator 2000 is applied to the space of the buffer unit 3000 filled with gas. All.

Since the conventional pressure control device shown in FIG. 3 uses a 2-way valve 2100 and does not have a separate buffer part, when the port connected to the positive pressure generator 2000 is blocked through the 2-way valve, the positive pressure generator 2000 and A positive pressure was applied to the space between the two-way valves 2100 . At this time, since the positive pressure generated by the positive pressure generator 2000 is a control pressure set based on the volume going out through the output pipe 4000 (hereinafter, “control target volume”), the positive pressure generator 2000 and the two-way valve 2100 ), the pressure control becomes unstable as the same pressure is applied to the relatively narrow space between In addition, since the pressure is adjusted according to the narrow space, when the port connected to the positive pressure generator 2000 is opened through the 2-way valve, the pressure adjusted to the narrow space reaches the control pressure set based on the control target volume again There was a problem that it took time to do.

The present invention, as shown in FIG. 4, changes the direction in which the second valve 2200 of the 3-way method was opened toward the output pipe 4000 and opens toward the buffer part 3000, and the buffer part 3000 Since the difference between the volume and the control target volume for setting the control pressure is relatively small, the pressure control of the positive pressure generator 2000 is stably maintained. In addition, since the pressure is maintained for a relatively sufficient volume due to the buffer unit 3000, the control pressure when opened toward the output pipe 4000 is maintained similarly, and the second valve 2200 is again the output pipe 4000 The time to reach the control pressure set on the basis of the control target volume when opened toward the

4 is a view for explaining one form of the buffer used in the pressure control device according to the embodiment of the present invention.

As described above, in the present invention, the buffer unit connected to the second valve of the 3-way type is a space filled with added gas to reduce the difference from the control target volume, and since the volume inside the space is important, the gas forms a space Any possible structure can be applied. Typically, the buffer may be configured by connecting a reservoir such as a pocket or case having a sufficient volume without the gas leaking out.

On the other hand, since the internal volume is increased by increasing the length of the tube, the buffer can be configured by connecting a long tube to the second valve without connecting a separate reservoir to the structure. If you roll the tube together, the space utilization increases. The PFA tube with excellent chemical resistance can be fixed by applying heat in the state of being rolled several times to maintain its rolled shape. If there is no separate chemical resistance and heat resistance requirement, it can be rolled up in multiple layers without additional work using a urethane tube. It can be connected to the second valve.

Figure 5 is a graph showing the pressure measurement results according to the length of the buffer tube used in the pressure control device according to the comparative example and the embodiment of the present invention, Figure 6 is a second graph to explain the shape of the measured buffer is a diagram for, and FIG. 7 is a view for explaining the shape of the buffer part in which the third graph is measured.

The tube was connected to the second valve to constitute a buffer, and the length of the tube was adjusted differently. At the top, the length of the tube is 0, which is the same as the case where the conventional pressure control device shown in FIG. 3 is applied, and FIG. 8, where the second graph is measured, shows that the length of the tube is 200 mm, and FIG. 9 where the third graph is measured. The length of the tube is 530 mm. Since the space in which the buffer part 3000 is installed is limited, even when the length of the tube is 200mm, it was sufficient to position it bent once as shown in FIG. 8, but when the length of the tube is longer to 530mm, FIG. The tube was rolled several times and placed as shown in Figure 9. When the length of the tube increases, the volume of the buffer part 3000 increases, and when the tube is rolled and installed, the volume of the buffer part 3000 can be sufficiently increased even in a limited space.

The valve connected to the positive pressure generator was operated in a state set to control at a control pressure of 30 kPa for a control target volume of 600 cc.

As shown, in the conventional pressure control device without a buffer, a pressure hunting of 20 kPa was observed when the valve was opened and closed. On the other hand, when the buffer part was constructed using a 200 mm tube, pressure hunting of 5 kPa occurred when the second valve was opened and closed, and when the buffer part with a wider volume was formed by extending the tube length to 530 mm, a pressure hunting of 1 kPa occurred. Thus, it was possible to confirm the decrease in pressure hunting according to the addition of the buffer unit.

In addition, when there is no buffer part, it took 4.2 seconds to reach the control pressure again, but when the buffer part was added, this time was greatly reduced.

As described above, it can be seen that adding the buffer reduces the pressure stability and the time to reach the control pressure, and the effect increases as the volume of the buffer increases.

In order to obtain the minimum effect by adding the buffer part, the volume of the buffer part needs to be 10% or more of the control target volume, and in order to obtain a sufficient effect, the volume of the buffer part is preferably 50% or more of the control target volume, and to minimize pressure hunting For this purpose, it is preferably in the range of 90-100% of the volume to be controlled.

By adding a buffer to reduce pressure hunting, precise pressure control is possible, and the precision of the inkjet printer is greatly improved. In addition, by reducing the time required to reach the control pressure by the buffer unit, the working efficiency of the inkjet printer is greatly improved.

On the other hand, the negative pressure applied to the head supply storage unit 200 through the output tube 4000 causes the inkjet head 100 to maintain a meniscus state, and to discharge an accurate amount of ink, the meniscus state is always maintained. should be maintained

When the inkjet printer operates, since the ink is continuously circulated while the ink is discharged through the inkjet head, a pressure control device ( 300) continues to operate. However, in the operation process of the inkjet printer, there is a phenomenon in which the pressure control by the pressure control device 300 is slightly shifted, and this error in the pressure control process is not a big problem in general cases. It is gradually becoming a problem.

8 is a graph comparing the pressure measured by the pressure sensor installed inside the pressure control device and the actual pressure measured from the outside.

The pressure sensor is connected to the pressure control tube 310 and installed in the output tube through which negative or positive pressure is selectively transmitted, and the pressure inside the output tube is the same as the pressure applied to the head supply storage unit 200 according to the operation of the valve.

The graph shown in blue is a graph showing the pressure measured by the pressure sensor installed in the output pipe, and the graph shown in red is the pressure measured by the external pressure sensor located a predetermined distance away by connecting the pipe to the output pipe.

The pressure control device is set to constantly operate with a predetermined output pressure, and the pressure measured in blue on the pressure sensor changes from 0 to a negative or positive value as the pressure control device operates, and the set output pressure value It can be confirmed that a constant value is measured after a predetermined period of time by being controlled to be maintained. This is because the operation of the pressure control device itself is controlled based on the value of the pressure sensor that measures the pressure inside the output pipe.

On the other hand, in the red graph measured by the external pressure sensor, the pressure is generated with a time lag compared to the blue graph due to the characteristics of the location installed from the outside. It can be seen that the difference with the blue graph is widening.

The red graph corresponds to the actual pressure applied to the ink storage unit because it is a value measured by an external pressure sensor located a certain distance away. Hereinafter, the pressure value in the blue graph is called 'sensor output pressure', and the pressure in the red graph is The value is called 'actual output pressure'. As a result, it can be seen that an error occurs in the process of controlling the pressure of the ink storage unit because the sensor output pressure used as a control criterion in the pressure control device is different from the actual output pressure applied to the ink storage unit.

The inventors of the present invention were able to confirm that the difference generated in the graph of FIG. 8 was a problem due to temperature through research, and FIG. 9 is a graph in which a temperature change is added to the graph of FIG. 8 . As shown, an error occurred between the sensor output pressure and the actual output pressure from the moment when the measured temperature value indicated by the dotted line exceeded the specific temperature indicated by ①, and as the temperature increased, the error occurred between the sensor output pressure and the actual output pressure. is increased, and it can be seen that the error value is kept constant while the temperature does not rise any more in ②.

The pressure of the gas is also affected by the temperature by the gaseous state equation, and when the inkjet printer is operated, various electronic components and valves, and the pressure control device 300 composed of a positive pressure generator and a negative pressure generator cause heat generated from itself around the pressure sensor. temperature will rise. Furthermore, the temperature around the pressure sensor may rise due to heat generated from parts outside the pressure control device. As a result, the temperature of the part measured by the pressure sensor continuously increases, and accordingly, the sensor output pressure measured by the pressure sensor is different from the actual output pressure.

Accordingly, the inventors of the present invention added a temperature sensor and configured to perform temperature-dependent correction on the sensor output pressure measured by the pressure sensor.

Since the temperature sensor is to correct the pressure measured by the pressure sensor, it is installed at a position where the temperature around the pressure sensor can be measured.

10 is a temperature compensation table prepared for correction of a pressure sensor in the pressure control device.

Since it exhibits unique characteristics depending on the type of pressure sensor, it is difficult to correct it to a constant value, and a temperature compensation table was individually prepared for each pressure sensor used and input to the pressure control device 300 .

The pressure control device 300 controls the pressure control device based on the 'correction sensor output pressure' in which the temperature compensation table of FIG. 10 is reflected in the temperature value measured by the temperature sensor with respect to the pressure measured by the pressure sensor.

11 is a graph comparing an output pressure of a correction sensor reflecting the temperature compensation of the pressure control device according to an embodiment of the present invention and an actual pressure measured from the outside.

The graph shown in blue is the 'corrected sensor output pressure', the temperature value measured by the temperature sensor is corrected according to the temperature compensation table, and the graph shown in red is the 'actual output pressure' measured by the external pressure sensor located a certain distance away. . As a result of the pressure controller 300 controlling the pressure controller based on the corrected sensor output pressure, it can be seen that almost no error occurs between the corrected sensor output pressure and the actual output pressure.

On the other hand, as described above, the configuration in which one control valve is installed in each of the negative pressure generator and the positive pressure generator is general, but is not limited thereto. For more precise control, an additional control valve and a negative pressure generator or a positive pressure generator may be further provided. For example, more precise pressure control may be performed by installing a plurality of control valves on a pipe connected to the negative pressure generator and individually controlling them, and a plurality of negative pressure generators may be installed and a control valve may be installed in each of the negative pressure generators. may be At this time, in order to control each control valve, a plurality of pressure sensors may be installed in the pressure control device, and a temperature correction is performed for each of the plurality of pressure sensors. Furthermore, since a temperature difference may occur due to a difference in a location where a plurality of pressure sensors are installed, a plurality of temperature sensors may be applied to each of the plurality of pressure sensors to measure ambient temperature. In addition, a temperature compensation table may be individually created for each of the plurality of pressure sensors and input to the control unit.

As such, the pressure control device of the silver configuration performs control based on the pressure sensor installed inside, but further comprises a temperature sensor that measures the temperature around the pressure sensor, and performs correction according to the temperature to further increase the actual output pressure. There is an effect that can be precisely controlled.

In addition, by accurately controlling the output pressure of the pressure control device, the internal pressure of the ink storage unit can be more accurately controlled, and the printing precision of the inkjet printer can be maintained even when continuously used for a long time.

The present invention has been described through preferred embodiments, but the above-described embodiments are merely illustrative of the technical spirit of the present invention, and various changes are possible without departing from the technical spirit of the present invention in this field. Those of ordinary skill in the art will be able to understand. Therefore, the protection scope of the present invention should be interpreted by the matters described in the claims, not specific embodiments, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention.

10: inkjet head
11: Supply flow
12: recovery path
20, 200: storage for head supply
30, 300: pressure control device
31: pressure regulator
400: buffer storage
500: ink storage tank
1000: sound pressure generator
1100: first valve
2000: positive pressure generator
2100: 2-way valve
2200: 2nd valve, 3-way valve
3000: buffer
4000: output tube

Claims (9)

A device for controlling pressure by being connected to a head supply storage unit for supplying ink to an inkjet head having a plurality of nozzles for discharging ink,
a negative pressure generator for applying negative pressure to the storage unit for supplying the head;
a positive pressure generator for applying positive pressure to the storage unit for supplying the head;
an output pipe through which the negative pressure or positive pressure generated by the negative pressure generator or the positive pressure generator is output to the outside;
a first valve installed between the sound pressure generator and the output pipe;
a second valve which is a three-way valve installed between the positive pressure generator and the output pipe; and
It includes a buffer connected to the second valve,
The pressure control device of the inkjet printer, characterized in that the buffer portion is a closed space filled with gas.
The method according to claim 1,
The pressure control apparatus of an inkjet printer, characterized in that the volume of the buffer part is 10% or more of the volume to be controlled by the volume set to be controlled by the positive pressure generator.
The method according to claim 1,
The pressure control apparatus of an inkjet printer, characterized in that the volume of the buffer part is set to be controlled by the positive pressure generator and is 50% or more of the volume to be controlled.
The method according to claim 1,
A pressure control device for an inkjet printer, characterized in that the volume of the buffer part is set to be controlled by the positive pressure generator and is in the range of 90 to 100% of the control target volume.
The method according to claim 1,
The pressure control device for an inkjet printer, characterized in that the buffer is a pocket or case-type reservoir connected by a tube.
The method according to claim 1,
The pressure control device for an inkjet printer, characterized in that the buffer portion is in the form of a tube having a predetermined length or longer.
7. The method of claim 6,
The tube is a pressure control device for an inkjet printer, characterized in that it is in a rolled form.
The method according to claim 1,
A pressure sensor for measuring pressure information and a temperature sensor for measuring temperature information are installed in the output tube,
The pressure control apparatus of an inkjet printer, characterized in that temperature correction is performed on the pressure information measured by the pressure sensor based on the temperature measured by the temperature sensor.
9. The method of claim 8,
Two or more pressure sensors are installed, and a temperature sensor is provided for each of the plurality of pressure sensors.

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