JP2020082536A - Printer - Google Patents

Abstract

To provide a printer capable of suppressing reduction in productivity.SOLUTION: An agitation part 51 supplies ink to a print part 2 while agitating the ink. When new ink is introduced to the agitation part during print operation, the agitation part 51 stops the supply of the ink to the print part 2 and agitates the ink. A sub-tank 52 stores the ink used for printing by the print part 2 in an initial agitation period during which the agitation part 51 stops the supply of the ink to the print part 2 and the new ink is introduced and the introduced ink is agitated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printing device that prints on a print medium.

In an inkjet printing apparatus, printing may be performed using MICR (Magnetic Ink Character Reader) ink, which is an ink containing a magnetic material (see Patent Document 1).

When left in the MICR ink, precipitation of the magnetic substance component occurs. When printing is performed by an inkjet printing apparatus using the MICR ink in which the magnetic substance component is precipitated, ejection failure may occur when ejecting a portion of the MICR ink in which the magnetic substance component is dark. In addition, the function of the MICR ink deteriorates in the portion where the magnetic substance component of the MICR ink is thin.

Therefore, in the ink jet printing apparatus using the MICR ink, the MICR ink is constantly stirred to prevent precipitation of the magnetic substance component.

Here, the MICR ink is introduced into the inkjet printing apparatus from the ink cartridge, but the magnetic substance component of the MICR ink may be precipitated in the ink cartridge.

For this reason, in a system in which a reduced amount of ink is supplied from an ink cartridge like normal ink, a portion where the magnetic substance component of MICR ink is dark or a portion where it is thin may be supplied. .. From this, even if the MICR ink is stirred in the apparatus, the concentration of the entire MICR ink in the apparatus may change.

In order to prevent this, there is a system in which all of the MICR ink in the ink cartridge is introduced into the apparatus at once and stirred. With this method, the density of MICR ink in the apparatus can be kept constant, and stable ejection performance and print quality can be secured.

JP, 2016-221807, A

However, in the above-described method, when the MICR ink is exhausted during the printing operation, all the MICR ink in the ink cartridge is introduced into the apparatus and the stirring operation is performed. Therefore, the printing operation is stopped until the stirring operation ends. .. As a result, productivity is reduced.

The present invention has been made in view of the above, and an object of the present invention is to provide a printing apparatus capable of suppressing a decrease in productivity.

In order to achieve the above-mentioned object, the printing apparatus of the present invention supplies ink to the printing unit while stirring the ink and the printing unit when new ink is introduced during the printing operation. A stirrer that stops the supply of ink to the printer to stir the ink, and the stirrer stops the supply of ink to the printer to introduce new ink and stir the introduced ink. A storage unit for storing ink to be used for printing by the printing unit during the initial agitation period is provided.

According to the printing apparatus of the present invention, it is possible to suppress a decrease in productivity.

1 is a schematic configuration diagram of a printing apparatus according to a first embodiment. 6 is a flowchart for explaining an operation of supplying ink to the printing unit in the first embodiment. It is a flow chart for explaining the initial stirring operation in the first embodiment. It is a schematic block diagram of the printing apparatus which concerns on 2nd Embodiment. 9 is a flowchart for explaining an operation of supplying ink to the printing unit in the second embodiment. It is a flow chart for explaining the initial stirring operation in the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts or components are designated with the same or equivalent reference numerals.

The embodiments described below exemplify devices and the like for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, arrangement, etc. of each component. Is not specified below. The technical idea of the present invention can be modified in various ways within the scope of the claims.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a printing apparatus according to the first embodiment of the present invention. Note that the up-down direction in the following description is the vertical direction, and the up-down direction of the paper surface in FIG. 1 is the up-down direction.

As shown in FIG. 1, the printing apparatus 1 according to the first embodiment includes a printing unit 2, a supply unit 3, a pressure generation unit 4, and a control unit 5.

The printing unit 2 circulates the ink and ejects the ink onto a sheet conveyed by a conveying unit (not shown) to print an image. Here, the ink used for printing in the printing apparatus 1 is MICR ink containing a magnetic material. The printing unit 2 includes an inkjet head 11 and an ink circulation unit 12.

The inkjet head 11 ejects the ink supplied by the ink circulation unit 12. The inkjet head 11 has a plurality of head modules 16.

The head module 16 has an ink chamber (not shown) that stores ink and a plurality of nozzles (not shown) that eject ink. A piezo element (not shown) is arranged in the ink chamber. Ink is ejected from the nozzle by driving the piezo element.

The ink circulation unit 12 includes a pressure tank 21, a distributor 22, a collector 23, a negative pressure tank 24, a circulation pump 25, an ink temperature adjustment unit 26, and circulation pipes 27 to 29.

The pressure tank 21 stores the ink supplied to the inkjet head 11. The ink in the pressure tank 21 is supplied to the inkjet head 11 via the circulation pipe 27 and the distributor 22. In the pressure tank 21, an air layer 31 is formed on the ink surface. The pressure tank 21 communicates with a pressure generation chamber 81 described later through a pressure side communication pipe 82 described below. The pressure tank 21 is arranged at a position lower than the inkjet head 11.

The pressurized tank 21 is provided with a pressurized tank liquid level sensor 32. The pressure tank liquid level sensor 32 detects whether or not the liquid level of the ink in the pressure tank 21 has reached a predetermined reference height. The pressurized tank liquid level sensor 32 outputs a signal indicating "ON" when the liquid level in the pressurized tank 21 is equal to or higher than the reference height, and outputs "OFF" when it is less than the reference height. It outputs the indicated signal.

The distributor 22 distributes the ink supplied from the pressure tank 21 via the circulation pipe 27 to each head module 16 of the inkjet head 11.

The aggregator 23 collects the ink not consumed by the inkjet head 11 from each head module 16. The ink collected by the collector 23 flows to the negative pressure tank 24 via the circulation pipe 28.

The negative pressure tank 24 receives the ink not consumed by the inkjet head 11 from the collector 23 and stores it. Further, the negative pressure tank 24 stores the ink replenished from the replenishment unit 3. In the negative pressure tank 24, an air layer 36 is formed on the ink surface. The negative pressure tank 24 is communicated with a negative pressure generating chamber 88, which will be described later, via a negative pressure side communication pipe 89, which will be described later. The negative pressure tank 24 is arranged at the same height as the pressure tank 21.

The negative pressure tank 24 is provided with a negative pressure tank liquid level sensor 37. The negative pressure tank liquid level sensor 37 detects whether or not the liquid level of the ink in the negative pressure tank 24 has reached a predetermined reference height. The negative pressure tank liquid level sensor 37 outputs a signal indicating “ON” when the liquid level in the negative pressure tank 24 is equal to or higher than the reference height, and outputs “OFF” when it is less than the reference height. It outputs the indicated signal.

The circulation pump 25 sends ink from the negative pressure tank 24 to the pressure tank 21. The circulation pump 25 is provided in the middle of the circulation pipe 29.

The ink temperature adjustment unit 26 adjusts the temperature of the ink in the ink circulation unit 12. The ink temperature adjusting unit 26 is provided in the middle of the circulation pipe 27. The ink temperature adjusting unit 26 includes a heater 41, a heat sink 42, and a cooling fan 43.

The heater 41 warms the ink in the circulation pipe 27. The heat sink 42 cools the ink in the circulation tube 27 by radiating heat. The cooling fan 43 sends cooling air to the heat sink 42.

The circulation pipe 27 connects the pressure tank 21 and the distributor 22. The circulation pipe 28 connects the collector 23 and the negative pressure tank 24. The circulation pipe 29 connects the negative pressure tank 24 and the pressure tank 21. The circulation pipes 27 to 29, the pressure tank 21, the distributor 22, the collector 23, and the negative pressure tank 24 constitute a circulation path for supplying ink to the inkjet head 11 while circulating the ink.

The replenishing unit 3 agitates the ink and replenishes the printing unit 2 with the ink. The reason for stirring the ink is to prevent precipitation of the magnetic substance component of the MICR ink. The replenishment unit 3 includes a stirring unit 51, a sub-tank (corresponding to a storage unit) 52, a replenishment valve 53, a replenishment pipe 54, an ink cartridge 55, an introduction valve 56, an introduction pump 57, and an introduction pipe 58. Prepare

The stirring unit 51 supplies the ink to the printing unit 2 via the sub tank 52 while stirring the ink. When new ink is introduced from the ink cartridge 55 during the printing operation, the stirring unit 51 stops the ink supply to the printing unit 2 and stirs the ink. The stirring unit 51 includes a stirring tank 61, a stirring pump 62, stirring circulation pipes 63 to 65, and switching valves 66 and 67.

The agitation tank 61 stores the ink introduced from the ink cartridge 55 for agitation. In the stirring tank 61, an air layer 71 is formed on the liquid surface of the ink.

The stirring tank 61 is provided with an atmosphere open pipe 72. One end of the atmosphere open pipe 72 is connected to the air layer 71, and the other end (upper end) communicates with the atmosphere through the air filter 73. As a result, the stirring tank 61 is open to the atmosphere. The air filter 73 prevents dust and the like in the air from entering the stirring tank 61.

Further, the stirring tank 61 is provided with a stirring tank upper limit sensor 74 and a stirring tank lower limit sensor 75.

The stirring tank upper limit sensor 74 detects whether or not the liquid level of the ink in the stirring tank 61 has reached a predetermined upper limit height. The stirring tank upper limit sensor 74 outputs a signal indicating "ON" when the liquid level in the stirring tank 61 is equal to or higher than the upper limit height, and outputs a signal indicating "OFF" when it is lower than the upper limit height. Output.

The stirring tank lower limit sensor 75 detects whether or not the liquid level of the ink in the stirring tank 61 has reached a predetermined lower limit height lower than the upper limit height. The stirring tank lower limit sensor 75 outputs a signal indicating “ON” when the liquid level in the stirring tank 61 is equal to or higher than the lower limit height, and outputs a signal indicating “OFF” when it is lower than the lower limit height. Output.

The stirring pump 62 stirs the ink by circulating the ink through a normal stirring path Ct and an initial stirring path Cs described later. The stirring pump 62 is arranged on the introduction pipe 58 side of the switching valve 67 of the stirring circulation pipe 64.

The stirring circulation pipe 63 connects the stirring tank 61 and the sub tank 52. The stirring circulation pipe 64 connects the sub tank 52 and the introduction pipe 58. The stirring circulation pipe 65 connects the stirring circulation pipe 63 and the stirring circulation pipe 64 via the switching valves 66 and 67.

The switching valve 66 is arranged in the middle of the stirring circulation pipe 63, and the communication destination of the portion of the stirring circulation pipe 63 on the side of the stirring tank 61 from the switching valve 66 is the portion of the stirring circulation pipe 63 on the side of the sub-tank 52 side of the switching valve 66. It selectively switches to the stirring circulation pipe 65. Here, in the switching valve 66, the setting for communicating the portion of the stirring circulation pipe 63 on the side of the stirring tank 61 with respect to the switching valve 66 and the portion of the stirring circulation pipe 63 on the side of the sub-tank 52 on the side of the sub-tank 52 are referred to as normal circulation settings. .. Further, in the switching valve 66, the setting for connecting the portion of the stirring circulation pipe 63 on the stirring tank 61 side of the switching valve 66 and the stirring circulation pipe 65 is referred to as an initial circulation setting.

The switching valve 67 is arranged in the middle of the stirring circulation pipe 64, and the communication destination of the portion of the stirring circulation pipe 64 on the side of the sub tank 52 from the switching valve 67 is the portion of the stirring circulation pipe 64 on the side of the introduction pipe 58 from the switching valve 67. It selectively switches to the stirring circulation pipe 65. Here, in the switching valve 67, the setting for communicating the portion of the stirring circulation pipe 64 on the side of the sub tank 52 with respect to the switching valve 67 and the portion of the stirring circulation pipe 64 on the side of the introduction pipe 58 with respect to the switching valve 67 is the normal circulation setting. .. In addition, in the switching valve 67, the setting for connecting the portion of the stirring circulation pipe 64 on the sub tank 52 side of the switching valve 67 and the stirring circulation pipe 65 is referred to as an initial circulation setting.

When the switching valves 66 and 67 are set to the normal circulation mode, the normal stirring path (corresponding to the first path) Ct is formed.

The normal stirring path Ct is a path used in the normal stirring operation during the printing operation. The normal stirring path Ct is a path for stirring the ink in the stirring tank 61 while circulating the ink via the sub tank 52. The normal stirring path Ct is composed of the stirring circulation pipes 63 and 64 and a portion of the introduction pipe 58 closer to the stirring tank 61 than the point where the stirring circulation pipe 64 is connected.

When the switching valves 66 and 67 are set to the initial circulation, the initial stirring path (corresponding to the second path) Cs is formed.

The initial stirring path Cs is a path used in the initial stirring operation which is the stirring operation performed when the ink is introduced from the ink cartridge 55 to the stirring section 51. The initial stirring path Cs is a path for separating the sub tank 52 from the stirring tank 61 and stirring the ink in the stirring tank 61 while circulating the ink without passing through the sub tank 52. The initial stirring path Cs includes a portion of the stirring circulation pipe 63 closer to the stirring tank 61 than the switching valve 66, a portion of the stirring circulation pipe 65, a portion closer to the introduction pipe 58 than the switching valve 67 of the stirring circulation pipe 64, and a portion of the introduction pipe 58. It is composed of a portion on the side of the stirring tank 61 from the point where the stirring circulation pipe 64 is connected.

The sub tank 52 stores ink to be used for printing by the printing unit 2 during the initial stirring period. The initial stirring period is a period from the start of the introduction of the ink from the ink cartridge 55 to the stirring tank 61 to the end of the initial stirring operation. The sub-tank 52 has a capacity that is equal to or larger than the maximum amount of ink used in printing during the initial stirring period. In the sub tank 52, an air layer 76 is formed on the ink surface.

An atmosphere opening pipe 77 is provided in the sub tank 52. The atmosphere open pipe 77 has one end connected to the air layer 76 and the other end (upper end) communicating with the atmosphere via an air filter 78. As a result, the sub tank 52 is open to the atmosphere. The air filter 78 prevents dust and the like in the air from entering the sub tank 52.

The supply valve 53 opens and closes the ink flow path in the supply pipe 54. When ink is supplied to the negative pressure tank 24, the supply valve 53 is opened.

The supply pipe 54 connects the sub tank 52 and the negative pressure tank 24.

The ink cartridge 55 contains MICR ink which is ink used for printing by the inkjet head 11. The ink in the ink cartridge 55 is immediately introduced into the stirring tank 61 via the introduction pipe 58.

The introduction valve 56 opens and closes the ink flow path in the introduction tube 58. When introducing the ink into the stirring tank 61, the introduction valve 56 is opened.

The introduction pump 57 feeds the ink from the ink cartridge 55 to the stirring tank 61. The introduction pump 57 is arranged between the point where the stirring circulation pipe 64 of the introduction pipe 58 is connected and the introduction valve 56.

The introduction pipe 58 connects the ink cartridge 55 and the stirring tank 61. Further, the introduction pipe 58 constitutes a part of the normal stirring path Ct and a part of the initial stirring path Cs.

The pressure generation unit 4 generates a pressure for ink circulation in the pressure tank 21 and the negative pressure tank 24. The pressure generation unit 4 includes a pressure generation chamber 81, a pressure side communication pipe 82, a pressure side atmosphere opening valve 83, a pressure side atmosphere opening pipe 84, a pressure side pressure adjusting valve 85, and a pressure side pressure adjusting pipe 86. A pressurizing side pressure sensor 87, a negative pressure generating chamber 88, a negative pressure side communicating pipe 89, a negative pressure side atmosphere opening valve 90, an atmosphere communicating pipe 91, an air filter 92, a negative pressure side pressure adjusting valve 93, A negative pressure side pressure adjusting pipe 94, a negative pressure side pressure sensor 95, an air pump 96, and an air pump pipe 97 are provided.

The pressure generating chamber 81 is an air chamber in which air is sent from the air pump 96 and is pressurized. The pressure generation chamber 81 is connected to the pressure tank 21 via a pressure side communication pipe 82.

The pressure side communication pipe 82 connects the pressure generation chamber 81 and the air layer 31 of the pressure tank 21. The pressure-side communication pipe 82 has one end connected to the pressure generation chamber 81 and the other end connected to the air layer 31 of the pressure tank 21.

The pressurization side air release valve 83 is provided to switch the pressurization tank 21 between the closed state (the state where it is shut off from the atmosphere) and the air release state (the state where it is connected to the atmosphere) via the pressurization generation chamber 81. The air flow path in the pressure side atmosphere open pipe 84 is opened and closed. The pressurizing-side atmosphere opening valve 83 is provided in the middle of the pressurizing-side atmosphere opening pipe 84.

The pressurization-side atmosphere open pipe 84 forms an air flow path for opening the pressurization tank 21 to the atmosphere via the pressurization generation chamber 81. The pressure-side atmosphere open pipe 84 has one end connected to the pressure generation chamber 81 and the other end connected to the atmosphere communication pipe 91.

The pressurizing-side pressure adjusting valve 85 opens and closes the air passage in the pressurizing-side pressure adjusting pipe 86 in order to adjust the pressures of the pressurizing generation chamber 81 and the pressurizing tank 21. The pressurizing-side pressure adjusting valve 85 is provided in the middle of the pressurizing-side pressure adjusting pipe 86.

The pressure side pressure adjusting pipe 86 forms an air flow path for adjusting the pressure of the pressure generating chamber 81 and the pressure tank 21. The pressurizing-side pressure adjusting pipe 86 is composed of a pipe having a larger flow resistance than the pressurizing-side atmospheric open pipe 84 and the atmospheric communicating pipe 91. Specifically, the pressurizing-side pressure adjusting pipe 86 is composed of a pipe thinner than the pressurizing-side atmosphere open pipe 84 and the atmospheric communicating pipe 91. The pressurization-side pressure adjustment pipe 86 has one end connected to the pressurization generation chamber 81 and the other end connected to the atmosphere communication pipe 91.

The pressure side pressure sensor 87 detects the pressure in the pressure generation chamber 81. The pressure in the pressure generation chamber 81 is equal to the pressure in the pressure tank 21. This is because the pressure generation chamber 81 and the air layer 31 of the pressure tank 21 communicate with each other.

The negative pressure generating chamber 88 is an air chamber in which air is sucked by the air pump 96 and decompressed. The negative pressure generation chamber 88 is connected to the negative pressure tank 24 via a negative pressure side communication pipe 89.

The negative pressure side communication pipe 89 connects the negative pressure generation chamber 88 and the air layer 36 of the negative pressure tank 24. The negative pressure side communication pipe 89 has one end connected to the negative pressure generation chamber 88 and the other end connected to the air layer 36 of the negative pressure tank 24.

The negative pressure side atmosphere opening valve 90 opens and closes the air flow path in the atmosphere communication pipe 91 in order to switch the negative pressure tank 24 between the closed state and the atmosphere opened state via the negative pressure generation chamber 88. The negative pressure side air release valve 90 is arranged between the point where the negative pressure side pressure adjustment pipe 94 of the atmosphere communication pipe 91 is connected and the negative pressure generation chamber 88.

The atmosphere communication pipe 91 forms an air flow path for communicating the pressure-side atmosphere open pipe 84, the pressure-side pressure adjustment pipe 86, the negative pressure generation chamber 88, and the negative pressure-side pressure adjustment pipe 94 with the atmosphere. One end of the atmosphere communication pipe 91 is connected to the negative pressure generating chamber 88, and the other end (atmosphere open end) communicates with the atmosphere via the air filter 92. A pressure side atmosphere open pipe 84, a pressure side pressure adjusting pipe 86, and a negative pressure side pressure adjusting pipe 94 are connected to the atmosphere communicating pipe 91.

The air filter 92 prevents dust and the like in the air from entering the atmosphere communication pipe 91. The air filter 92 is installed at the open end of the atmosphere communication pipe 91.

The negative pressure side pressure adjusting valve 93 opens and closes an air flow path in the negative pressure side pressure adjusting pipe 94 in order to adjust the pressures of the negative pressure generating chamber 88 and the negative pressure tank 24. The negative pressure side pressure adjusting valve 93 is provided in the middle of the negative pressure side pressure adjusting pipe 94.

The negative pressure side pressure adjusting pipe 94 forms an air flow path for adjusting the pressure of the negative pressure generating chamber 88 and the negative pressure tank 24. The negative pressure side pressure adjusting pipe 94, like the pressurizing side pressure adjusting pipe 86, is composed of a pipe having a flow passage resistance larger than those of the pressurizing side atmosphere open pipe 84 and the atmosphere communicating pipe 91. The negative pressure side pressure adjustment pipe 94 has one end connected to the negative pressure generation chamber 88 and the other end connected to the atmosphere communication pipe 91.

The negative pressure side pressure sensor 95 detects the pressure in the negative pressure generation chamber 88. The pressure in the negative pressure generation chamber 88 is equal to the pressure in the negative pressure tank 24. This is because the negative pressure generation chamber 88 and the air layer 36 of the negative pressure tank 24 communicate with each other.

The air pump 96 sucks air from the negative pressure generation chamber 88 and sends the air to the pressure generation chamber 81. As a result, positive pressure is generated in the pressure tank 21 and negative pressure is generated in the negative pressure tank 24. The air pump 96 is provided in the middle of the air pump pipe 97.

The air pump pipe 97 forms a flow path of air sent from the negative pressure generation chamber 88 to the pressure generation chamber 81 by the air pump 96. One end of the air pump pipe 97 is connected to the pressure generation chamber 81 and the other end is connected to the negative pressure generation chamber 88.

The control unit 5 controls the operation of each unit of the printing apparatus 1. The control unit 5 includes a CPU, a RAM, a ROM, a hard disk, and the like.

Next, the operation of the printing apparatus 1 will be described.

When the print job is input, the control unit 5 closes the pressurizing-side atmosphere opening valve 83 and the negative-pressure side atmosphere opening valve 90. As a result, the pressure tank 21 is closed via the pressure generation chamber 81, and the negative pressure tank 24 is closed via the negative pressure generation chamber 88.

Here, while the printing apparatus 1 is on standby, the pressurizing-side atmospheric opening valve 83 and the negative pressure-side atmospheric opening valve 90 are open, and the pressurizing-side pressure adjusting valve 85 and the negative pressure-side pressure adjusting valve 93 are closed. Further, the supply valve 53 and the introduction valve 56 are closed. The switching valves 66 and 67 are normally set to circulate.

Next, the control unit 5 starts driving the air pump 96. As a result, the negative pressure generation chamber 88 and the negative pressure tank 24 are decompressed, and the pressure generation chamber 81 and the pressure tank 21 are pressurized. As a result, ink flows from the pressure tank 21 toward the negative pressure tank 24 via the inkjet head 11, and ink circulation starts. After the driving of the air pump 96 is started, the control unit 5 controls the pressure side pressure sensor 87 and the negative pressure side so that the pressures of the pressure tank 21 and the negative pressure tank 24 reach the respective set pressures Pk and Pf and are maintained. Based on the detection value of the pressure sensor 95, driving of the air pump 96, opening/closing of the pressurizing side pressure adjusting valve 85, and opening/closing of the negative pressure side pressure adjusting valve 93 are controlled.

The set pressures Pk and Pf are preset as pressure values for making the nozzle pressure of the head module 16 of the inkjet head 11 an appropriate value while circulating the ink. The set pressure Pk of the pressurizing tank 21 is a positive pressure, and the set pressure Pf of the negative pressure tank 24 is a negative pressure.

Further, the control unit 5 causes the stirring unit 51 to start the ink stirring operation. Specifically, the control unit 5 starts driving the stirring pump 62. As a result, the ink is circulated along the normal stirring path Ct, and the inks in the stirring tank 61 and the sub tank 52 are stirred.

After the pressures in the pressure tank 21 and the negative pressure tank 24 have reached the set pressures Pk and Pf, the control unit 5 starts executing the print job. Specifically, based on the print job, the control unit 5 causes the head module 16 of the inkjet head 11 to eject ink onto a sheet conveyed by a conveying unit (not shown) to print an image.

During the printing operation, ink is supplied from the pressure tank 21 to the inkjet head 11, and the ink not consumed by the inkjet head 11 is collected in the negative pressure tank 24. When the pressurized tank liquid level sensor 32 is turned off, the control unit 5 drives the circulation pump 25 until the pressurized tank liquid level sensor 32 is turned on. In this way, ink circulation and printing are performed.

In addition, ink is replenished from the replenishing unit 3 to the printing unit 2 during the printing operation. The operation of supplying ink to the printing unit 2 will be described with reference to the flowchart of FIG.

In step S1 of FIG. 2, the control unit 5 determines whether the negative pressure tank liquid level sensor 37 is off. When it is determined that the negative pressure tank liquid level sensor 37 is on (step S1: NO), the control unit 5 repeats step S1.

When it is determined that the negative pressure tank liquid level sensor 37 is off (step S1: YES), the control unit 5 opens the supply valve 53 in step S2. As a result, ink is supplied from the stirring tank 61 to the negative pressure tank 24 via the sub tank 52.

Next, in step S3, it is determined whether or not the negative pressure tank liquid level sensor 37 is on.

When it is determined that the negative pressure tank liquid level sensor 37 is off (step S3: NO), the control unit 5 opens the replenishment valve 53 and then the negative pressure tank liquid level sensor 37 turns on in step S4. Instead, it determines whether or not a timeout has occurred. When it is determined that the timeout has not occurred (step S4: NO), the control unit 5 returns to step S3.

When it is determined that the time-out has occurred (step S4: YES), the control unit 5 gives an error notification in step S5. Specifically, the control unit 5 causes a display unit (not shown) to display a screen notifying the user that an error has occurred. This completes the series of processes.

When it is determined in step S3 that the negative pressure tank liquid level sensor 37 is on (step S3: YES), the control unit 5 closes the supply valve 53 in step S6. As a result, the ink supply to the negative pressure tank 24 is stopped. Then, the control unit 5 returns to step S1.

When the printing based on the print job ends, the control unit 5 ends the process of the flowchart of FIG. 3 at that point.

The ink supplied from the replenishing unit 3 to the printing unit 2 as described above is agitated in the replenishing unit 3, so that the density is kept constant. In the printing unit 2, the ink is agitated by the ink circulation by the ink circulation unit 12. This ensures stable ejection performance and print quality.

Next, the initial stirring operation will be described.

As the ink is consumed by the printing operation, the ink in the stirring tank 61 decreases. As a result, when the stirring tank lower limit sensor 75 is turned off, ink is introduced from the ink cartridge 55 into the stirring tank 61. The initial stirring operation is an operation of stirring the ink newly introduced into the stirring tank 61. Since the magnetic substance component of the MICR ink may be precipitated in the ink cartridge 55, all the ink in the ink cartridge 55 is immediately introduced into the stirring tank 61 and the initial stirring operation is performed.

FIG. 3 is a flow chart for explaining the initial stirring operation in the first embodiment. The process of the flowchart in FIG. 3 starts when the printing operation starts.

In step S11 of FIG. 3, the control unit 5 determines whether or not the stirring tank lower limit sensor 75 is off.

When it is determined that the stirring tank lower limit sensor 75 is on (step S11: NO), the control unit 5 determines in step S12 whether or not the printing operation is in progress. When it is determined that the printing operation is being performed (step S12: YES), the control unit 5 returns to step S11.

When it is determined in step S11 that the stirring tank lower limit sensor 75 is off (step S11: YES), in step S13, the control unit 5 changes the path used for the stirring operation from the normal stirring path Ct to the initial stirring path Cs. Switch. Specifically, the control unit 5 switches the switching valves 66 and 67 from the normal circulation setting to the initial circulation setting.

Next, in step S14, the control unit 5 opens the introduction valve 56 and starts driving the introduction pump 57. As a result, ink begins to be introduced from the ink cartridge 55 into the stirring tank 61 via the introduction pipe 58.

Here, as described above, the stirring pump 62 is driven from the start of the printing operation. Therefore, while the ink is being introduced from the ink cartridge 55 into the stirring tank 61, the ink is circulated along the initial stirring path Cs and stirred.

Next, in step S15, the control unit 5 determines whether the stirring tank upper limit sensor 74 is on.

When it is determined that the stirring tank upper limit sensor 74 is off (step S15: NO), the control unit 5 does not turn on the stirring tank upper limit sensor 74 after starting driving of the introduction pump 57 in step S16. Judge whether it has timed out. When it is determined that the timeout has not occurred (step S16: NO), the control unit 5 returns to step S15.

When it is determined that the time-out has occurred (step S16: YES), the control unit 5 gives an error notification in step S17. This completes the series of processes.

When it is determined in step S15 that the stirring tank upper limit sensor 74 is on (step S15: YES), the controller 5 closes the introduction valve 56 and stops the introduction pump 57 in step S18.

Here, the position of the stirring tank upper limit sensor 74 is set so that the stirring tank upper limit sensor 74 is turned on when all the ink in the ink cartridge 55 is introduced into the stirring tank 61.

Even after all the ink in the ink cartridge 55 is introduced into the stirring tank 61 and the introduction pump 57 is stopped, the driving of the stirring pump 62 is continued. As a result, the ink circulates in the initial stirring path Cs, whereby the ink in the stirring tank 61 is stirred.

Then, in step S19, the control unit 5 determines whether or not the initial stirring period has ended. Here, the control unit 5 determines that the initial stirring period has ended when a specified time has elapsed since the introduction of the ink to the stirring tank 61 was started in step S14. When determining that the initial stirring period has not ended (step S19: NO), the control unit 5 repeats step S19.

When determining that the initial stirring period has ended (step S19: YES), the control unit 5 switches the path used for the stirring operation from the initial stirring path Cs to the normal stirring path Ct in step S20. Specifically, the control unit 5 switches the switching valves 66 and 67 from the initial circulation setting to the normal circulation setting. As a result, the initial stirring operation ends, and the normal stirring operation using the normal stirring path Ct is started. Then, the control unit 5 returns to step S1.

When it is determined in step S12 that the printing operation is not in progress (step S12: NO), the control unit 5 stops the stirring pump 62 in step S21. As a result, the stirring operation ends, and the series of processing ends.

As described above, in the initial stirring period, the ink is stirred in the initial stirring path Cs, and the stirring tank 61 and the sub tank 52 are separated from each other. Therefore, the stirring tank 61 transfers to the printing unit 2 via the sub tank 52. Ink supply is stopped. During the initial agitation period, the ink stored in the sub tank 52 separated from the agitation tank 61 is supplied to the printing unit 2 to enable printing. That is, during the initial stirring period, the printing unit 2 prints using the ink stored in the sub tank 52.

During the printing operation other than the initial stirring period, the ink is supplied from the stirring tank 61 to the printing unit 2 via the sub tank 52 while the ink is stirred by the normal stirring path Ct.

As described above, the printing apparatus 1 includes the sub tank 52 that stores the ink used for printing by the printing unit 2 during the initial agitation period. As a result, it is possible to perform the printing operation even during the initial agitation period, and thus it is possible to suppress a decrease in productivity.

Specifically, in the printing apparatus 1, when the new ink is introduced from the ink cartridge to the stirring tank 61, the stirring unit 51 stirs the ink through the initial stirring path Cs. Then, the printing unit 2 performs printing using the ink stored in the sub tank 52 during the initial stirring period. Thereby, the printing operation during the initial stirring period can be realized.

[Second Embodiment]
Next, a second embodiment in which a part of the above-described first embodiment is modified will be described. FIG. 4 is a schematic configuration diagram of the printing apparatus according to the second embodiment.

As shown in FIG. 4, the printing apparatus 1A according to the second embodiment has a configuration in which the printing unit 2 of the printing apparatus 1 of the first embodiment described above is replaced with the printing unit 2A and the replenishment unit 3 is replaced with the replenishment unit 3A. Is.

The printing unit 2A has a configuration in which the ink circulation unit 12 of the printing unit 2 of the first embodiment is replaced with the ink circulation unit 12A.

The ink circulation unit 12A has a configuration in which the negative pressure tank liquid level sensor 37 of the ink circulation unit 12 of the first embodiment is omitted and a negative pressure tank upper limit sensor 101 and a negative pressure tank lower limit sensor 102 are provided.

The negative pressure tank upper limit sensor 101 detects whether or not the liquid level of the ink in the negative pressure tank 24 has reached a predetermined upper limit height. The negative pressure tank upper limit sensor 101 outputs a signal indicating “ON” when the liquid level inside the negative pressure tank 24 is equal to or higher than the upper limit height, and indicates “OFF” when it is lower than the upper limit height. Output a signal.

The negative pressure tank lower limit sensor 102 detects whether or not the liquid level of the ink in the negative pressure tank 24 has reached a predetermined lower limit height lower than the upper limit height. The negative pressure tank lower limit sensor 102 outputs a signal indicating “ON” when the liquid level height in the negative pressure tank 24 is equal to or higher than the lower limit height, and indicates “OFF” when it is lower than the lower limit height. Output a signal.

In the printing apparatus 1A, the negative pressure tank 24 is used for printing by the printing unit 2 during the initial stirring period in which the stirring unit 51A described later introduces the ink into the stirring tank 61 and the initial stirring operation is performed. To store. Accordingly, the ink circulation path of the ink circulation unit 12A has a function as a storage unit that stores ink to be used for printing by the printing unit 2 during the initial stirring period. In the negative pressure tank 24, an ink amount that is a difference between the ink amount when the liquid level height is the upper limit height and the ink amount when the liquid level height is the lower limit height is assumed for printing during the initial stirring period. The maximum amount of ink used is equal to or larger than the maximum amount of ink used.

The replenishment unit 3A has a configuration in which the stirring unit 51 of the replenishment unit 3 of the first embodiment is replaced with the stirring unit 51A, and the sub tank 52, the replenishment valve 53, the replenishment pipe 54, the introduction pump 57, and the introduction pipe 58 are omitted.

The stirring unit 51A is different from the stirring unit 51 of the first embodiment in that the stirring circulation pipes 63 to 65 are replaced with the stirring circulation pipes 111 and 112, the switching valves 66 and 67 are omitted, and the circulation valve 113, the supply valve 114, and This is a configuration in which a supply pipe 115 is provided.

The stirring circulation pipe 111 forms a part of a stirring path for stirring the ink in the stirring tank 61, and connects the stirring tank 61 and the ink cartridge 55.

A stirring pump 62 is disposed between the stirring tank 61 and a point of the stirring circulation pipe 111 to which the stirring circulation pipe 112 is connected. In the printer 1</b>A, the stirring pump 62 is also used for sending ink from the ink cartridge 55 to the stirring tank 61.

An introduction valve 56 is arranged between the ink cartridge 55 and a point of the stirring circulation pipe 111 where the stirring circulation pipe 112 is connected.

The stirring circulation pipe 112 forms a part of the stirring path. The stirring circulation pipe 112 has one end connected to the stirring tank 61 and the other end connected to the stirring circulation pipe 111.

The circulation valve 113 opens and closes the ink flow path in the stirring circulation pipe 112. The circulation valve 113 is closed when the ink is sent from the ink cartridge 55 to the stirring tank 61.

The supply valve 114 opens and closes the ink flow path in the supply pipe 115. When supplying ink to the negative pressure tank 24, the supply valve 114 is opened.

The supply pipe 115 connects the stirring tank 61 and the negative pressure tank 24.

When performing printing with the printing device 1A, the control unit 5 applies pressure for ink circulation to the pressure tank 21 and the negative pressure tank 24 by the pressure generation unit 4 as in the first embodiment, and the ink circulation unit. The ink is ejected from the inkjet head 11 while circulating the ink at 12A.

Further, the control unit 5 causes the stirring unit 51A to perform the ink stirring operation during the printing operation. Specifically, the control unit 5 opens the circulation valve 113 and drives the stirring pump 62. As a result, the ink circulates through the stirring circulation pipes 111 and 112, and the ink in the stirring tank 61 is stirred.

Here, in the printing apparatus 1A, the ink supply to the printing unit 2 during the printing operation is performed based on the output signal of the negative pressure tank upper limit sensor 101. The operation of supplying ink to the printing unit 2 will be described with reference to the flowchart of FIG.

In step S31 of FIG. 5, the control unit 5 determines whether the negative pressure tank upper limit sensor 101 is off. When it is determined that the negative pressure tank upper limit sensor 101 is on (step S31: NO), the control unit 5 repeats step S1.

When it is determined that the negative pressure tank upper limit sensor 101 is off (step S31: YES), the control section 5 determines whether or not the ink introduction flag is on in step S32.

Here, the ink introduction flag indicates whether or not the introduction of ink from the ink cartridge 55 to the stirring tank 61 and the initial stirring operation are being performed, that is, whether or not the initial stirring period is in progress. It is a thing. When the initial stirring period is in progress, the ink introduction flag is on, and when the initial stirring period is not in progress, the ink introduction flag is off.

When it is determined that the ink introduction flag is on (step S32: YES), the control unit 5 determines whether or not the negative pressure tank lower limit sensor 102 is off in step S33. When it is determined that the negative pressure tank lower limit sensor 102 is on (step S33: NO), the control unit 5 returns to step S1.

When it is determined that the negative pressure tank lower limit sensor 102 is off (step S33: NO), the control unit 5 gives an error notification in step S34. This completes the series of processes.

Here, in the printing apparatus 1A, ink is not supplied from the stirring unit 51A to the printing unit 2 during the initial stirring period. That is, the supply valve 114 is not opened while the ink introduction flag is on. Therefore, when printing is performed during the initial stirring period, the amount of ink in the negative pressure tank 24 decreases.

On the other hand, as described above, in the negative pressure tank 24, the difference in ink amount between the ink amount when the liquid level height is the upper limit height and the ink amount when the liquid level height is the lower limit height is The ink usage amount is equal to or larger than the maximum ink usage amount assumed for printing in the initial stirring period. Therefore, even if printing is performed during the initial agitation period, the negative pressure tank lower limit sensor 102 is not turned off if the printing apparatus 1A is in a normal state. Therefore, when the negative pressure tank lower limit sensor 102 is turned off, the control unit 5 issues an error notification as described above (step S34).

When it is determined that the ink introduction flag is off (step S32: NO), the controller 5 opens the supply valve 114 in step S35. As a result, ink is started to be supplied from the stirring tank 61 to the printing unit 2.

Next, in step S36, the control unit 5 determines whether or not the stirring tank lower limit sensor 75 is on.

When it is determined that the stirring tank lower limit sensor 75 is on (step S36: YES), the control unit 5 determines whether or not the negative pressure tank upper limit sensor 101 is on in step S37. When it is determined that the negative pressure tank upper limit sensor 101 is off (step S37: NO), the control unit 5 returns to step S36.

When it is determined that the negative pressure tank upper limit sensor 101 is on (step S37: YES), the control unit 5 opens the supply valve 114 in step S38. As a result, the supply of ink from the stirring tank 61 to the printing unit 2 is stopped. Then, the control unit 5 returns to step S31.

When it is determined in step S36 that the stirring tank lower limit sensor 75 is off (step S36: NO), the controller 5 turns on the ink introduction flag in step S39. As a result, introduction of ink from the ink cartridge 55 to the agitation tank 61 is started, as will be described later.

Next, in step S40, the control unit 5 determines whether or not the negative pressure tank upper limit sensor 101 is on. When it is determined that the negative pressure tank upper limit sensor 101 is off (step S40: NO), the control unit 5 repeats step S40.

When it is determined that the negative pressure tank upper limit sensor 101 is on (step S40: YES), the controller 5 opens the supply valve 114 in step S38. As a result, the supply of ink from the stirring tank 61 to the printing unit 2 is stopped. Then, the control unit 5 returns to step S31.

When the printing based on the print job ends, the control unit 5 ends the process of the flowchart of FIG. 5 at that point.

Next, the initial stirring operation will be described.

FIG. 6 is a flow chart for explaining the initial stirring operation in the second embodiment. The process of the flowchart of FIG. 6 starts when the printing operation starts.

In step S51 of FIG. 6, the controller 5 determines whether the ink introduction flag is on.

When it is determined that the ink introduction flag is off (step S51: NO), the control unit 5 determines in step S52 whether or not the printing operation is in progress. When it is determined that the printing operation is in progress (step S52: YES), the control unit 5 returns to step S51.

When it is determined that the ink introduction flag is on (step S51: YES), the control unit 5 closes the circulation valve 113 in step S53. As a result, the stirring operation in the stirring section 51A is stopped.

Next, in step S54, the control unit 5 opens the introduction valve 56. As a result, ink begins to be introduced from the ink cartridge 55 into the stirring tank 61 via the stirring circulation pipe 111.

Next, in step S55, the control unit 5 determines whether or not the stirring tank upper limit sensor 74 is on.

When it is determined that the stirring tank upper limit sensor 74 is off (step S55: NO), in step S16, the control unit 5 opens the introduction valve 56 and then the stirring tank upper limit sensor 74 does not turn on and times out. Determine whether or not. When it is determined that the timeout has not occurred (step S56: NO), the control unit 5 returns to step S55.

When it is determined that the time-out has occurred (step S56: YES), the control unit 5 gives an error notification in step S57. This completes the series of processes.

When it is determined in step S55 that the stirring tank upper limit sensor 74 is on (step S55: YES), the control unit 5 closes the introduction valve 56 in step S58.

Next, in step S59, the control unit 5 opens the circulation valve 113. As a result, the stirring operation in the stirring unit 51A is restarted. This stirring operation is an initial stirring operation of stirring the ink newly introduced from the ink cartridge 55 into the stirring tank 61.

Next, in step S60, the control unit 5 determines whether or not the initial stirring period has ended. Here, the control unit 5 determines that the initial stirring period has ended when the specified time has elapsed since the circulation valve 113 was opened in step S59. When determining that the initial stirring period has not ended (step S60: NO), the control unit 5 repeats step S60.

When it is determined that the initial stirring period has ended (step S60: YES), the control unit 5 turns off the ink introduction flag in step S61. After that, the control unit 5 returns to step S51.

When determining in step S52 that the printing operation is not in progress (step S52: NO), the control unit 5 stops the stirring pump 62 in step S62. As a result, the stirring operation ends, and the series of processing ends.

As described above, in the printing apparatus 1A, the negative pressure tank 24 stores the ink used for printing by the printing unit 2 during the initial agitation period. As a result, it is possible to perform the printing operation even during the initial agitation period, and thus it is possible to suppress a decrease in productivity.

Further, since the ink used for printing by the printing unit 2 during the initial agitation period is stored in the negative pressure tank 24 on the circulation path in the ink circulation unit 12A, the sub tank 52 in the first embodiment is unnecessary. is there. Accordingly, it is possible to realize the printing operation during the initial stirring period while suppressing the complication of the apparatus configuration.

[Other Embodiments]
As described above, the present invention has been described by the first and second embodiments, but it should not be understood that the description and drawings forming a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

In the above-described first and second embodiments, the MICR ink containing a magnetic material is used, but other types of ink that require agitation may be used.

As described above, needless to say, the present invention includes various embodiments and the like not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention according to the scope of claims appropriate from the above description.

[Appendix]
This application discloses the following inventions.

(Appendix 1)
Printing department,
An agitating unit that supplies ink to the printing unit while agitating the ink, and agitates the ink by stopping the supply of the ink to the printing unit when new ink is introduced during a printing operation,
The stirring unit stops the supply of ink to the printing unit to introduce new ink and stir the introduced ink, and stores ink to be used for printing by the printing unit during an initial stirring period. And a storage section for storing the printing unit.

(Appendix 2)
The stirring unit,
A first path for stirring ink while circulating the ink via the storage section;
A second path for agitating while circulating the ink without passing through the reservoir,
During the printing operation other than the initial stirring period, the ink is supplied to the printing unit while stirring the ink through the first path,
During the initial stirring period, the ink supply to the printing unit is stopped, and the ink is stirred by the second path,
The printing apparatus according to appendix 1, wherein the printing unit performs printing using the ink stored in the storage unit during the initial stirring period.

(Appendix 3)
The printing unit prints while circulating ink along a circulation path,
The printing apparatus according to appendix 1, wherein the circulation path is the storage section.

1, 1A Printing device 2, 2A Printing unit 3, 3A Replenishment unit 4 Pressure generation unit 5 Control unit 11 Inkjet head 12, 12A Ink circulation unit 21 Pressurized tank 22 Distributor 23 Aggregator 24 Negative pressure tank 25 Circulation pump 27- 29 Circulation pipe 51, 51A Stirring part 52 Sub-tank 53 Replenishment valve 54 Replenishment pipe 55 Ink cartridge 56 Introduction valve 57 Introduction pump 58 Introduction pipe 61 Agitation tank 62 Agitation pump 63-65, 111, 112 Agitation circulation pipe 66, 67 Switching valve 101 Negative pressure tank upper limit sensor 102 Negative pressure tank lower limit sensor 113 Circulation valve 114 Supply valve 115 Supply pipe

Claims (3)

Printing department,
An agitating unit that supplies ink to the printing unit while agitating the ink, and agitates the ink by stopping the supply of the ink to the printing unit when new ink is introduced during a printing operation,
The stirring unit stops the supply of ink to the printing unit to introduce new ink and stir the introduced ink, and stores ink to be used for printing by the printing unit during an initial stirring period. And a storage section for storing the printing unit. The stirring unit,
A first path for stirring ink while circulating the ink via the storage section;
A second path for agitating while circulating the ink without passing through the reservoir,
During the printing operation other than the initial stirring period, the ink is supplied to the printing unit while stirring the ink through the first path,
During the initial stirring period, the ink supply to the printing unit is stopped, and the ink is stirred by the second path,
The printing apparatus according to claim 1, wherein the printing unit performs printing using the ink stored in the storage unit during the initial stirring period. The printing unit prints while circulating ink along a circulation path,
The printing apparatus according to claim 1, wherein the circulation path is the storage unit.