Image forming device

Abstract

To provide an image formation apparatus which can suppress reaction between an evaporated pretreatment agent applied to a recording medium and ink in a head even when the pretreatment agent includes a volatile component.SOLUTION: An image formation apparatus cools a pretreatment agent 80 with cooling units 71-75. The cooling unit 71 cools the pretreatment agent 80 stored in a tank 77. The cooling unit 72 cools the pretreatment agent 80 stored in a sub pouch 8. The cooling unit 73A cools the pretreatment agent 80 in a pretreatment agent channel 26. The cooling unit 73B cools the pretreatment agent 80 in a pretreatment agent channel 27. The cooling unit 74 cools the pretreatment agent 80 in a head 14A. The cooling unit 75 cools the pretreatment agent 80 applied to a recording medium placed on a platen 15.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] Printers that apply a pretreatment agent to a printing medium before ejecting the ink to improve fixation of the ink ejected onto the printing medium are known. The printer described in Patent Document 1 applies a pretreatment agent to a fabric, and then ejects ink onto the fabric while it is wet with the applied pretreatment agent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-299240 Summary of the Invention [Problem to be solved by the invention]

[0004] The pretreatment agent applied to the fabric may volatilize when the ink is ejected. If the volatilized pretreatment agent adheres to the inkjet nozzle that ejects the ink, the adhered pretreatment agent may react with the ink inside the inkjet nozzle, causing the ink to thicken or aggregate, for example. This can cause the inkjet nozzle to have difficulty ejecting the ink. Another problem can be that the ink inside the inkjet nozzle may react with the pretreatment agent, causing a color change, for example.

[0005] An object of the present invention is to provide an image forming apparatus that prevents a pretreatment agent applied to a recording medium from volatilizing and reacting with ink in the head, even when the pretreatment agent contains a volatile component. [Means for solving the problem]

[0006] An image forming apparatus according to one aspect of the present invention is characterized by including a head that ejects ink, and a cooling unit that cools a pretreatment agent that contains a volatile component and reacts with the ink.

[0007] According to the above aspect, the cooling unit cools the pretreatment agent. As a result, the pretreatment agent applied to the recording medium is less likely to volatilize than a pretreatment agent that is not cooled. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0008] The apparatus may further include a discharge unit that discharges the pretreatment agent, and the cooling unit may cool the pretreatment agent before it is discharged by the discharge unit.

[0009] In this case, the cooling unit cools the pretreatment agent before it is ejected by the ejection unit. Because the cooled pretreatment agent is ejected, the ejected pretreatment agent is less likely to volatilize than a pretreatment agent that is not cooled before being ejected. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0010] The apparatus may further include a storage section that stores the pretreatment agent, and the cooling section may cool the pretreatment agent stored in the storage section.

[0011] In this case, the cooling unit cools the pretreatment agent contained in the container. Because the pretreatment agent cooled in the container is ejected, the ejected pretreatment agent is less likely to volatilize than a pretreatment agent that is not cooled in the container. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0012] The housing may include a thermal insulator.

[0013] In this case, the storage unit prevents the temperature of the pretreatment agent cooled by the cooling unit from rising due to the ambient air surrounding the storage unit. Because the pretreatment agent cooled by the cooling unit is ejected in a state where the temperature caused by the ambient air is suppressed, the ejected pretreatment agent is less likely to volatilize than a pretreatment agent stored in a storage unit without a thermal insulator. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0014] The ink jet recording apparatus may include a discharge unit that discharges the pretreatment agent and a storage unit that stores the pretreatment agent, and the cooling unit may cool the pretreatment agent in a flow path that connects the storage unit and the discharge unit.

[0015] In this case, the cooling unit cools the pretreatment agent in the flow path connecting the storage unit and the ejection unit. Because the pretreatment agent is ejected after being cooled in the flow path, the ejected pretreatment agent is less likely to volatilize than pretreatment agent that is not cooled in the flow path. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0016] The cooling unit may cool the pre-treatment agent in the discharge unit.

[0017] In this case, the cooling unit cools the pretreatment agent in the ejection unit. Because the cooled pretreatment agent is ejected by the ejection unit, the ejected pretreatment agent is less likely to volatilize than a pretreatment agent that is not cooled by the ejection unit. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0018] The recording medium may further include a platen that supports the recording medium on which the pretreatment agent has been applied, and the cooling section may cool the pretreatment agent that has been applied to the recording medium supported by the platen.

[0019] In this case, the cooling unit cools the pretreatment agent applied to the recording medium supported by the platen. Because the pretreatment agent applied to the recording medium is cooled by the cooling unit, it is less likely to volatilize while applied to the recording medium than a pretreatment agent that is not cooled. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0020] The apparatus may further include a first control unit that controls the cooling unit, and the first control unit may cause the cooling unit to cool the pretreatment agent when at least one of a temperature measured by a thermometer-side unit that measures temperature is equal to or higher than a predetermined temperature and a humidity measured by a hygrometer-side unit that measures humidity is equal to or lower than a predetermined humidity.

[0021] In this case, the first control unit causes the cooling unit to cool the pretreatment agent when at least one of the following occurs: the temperature measured by the temperature measuring unit is equal to or higher than a predetermined temperature; and the humidity measured by the humidity measuring unit is equal to or lower than a predetermined humidity. As a result, even in an environment where the pretreatment agent is likely to volatilize, the pretreatment agent applied to the recording medium becomes less likely to volatilize due to cooling. Therefore, even if the pretreatment agent contains a volatile component, the image forming apparatus can prevent the pretreatment agent from volatilizing and reacting with the ink in the head.

[0022] The image forming apparatus may further include a second control unit that controls the cooling unit, and the second control unit may control the cooling unit based on an operating time of the image forming apparatus within a predetermined time.

[0023] During operation, the image forming apparatus ejects ink from the head onto a recording medium to which a pretreatment agent has been applied. During operation, the second control unit causes the cooling unit to cool the pretreatment agent. Therefore, by not cooling the pretreatment agent outside of operation, the image forming apparatus 1 can reduce the power consumption of the cooling unit.

[0024] The cooling unit may cool the pretreatment agent so that the temperature of the pretreatment agent becomes higher than the freezing point of the pretreatment agent.

[0025] The cooling unit cools the pretreatment agent so that the temperature of the pretreatment agent is higher than the freezing point of the pretreatment agent. This allows the image forming device to prevent the pretreatment agent from solidifying due to cooling. Therefore, the image forming device can prevent the pretreatment agent from solidifying due to cooling, making it difficult to apply the pretreatment agent to the recording medium. Alternatively, the image forming device can prevent the pretreatment agent from solidifying due to cooling, making it difficult to apply the pretreatment agent to the recording medium. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of an image forming apparatus 1. [Figure 2] 1 is a diagram illustrating a flow path configuration for supplying a pre-treatment agent 80 and a flow path configuration for cooling the pre-treatment agent 80. FIG. [Figure 3] 2 is a block diagram showing the electrical configuration of the image forming apparatus 1. FIG. [Figure 4] 10 is a flowchart of a cooling control process. [Figure 5] FIG. 10 is a diagram illustrating a preset 90. DETAILED DESCRIPTION OF THE INVENTION

[0027] <Schematic Configuration of Image Forming Apparatus 1> An image forming apparatus 1 according to one embodiment of the present invention will now be described. In this embodiment, the mechanical elements in the drawings are shown to their actual scale. The image forming apparatus 1 in FIG. 1 is, for example, an inkjet printer, which ejects ink or a pretreatment agent 80 shown in FIG. 2 onto a recording medium (not shown) to perform printing. The recording medium is fabric, paper, or the like, such as a T-shirt.

[0028] The inks are, for example, white (W), black (K), yellow (Y), cyan (C), or magenta (M). In the following, the white ink among the five colors of ink will be referred to as "white ink," and when the four colors of ink, black, cyan, yellow, and magenta, are collectively referred to or when one of them is not specified, they will be referred to as "color ink."

[0029] White ink is used in printing to represent the white part of an image or as a base for color inks. The color inks are ejected directly onto a recording medium or onto a base of white ink to print color images.

[0030] The pretreatment agent 80 is, for example, a base coat agent, and is applied to the recording medium before printing with color ink or white ink. The pretreatment agent 80 applied to the recording medium reacts with the ink and improves the fixation of the ink to the recording medium or the color development of the ink. The pretreatment agent 80 contains, for example, formic acid and acetic acid as components that react with the ink. Formic acid and acetic acid are highly volatile, and the pretreatment agent 80 is volatile. In this embodiment, "the pretreatment agent 80 reacts with the ink" means that the pretreatment agent 80 thickens the ink or causes the ink to aggregate.

[0031] <Mechanical configuration of image forming apparatus 1> In the following description, the upper left, lower right, lower left, upper right, top, and bottom of FIG. 1 will be referred to as the left, right, front, rear, top, and bottom of the image forming apparatus 1, respectively.

[0032] As shown in FIG. 1, the image forming apparatus 1 includes a housing 2, a frame 10, a transport unit 11, a platen 15, a guide shaft 12A, rails 12B, a carriage 13, and multiple heads 14. The frame 10 is rectangular in plan view and is installed on top of the housing 2. The frame 10 supports a guide shaft 12A at the front and a rail 12B at the rear. The guide shaft 12A extends left and right inside the frame 10. The rail 12B is disposed opposite the guide shaft 12A and extends left and right. The carriage 13 is supported so as to be movable left and right along the guide shaft 12A.

[0033] The transport unit 11 includes, for example, a shaft extending in the front-rear direction. The platen 15 is located above the transport unit 11 and is supported by the transport unit 11. The platen 15 is plate-shaped and extends in the front-rear and left-right directions. A recording medium (not shown) is placed on the upper surface of the platen 15. The platen 15 is transported in the front-rear direction along the transport unit 11 by driving a sub-scanning motor 52 shown in FIG. 3. Therefore, in this embodiment, the front-rear direction of the image forming apparatus 1 is the sub-scanning direction.

[0034] Heads 14A and 14B are mounted on the carriage 13. Hereinafter, when there is no need to distinguish between them, they will be collectively referred to as "heads 14." The underside of the head 14 is located above the platen 15 and is exposed downward from the carriage 13. A plurality of nozzles (not shown) are provided on the underside of the head 14. The head 14 ejects ink or pretreatment agent 80 from the plurality of nozzles when driven by a head drive unit 53 shown in FIG. 3. The head drive unit 53 is configured by, for example, a piezoelectric element or a heat generating element. Head 14A ejects pretreatment agent 80. The pretreatment agent 80 is supplied to head 14A from a tank 77 (see FIG. 2). Head 14B ejects color ink. The color ink is supplied to head 14B from a tank (not shown).

[0035] The carriage 13 is driven by a main scanning motor 51 shown in Fig. 3 to be transported in the left-right direction along the guide shaft 12A and the rail 12B. This causes the head 14 to be transported in the left-right direction as well. Therefore, in this embodiment, the left-right direction of the image forming apparatus 1 is the main scanning direction.

[0036] As shown in FIG. 2, the image forming apparatus 1 includes a tank 77 that contains a pretreatment agent 80. The tank 77 is surrounded by a heat insulating material 76. The heat insulating material 76 is a member for preventing heat transfer due to conduction, convection, and radiation. The heat insulating material 76 may be made of, for example, foamed polyethylene. The heat insulating material 76 prevents the temperature of the pretreatment agent 80 contained in the tank 77 from increasing due to heat transfer from the surrounding atmosphere. The material for the heat insulating material 76 is not limited to foamed polyethylene, and other foam-based heat insulating materials may be used. Furthermore, the heat insulating material 76 may be, for example, a fiber-based heat insulating material such as glass wool or rock wool. Alternatively, the heat insulating material 76 may be a container with a vacuum drawn between its inner and outer layers.

[0037] <Flow path configuration for supplying pretreatment agent 80> 2, the flow path configuration for supplying pretreatment agent 80 from tank 77 to head 14A will be described. Pretreatment agent supply unit 61 supplies pretreatment agent 80 from tank 77 to head 14A. Pretreatment agent supply unit 61 includes sub-pouch 8, pretreatment agent flow paths 26 and 27, pump 20, valve 22, and a filter (not shown).

[0038] The sub-pouch 8 is bag-shaped. The pre-treatment agent channels 26 and 27 are, for example, hollow tubes. The pre-treatment agent channel 26 connects the tank 77 to the sub-pouch 8. The pre-treatment agent channel 27 connects the sub-pouch 8 to the head 14A.

[0039] The pump 20 is provided in the pretreatment agent flow path 26. The pump 20 is driven by a pump motor 54 shown in FIG. 3. The pump 20 sucks pretreatment agent 80 from the tank 77 and sends it toward the head 14A via the pretreatment agent flow path 26, the sub-pouch 8, and the pretreatment agent flow path 27. The sub-pouch 8 stores the pretreatment agent 80 sent from the tank 77.

[0040] The valve 22 is provided in the pretreatment agent flow path 26 downstream of the pump 20. The valve 22 opens and closes the pretreatment agent flow path 26. The filters are provided in the pretreatment agent flow paths 26 and 27 and filter the pretreatment agent 80.

[0041] <Outline of pre-processing and printing process> Image forming apparatus 1 performs pre-processing before printing. Before pre-processing, the user places a recording medium on platen 15. For example, in pre-processing, image forming apparatus 1 drives sub-scanning motor 52 shown in FIG. 3 to move platen 15 in the front-to-rear direction, while driving main scanning motor 51 shown in FIG. 3 to reciprocate carriage 13 in the left-to-right direction. While moving left-to-right, head 14A ejects pre-processing agent 80 supplied from tank 77. As a result, pre-processing agent 80 is applied to the recording medium placed on platen 15.

[0042] After the pretreatment, the image forming apparatus 1 performs the printing process. Note that this embodiment does not have a heat treatment mechanism for heating the recording medium after the pretreatment, so the recording medium is wet with the pretreatment agent 80. For example, in the printing process, the image forming apparatus 1 moves the platen 15 in the front-to-rear direction by driving the sub-scanning motor 52 shown in FIG. 3, while moving the carriage 13 back and forth in the left-to-right direction by driving the main scanning motor 51 shown in FIG. 3. As the head 14B moves left and right, it ejects ink supplied from a tank (not shown). As a result, a print image is printed on the recording medium placed on the platen 15.

[0043] <Configuration for Suppressing Volatilization of Pretreatment Agent 80 from the Recording Medium> To prevent pretreatment agent 80 applied to the recording medium from volatilizing, image forming apparatus 1 cools pretreatment agent 80 using cooling units 71 to 75. Hereinafter, when referring to cooling units 71 to 75 collectively or when no specific unit is specified, they will be referred to as cooling unit 70. Cooling unit 70 cools pretreatment agent 80 using a refrigerant. The refrigerant is, for example, a hydrofluorocarbon.

[0044] The cooling unit 71 is provided between the heat insulating material 76 and the tank 77. The cooling unit 71 cools the tank 77, thereby cooling the pre-treatment agent 80 contained in the tank 77. The heat insulating material 76 provided around the tank 77 covers the periphery of the pre-treatment agent 80 cooled by the cooling unit 71 from the outside of the tank 77, thereby preventing the temperature of the cooled pre-treatment agent 80 from rising due to the transfer of heat from the surrounding atmosphere.

[0045] Cooling section 72 covers the periphery of sub-pouch 8. Cooling section 72 cools pretreatment agent 80 contained in sub-pouch 8. Cooling section 73A is provided in pretreatment agent flow path 26. Cooling section 73A cools pretreatment agent 80 inside pretreatment agent flow path 26. Cooling section 73B is provided in pretreatment agent flow path 27. Cooling section 73B cools pretreatment agent 80 inside pretreatment agent flow path 27. Cooling section 74 is provided in head 14A. Cooling section 74 cools pretreatment agent 80 inside head 14A. Cooling section 75 is fixed to the lower surface of platen 15. Cooling section 75 cools pretreatment agent 80 applied to a recording medium placed on platen 15.

[0046] The refrigerant circulation unit 62 supplies the refrigerant to the cooling unit 70. The refrigerant circulation unit 62 includes refrigerant flow paths 28 and 29 and a heat exchanger 81. The refrigerant flow paths 28 and 29 are, for example, hollow tubes. The refrigerant flow paths 28 and 29 connect the cooling unit 70 and the heat exchanger 81. The heat exchanger 81 includes a compressor 82 (see FIG. 3), a condenser (not shown), a fan 83 (see FIG. 3), and an expansion valve (not shown). The compressor 82 compresses the refrigerant. The condenser and fan 83 release heat from the compressed refrigerant. The expansion valve adjusts the pressure of the refrigerant from which heat has been released, thereby cooling the refrigerant.

[0047] The refrigerant cooled by the heat exchanger 81 is sent from the heat exchanger 81 to the cooling unit 70 via the refrigerant flow path 28. The refrigerant used to cool the pre-treatment agent 80 in the cooling unit 70 is sent from the cooling unit 70 to the heat exchanger 81 via the refrigerant flow path 29. The refrigerant sent to the heat exchanger 81 via the refrigerant flow path 29 is cooled by the heat exchanger 81. That is, the refrigerant circulates between the cooling unit 70 and the heat exchanger 81 via the refrigerant flow paths 28 and 29.

[0048] <Electrical configuration of image forming apparatus 1> 3, the image forming apparatus 1 includes a control device 40. The control device 40 is fixed to the frame 10 and includes a CPU 41, a ROM 42, a RAM 43, a flash memory 44, and an RTC 45. The CPU 41 controls the image forming apparatus 1 and functions as a processor. The CPU 41 controls, for example, pre-processing and printing processing. The CPU 41 is electrically connected to the ROM 42, the RAM 43, the flash memory 44, and the RTC 45.

[0049] The ROM 42 stores control programs for the CPU 41 to control the operation of the image forming apparatus 1, information required by the CPU 41 when executing various programs, etc. The RAM 43 temporarily stores various data used in the control programs, etc. The flash memory 44 is a non-volatile memory and stores various settings of the image forming apparatus 1, etc. The RTC 45 serves as an internal clock of the image forming apparatus 1 and keeps track of the current time.

[0050] The CPU 41 is electrically connected to the main scanning motor 51, the sub-scanning motor 52, the head driving unit 53, the pump motor 54, the compressor 82, the fan 83, the temperature sensor 55, the humidity sensor 56, and the operation unit 57. The main scanning motor 51, the sub-scanning motor 52, the head driving unit 53, the compressor 82, and the fan 83 are driven under the control of the CPU 41.

[0051] The temperature sensor 55 is provided in the pretreatment agent flow path 27. The temperature sensor 55 detects the temperature T of the pretreatment agent 80 inside the pretreatment agent flow path 27 via the pretreatment agent flow path 27. The temperature sensor 55 outputs a signal indicating the detected temperature T to the CPU 41. The humidity sensor 56 is provided in the frame 10. The humidity sensor 56 detects the humidity H inside the housing 2 of the image forming apparatus 1. The humidity sensor 56 outputs a signal indicating the detected humidity H to the CPU 41. The position at which the temperature sensor 55 is provided is not limited to the pretreatment agent flow path 27, and may be any other position at which the temperature of the pretreatment agent 80 before ejection can be measured. For example, the temperature sensor 55 may be provided in any of the tank 77, the pretreatment agent flow path 26, the sub-pouch 8, and the head 14A.

[0052] The operation unit 57 is a touch panel display or the like, which displays various information and outputs information according to operations by a user to the CPU 41. By operating the operation unit 57, the user can input preprocessing instructions to the image forming apparatus 1 to start preprocessing by the image forming apparatus 1, etc.

[0053] <Preparation> The user determines the cooling start time, which is the time to start temperature control of the pretreatment agent 80, based on the operating hours of the image forming apparatus 1 in one day. The operating hours of the image forming apparatus 1 are, for example, the time during which pretreatment and printing are performed. For example, the user determines the cooling start time to be one hour before the time when pretreatment is expected to start for the first time in one day. The user inputs the determined cooling start time into the image forming apparatus 1 by operating the operation unit 57. The CPU 41 stores the input cooling start time in the flash memory 44.

[0054] The user also determines the cooling end time, which is the time to end temperature control of the pretreatment agent 80, based on the operating hours of the image forming apparatus 1 in one day. For example, the user determines the cooling end time to be 30 minutes after the time when all printing processes in one day are completed. The user operates the operation unit 57 to input the determined cooling end time into the image forming apparatus 1. The CPU 41 stores the input cooling end time in the flash memory 44.

[0055] <Cooling control processing> For example, when the image forming apparatus 1 is powered on with the cooling start time and cooling end time stored in the flash memory 44, the CPU 41 reads and runs a control program from the ROM 42, thereby executing the cooling control process shown in Fig. 4. By executing the cooling control process, the CPU 41 controls the cooling of the pre-processing agent 80 by the cooling unit 70.

[0056] 4, when the cooling control process starts, the CPU 41 determines whether the current time matches the cooling start time stored in the flash memory 44 based on the RTC 45 (S1). If the current time does not match the cooling start time (S1: NO), the CPU 41 returns the process to S1. If the current time matches the cooling start time (S1: YES), the CPU 41 acquires the temperature T of the pre-processing agent 80 from the temperature sensor 55 (S2). The CPU 41 determines whether the temperature T is equal to or lower than the upper limit temperature T H It is determined whether the upper limit temperature T H is a threshold value for determining whether to start or continue cooling the pre-treatment agent 80, and is stored in the flash memory 44.

[0057] Temperature T is the upper limit temperature T H If this is the case (S3: YES), the CPU 41 executes a cooling process (S4). In the cooling process, the CPU 41 drives the compressor 82 and the fan 83. The refrigerant circulates between the cooling unit 70 and the heat exchanger 81, and the cooling unit 70 cools the pre-processing agent 80. The CPU 41 shifts the process to S11.

[0058] Temperature T is the upper limit temperature T H If the temperature T is smaller than the lower limit temperature T L It is determined whether the temperature is equal to or lower than the lower limit temperature T (S5). L is a threshold value for determining whether or not to stop cooling the pre-treatment agent 80, and is stored in the flash memory 44. L is higher than the freezing point of the pretreatment agent 80. The freezing point of the pretreatment agent 80 is, for example, 0°C.

[0059] Temperature T is lower limit temperature T L If the following conditions are met (S5: YES), the CPU 41 executes a cooling stop process (S6). In the cooling stop process, the CPU 41 stops driving the compressor 82 and the fan 83. The circulation of the refrigerant between the cooling unit 70 and the heat exchanger 81 is stopped, and the cooling unit 70 stops cooling the pre-processing agent 80. The CPU 41 shifts the process to S11.

[0060] Temperature T is lower limit temperature TL If the humidity H inside the housing 2 of the image forming apparatus 1 is higher than the lower limit humidity H (S5: NO), the CPU 41 acquires the humidity H inside the housing 2 of the image forming apparatus 1 from the humidity sensor 56 (S7). L It is determined whether the humidity is equal to or lower than the lower limit humidity H (S8). L is a threshold value for determining whether to start or continue cooling the pre-treatment agent 80, and is stored in the flash memory 44.

[0061] The humidity H inside the housing 2 of the image forming apparatus 1 is lower than the lower limit humidity H L If the humidity H inside the housing 2 of the image forming apparatus 1 is equal to or lower than the lower limit humidity H (S8: YES), the CPU 41 executes the cooling process (S9). The cooling process executed in S9 is the same as the cooling process executed in S4. The CPU 41 shifts the process to S11. L If the difference is greater than the predetermined value (S8: NO), the CPU 41 executes the cooling stop process (S10). The cooling stop process executed in S10 is the same as the cooling stop process executed in S6. The CPU 41 proceeds to S11.

[0062] The CPU 41 determines based on the RTC 45 whether the current time matches the cooling end time stored in the flash memory 44 (S11). If the current time does not match the cooling end time (S11: NO), the CPU 41 returns the process to S2. If the current time matches the cooling end time (S11: YES), the CPU 41 executes cooling stop processing (S12). The cooling stop processing executed in S12 is the same as the cooling stop processing executed in S6 and S10. The CPU 41 returns the process to S1.

[0063] Note that formic acid and acetic acid are examples of "volatile components" of the present invention. Head 14A is an example of an "ejection section" of the present invention. Tank 77 and sub-pouch 8 are examples of a "storage section" of the present invention. Pretreatment agent flow paths 26 and 27 are examples of a "flow path" of the present invention. CPU 41 is an example of a "first control section" and a "second control section" of the present invention. Temperature sensor 55 is an example of a "thermometer side section" of the present invention. Humidity sensor 56 is an example of a "hygrometer side section" of the present invention. One day is an example of a "predetermined period of time" of the present invention.

[0064] <Actions and Effects of This Embodiment> In the image forming apparatus 1, the cooling unit 70 cools the pretreatment agent 80. As a result, the pretreatment agent 80 applied to the recording medium is less likely to volatilize than pretreatment agent 80 that is not cooled. This allows the image forming apparatus 1 to prevent the ink in the head 14B from reacting with the volatilized pretreatment agent 80. This allows the image forming apparatus 1 to prevent the head 14B from having difficulty ejecting ink.

[0065] In the image forming apparatus 1, the cooling units 71 to 74 cool the pretreatment agent 80 before it is ejected by the head 14A. Because the cooled pretreatment agent 80 is ejected from the head 14A, the ejected pretreatment agent 80 is less likely to volatilize than pretreatment agent 80 that is not cooled before being ejected. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0066] In the image forming apparatus 1, the cooling unit 71 cools the pretreatment agent 80 contained in the tank 77. The cooling unit 72 cools the pretreatment agent 80 contained in the sub-pouch 8. Because the pretreatment agent 80 cooled in the tank 77 or the sub-pouch 8 is ejected, the ejected pretreatment agent 80 is less likely to volatilize than pretreatment agent 80 that is not cooled in the tank 77. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0067] The heat insulating material 76 of the tank 77 prevents the temperature of the pretreatment agent 80 contained in the tank 77 from increasing due to heat transfer from the surrounding atmosphere. Because the pretreatment agent 80 cooled in the tank 77 is ejected in a state where the temperature increase due to the surrounding atmosphere is suppressed, the ejected pretreatment agent 80 is less likely to volatilize than pretreatment agent 80 cooled in a tank 77 that does not have the heat insulating material 76. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0068] The cooling unit 73A cools the pretreatment agent 80 inside the pretreatment agent flow path 26. The cooling unit 73B cools the pretreatment agent 80 inside the pretreatment agent flow path 27. Because the pretreatment agent 80 is ejected after being cooled in the pretreatment agent flow paths 26, 27, the ejected pretreatment agent 80 is less likely to volatilize than pretreatment agent 80 that is not cooled in the pretreatment agent flow paths 26, 27. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0069] The cooling unit 74 cools the pretreatment agent 80 inside the head 14A. Because the pretreatment agent 80 is ejected after being cooled by the head 14A, the ejected pretreatment agent 80 is less likely to volatilize than pretreatment agent 80 that is not cooled by the head 14A. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink inside the head 14B.

[0070] The cooling unit 75 cools the pretreatment agent 80 applied to the recording medium placed on the platen 15. Because the pretreatment agent 80 applied to the recording medium is cooled by the cooling unit 75, it is less likely to volatilize while applied to the recording medium than pretreatment agent 80 that is not cooled. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0071] The temperature T of the pretreatment agent 80 is the upper limit temperature T H If the humidity H inside the housing 2 of the image forming apparatus 1 is equal to or higher than the lower limit humidity H (S3: YES), the CPU 41 executes the cooling process (S4). L If the above is true (S8: YES), the CPU 41 executes a cooling process (S9). The CPU 41 causes the cooling unit 70 to cool the pretreatment agent 80 based on the temperature T detected by the temperature sensor 55 and the humidity H detected by the humidity sensor 56. As a result, even in an environment where the pretreatment agent 80 is likely to volatilize, the cooling makes the pretreatment agent 80 applied to the recording medium less likely to volatilize. Therefore, the image forming apparatus 1 can prevent the pretreatment agent 80 from volatilizing and reacting with the ink in the head 14B.

[0072] During the period from the current cooling start time to the current cooling end time, the CPU 41 controls the temperature of the pretreatment agent 80 using the cooling unit 70. The cooling start time and cooling end time are determined based on the operating hours of the image forming apparatus 1 in one day. Therefore, the image forming apparatus 1 can reduce the power consumption of the cooling unit 70 by not cooling the pretreatment agent 80 outside of the operating hours.

[0073] The temperature T of the pretreatment agent 80 is the lower limit temperature T L If the temperature is equal to or lower than the lower limit temperature T (S5: YES), the CPU 41 executes the cooling stop process (S6). L is higher than the freezing point of pretreatment agent 80. By executing the cooling stop process, CPU 41 controls the cooling of pretreatment agent 80 so that temperature T becomes higher than the freezing point of pretreatment agent 80. This allows image forming apparatus 1 to prevent pretreatment agent 80 from solidifying due to cooling. Therefore, image forming apparatus 1 can prevent pretreatment agent 80 from solidifying due to cooling, making it difficult to apply pretreatment agent 80 to the recording medium. Alternatively, image forming apparatus 1 can prevent pretreatment agent 80 from solidifying due to cooling, making it difficult to apply pretreatment agent 80 to the recording medium.

[0074] <Modification> The present invention can be modified in various ways from the above-described embodiment. The various modifications described below can be combined with each other as long as no contradictions arise. The pretreatment agent 80 may contain a substance other than formic acid and acetic acid as a highly volatile component. Furthermore, such a highly volatile component does not necessarily thicken or aggregate the ink. For example, the pretreatment agent 80 may react with the ink to discolor it.

[0075] The configuration of image forming apparatus 1 is not limited to the above embodiment. Pretreatment agent 80 does not have to be ejected from head 14A. Pretreatment agent 80 may be applied to the recording medium using, for example, a spray, a stamp, a brush, a roller, or the like.

[0076] The pretreatment agent 80 may be volatile and may contain a component that reacts with the ink. The pretreatment agent 80 may contain a component that discolors the ink, but may not contain a component that thickens the ink or a component that causes the ink to aggregate.

[0077] The image forming apparatus 1 may be capable of detachably mounting a cartridge that houses a tank that stores pretreatment agent 80. The pretreatment agent 80 may be supplied to the head 14A from the tank of a cartridge that is attached to the image forming apparatus 1. The image forming apparatus 1 does not need to be provided with a sub-pouch 8 that houses pretreatment agent 80. A cooling unit may be provided in only one of the pretreatment agent flow paths 26, 27. The pretreatment agent flow paths 26, 27 may not need to be provided with a cooling unit.

[0078] The tank 77 may be covered by a double-walled structure, such as a Dewar vessel, instead of the insulating material 76. The tank 77 does not have to be provided with the insulating material 76. The sub-pouch 8 may be covered by an insulating material. The temperature rise of the pretreatment agent 80 contained in the sub-pouch 8 may be suppressed by the insulating material. The pretreatment agent flow paths 26, 27 may be covered by an insulating material. The temperature rise of the pretreatment agent 80 inside the pretreatment agent flow paths 26, 27 may be suppressed by the insulating material. The portion of the head 14A excluding the nozzle may be covered by an insulating material. The temperature rise of the pretreatment agent 80 inside the head 14A may be suppressed by the insulating material. At least one of the cooling sections 71 to 75 may be provided with an insulating material.

[0079] The configuration of the cooling unit 70 is not limited to that described in the above embodiment. The image forming apparatus 1 may include at least one of the cooling units 71 to 75. The refrigerant used to cool the pretreatment agent 80 may be solid, liquid, or gas. The cooling unit 70 does not have to cool the pretreatment agent 80 using a circulating refrigerant. The cooling unit 70 may cool the pretreatment agent 80 using an electronic cooling system using, for example, a Peltier element. The cooling unit 71 may be provided inside the tank 77. In this case, the cooling unit 71 may cool the pretreatment agent 80 from inside the tank 77. Alternatively, the cooling unit 71 may be provided both inside and outside the tank 77. The cooling unit 72 may be provided inside the sub-pouch 8. In this case, the cooling unit 72 may cool the pretreatment agent 80 from inside the sub-pouch 8. Alternatively, the cooling unit 72 may be provided both inside and outside the sub-pouch 8. Cooling unit 73A may cool pretreatment agent 80 from the outside of pretreatment agent flow path 26, or from the inside of pretreatment agent flow path 27. Cooling unit 73B may cool pretreatment agent 80 from the outside of pretreatment agent flow path 27, or from the inside of pretreatment agent flow path 27. Cooling unit 74 may cool pretreatment agent 80 from the outside of head 14A, or from the inside of head 14A. Cooling unit 75 may cool pretreatment agent 80 applied to the recording medium placed on platen 15, for example, by blowing cool air onto the recording medium placed on platen 15. The cooling units 71 to 75 may have the same configuration or different configurations.

[0080] The CPU 41 may not execute the cooling process or the cooling stop process based on the temperature T detected by the temperature sensor 55 and the humidity H detected by the humidity sensor 56. In this case, the CPU 41 may omit the processes of S2, S3, and S5 to S10 in the cooling process. The CPU 41 may execute the cooling process based on either the temperature T detected by the temperature sensor 55 or the humidity H detected by the humidity sensor 56. When the cooling process is executed based on the temperature T detected by the temperature sensor 55, the CPU 41 may omit the processes of S7 to S9 in the cooling control process. In this case, the image forming apparatus 1 may not include the humidity sensor 56. When the cooling process is executed based on the humidity H detected by the humidity sensor 56, the CPU 41 may omit the processes of S2 to S6 in the cooling control process. In this case, the image forming apparatus 1 may not include the temperature sensor 55.

[0081] In the above embodiment, the temperature sensor 55 is provided in the pretreatment agent flow path 27, but this is not limited thereto. The temperature sensor 55 may also be provided in, for example, at least one of the platen 15, the tank 77, the pretreatment agent supply unit 61, and the head 14A. The temperature sensor 55 may also detect the temperature of the pretreatment agent 80 applied to the recording medium. The temperature sensor 55 may also detect the temperature around the image forming apparatus 1. In the above embodiment, the humidity sensor 56 is provided in the frame 10 and detects the humidity H inside the housing 2 of the image forming apparatus 1, but this is not limited thereto. The humidity sensor 56 may also detect the humidity outside the housing 2 of the image forming apparatus 1. The image forming apparatus 1 does not necessarily have to have at least one of the temperature sensor 55 and the humidity sensor 56. The image forming apparatus 1 does not necessarily have to be provided with the temperature sensor 55 or the humidity sensor 56.

[0082] In the cooling control process, the CPU 41 may perform control processing (S7) based on the humidity H detected by the humidity sensor 56 before performing control processing (S3, S5) based on the temperature T detected by the temperature sensor 55. In this case, the order of S4, S6, S9, and S10 is changed. The CPU 41 may perform processing of S5 before processing of S3. In this case, the order of S4 and S6 is changed.

[0083] The CPU 41 may control the cooling of the pretreatment agent 80 by the cooling unit 70 in accordance with the combination of the temperature T detected by the temperature sensor 55 and the humidity H detected by the humidity sensor 56. In this case, the flash memory 44 stores a preset 90 shown in FIG. 5. The preset 90 stores control information indicating whether to perform a cooling process or a cooling stop process, in association with the combination of the temperature T and the humidity H. When the CPU 41 acquires the temperature T and the humidity H in the cooling control process, the CPU 41 executes either the cooling process or the cooling stop process based on the control information corresponding to the acquired combination of the temperature T and the humidity H, in accordance with the preset 90.

[0084] The CPU 41 may not control the cooling unit 70 based on the operation time of the image forming apparatus 1 within a predetermined time. In this case, the CPU 41 may omit the processes of S1, S11, and S12 in the cooling process. The cooling start time is not limited to the above embodiment. The cooling start time may be determined based on, for example, the operation time of the image forming apparatus 1 in a week. The cooling start time may be determined based on the time when the image forming apparatus 1 starts executing a print process in a day. The cooling start time may be determined by the CPU 41 based on the past operation time of the image forming apparatus 1. In this case, the CPU 41 may determine the cooling start time during the execution of the cooling control process (for example, while the process is returned from S12 to S1).

[0085] The cooling end time is not limited to the above embodiment. The cooling end time may be determined based on, for example, the operating hours of the image forming apparatus 1 in a week. The cooling end time may also be determined based on the time when the execution of pre-processing by the image forming apparatus 1 in a day ends. The cooling end time may also be determined by the CPU 41 based on the past operating hours of the image forming apparatus 1. In this case, the CPU 41 may determine the cooling end time during the execution of the cooling control process (for example, while the process is returned from S12 to S1).

[0086] The flash memory 44 may store a standby time instead of the cooling start time. In this case, the CPU 41 may determine whether the standby time has elapsed in the process of S1. If the standby time has elapsed, the CPU 41 may perform the processes from S2 to S11. For example, if the standby time is one hour, the CPU 41 performs the cooling control process every hour. In this way, the CPU 41 may perform the cooling control process periodically.

[0087] In the cooling control process, the CPU 41 may perform the processes from S2 to S11 irregularly. In other words, the CPU 41 does not have to perform the processes from S2 to S11 at a fixed time (cooling start time). For example, when a user operates the operation unit 57 and inputs a cooling start instruction to the image forming apparatus 1, the CPU 41 may perform the processes from S2 to S11.

[0088] The execution time may be stored instead of the cooling end time in the flash memory 44. In this case, the CPU 41 may perform the process of S12 when the execution time has elapsed since the cooling start time in the process of S11.

[0089] In the cooling control process, the CPU 41 may perform the process of S12 irregularly. In other words, the CPU 41 does not have to perform the process of S12 at a fixed time (cooling end time). For example, the CPU 41 may perform the process of S12 when the user operates the operation unit 57 and inputs a cooling end instruction to the image forming apparatus 1.

[0090] Lower limit temperature T L The lower limit temperature T in the cooling units 71 to 75 may be lower than the freezing point of the pretreatment agent 80. For example, the cooling unit 75 may cool the pretreatment agent 80 at a temperature lower than the freezing point of the pretreatment agent 80. The image forming apparatus 1 may heat the pretreatment agent 80 solidified by the cooling unit 70 to a temperature equal to or higher than the melting point, for example, by using a heater. L may be the same or different. LThe upper limit temperature T H may be the same or different. H may fluctuate based on, for example, any of the temperature, humidity, and air pressure inside the housing 2 of the image forming apparatus 1.

[0091] Lower limit humidity H in cooling sections 71 to 75 L The lower limit humidity H may be the same or different. L may fluctuate based on, for example, any of the temperature, humidity, and air pressure inside the housing 2 of the image forming apparatus 1.

[0092] Instead of the CPU 41, a microcomputer, an ASIC (Application Specific Integrated Circuits), an FPGA (Field Programmable Gate Array), or the like may be used as the processor. The cooling control process may be distributed among multiple processors. The non-transitory storage medium, such as the ROM 42 or the flash memory 44, may be any storage medium capable of retaining information regardless of the period for which the information is stored. The non-transitory storage medium may not include a temporary storage medium (e.g., a transmitted signal). The control program may be downloaded (i.e., transmitted as a transmission signal) from a server connected to a network (not shown) and stored in the ROM 42 or the flash memory 44. In this case, the control program may be stored in a non-transitory storage medium, such as a hard disk drive (HDD), provided in the server. [Explanation of symbols]

[0093] 1. Image forming device 14 heads 15 Platen 26, 27 Pretreatment agent flow path 41 CPU 55 Temperature Sensor 56 Humidity Sensor 70~75 Cooling section 76 Insulation section 77 Tank 80 Pretreatment agent

Claims

1. a head that ejects ink; a cooling unit that cools the pretreatment agent that contains a volatile component and reacts with the ink; a discharge unit that discharges the pretreatment agent; a storage section that stores the pretreatment agent; Equipped with The cooling unit is The pre-treatment agent is cooled in a flow path connecting the storage unit and the discharge unit before being discharged by the discharge unit. An image forming apparatus characterized by:

2. A head that ejects ink; a cooling unit that cools the pretreatment agent that contains a volatile component and reacts with the ink; a platen that supports the recording medium on which the pretreatment agent has been applied; Equipped with The image forming apparatus is characterized in that the cooling section cools the pretreatment agent applied to the recording medium via the platen.

3. A head that ejects ink; a cooling unit that cools the pretreatment agent that contains a volatile component and reacts with the ink; a second control unit that controls the cooling unit; Equipped with The image forming apparatus, wherein the second control unit controls the cooling unit based on an operating time of the image forming apparatus within a predetermined time.

4. a discharge unit that discharges the pretreatment agent, The cooling unit cools the pretreatment agent before it is discharged by the discharge unit.

4. The image forming apparatus according to claim 2, wherein:

5. a storage unit that stores the pretreatment agent, 5. The image forming apparatus according to claim 2, wherein the cooling section cools the pretreatment agent contained in the container section.

6. 6. The image forming apparatus according to claim 1, wherein the container portion has a heat insulating material.

7. a storage unit that stores the pretreatment agent, 5. The image forming apparatus according to claim 4, wherein the cooling section cools the pretreatment agent in a flow path connecting the container section and the ejection section.

8. 8. The image forming apparatus according to claim 1, wherein the cooling section cools the pretreatment agent in the ejection section.

9. a platen for supporting the recording medium on which the pretreatment agent has been applied; 4. The image forming apparatus according to claim 1, wherein the cooling section cools the pretreatment agent applied to the recording medium via the platen.

10. a first control unit that controls the cooling unit; 10. The image forming apparatus according to claim 1, wherein the first control unit causes the cooling unit to cool the pretreatment agent when at least one of a temperature measured by a thermometer-side unit that measures temperature is equal to or higher than a predetermined temperature and a humidity measured by a hygrometer-side unit that measures humidity is equal to or lower than a predetermined humidity.

11. a second control unit that controls the cooling unit; 3. The image forming apparatus according to claim 1, wherein the second control unit controls the cooling unit based on an operating time of the image forming apparatus within a predetermined time.

12. 12. The image forming apparatus according to claim 1, wherein the cooling unit cools the pretreatment agent so that the temperature of the pretreatment agent becomes higher than the freezing point of the pretreatment agent.

Images