Heater control device, ink supply device, image forming system, heater control method

Abstract

To make it easier to reduce the processing load of the control that heats the ink during startup. [Solution] The heater control device 6 is a heater control device that controls a heater 51 that heats the ink supplied from an ink container 21 containing ink to a recording head, and includes a control unit 61. When the heater 51 is in operation, the control unit 61 controls the heater 51 with a first output, and when the heater 51 is switched from a non-operating state to an operating state, it performs output increase control which controls the heater 51 with a second output that is greater than the first output until a predetermined time has elapsed from the time of the switch.

Description

Technical Field

[0001] The present invention relates to a heater control device for controlling a heater that warms ink, an ink supply device, an image forming system, and a heater control method.

Background Art

[0002] As related art, an inkjet printer that warms ink to a predetermined temperature is known (for example, see Patent Document 1). In this inkjet printer, when the measured value of the ink temperature is equal to or higher than a first reference temperature and lower than a second reference temperature, the printing rate of a page to be printed is calculated, and the amount of power supplied to the heater is changed according to the calculated printing rate.

[0003] Also, as related art, in a temperature adjustment unit provided in the middle of an ink supply path, the ink temperature at startup is compared with a predetermined threshold temperature, and temperature control is performed to vary the ink circulation amount according to the comparison result and accelerate the recording start time. An inkjet recording device is known (for example, see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the above related art is adopted for the control of warming ink at startup, it is necessary to control elements other than the heater, such as calculating the printing rate of a page to be printed or varying the ink circulation amount. There is a problem that the control of warming ink at startup becomes complicated and the processing load tends to increase.

[0006] The object of the present invention is to provide a heater control device, an ink supply device, an image forming system, and a heater control method that can easily reduce the processing load of the control for heating the ink at startup. [Means for solving the problem]

[0007] A heater control device according to one aspect of the present invention is a heater control device that controls a heater for heating ink supplied from an ink container containing ink to a recording head, and comprises a control unit. The control unit controls the heater with a first output when the heater is in operation, and when the heater is switched from a non-operating state to an operating state, it performs output increase control which controls the heater with a second output greater than the first output until a predetermined time has elapsed from the time of the switch.

[0008] An ink supply device according to another aspect of the present invention comprises the heater control device, the heater, the ink container, and an ink supply path for supplying the ink from the ink container to the recording head.

[0009] An image forming system according to another aspect of the present invention comprises the ink supply device and an inkjet recording device that ejects the ink supplied from the ink container from the recording head to form an image.

[0010] Another aspect of the present invention relates to a heater control method for controlling a heater that heats the ink supplied from an ink container containing ink to a recording head, and includes a control step. In the control step, if the heater is in an operating state, the heater is controlled with a first output, and if the heater is switched from a non-operating state to an operating state, output increase control is performed to control the heater with a second output greater than the first output until a predetermined time has elapsed from the time of the switch. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a heater control device, an ink supply device, an image forming system, and a heater control method that can easily reduce the processing load of the control for heating the ink at startup. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram showing the configuration of the image forming system according to the embodiment. [Figure 2] Figure 2 is a schematic diagram showing the configuration of the ink supply device and ink supply path according to the embodiment. [Figure 3] Figure 3 is a block diagram showing the configuration of a heater control device according to an embodiment. [Figure 4] Figure 4 is a flowchart showing an example of operation of the heater control device according to the embodiment. [Figure 5] Figure 5 shows a specific example of the operation of the heater control device according to the embodiment. [Figure 6] Figure 6 is a block diagram showing the configuration of a heater control device according to a modified embodiment. [Figure 7] Figure 7 is a flowchart showing an example of operation of a heater control device according to another modified embodiment. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be described below with reference to the attached drawings. The following embodiments are examples that embody the present invention and are not intended to limit the technical scope of the present invention.

[0014] [1] Overall configuration of the image forming system First, the image forming system 100 according to this embodiment will be described with reference to Figures 1 and 2. The image forming system 100 comprises a printer (inkjet recording device) 1 and an ink supply device 2. Hereinafter, the front side in Figure 1 (the side in front of the paper in Figure 1) will be considered the front side of the printer 1 and ink supply device 2, and the up, down, left, and right directions will be described based on the direction in which the printer 1 and ink supply device 2 are viewed from the front. Note that these directions are not intended to limit the manner in which the printer 1 and ink supply device 2 are used.

[0015] In this embodiment, as an example, the printer 1 is an inkjet recording device that has a recording head 16 that ejects ink onto the surface of a sheet Sh1, and is capable of performing printing processing using an inkjet method in which an image is formed on the sheet Sh1 by the recording head 16. In other words, the printer 1 is an inkjet recording device that ejects ink supplied from an ink container 21 (described later) from the recording head 16 to form an image (ink image). Printing processing is the process of forming an image on an image-forming object. Sheet Sh1 is an example of an image-forming object (recording medium) on which an image is formed by the printer 1, and is a sheet-like medium such as paper or a resin film.

[0016] Printer 1 only needs to have the function of forming images using an inkjet method. For example, it may be a multifunction device that has multiple functions in addition to the printing function, such as a scanning function to read image data from a document, a facsimile function, and a copy function. Alternatively, Printer 1 may be a facsimile machine or a copier, etc.

[0017] As shown in FIG. 1, the printer 1 includes a housing 10 that forms the outer shell of the printer 1 and houses various devices. At the lower part inside the housing 10, there is provided a drawer-type paper feed cassette 11 for accommodating the sheet Sh1. On the right side of the housing 10, there is provided a manual feed tray 12 on which the sheet Sh1 can be manually loaded. Above the manual feed tray 12, there is provided a discharge tray 13 on which the printed sheet Sh1 is loaded. On the upper side of the left side of the housing 10, there is provided an outlet 14 for transporting the sheet Sh1 to a post-processing device (not shown) adjacent to the printer 1. The post-processing device has post-processing functions such as, for example, a stapling function, a folding function, an inserter function, or a punching function. Note that the post-processing device is not essential when using the image forming system 100 of the present embodiment.

[0018] At the central part inside the housing 10, there are provided head units 15Y, 15Bk, 15C, 15M (hereinafter, collectively referred to as "head unit 15" when not particularly distinguished) each including one or more recording heads 16 for discharging ink onto the sheet Sh1. The head units 15Y, 15Bk, 15C, 15M discharge yellow, black, cyan, and magenta inks, respectively. Below the head unit 15, there is provided a transport unit 17 that adsorbs and transports the sheet Sh1 on which an image is to be formed to a transport belt 18. To the left of the transport unit 17, there is provided a drying unit 19 that dries the printed sheet Sh1 while transporting it. Also, at the lower left part inside the housing 10, there are housed ink containers 3Y, 3Bk, 3C, 3M (hereinafter, collectively referred to as "ink container 3" when not particularly distinguished) each containing the corresponding color ink.

[0019] On the right side of the conveying unit 17, there are provided a first conveying path 41 from the paper feed cassette 11 to the conveying unit 17 and a manual conveying path 40 that merges from the manual feed tray 12 into the first conveying path 41. On the left side of the drying unit 19, there is provided a second conveying path 42 from the drying unit 19 to the discharge port 14. Above the head unit 15, there are provided a third conveying path 43 that branches from the second conveying path 42 and leads to the discharge tray 13, and a fourth conveying path 44 that branches from the third conveying path 43 and merges into the first conveying path. Note that at the branch point between the second conveying path 42 and the third conveying path 43, and at the branch point between the third conveying path 43 and the fourth conveying path 44, there are provided guiding members (not shown) for guiding the conveyance of the sheet Sh1, respectively.

[0020] Next, an overview of the image forming operation of the printer 1 will be described. When an image forming job is input to the printer 1, the sheet Sh1 is sent out from the paper feed cassette 11 or the manual feed tray 12 and conveyed in the first direction D1 along the first conveying path 41. The sheet Sh1 is adsorbed and conveyed by the conveying belt 18 of the conveying unit 17. Thereafter, ink droplets are ejected from the head unit 15 onto the sheet Sh1, thereby forming an image on the surface of the sheet Sh1. The sheet Sh1 with an image formed on its surface is dried by the drying unit 19 to promote the drying of the ink. Then, the sheet Sh1 is conveyed along the second conveying path 42 and the third conveying path 43 and discharged onto the discharge tray 13.

[0021] Note that when forming images on both sides of the sheet Sh1, the sheet Sh1 is conveyed in the second direction D2 along the fourth conveying path 44 from the third conveying path 43 and is turned over from the front side to the back side in the middle of the fourth conveying path 44. Then, the sheet Sh1 is conveyed in the third direction D3 along the fourth conveying path 44, and is again adsorbed and conveyed by the conveying belt 18 of the conveying unit 17. Thereafter, ink droplets are ejected from the head unit 15 onto the sheet Sh1, thereby forming an image on the back side of the sheet Sh1. The sheet Sh1 with an image formed on its back side is dried by the drying unit 19 to promote the drying of the ink. Then, the sheet Sh1 is conveyed along the second conveying path 42 and the third conveying path 43 and discharged onto the discharge tray 13.

[0022] Next, the ink supply path in printer 1 will be explained using Figure 2. Although Figure 2 shows a configuration corresponding to one color of ink, in this embodiment printer 1 uses four colors of ink, so printer 1 actually has additional configurations corresponding to the remaining three colors of ink.

[0023] The printer 1 includes a container mounting section 31 to which an ink container 3 for storing ink is mounted, a pump 32 for drawing ink from the ink container 3, a filter 33 for filtering the ink drawn into the pump 32, and a sub-tank 34 for storing the ink sent out from the pump 32. The printer 1 also includes a pump (not shown) for sending the ink stored in the sub-tank 34 to the head unit 15. The ink container 3, filter 33, pump 32, and sub-tank 34 are connected to each other by a main pipe 35. The lower end of the main pipe 35 is connected to either a first relay pipe 36 or a second relay pipe 37. When the ink supply device 2 is not used, the lower end of the main pipe 35 is connected to the ink container 3 via the first relay pipe 36. When the ink supply device 2 is used, the lower end of the main pipe 35 is connected to a coupling 38 provided on the back of the housing 10 via the second relay pipe 37.

[0024] [2] Configuration of the ink supply device Next, the ink supply device 2 will be explained using Figure 2. Although Figure 2 shows a configuration corresponding to one color of ink, in this embodiment four colors of ink are used, so the ink supply device 2 is actually further equipped with configurations corresponding to the remaining three colors of ink.

[0025] The ink supply device 2 includes a container mounting section 22 into which an ink container 21 containing ink is mounted, a spare container mounting section 23 into which a spare ink container 21 is mounted, and a heater unit 5 for heating the ink dispensed from the ink container 21. In this embodiment, the ink supply device 2 includes a spare container mounting section 23, but it is not required to include a spare container mounting section 23. Although not shown in Figure 2, the ink supply device 2 further includes a heater control device 6 for controlling the heater unit 5. The heater control device 6 will be described in detail in "[3] Configuration of the Heater Control Device".

[0026] The ink container 21 has a larger volume than the ink container 3 installed inside the printer 1. In this embodiment, since the printer 1 uses four colors of ink, the ink supply device 2 is provided with four ink containers 21, each containing yellow, black, cyan, and magenta ink. The same applies to the spare ink container 21.

[0027] The heater unit 5 comprises a metal plate (not shown), piping 52, and a heater 51 (see Figure 3). In this embodiment, two metal plates facing each other are provided inside the housing (not shown) that forms the outer casing of the heater unit 5. The metal plates are, for example, plates of an aluminum alloy or a copper alloy.

[0028] The pipe 52 is installed between two metal plates and is in contact with each metal plate. The pipe 52 is made of, for example, stainless steel. The pipe 52 comprises a plurality of straight sections 53 formed in a straight line and a U-shaped curved section 54 that connects the plurality of straight sections 53 in series. The pipe 52 is formed in a meandering shape as a whole because the plurality of straight sections 53 are arranged parallel to each other and at equal intervals.

[0029] The lower left end of pipe 52 is connected to the ink container 21 via relay pipe 55, and serves as the inlet for ink dispensed from the ink container 21. The upper left end of pipe 52 is connected to the coupling 38 of printer 1 via relay pipe 56, and serves as the outlet for ink dispensed from the ink container 21 through pipe 52. In other words, pipe 52 corresponds to the ink supply path that supplies ink from the ink container 21 to the recording head 16.

[0030] The heater 51 is formed in a linear shape and heats the ink supplied from the ink container 21, which contains the ink, to the recording head 16. The heater 51 is, for example, a cord heater made of a heating wire covered with silicone resin. Multiple heaters 51 are provided along the piping 52, sandwiching each metal plate. Specifically, multiple heaters 51 are provided sandwiching one of the two metal plates, and these multiple heaters 51 are in contact with that metal plate. Similarly, multiple heaters 51 are provided sandwiching the other metal plate, and these multiple heaters 51 are in contact with that metal plate. Each heater 51 is connected in parallel to a power supply (not shown) via a power supply line (not shown), and generates heat when power is supplied from the power supply.

[0031] [3] Configuration of heater control device Incidentally, in printers (inkjet recording devices), if the ink cools below a certain temperature, the viscosity of the ink decreases, making it difficult to supply ink stably. For this reason, a system (heater control device) that uses a heater to warm the ink in the ink supply path from the ink container to the recording head is sometimes introduced.

[0032] In such ink heating systems, when the heater 51 is switched from a non-operating state to an operating state, such as when the printer is switched from sleep mode or power off to on, in other words, when the printer is started, if the ink has cooled down before startup, it may take time to heat the ink, which can increase the time until printing is possible (startup time). Here, "non-operating state" refers to a state in which the heater 51 is not heating the target or is not receiving power. Also, "operating state" refers to a state in which the heater 51 is heating the target or is receiving power.

[0033] In this context, a related technology known is an inkjet printer that heats the ink to a predetermined temperature. In this inkjet printer, when the measured ink temperature is between a first reference temperature and a second reference temperature, the print coverage of the page to be printed is calculated, and the amount of power supplied to the heater is changed according to the calculated print coverage.

[0034] Furthermore, as a related technology, there is known in which an inkjet recording device performs temperature control in a temperature control unit installed in the ink supply path, comparing the ink temperature at startup with a predetermined threshold temperature, and varying the ink circulation amount according to the comparison result to advance the recording start time.

[0035] However, if the above-mentioned related technologies are used to control the heating of the ink at startup, it becomes necessary to control factors other than the heater, such as calculating the print density of the page to be printed or varying the amount of ink circulated. This makes the control of heating the ink at startup complex and tends to increase the processing load.

[0036] In contrast, in this embodiment, the heater control device 6 described below makes it possible to realize a heater control device 6 and heater control method that shorten the startup time and easily reduce the processing load of the control that heats the ink at startup.

[0037] The heater control device 6 will be described below with reference to Figure 3. The heater control device 6 controls each heater 51 provided in each heater unit 5. The heater control device 6 mainly consists of a computer system having one or more processors and one or more non-volatile memories. The functions of the heater control device 6 are realized when one or more processors execute a program. The program may be pre-recorded in memory (storage unit), provided via a telecommunication line such as the Internet, or provided by being recorded on a non-temporary recording medium readable by the computer system, such as a memory card or optical disc. One or more processors consist of one or more electronic circuits including semiconductor integrated circuits. Furthermore, the computer system referred to here includes a microcontroller having one or more processors and one or more memories.

[0038] The heater control device 6 includes a control unit 61. Specifically, one or more processors in the heater control device 6 execute a program stored in memory. As a result, the heater control device 6 functions as a control unit 61.

[0039] The control unit 61 controls the heater 51 with a first output when the heater 51 is operating. Specifically, the control unit 61 controls each heater 51 of each heater unit 5 with a first output when the heater control device 6 and the printer 1 are powered on, in other words, during normal operation of the heater control device 6 and the printer 1. Here, the first output is the amount of power supplied to the heater 51 to heat the ink in order to maintain the temperature of the ink sent from the ink container 21 within a predetermined range. The predetermined range is, for example, the temperature range in which the viscosity of the ink is appropriate.

[0040] In this embodiment, the control unit 61 controls the heater 51 with a first output by controlling the voltage applied to the heater 51 using PWM (Pulse Width Modulation). However, the control unit 61 is not limited to PWM control; for example, it may control the heater 51 with a first output by increasing or decreasing the voltage applied to the heater 51 or the current flowing through each heater 51.

[0041] Furthermore, when the heater 51 is switched from a non-operating state to an operating state, in other words, when the heater control device 6 and printer 1 are started up, the control unit 61 performs output increase control, which controls the heater 51 with a second output that is greater than the first output, until a predetermined time has elapsed from the time of the switch. In other words, the control unit 61 performs the operation of controlling the heater 51 with an output (second output) that is greater than the normal output (first output) until a predetermined time has elapsed from the time the heater control device 6 and printer 1 are started up.

[0042] In this embodiment, the control unit 61 controls the heater 51 with a second output by PWM control of the voltage applied to the heater 51. However, the control unit 61 is not limited to PWM control; for example, it may control the heater 51 with a second output by increasing or decreasing the voltage applied to the heater 51 or the current flowing through the heater 51.

[0043] In this embodiment, the predetermined time is stored in the memory of the heater control device 6 beforehand. In other words, in this embodiment, the heater control device 6 does not calculate the predetermined time when it is started up, but rather refers to the predetermined time that is stored in the memory beforehand.

[0044] In this embodiment, for example, if the ink coagulation temperature is "T1", the temperature of the heater 51 when controlled by the first output is "T2", and the temperature of the heater 51 when controlled by the second output is "T3", then the second output is set such that T1 > T3 > T2. Here, the coagulation temperature is the temperature at which coagulation begins when the ink is continuously heated, and is an intrinsic value for each type of ink. More specifically, the coagulation temperature is the temperature at which coagulation begins when the ink is continuously heated, and at which, for example, a number of coarse particles with a diameter of several hundred nanometers or more begin to be generated.

[0045] In this embodiment, the predetermined time is determined based on the above-mentioned coagulation temperature and the heating rate when heating the ink with the second output. The heating rate corresponds to the amount of temperature increase of the ink per unit time. For example, if the second output is large, that is, if the heating rate is large, the predetermined time is set to be shorter. Conversely, for example, if the second output is small, that is, if the heating rate is small, the predetermined time is set to be longer.

[0046] By setting a predetermined time in this way, it becomes easier to avoid ink aggregation by continuously controlling the heater 51 with the second output.

[0047] Furthermore, in this embodiment, the predetermined time is determined based on the temperature of the environment in which the heater control device 6 is installed (hereinafter referred to as "ambient temperature"). Here, ambient temperature refers to, for example, the temperature of the room in which the heater control device 6 is installed, the ambient temperature of the location where the heater control device 6 is installed, or the temperature inside the heater control device 6. Here, if the ambient temperature, i.e., the temperature of the room in which the heater control device 6 is installed, is "Tc", the heating rate is "V1", and the predetermined time is "P1", then the predetermined time is determined such that T1 ≥ Tc + V1 × P1.

[0048] In this embodiment, the heater control device 6 does not have a temperature sensor for measuring ambient temperature, nor does it have a function to acquire ambient temperature from an external temperature sensor. Therefore, in this embodiment, the ambient temperature is set to the maximum value of the ambient temperature that can occur in the environment where the heater control device 6 is installed, which has been measured in advance. Here, the ambient temperature may be set for each season, for example. For example, if the heater control device 6 has a function to measure the current date and time, the ambient temperature corresponding to the current date and time may be read from memory and used.

[0049] By setting a predetermined time in this way, it becomes easier to avoid ink aggregation by continuously controlling the heater 51 with the second output, compared to when ambient temperature is not taken into consideration.

[0050] [4] Operation of the heater control device Hereinafter, with reference to Figure 4, an example of the heater control method of this embodiment will be described along with an example of the procedure for the decision processing performed by the heater control device 6. Here, steps S11, S12, ... represent the numbers of the processing procedures (steps) performed by the heater control device 6.

[0051] <Step S11> The control unit 61 of the heater control device 6 does not operate while the heater 51 is in a non-operating state (step S11: No). Then, when the heater 51 is switched from a non-operating state to an operating state (step S11: Yes), the control unit 61 executes step S12.

[0052] <Step S12> When the heater control device 6 is switched from a non-operating state to an operating state, the control unit 61 of the heater control device 6 executes output increase control to control the heater 51 with the second output. Here, the control unit 61 counts the elapsed time from the start of the output increase control (i.e., the time of switching).

[0053] <Step S13> The control unit 61 of the heater control device 6 continues the output increase control until the elapsed time being counted reaches a predetermined time, that is, until a predetermined time has elapsed from the start of the output increase control (step S13: No). Then, when the elapsed time being counted reaches a predetermined time, that is, when a predetermined time has elapsed from the start of the output increase control (step S13: Yes), the control unit 61 executes step S14.

[0054] <Step S14> The control unit 61 of the heater control device 6 stops the output increase control. Then, the control unit 61 controls the heater 51 with the first output. After that, the control unit 61 continues the above control until the heater 51 is switched from the operating state to the non-operating state.

[0055] The operation of the heater control device 6 will be explained below using Figure 5. In Figure 5, the vertical axis represents temperature, and the horizontal axis represents the elapsed time since the heater control device 6 was started. In Figure 5, the solid line represents the temperature of the heater 51, and the dashed line represents the temperature of the ink. In the example shown in Figure 5, it is assumed that the heater 51 has been in a sufficiently long non-operating state before starting up, and that the ink temperature has cooled to approximately the ambient temperature.

[0056] As shown in Figure 5, the control unit 61 of the heater control device 6 performs output increase control, which controls the heater 51 with the second output, from time t0 (i.e., when the heater control device 6 is started). As a result, the heater temperature reaches "T3", and the ink is heated by the heater 51. Then, the ink temperature rises from the ambient temperature "Tc" as time progresses.

[0057] Subsequently, the control unit 61 stops the output increase control at time t1 (i.e., when a predetermined time "P1" has elapsed since the heater control device 6 was started). This prevents the ink temperature from rising to the coagulation temperature "T1".

[0058] From time t1 onward, the control unit 61 controls the heater 51 with the first output. As a result, the temperature of the heater 51 becomes "T2", and the ink temperature also converges to the heater 51 temperature "T2" over time.

[0059] As described above, in the heater control device 6 according to this embodiment, when the heater 51 is switched from a non-operating state to an operating state, that is, when the heater control device 6 is started up, output increase control is performed to control the heater 51 with the second output. Therefore, in the heater control device 6 according to this embodiment, the output of the heater 51 is temporarily increased when the heater control device 6 is started up to heat the ink, so it is possible to shorten the startup time compared to when the output of the heater 51 is not increased.

[0060] Furthermore, in the heater control device 6 according to this embodiment, the control for heating the ink at startup is performed by increasing the output for a predetermined period of time starting from the time of switching. Therefore, unlike the related technologies already described, there is no need to control elements other than the heater 51, and the processing load for the control of heating the ink at startup is easily reduced.

[0061] [5] Variant The heater control device 6 according to this embodiment does not have a function to acquire ambient temperature, but it may have a function to acquire ambient temperature. Specifically, the heater control device 6 may further include an acquisition unit 62 as shown in Figure 6.

[0062] The acquisition unit 62 acquires the ambient temperature when the heater 51 is switched from a non-operating state to an operating state. For example, the acquisition unit 62 acquires the ambient temperature by receiving the detection result of a sensor that measures ambient temperature through communication with the sensor. Alternatively, the acquisition unit 62 may acquire the ambient temperature entered by the user through the user interface of the printer 1 by communicating with the printer 1, for example.

[0063] In the above configuration, the heater control device 6 may calculate a predetermined time according to the ambient temperature acquired by the acquisition unit 62. For example, if the ambient temperature acquired by the acquisition unit 62 deviates from the range including the default value of the ambient temperature, the heater control device 6 may recalculate the predetermined time according to the ambient temperature acquired by the acquisition unit 62. Specifically, if the ambient temperature acquired by the acquisition unit 62 exceeds the above range, the heater control device 6 may recalculate the predetermined time so that it becomes shorter. Also, if the ambient temperature acquired by the acquisition unit 62 falls below the above range, the heater control device 6 may recalculate the predetermined time so that it becomes longer. Note that if the ambient temperature acquired by the acquisition unit 62 is within the above range, the heater control device 6 does not need to recalculate the predetermined time.

[0064] In this embodiment, the control unit 61 of the heater control device 6 may decide whether or not to perform output increase control based on the duration of the non-operating state of the heater 51. The duration can be calculated, for example, from the difference between the time when the heater 51 switched from the operating state to the non-operating state and the time when the heater 51 switched from the non-operating state to the operating state. For example, the control unit 61 may decide to perform output increase control if the duration is greater than or equal to a preset threshold time, and decide not to perform output increase control if the duration is shorter than the threshold time.

[0065] Figure 7 is a flowchart showing an example of the operation of the above configuration. Steps S11 to S14 have already been explained, so their explanation is omitted here.

[0066] <Step S15> Step S15 is performed when the heater 51 is switched from a non-operating state to an operating state (Step S11: Yes). In step S15, the heater control device 6 calculates the duration.

[0067] <Step S16> If the calculated duration is greater than or equal to the threshold time (step S16: Yes), the heater control device 6 executes step S12, that is, performs output increase control. On the other hand, if the calculated duration is shorter than the threshold time (step S16: No), the heater control device 6 executes step S14 without executing step S12, that is, does not perform output increase control.

[0068] With this configuration, output increase control is not performed when the duration is shorter than the threshold time, i.e., when it is assumed that the ink has not cooled down much, thus making it easier to reduce the processing load of the ink heating control at startup.

[0069] In this embodiment, the heater 51 is a cord heater, but it is not limited to this. Also, although the heater 51 indirectly heats the ink passing through the pipe 52 via a metal plate, it may also heat the ink passing through the pipe 52 directly without using a metal plate. Furthermore, the heater 51 may heat the ink without contact with the pipe 52, for example. If the configuration of the heater 51 is changed from the configuration of this embodiment, the above temperatures "T1", "T2", and "T3" should be changed according to the configuration of the heater 51.

[0070] In this embodiment, the heater control device 6 is provided in the ink supply device 2, but is not limited to this. For example, the heater control device 6 may be provided in the printer 1. In this case, the heater control device 6 may be configured to heat the ink by controlling a heater 51 provided in the ink supply path (e.g., main piping 35, etc.) from the ink container 3 provided in the printer 1 to the recording head 16.

[0071] Furthermore, the image-forming object on which the image is formed by printer 1 is not limited to a sheet Sh1 such as paper or resin film, but may also be a roll of fabric such as nonwoven fabric or cloth. In this case, printer 1 is a textile printing machine (textile printer) that records an image on the fabric by ejecting ink onto the fabric and dyeing the fibers of the fabric with the ink.

[0072] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0073] <Note 1> A heater control device that controls a heater for heating the ink supplied from an ink container containing ink to a recording head, The control unit includes a control unit that controls the heater with a first output when the heater is in operation, and when the heater is switched from a non-operating state to an operating state, controls the heater with a second output that is greater than the first output until a predetermined time has elapsed from the time of the switch. Heater control device.

[0074] <Note 2> The predetermined time is determined based on the aggregation temperature at which aggregation begins when the ink is continuously heated, and the heating rate when the ink is heated by the second output. The heater control device described in Appendix 1.

[0075] <Note 3> The predetermined time is determined based on the temperature of the environment in which the heater control device is installed. The heater control device described in Appendix 2.

[0076] <Note 4> The control unit determines whether or not to perform the output increase control based on the duration of the previous non-operating state. A heater control device as described in any one of the appendices 1 to 3.

[0077] <Note 5> The heater control device described in any one of the appendices 1 to 4, The aforementioned heater, The aforementioned ink container, The system includes an ink supply path that supplies the ink from the ink container to the recording head. Ink supply device.

[0078] <Note 6> The ink supply device described in Appendix 5, The device comprises an inkjet recording apparatus that ejects the ink supplied from the ink container from the recording head to form an image, Image forming system.

[0079] <Note 7> A heater control method for controlling a heater that heats the ink supplied from an ink container containing ink to a recording head, The control step includes controlling the heater with a first output when the heater is in operation, and, when the heater is switched from a non-operating state to an operating state, performing output increase control to control the heater with a second output greater than the first output until a predetermined time has elapsed from the time of the switch. Heater control method. [Explanation of Symbols]

[0080] 1. Printer (inkjet recording device) 16 Recording head 2. Ink supply device 21 Ink Containers 3 Ink Containers 51 Heater 52 Piping (ink supply path) 6. Heater control device 61 Control Unit 62 Acquisition unit 100 Image forming system

Claims

1. A heater control device that controls a heater for heating the ink supplied from an ink container containing ink to a recording head, The control unit includes a control unit that controls the heater with a first output when the heater is in operation, and controls the heater with a second output greater than the first output until a predetermined time has elapsed from the time of the switch when the heater is switched from a non-operating state to an operating state. Heater control device.

2. The predetermined time is determined based on the aggregation temperature at which aggregation begins when the ink is continuously heated, and the heating rate when the ink is heated with the second output. The heater control device according to claim 1.

3. The predetermined time is determined based on the temperature of the environment in which the heater control device is installed. The heater control device according to claim 2.

4. The control unit determines whether or not to perform the output increase control based on the duration of the non-operating state. A heater control device according to any one of claims 1 to 3.

5. The heater control device according to any one of claims 1 to 3, The aforementioned heater, The aforementioned ink container, The system includes an ink supply path that supplies the ink from the ink container to the recording head. Ink supply device.

6. The ink supply device according to claim 5, The device comprises an inkjet recording apparatus that ejects the ink supplied from the ink container from the recording head to form an image, Image forming system.

7. A heater control method for controlling a heater that heats the ink supplied from an ink container containing ink to a recording head, The control step includes controlling the heater with a first output when the heater is in operation, and, when the heater is switched from a non-operating state to an operating state, performing output increase control to control the heater with a second output greater than the first output until a predetermined time has elapsed from the time of the switch. Heater control method.

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