JP2016097568A - Head unit and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head unit which inhibits discharge failure during image recording, and to provide an ink jet recording device.SOLUTION: A head unit forming an ink jet head includes: a second tank; a nozzle plate; flow passage modules; connection parts; a frame; a first heater; and a second heater. The second tank stores an ink. A plurality of nozzles for discharging the ink are formed on the nozzle plate. An ink flow passage for making the ink flow to each of the plurality of nozzles is formed on the flow passage module. The flow passage module includes a plurality of driving elements which are provided correspondingly to each of the plurality of nozzles, at branch parts of the ink flow passage. The ink supplied from the second tank to each passage module flows in the connection part. The frame connects the nozzle plate with the flow passage modules. The first heater is provided to the frame. The second heater is provided to the second tank.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a head unit for forming an ink jet head and an ink jet recording apparatus.

  Technologies related to inkjet have been proposed. For example, Patent Document 1 discloses an ink jet recording apparatus. The ink jet recording apparatus includes an ink jet recording head unit and a control unit. An ink cartridge is detachably provided in the ink jet recording head unit. The ink jet recording head unit includes a metal frame, and a base plate portion is formed at a lower portion of the frame. A plurality of head bodies are attached to the lower surface of the base plate portion from below. Each head main body and each ink chamber in the ink cartridge are communicated with each other through an ink supply path, and each ink stored in the ink cartridge is supplied to each head main body. The flow path unit constituting the head body includes a reservoir forming substrate on which a reservoir is formed, a compliance substrate joined to the reservoir forming substrate, and a nozzle plate on which nozzle openings are formed. The compliance substrate includes an upper compliance substrate and a lower compliance substrate, and spaces are formed in regions facing the reservoir between the upper and lower substrates. A heating layer is provided in this space. The control unit is connected to the heating layer and is connected to a temperature sensor provided in each ink chamber. Each heating layer is controlled by the controller so that the temperature of the ink ejected from each nozzle opening is uniform according to the temperature of each ink in each ink chamber detected by each temperature sensor.

  Patent Document 2 discloses an ink jet printer. The ink jet printer includes a recording unit including a recording head. The recording head includes a nozzle substrate, a heater, and a head cover. Nozzle openings for ejecting ink are formed in the nozzle substrate. The heater heats the ink. The head cover is provided in contact with the nozzle substrate and protects the nozzle substrate. The heater heats ink through the head cover and the nozzle substrate. The applicant has also proposed the technique shown in Patent Document 3.

JP 2008-296498 A JP 2009-262543 A JP 2010-162786 A

  The ink jet recording apparatus can record an image on a recording medium with high quality. However, when the temperature of the ink used for image recording is low and the viscosity of the ink is high, ink ejection defects are likely to occur during image recording. When ink ejection failure occurs, the quality of the image recorded on the recording medium may be degraded.

  An object of the present invention is to provide a head unit and an ink jet recording apparatus that can suppress ejection defects during image recording.

  One aspect of the present invention is a head unit that forms an inkjet head of an inkjet recording apparatus that ejects ink of a predetermined color, and the ink supplied from a first tank of the inkjet recording apparatus that stores the ink. A second tank to be stored, a nozzle plate on which a plurality of nozzles for discharging the ink are formed, and connected to the plurality of nozzles formed on the nozzle plate and supplied to each of the plurality of nozzles from the second tank An ink flow path for flowing the ink is formed, and the ink is supplied from the nozzles provided corresponding to each of the plurality of nozzles in each branch portion of the ink flow path connected to the plurality of nozzles. A flow path module including a plurality of drive elements to be discharged, and the second tank and the flow path module are connected. A connection portion through which the ink supplied from the second tank to the flow path module flows, the nozzle plate is attached, the flow path module is detachably attached, and the nozzle plate and the flow path module are connected to each other. The head unit includes a frame to be connected, a first heater provided in the frame, and a second heater provided in the second tank.

  According to this, by heating the second tank with the second heater, the ink stored in the second tank can be warmed, and the warmed ink can be flowed into the flow path module connected to the nozzle. The flow path module can be warmed by forming the head unit by the nozzle plate, the flow path module, and the frame, and providing the first heater on the frame to heat the frame. The nozzle plate attached to the frame can be warmed. Since the nozzle plate is also warmed, heat conduction from the flow path module to the nozzle plate can be suppressed. The ink before flowing from the nozzle through the ink flow path in the flow path module can be warmed. The ink ejected from the nozzles can be set to a temperature suitable for ejection. Since the nozzle plate and the flow path module are connected via the frame, it is not necessary to connect them directly by, for example, an adhesive or screws.

  In the head unit, the first heater is provided in contact with the frame and in a non-contact state with the nozzle plate and the flow path module, and the nozzle is disposed between the flow path module and the first heater. An air gap may be formed in a state where the plate and the flow path module are attached to the frame. According to this, heat from the first heater can be conducted to the frame in direct contact. The channel module and the nozzle plate can be indirectly heated through the frame. By forming a gap between the first heater and the flow path module, the flow path module can be insulated from the heat from the first heater. Generation | occurrence | production of the state that the temperature of the part of the flow path module which approached the 1st heater becomes high can be suppressed.

  The second tank may be provided above the flow path module. According to this, it can be set as a compact head unit.

  The head unit may include a cover that covers the flow path module attached to the frame. According to this, the heat retaining property of the flow channel module can be improved and the flow channel module can be warmed.

  The flow path module is connected to a plurality of first nozzles forming a first nozzle group among the plurality of nozzles formed on the nozzle plate, and the second tank is connected to each first nozzle of the first nozzle group. The first ink flow path, which is the first portion of the ink flow path, for flowing the ink supplied from the first flow path is formed, and each of the plurality of branch portions of the first ink flow path is connected to the plurality of first nozzles. A first flow path module including a plurality of first drive elements included in the plurality of drive elements, each of which is provided corresponding to each of the first nozzles and ejects the ink from the first nozzle; and the nozzle plate Of the plurality of nozzles formed on the second nozzle group, the second nozzle group is connected to the second nozzle group and is supplied from the second tank to the second nozzle group. A plurality of second nozzles are formed in each branch portion of the second ink flow path, each of which is connected to the plurality of second nozzles. And a second flow path module including a plurality of second drive elements included in the plurality of drive elements, each of which is provided corresponding to each of the plurality of drive elements and ejects the ink from the second nozzle. Connects the second tank and the first flow path module, the first connection part through which the ink supplied from the second tank to the first flow path module flows, the second tank and the second flow path And a second connection part through which the ink supplied from the second tank to the second flow path module flows. The frame includes the first flow path module and the second flow path module. Detachably attached in a state where adjacent the frame, and the nozzle plate, for connecting, said first channel module and the second channel module, may be so. According to this, the plurality of flow path modules can be heated by heating the frame. Ink can be supplied from one second tank to a plurality of flow path modules. Compared to a configuration in which a tank corresponding to the second tank is provided for each of the plurality of flow path modules, a simple head unit can be obtained. The first channel module or the second channel module can be replaced individually. When the first channel module fails, only the first channel module can be replaced, and when the second channel module fails, only the second channel module can be replaced.

  According to another aspect of the present invention, a head includes a first tank that stores ink of a predetermined color, the ink is ejected, and includes a first heater, a second heater, a first temperature detection unit, and a second temperature detection unit. An ink jet head formed by arranging a plurality of units, and a control unit that controls heating by the first heater and heating by the second heater, and the head unit is supplied from the first tank. A second tank for storing the ink; a nozzle plate having a plurality of nozzles for discharging the ink; and the plurality of nozzles formed on the nozzle plate and connected to the plurality of nozzles. An ink flow path for flowing the ink supplied from the two tanks is formed, and each of the plurality of nozzles is connected to each branch portion of the ink flow path connected to the plurality of nozzles. Correspondingly, a flow path module provided with a plurality of drive elements for ejecting the ink from the nozzles, the second tank and the flow path module are connected, and the second tank and the flow path A connection part through which the ink supplied to the module flows, a nozzle plate is attached, the flow channel module is detachably attached, and a frame that connects the nozzle plate and the flow channel module. The first heater is provided on the frame, the second heater is provided on the second tank, and the first temperature detection unit is provided on the nozzle plate, the flow path module, or the frame, The two temperature detector is provided in the second tank, and the controller is a first detected temperature detected by temperature information from the first temperature detector. Is lower than the first preset temperature, the heating by the first heater corresponding to the first preset temperature is controlled, and the second detected temperature detected by the temperature information from the second temperature detector is the second preset temperature. If lower, the heating by the second heater corresponding to the second set temperature is controlled, and the heating by the second heater corresponding to the second set temperature is controlled or corresponding to the second set temperature When the first detected temperature is lower than the first lower limit temperature lower than the first set temperature in a state where the heating by the second heater is not controlled, it corresponds to the third set temperature higher than the second set temperature. An inkjet recording apparatus that controls heating by the second heater.

  According to this, when the first detected temperature is lower than the first set temperature, the frame can be heated by the first heater, and the first detected temperature can be raised to the first set temperature. When the second detected temperature is lower than the second set temperature, the second tank can be heated by the second heater, and the second detected temperature can be raised to the second set temperature. The ink stored in the second tank can be warmed, and the temperature of the ink stored in the second tank can be set to the second set temperature or a temperature equivalent thereto. The warmed ink can be allowed to flow into the channel module that leads to the nozzle. The flow path module can be warmed by forming the head unit by the nozzle plate, the flow path module, and the frame, and providing the first heater on the frame to heat the frame. The nozzle plate attached to the frame can be warmed. Since the nozzle plate is also warmed, heat conduction from the flow path module to the nozzle plate can be suppressed. The ink before flowing from the nozzle through the ink flow path in the flow path module can be warmed. The temperature of the ink before ejection can be set to the first set temperature or a temperature equivalent thereto. The first set temperature is set to a temperature suitable for ejection from the nozzle in consideration of the characteristics of the ink used for image recording. The first set temperature and the second set temperature may be the same temperature. When the first detection temperature is lower than the first lower limit temperature (first lower limit temperature <first set temperature), the temperature of the ink flowing through the ink flow path in the flow path module is also assumed to be lower than the first lower limit temperature. In such a case, the temperature of the ink flowing through the ink flow path is increased by setting the temperature of the second heater to a third set temperature higher than the second set temperature and increasing the temperature of the ink supplied to the flow path module. It can be returned to a preset temperature or a temperature equivalent thereto. Since the nozzle plate and the flow path module are connected via the frame, it is not necessary to connect them directly by, for example, an adhesive or screws. “Second detection temperature” is widely interpreted. For example, the “second detected temperature” corresponds to the temperature of the outer surface or the inner surface of the second tank, or the temperature of the ink stored in the second tank.

  In this ink jet recording apparatus, the control unit may control heating by the second heater corresponding to the second set temperature when the second detected temperature is higher than the third set temperature. According to this, when the second detected temperature is higher than the third set temperature, the heating temperature at the second heater can be set as the second set temperature, and the second detected temperature can be lowered to the second set temperature. The temperature rise of the ink stored in the second tank can be suppressed, and the temperature of the ink can be returned to the second set temperature or a temperature equivalent thereto.

  When the second detected temperature is lower than the second set temperature, the control unit controls continuous heating by the second heater corresponding to the second set temperature, and the second detected temperature is the second set temperature. If higher, intermittent heating by the second heater corresponding to the second set temperature may be controlled. According to this, when the second detected temperature is lower than the second set temperature, the heating by the second heater is set to continuous heating corresponding to the second set temperature, and the second detected temperature can be raised to the second set temperature. . When the second detected temperature is lower than the second set temperature, it is assumed that the temperature of the ink stored in the second tank is also lower than the second set temperature. The temperature of the ink stored in the second tank can be set to the second set temperature or a temperature equivalent thereto. On the other hand, when the second detected temperature is higher than the second set temperature, the heating by the second heater is intermittent heating corresponding to the second set temperature, and the second detected temperature can be lowered to the second set temperature. When the second detected temperature is higher than the second set temperature, it is assumed that the temperature of the ink stored in the second tank is also higher than the second set temperature. The temperature rise of the ink stored in the second tank can be suppressed, and the temperature of the ink can be returned to the second set temperature or a temperature equivalent thereto. The temperature of the ink stored in the second tank can be maintained at the second set temperature or a temperature equivalent thereto.

  When the first detected temperature is lower than the first lower limit temperature, the control unit controls continuous heating by the second heater corresponding to the third set temperature, and the second detected temperature is the third set temperature. If higher, intermittent heating by the second heater corresponding to the second set temperature may be controlled. According to this, when the first detected temperature is lower than the first lower limit temperature (first lower limit temperature <first set temperature), the heating by the second heater is set to continuous heating corresponding to the third set temperature, and the second detected temperature Can be raised to a third preset temperature. When the second detected temperature is higher than the third set temperature, heating by the second heater can be intermittent heating corresponding to the second set temperature, and the second detected temperature can be lowered to the second set temperature. The temperature rise of the ink stored in the second tank can be suppressed, and the temperature of the ink can be returned to the second set temperature or a temperature equivalent thereto.

  The head unit includes a cover that covers the flow path module attached to the frame, and a third temperature detection unit provided on the cover, and the control unit has the first detection temperature set to the first setting. When the temperature is lower than the temperature, the continuous heating by the first heater corresponding to the first set temperature is controlled, the first detected temperature is higher than the first set temperature, and detected by the temperature information from the third temperature detecting unit. If the third detected temperature is lower than the fourth set temperature, the intermittent heating by the first heater corresponding to the first set temperature is controlled, the first detected temperature is higher than the first set temperature, When the three detected temperatures are higher than the fourth set temperature, the stop of heating by the first heater may be controlled. According to this, the heat retaining property of the flow channel module can be improved and the flow channel module can be warmed. When the first detected temperature is lower than the first set temperature, the heating by the first heater is set to continuous heating corresponding to the first set temperature, and the first detected temperature can be raised to the first set temperature. When the first detected temperature is higher than the first set temperature but the third detected temperature is lower than the fourth set temperature, the heat of the frame may be transferred to the atmosphere inside the cover, and the first detected temperature may be lowered. By making the heating by the first heater intermittent heating corresponding to the first set temperature, it is possible to suppress a decrease in the first detected temperature. When the first detected temperature is higher than the first set temperature and the third detected temperature is higher than the fourth set temperature, it is estimated that the heat retention inside the cover is secured. In such a case, power consumption required for heating can be suppressed by stopping heating by the first heater. The fourth set temperature may be the same temperature as the first set temperature. “Third detection temperature” is widely interpreted. For example, the “third detection temperature” corresponds to the temperature of the outer surface or the inner surface of the cover, or the temperature inside the cover.

  ADVANTAGE OF THE INVENTION According to this invention, the head unit and inkjet recording device which can suppress the discharge defect at the time of image recording can be obtained.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus. It is a block diagram which shows an inkjet recording device. It is a perspective view which shows schematic structure of the inkjet head formed of the several head unit. It is a perspective view which shows schematic structure of a head unit. It is a perspective view which shows schematic structure of a head unit (during assembly). It is a perspective view which shows schematic structure of a flow path module, a flame | frame, and a nozzle plate. It is a figure which shows the internal structure of a head unit, Comprising: It is the MM sectional view taken on the line of FIG. It is a perspective view which shows schematic structure of a 2nd tank, a cover, and a head unit (during assembly). It is a flowchart of a 1st heat processing. It is a flowchart of a 2nd heat processing. It is a figure which shows the voltage waveform of the electric power supplied to a 1st heater and a 2nd heater. (A) shows the voltage waveform in continuous heating. (B) shows a voltage waveform in intermittent heating. It is a flowchart of the 2nd heat processing of a modification.

  Embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the configurations described below, and various configurations can be employed in the same technical idea. For example, some of the configurations shown below may be omitted or replaced with other configurations. Other configurations may be included.

<Inkjet recording apparatus>
The ink jet recording apparatus 10 will be described with reference to FIGS. In the inkjet recording apparatus 10, the recording medium 14 is conveyed and an image is recorded on the recording surface 15 of the recording medium 14. In the ink jet recording apparatus 10, images are recorded on various recording media 14. Examples of the recording medium 14 include fabrics and building materials. In the present embodiment, a case where the recording medium 14 is a long fabric will be described as an example.

  Various inks are used for image recording. For example, an active energy curable ink is used for image recording. The active energy curable ink is cured by irradiation with active energy rays. Examples of the active energy curable ink include ultraviolet curable ink that is cured by irradiation with ultraviolet rays and electron beam curable ink that is cured by irradiation with electron beams. In addition, water-based ink may be used. Examples of ink colors include black, magenta, yellow, and cyan. The ink color may be a color other than these. The number of ink colors may be 3 colors or less or 5 colors or more. In the present embodiment, a description will be given by taking four colors of ultraviolet curable inks of black, magenta, yellow, and cyan as an example. The halftone dot pattern attached to the portion of the recording medium 14 illustrated on the downstream side in the transport direction in FIG. 1 corresponds to the image recorded on the recording medium 14.

  As shown in FIGS. 1 and 2, the ink jet recording apparatus 10 includes a transport unit 20, a recording unit 30, an irradiation unit 38, a moving unit 40, first tanks 50K, 50M, 50Y, and 50C, and a control device. 120. The transport unit 20 transports the recording medium 14 along the longitudinal direction of the recording medium 14. The recording medium 14 transported by the transport unit 20 passes through the recording unit 30 and the irradiation unit 38. In the present embodiment, the direction in which the recording medium 14 is transported by the transport unit 20 is referred to as “transport direction”. The transport direction is a direction along the longitudinal direction of the recording medium 14 and is a direction orthogonal to the short direction of the recording medium 14. The short direction of the recording medium 14 is the width direction of the recording medium 14 and coincides with the direction (main scanning direction) in which the recording unit 30 is reciprocated by the moving unit 40 as described later. In the present embodiment, the transport direction and the opposite direction are referred to as “longitudinal direction” in accordance with the longitudinal direction of the recording medium 14. The conveyance direction and the opposite direction may be referred to as “sub-scanning direction” with respect to the main scanning direction described above. The direction orthogonal to each of the transport direction and the opposite direction is referred to as the “short direction” according to the short direction of the recording medium 14.

  The recording unit 30 includes inkjet heads 31K, 31M, 31Y, 31C and a carriage 34. The inkjet head 31K is an inkjet head that discharges black ultraviolet curable ink and records an image with the black ultraviolet curable ink. A plurality of nozzles 32 for discharging black ultraviolet curable ink are formed in the inkjet head 31K. The inkjet head 31M is an inkjet head that discharges magenta ultraviolet curable ink and records an image with the magenta ultraviolet curable ink. A plurality of nozzles 32 for discharging magenta ultraviolet curable ink are formed in the inkjet head 31M. The inkjet head 31Y is an inkjet head that discharges yellow ultraviolet curable ink and records an image with the yellow ultraviolet curable ink. A plurality of nozzles 32 that discharge yellow ultraviolet curable ink are formed in the inkjet head 31Y. The ink jet head 31C is an ink jet head that discharges cyan ultraviolet curable ink and records an image with the cyan ultraviolet curable ink. A plurality of nozzles 32 that discharge cyan ultraviolet curable ink are formed in the inkjet head 31C.

  The inkjet heads 31K, 31M, 31Y, and 31C have the same configuration. In the present embodiment, the inkjet heads 31K, 31M, 31Y, and 31C are referred to as “inkjet head 31” when they are not distinguished or are collectively referred to.

  Each color inkjet head 31 is formed by a plurality of head units 60 (see FIG. 3). Each head unit 60 forming the inkjet head 31 for each color includes a first heater 101, a second heater 102, a first temperature detector 111, a second temperature detector 112, and a third temperature detector 113. Provided (see FIG. 2 and FIG. 7 described later). As will be described later, two first heaters 101 are provided in each head unit 60. In FIG. 2, the individual illustrations of the inkjet heads 31K, 31M, 31Y, 31C and the head units 60 are omitted. In the inkjet head 31 for each color, the plurality of head units 60 are arranged as shown in FIG. That is, the inkjet head 31 is formed by arranging a plurality of groups of head units 60 arranged in the longitudinal direction in the short direction.

  A first unit row by a plurality of head units 60 arranged in the longitudinal direction on one side in the short direction (for example, “first side” see FIG. 1) and the other side in the short direction (for example, “second side” As shown in FIG. 3, the second unit row by the plurality of head units 60 arranged in the longitudinal direction in FIG. 1 is arranged in a state shifted by a predetermined amount in the longitudinal direction. In the first unit row or the second unit row, a region in the longitudinal direction where the nozzles 32 do not exist is formed in a region where the two head units 60 are adjacent in the longitudinal direction. By providing the first unit row and the second unit row shifted in the longitudinal direction, the nozzle of the head unit 60 that forms the other unit row corresponding to the longitudinal region where the nozzle 32 does not exist in one unit row. 32 can be superposed. In FIG. 3, five head units 60 are arranged in the longitudinal direction to form one unit row, and two unit rows are provided in the short direction, but such a configuration is an example. The number of head units 60 arranged in the longitudinal direction and the number of unit rows in the short direction may be different from those in FIG. The other description regarding the head unit 60 is mentioned later.

  Inkjet heads 31K, 31M, 31Y, and 31C are mounted on the carriage 34 in a state where they are positioned at predetermined positions. As shown in FIG. 1, the inkjet heads 31 </ b> K, 31 </ b> M, 31 </ b> Y, and 31 </ b> C are mounted on the carriage 34 while being adjacent to each other in the lateral direction. The order of arrangement of the inkjet heads 31 for each color may be different from that shown in FIG. These arrangement orders are appropriately determined in consideration of various conditions.

  The irradiation unit 38 irradiates ultraviolet rays as active energy rays. The ultraviolet rays irradiated from the irradiation unit 38 are applied to the ink dots of the respective colors of ultraviolet curable ink that have landed on the recording surface 15 of the recording medium 14. The ultraviolet curable ink that forms the ink dots of each color is cured by irradiation with ultraviolet rays. The irradiation unit 38 is attached to the carriage 34 in a state adjacent to the inkjet head 31C on the second side in the short side direction.

  The moving unit 40 reciprocates the recording unit 30 and the irradiation unit 38 in the short direction. As shown in FIG. 1, the moving unit 40 includes two pulleys 41 and 42 and a timing belt 43. The two pulleys 41 and 42 are provided on both sides in the lateral direction with respect to the transport unit 20. For example, a motor (not shown) is connected to the pulley 41, and the pulley 42 is rotatably supported. The pulley 41 rotates as the motor rotates. The timing belt 43 is stretched over pulleys 41 and 42 in a state where tension is applied. A recording unit 30 and an irradiation unit 38 are attached to the timing belt 43 via a support unit 46 fixed to the carriage 34.

  When an image is recorded by the ink jet recording apparatus 10, the motor connected to the pulley 41 reciprocally rotates in the clockwise and counterclockwise directions. As the motor rotates, the pulley 41 rotates back and forth on both the left and right sides. An “arc-shaped arrow” shown inside the pulley 41 in FIG. 1 indicates the rotation direction of the pulley 41. When the pulley 41 rotates counterclockwise by rotating the motor in a predetermined direction, the timing belt 43 also rotates counterclockwise. The pulley 42 rotates following the timing belt 43 that rotates counterclockwise. Along with this, the recording unit 30 and the irradiation unit 38 move from the second side in the lateral direction to the first side. When the recording unit 30 and the irradiation unit 38 reach the moving end on the first side in the short direction, the rotation direction of the motor is reversed and the pulley 41 rotates to the right. When the pulley 41 rotates to the right, the timing belt 43 also rotates to the right. The pulley 42 rotates following the timing belt 43 that rotates clockwise. Accordingly, the recording unit 30 and the irradiation unit 38 move from the first side in the lateral direction to the second side. When the recording unit 30 and the irradiation unit 38 reach the second moving end in the short direction, the rotation direction of the motor is reversed again, and the pulley 41 rotates counterclockwise again. The reciprocating movement of the recording unit 30 and the irradiation unit 38 in the short direction by the moving unit 40 is repeated until the image recording is completed.

  The first tank 50K is a main tank that stores black ultraviolet curable ink. The first tank 50K is connected to a plurality of head units 60 that form the ink jet head 31K via the supply tube 51K. The black ultraviolet curable ink flows out of the first tank 50K, flows through the supply tube 51K, and is supplied to each of the plurality of head units 60 forming the inkjet head 31K. The first tank 50M is a main tank that stores magenta ultraviolet curable ink. The first tank 50M is connected to a plurality of head units 60 that form the inkjet head 31M via supply tubes 51M. The magenta ultraviolet curable ink flows out of the first tank 50M, flows through the supply tube 51M, and is supplied to each of the plurality of head units 60 forming the inkjet head 31M.

  The first tank 50Y is a main tank that stores yellow ultraviolet curable ink. The first tank 50Y is connected to a plurality of head units 60 that form the ink jet head 31Y via the supply tube 51Y. The yellow ultraviolet curable ink flows out of the first tank 50Y, flows through the supply tube 51Y, and is supplied to each of the plurality of head units 60 forming the inkjet head 31Y. The first tank 50C is a main tank for storing cyan ultraviolet curable ink. The first tank 50C is connected to a plurality of head units 60 that form the inkjet head 31C via supply tubes 51C. The cyan ultraviolet curable ink flows out from the first tank 50C, flows through the supply tube 51C, and is supplied to each of the plurality of head units 60 forming the inkjet head 31C.

  In FIG. 1, the supply tubes 51K, 51M, 51Y, and 51C are simplified. The supply tubes 51K, 51M, 51Y, and 51C are provided in a state that can accommodate the reciprocating movement of the recording unit 30 in the short direction. In the present embodiment, the first tanks 50K, 50M, 50Y, and 50C are referred to as “first tank 50” when they are not distinguished or are collectively referred to. When the supply tubes 51K, 51M, 51Y, and 51C are not distinguished or are collectively referred to, they are referred to as “supply tubes 51”.

  The control device 120 includes a CPU 122, a storage unit 124, a RAM 126, a power supply 128, and a connection interface (hereinafter referred to as “connection I / F”) 130 (see FIG. 2). The CPU 122 executes arithmetic processing and controls various processes executed by the inkjet recording apparatus 10. The storage unit 124 includes a ROM and / or storage. The storage is exemplified by a hard disk or a flash memory. The storage unit 124 stores various processing programs executed by the inkjet recording apparatus 10. For example, programs for a first heat treatment (see FIG. 9) and a second heat treatment (see FIG. 10) described later are stored in the storage unit 124. In addition, a program for image recording processing is stored in the storage unit 124. The RAM 126 serves as a work area when the CPU 122 executes the program stored in the storage unit 124. The RAM 126 stores predetermined data during the execution of processing.

  The power supply 128 supplies power to the first heater 101 and the second heater 102. The first heater 101 and the second heater 102 are connected to a power source 128. The connection I / F 130 is a connection interface that connects each unit included in the inkjet recording apparatus 10 and the control device 120. An output signal to any of these units and an input signal from any of these units are input / output via the connection I / F 130. When the CPU 122 executes the program stored in the storage unit 124 using the RAM 126, the inkjet recording apparatus 10 includes various functional units, and various functions are realized.

  When the inkjet recording apparatus 10 records an image on the recording medium 14, the CPU 122 executes a recording processing program. Accordingly, the conveyance unit 20 is driven, and the recording medium 14 is conveyed in the conveyance direction by the conveyance unit 20. The conveyance of the recording medium 14 by the conveyance unit 20 is intermittently performed according to the movement of the recording unit 30 and the irradiation unit 38 via the moving unit 40 from the first side to the second side in the short direction. The ultraviolet curable ink of each color is formed on each of the inkjet heads 31K, 31M, 31Y, and 31C at a predetermined timing when the recording unit 30 and the irradiation unit 38 are moved from the second side to the first side in the short direction. Then, the ink is discharged from the nozzle 32 toward the recording medium 14. The ultraviolet curable ink of each color ejected from each nozzle 32 of the inkjet heads 31K, 31M, 31Y, 31C is landed on the recording surface 15 of the recording medium 14. An image is recorded on the recording surface 15 of the recording medium 14 by the landed ultraviolet curable ink of each color. The recording surface 15 of the recording medium 14 is a surface that faces the ejection surface 35 (see FIG. 7) of the inkjet head 31 for each color when the recording medium 14 passes through the recording unit 30. The ejection surface 35 is a surface on which the nozzles 32 are formed by the inkjet heads 31 for each color.

<Head unit>
The head unit 60 will be described with reference to FIGS. The inkjet heads 31K, 31M, 31Y, and 31C are formed by arranging the same head unit 60 (see FIG. 4) as shown in FIG. Accordingly, the following description will be made without distinguishing ink colors. Regarding the first heater 101 and the second heater 102, in FIG. 4 to FIG. 8, illustration of each lead wire connected to the power source 128 is omitted. Further, regarding the first temperature detection unit 111, the second temperature detection unit 112, and the third temperature detection unit 113, in FIG. 4, FIG. 7, and FIG. 8, illustration of each signal line connected to the connection I / F 130 is omitted. Yes. In FIG. 5, the second tank 62 and the second heater 102 are illustrated by a two-dot chain line (imaginary line), and in FIG. 6, the second tank 62 and the second heater 102 are not illustrated. 7 and 8, the broken line is a hide line indicating a hide shape. In FIG. 7, hatching indicates a cross-sectioned portion.

  The head unit 60 includes the first heater 101, the second heater 102, the first temperature detection unit 111, the second temperature detection unit 112, the third temperature detection unit 113, the second tank 62, and the connection unit 63A. , 63B, 63D, 63E, 63F, and 63G, a nozzle plate 70, flow path modules 80A, 80B, 80D, 80E, 80F, and 80G, a frame 90, and a cover 100 (see FIGS. 4 to 8). The head unit 60 is assembled as shown in FIGS. 4 and 7 (see FIGS. 5, 6, and 8).

  The second tank 62 is connected to the supply tube 51 (see FIGS. 3 and 7). The second tank 62 is a sub tank that stores the ultraviolet curable ink supplied from the first tank 50 via the supply tube 51. One second tank 62 is provided in one head unit 60. In other words, one second tank 62 is provided for the six flow path modules 80A, 80B, 80D, 80E, 80F, and 80G. The second tank 62 is provided above the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G (see FIG. 7).

  The connecting portion 63A connects the second tank 62 and the flow path module 80A (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connection portion 63A and is supplied to the flow path module 80A. The connection part 63B connects the second tank 62 and the flow path module 80B (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connecting portion 63B and is supplied to the flow path module 80B. The connection part 63D connects the second tank 62 and the flow path module 80D (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connection portion 63D and is supplied to the flow path module 80D.

  The connection part 63E connects the second tank 62 and the flow path module 80E (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connection portion 63E and is supplied to the flow path module 80E. The connection part 63F connects the second tank 62 and the flow path module 80F (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connection portion 63F and is supplied to the flow path module 80F. The connection part 63G connects the second tank 62 and the flow path module 80G (see FIGS. 5 and 7). The ultraviolet curable ink stored in the second tank 62 flows from the second tank 62 through the connection portion 63G and is supplied to the flow path module 80G. In the present embodiment, the connection portions 63A, 63B, 63D, 63E, 63F, and 63G are not distinguished, or are collectively referred to as “connection portion 63”.

  The nozzle plate 70 is formed of a thin plate having a thickness of about 0.02 mm to 1 mm, for example. The nozzle plate 70 is formed with a plurality of nozzles 32 for discharging ultraviolet curable ink (see FIGS. 6 and 7). The plurality of nozzles 32 formed on the nozzle plate 70 include a plurality of nozzles 32A forming a nozzle group 33A, a plurality of nozzles 32B forming a nozzle group 33B, a plurality of nozzles 32D forming a nozzle group 33D, and a nozzle The plurality of nozzles 32E forming the group 33E, the plurality of nozzles 32F forming the nozzle group 33F, and the plurality of nozzles 32G forming the nozzle group 33G are classified. The nozzle group 33A corresponds to the flow path module 80A, the nozzle group 33B corresponds to the flow path module 80B, and the nozzle group 33D corresponds to the flow path module 80D. The nozzle group 33E corresponds to the flow path module 80E, the nozzle group 33F corresponds to the flow path module 80F, and the nozzle group 33G corresponds to the flow path module 80G.

  In each of the nozzle groups 33A, 33B, 33D, 33E, 33F, and 33G, the plurality of nozzles 32A, 32B, 32D, 32E, 32F, and 32G are arranged, for example, in a staggered manner (see FIG. 6). However, the arrangement of the nozzles 32A, 32B, 32D, 32E, 32F, and 32G as shown in FIG. 6 is an example, and a different arrangement may be used. In the present embodiment, the “nozzle 32” is any one of the nozzles 32A, 32B, 32D, 32E, 32F, and 32G, or is a collective term for these. In the present embodiment, the nozzle groups 33A, 33B, 33D, 33E, 33F, and 33G are not distinguished or are collectively referred to as “nozzle group 33”. A positioning hole 71 is formed in the nozzle plate 70. The positioning holes 71 are formed, for example, inside two corners that are diagonal positions among the four corners (see FIG. 6).

  The flow path module 80A is a module that causes the ultraviolet curable ink supplied from the second tank 62 to flow through the connection portion 63A to the plurality of nozzles 32A of the nozzle group 33A and discharges the ultraviolet curable ink from each nozzle 32A. is there. The flow path module 80B is a module that causes the ultraviolet curable ink supplied from the second tank 62 to flow through the connection portion 63B to the plurality of nozzles 32B of the nozzle group 33B and discharges the ultraviolet curable ink from each nozzle 32B. is there. The flow path module 80D is a module that causes the ultraviolet curable ink supplied from the second tank 62 to flow through the connection portion 63D to the plurality of nozzles 32D of the nozzle group 33D and discharges the ultraviolet curable ink from each nozzle 32D. is there. The flow path module 80E is a module that causes the ultraviolet curable ink supplied from the second tank 62 to flow through the connection portion 63E to the plurality of nozzles 32E of the nozzle group 33E and discharges the ultraviolet curable ink from each nozzle 32E. is there. The flow path module 80F is a module that causes the ultraviolet curable ink supplied from the second tank 62 to flow through the connection portion 63F to the plurality of nozzles 32F of the nozzle group 33F and discharges the ultraviolet curable ink from each nozzle 32F. is there. The flow path module 80G is a module that causes the ultraviolet curable ink supplied from the second tank 62 through the connection portion 63G to flow through the plurality of nozzles 32G of the nozzle group 33G and discharges the ultraviolet curable ink from each nozzle 32G. is there. The flow path modules 80A, 80B, 80D, 80E, 80F, and 80G have the same configuration. In the present embodiment, the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G are not distinguished or are collectively referred to as “flow path module 80”.

  An ink flow path 81 is formed inside the flow path module 80 (see FIG. 7). The flow path module 80 includes a plurality of drive elements 83 (see FIGS. 5 to 8). The ink flow path 81 formed inside the flow path module 80 is connected to the plurality of nozzles 32 of the corresponding nozzle group 33 in the assembled state as the head unit 60. The ultraviolet curable ink that has flowed into the flow path module 80 via the connection portion 63 flows through the branch portion 82 of the ink flow path 81 connected to each nozzle 32 and reaches the nozzle 32. The plurality of driving elements 83 are provided corresponding to each of the plurality of nozzles 32 in each branch portion 82 of the ink flow path 81 connected to the plurality of nozzles 32. In the present embodiment in which a plurality of nozzles 32 are arranged in a staggered manner in each nozzle group 33, a plurality of drive elements 83 are provided on both sides in the lateral direction on the surface of the channel module 80 on the upper side in the vertical direction ( FIG. 5 to FIG. 8). The drive element 83 is a drive unit that discharges ultraviolet curable ink from the nozzle 32. Examples of the drive element 83 include a piezo element or a heater. The discharge of the ultraviolet curable ink through the driving of a driving element 83 such as a piezo element or a heater is performed in the same manner as a known ink jet recording apparatus.

  Positioning holes 84A, 84B, 84D, 84E, 84F, 84G and mounting holes 85A, 85B, 85D 85E, 85F, and 85G are formed (see FIG. 6).

  The frame 90 connects the nozzle plate 70 and the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G. The nozzle plate 70 and each flow path module 80 connected via the frame 90 are in a state as shown in FIG. The nozzle plate 70 is attached to the end surface of the frame 90 on the lower side in the vertical direction (see FIG. 5). For example, an adhesive is used to attach the nozzle plate 70 to the frame 90, and the nozzle plate 70 is fixed to the frame 90. Positioning pins 91 are provided on the end surface of the frame 90 on the lower side in the vertical direction. For example, as shown in FIG. 6, the positioning pins 91 are respectively formed inside two corners that are diagonal positions among the four corners. The nozzle plate 70 is attached to the frame 90 in a state where the two positioning holes 71 and the two positioning pins 91 are fitted together.

  Openings 92 and 93 are formed in the frame 90 (see FIG. 6). The openings 92 and 93 are formed so as to penetrate in the vertical direction and be adjacent to each other in the lateral direction. The flow path modules 80A, 80B, and 80D are mounted on the opening 92, and the flow path modules 80E, 80F, and 80G are mounted on the opening 93. On the end surface of the frame 90 on the upper side in the vertical direction, among the opening edge portions of the opening portion 92, two positioning edges 94A, 94B, 94D (total of 6) is provided, and three screw holes 95A, 95B, and 95D (total of 6) are respectively formed (see FIG. 6). The positioning pins 94A, the screw holes 95A, the positioning pins 94B, the screw holes 95B, the positioning pins 94D, and the screw holes 95D are at regular intervals in the short direction at each opening edge of the opening 92 along the short direction. Is provided. On the end face of the frame 90 on the upper side in the vertical direction, among the opening edge portions of the opening portion 93, two opening edge portions along the short direction on both sides in the longitudinal direction are provided with three positioning pins 94E, 94F, 94G (six in total) are provided, and three screw holes 95E, 95F, and 95G (six in total) are formed (see FIG. 6). The positioning pins 94E, the screw holes 95E, the positioning pins 94F, the screw holes 95F, the positioning pins 94G, and the screw holes 95G are at regular intervals in the short direction at each opening edge of the opening 93 along the short direction. Is provided.

  The channel module 80A is attached to the opening 92 in a state where the positioning hole 84A and the positioning pin 94A are fitted on each side in the longitudinal direction (see FIG. 5). Then, the flow path module 80A is attached to the frame 90 by two screws 96 that are respectively inserted into the two attachment holes 85A and screwed into the screw holes 95A (see FIG. 5). The flow path module 80B is attached to the opening 92 in a state where the positioning hole 84B and the positioning pin 94B are fitted on each side in the longitudinal direction (see FIG. 5). Then, the flow path module 80B is attached to the frame 90 by the two screws 96 that are respectively inserted into the two attachment holes 85B and screwed into the screw holes 95B (see FIG. 5). The channel module 80D is attached to the opening 92 in a state where the positioning hole 84D and the positioning pin 94D are fitted on each side in the longitudinal direction (see FIG. 5). The flow path module 80D is attached to the frame 90 by the two screws 96 that are respectively inserted into the two attachment holes 85D and screwed into the screw holes 95D (see FIG. 5).

  The flow path module 80E is attached to the opening 93 in a state where the positioning hole 84E and the positioning pin 94E are fitted on each side in the longitudinal direction (see FIG. 5). Then, the flow path module 80E is attached to the frame 90 by two screws 96 that are respectively inserted into the two attachment holes 85E and screwed into the screw holes 95E (see FIG. 5). The flow path module 80F is attached to the opening 93 in a state where the positioning hole 84F and the positioning pin 94F are fitted on each side in the longitudinal direction (see FIG. 5). The flow path module 80F is attached to the frame 90 by the two screws 96 that are respectively inserted into the two attachment holes 85F and screwed into the screw holes 95F (see FIG. 5). The channel module 80G is attached to the opening 93 in a state where the positioning hole 84G and the positioning pin 94G are fitted on each side in the longitudinal direction (see FIG. 5). The flow path module 80G is attached to the frame 90 by the two screws 96 that are respectively inserted into the two attachment holes 85G and screwed into the screw holes 95G (see FIG. 5).

  The flow path modules 80A, 80B, 80D, 80E, 80F, and 80G can be individually removed from the frame 90 by removing the screws 96 that attach the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G to the frame 90, respectively. Can do.

  The cover 100 is a state in which the nozzle plate 70 and the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G are attached to the frame 90 (see FIGS. 5 and 8), and the flow path modules 80A, 80B, 80D, and 80E. , 80F, 80G (see FIG. 4). Thereby, the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G are covered with the cover 100 in a state of being attached to the frame 90 (see FIG. 7). The cover 100 is attached to the head unit 60 with respect to the frame 90, for example. The inner peripheral surface of the cover 100 is shaped along the outer peripheral surface of the frame 90. The inner peripheral surface of the cover 100 and the outer peripheral surface of the frame 90 are fitted together (see FIGS. 7 and 8). The cover 100 may be screwed to the outer peripheral surface of the frame 90 in the fitted state.

  The first heater 101 is, for example, a sheet-like electric heater (see FIG. 6). As the first heater 101, a sheet-like polyimide heater is exemplified. The first heater 101 is provided on the frame 90. In the present embodiment, two first heaters 101 are provided for one frame 90 (see FIG. 6). For example, one of the two first heaters 101 is attached to the side surface of the opening 92 along the longitudinal direction facing in the short side direction, which is the channel module 80A side. In the first heater 101, the nozzle plate 70 and the flow path module 80A are not in contact with each other (see FIG. 7). A gap AS is formed between the first heater 101 and the flow path module 80A (see FIG. 7). The other first heater 101 is affixed to the side surface that is on the flow channel module 80G side among the side surfaces of the opening 93 along the longitudinal direction that opposes the short side direction. In the first heater 101, the nozzle plate 70 and the flow path module 80G are not in contact with each other. A gap AS is formed between the first heater 101 and the flow path module 80G. The heat of the first heater 101 is conducted to the frame 90 and further conducted to the nozzle plate 70 and the flow path modules 80A, 80B, 80D, 80E, 80F, 80G. The nozzle plate 70 and the flow path modules 80A, 80B, 80D, 80E, 80F, 80G are warmed by this heat.

  The second heater 102 is, for example, a sheet-like electric heater (see FIG. 4). An example of the second heater 102 is a sheet-like rubber heater. The second heater 102 is provided in the second tank 62. For example, the 2nd heater 102 is affixed on the perimeter of the outer peripheral surface of the 2nd tank 62 (refer FIG. 4). The heat of the second heater 102 is conducted to the second tank 62, and the second tank 62 is warmed by this heat.

  The first temperature detection unit 111 detects the temperature of the nozzle plate 70 that is heated by heat conduction from the frame 90 heated by the first heater 101. The first temperature detection unit 111 is provided at a predetermined position of the nozzle plate 70. For example, the 1st temperature detection part 111 is attached to the part in which the nozzle 32 is not formed among the discharge surfaces 35 (refer FIG. 7). The position of the nozzle plate 70 where the first temperature detection unit 111 is provided may be different from that in FIG. The second temperature detection unit 112 detects the temperature of the second tank 62 heated by the second heater 102. The second temperature detection unit 112 is provided at a predetermined position of the second tank 62. For example, the second temperature detection unit 112 is attached to the bottom outer surface of the second tank 62 (see FIG. 7). The third temperature detection unit 113 detects the temperature of the cover 100 attached to the frame 90. The third temperature detection unit 113 is provided at a predetermined position of the cover 100. For example, the third temperature detection unit 113 is attached to the outer surface of the top of the cover 100 (see FIGS. 4 and 7). The third temperature detection unit 113 may be attached to the inner surface of the top of the cover 100.

  The 1st temperature detection part 111, the 2nd temperature detection part 112, and the 3rd temperature detection part 113 are the predetermined sensors which can detect the temperature of each part in each position mentioned above. For example, the first temperature detection unit 111, the second temperature detection unit 112, and the third temperature detection unit 113 are thermistors. The first temperature detection unit 111 outputs temperature information continuously. The second temperature detection unit 112 outputs temperature information continuously. The third temperature detection unit 113 continuously outputs temperature information. Each temperature information from the first temperature detection unit 111, the second temperature detection unit 112, and the third temperature detection unit 113 is input to the control device 120 via the connection I / F 130. The CPU 122 acquires temperature information from the first temperature detection unit 111, the second temperature detection unit 112, and the third temperature detection unit 113 via the connection I / F 130.

<Heat treatment>
The heat treatment executed by the ink jet recording apparatus 10 will be described with reference to FIGS. The heat treatment is performed when heating the ultraviolet curable ink stored in the second tank 62 and the ultraviolet curable ink supplied from the second tank 62 to the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G. Executed. The heat treatment includes a first heat treatment (see FIG. 9) and a second heat treatment (see FIG. 10). The first heat treatment is a treatment for heating the frame 90 and maintaining it in a predetermined temperature range. By maintaining the frame 90 in a predetermined temperature range by the first heat treatment, the temperature of the nozzle plate 70 and the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G can be set to a predetermined temperature range. The second heat treatment is a treatment for heating the second tank 62 and maintaining it in a predetermined temperature range.

  In the inkjet recording apparatus 10, for example, the first heat treatment and the second heat treatment are started at a predetermined timing before the start of image recording. A plurality of first heat treatments and second heat treatments are executed corresponding to all the head units 60 that form each of the inkjet heads 31K, 31M, 31Y, and 31C. Further, the plurality of first heat treatments and the plurality of second heat treatments are executed in parallel and continuously during image recording. For example, the first heat treatment and the second heat treatment are finished when the power of the inkjet recording apparatus 10 is turned off.

<First heat treatment>
CPU122 which started the 1st heat processing acquires 1st preset temperature (S11). The first set temperature is the heating temperature at the first heater 101. An operator operates an operation unit (not shown) connected to the control device 120 to input a predetermined temperature to the control device 120. In the first heating process, the CPU 122 acquires a predetermined temperature input via the operation unit as the first set temperature. In the present embodiment using ultraviolet curable ink as an example, the first set temperature is, for example, about 50 ° C. In the case of water-based ink, the first set temperature is, for example, about 30 ° C. The CPU 122 stores the acquired first set temperature in the RAM 126. Subsequently, the CPU 122 starts continuous heating by the first heater 101 corresponding to the first set temperature (S13). Accordingly, power having a voltage value corresponding to the first set temperature is continuously supplied from the power supply 128 to the first heater 101 (see FIG. 11A).

  Next, the CPU 122 determines whether or not the first detected temperature detected by the temperature information from the first temperature detecting unit 111 is equal to or higher than the first set temperature (S15). In S <b> 15, the CPU 122 obtains the temperature information output from the first temperature detection unit 111 via the connection I / F 130. Then, the CPU 122 compares the first detected temperature detected from the acquired temperature information with the first set temperature stored in the RAM 126 in S11, and determines the magnitude relationship.

  When the first detected temperature is lower than the first set temperature (S15: No), the CPU 122 detects the first detected temperature detected by the temperature information from the first temperature detecting unit 111 sequentially obtained via the connection I / F 130. Based on the above, S15 is repeatedly executed. In this case, the CPU 122 continues the continuous heating by the first heater 101 corresponding to the first set temperature started in S13. When the first detected temperature is equal to or higher than the first set temperature (S15: Yes), the CPU 122 determines whether the third detected temperature detected by the temperature information from the third temperature detecting unit 113 is equal to or lower than the fourth set temperature. Is determined (S17). In S <b> 17, the CPU 122 acquires the temperature information output from the third temperature detection unit 113 via the connection I / F 130. Then, the CPU 122 compares the third detected temperature detected by the acquired temperature information with the fourth set temperature, and determines the magnitude relationship.

  The fourth set temperature is a temperature corresponding to the first set temperature. For example, the fourth set temperature is the same temperature as the first set temperature. In this case, the CPU 122 acquires the first set temperature stored in the RAM 126 in S11 as the fourth set temperature to be compared with the third detected temperature in S17. However, the fourth set temperature may be a temperature that is higher or lower by a predetermined amount than the first set temperature. The temperature that is the difference from the first set temperature is a value that indicates a ratio to the first set temperature or a value that directly indicates this temperature. The temperature that is the difference from the first set temperature is appropriately set in consideration of various conditions. The temperature which becomes this difference is memorize | stored in the memory | storage part 124 in the state registered into the program of 1st heat processing, for example. The CPU 122 acquires a temperature that is a difference from the storage unit 124, and calculates a fourth set temperature from the first set temperature stored in the RAM 126 in S11 and the acquired temperature that is the difference. The CPU 122 stores the fourth set temperature in the RAM 126.

  When the third detected temperature is equal to or lower than the fourth set temperature (S17: Yes), the CPU 122 starts intermittent heating by the first heater 101 corresponding to the first set temperature (S19). Accordingly, power having a voltage value corresponding to the first set temperature is intermittently supplied from the power supply 128 to the first heater 101 (see FIG. 11B). That is, in S19, the CPU 122 switches the heating in the first heater 101 from continuous heating corresponding to the first set temperature (see S13) to intermittent heating corresponding to the first set temperature. When the third detected temperature is higher than the fourth set temperature (S17: No), the CPU 122 stops heating by the first heater 101 (S21). Accordingly, the supply of power from the power supply 128 to the first heater 101 is stopped.

  After executing S19 or S21, the CPU 122 determines whether or not the first detected temperature is equal to or lower than the first lower limit temperature (S23). In S23, the CPU 122 acquires the temperature information output from the first temperature detection unit 111 via the connection I / F 130. Then, the CPU 122 compares the first detected temperature detected by the acquired temperature information with the first lower limit temperature, and determines the magnitude relationship. The first lower limit temperature is, for example, 95% of the first set temperature in S11. When the first preset temperature is 50 ° C., the first lower limit temperature is 47.5 ° C. The value indicating the ratio to the first set temperature for setting the first lower limit temperature is stored in the storage unit 124 in a state registered in the first heat treatment program, for example. CPU122 acquires the value which shows the ratio mentioned above from the memory | storage part 124, and calculates 1st minimum temperature from the value which shows the 1st preset temperature memorize | stored in RAM126 by S11 and the acquired ratio. The CPU 122 stores the first lower limit temperature in the RAM 126. The ratio described above may be a value different from 95%. Which value is set is appropriately set in consideration of various conditions. In addition, the value (for example, -2.5 degreeC) which shows the temperature with respect to the 1st preset temperature which sets the 1st minimum temperature or the 1st minimum temperature directly is registered into the program of the 1st heat treatment directly. Also good.

  When the first detection temperature is higher than the first lower limit temperature (S23: No), the CPU 122 detects the first detection temperature detected by the temperature information from the first temperature detection unit 111 sequentially acquired via the connection I / F 130. Based on the above, S23 is repeatedly executed. When the first detected temperature is equal to or lower than the first lower limit temperature (S23: Yes), the CPU 122 returns the process to S13 and executes the processes after S13. When S19 is executed, the CPU 122 switches the heating in the first heater 101 from the intermittent heating corresponding to the first set temperature to the continuous heating corresponding to the first set temperature in S13 to be executed again. When the fourth set temperature is set to a temperature higher or lower than the first set temperature by a predetermined amount, the CPU 122 uses the fourth lower limit temperature stored in the RAM 126 in S17 that is executed again after returning the process to S13. Further, the CPU 122 uses the first lower limit temperature stored in the RAM 126 in S23 which is executed again after returning the process to S13.

<Second heat treatment>
CPU122 which started the 2nd heat processing acquires 2nd preset temperature (S31). The second set temperature is a heating temperature in the second heater 102. In the present embodiment, the second set temperature is the same temperature as the first set temperature. As described above with reference to S <b> 11 of FIG. 9, the operator operates the operation unit (not shown) and inputs a predetermined temperature to the control device 120. In the second heat treatment, the CPU 122 acquires a predetermined temperature input via the operation unit as the second set temperature. The CPU 122 stores the acquired second set temperature in the RAM 126. Subsequently, the CPU 122 starts continuous heating by the second heater 102 corresponding to the second set temperature (S33). Accordingly, power having a voltage value corresponding to the second set temperature is continuously supplied from the power supply 128 to the second heater 102 (see FIG. 11A).

  Next, the CPU 122 determines whether or not the second detected temperature detected by the temperature information from the second temperature detection unit 112 is equal to or higher than the second set temperature (S35). In S <b> 35, the CPU 122 acquires the temperature information output from the second temperature detection unit 112 via the connection I / F 130. Then, the CPU 122 compares the second detected temperature detected from the acquired temperature information with the second set temperature stored in the RAM 126 in S31, and determines the magnitude relationship.

  When the second detected temperature is lower than the second set temperature (S35: No), the CPU 122 detects the second detected temperature detected by the temperature information from the second temperature detecting unit 112 sequentially acquired via the connection I / F 130. Based on the above, S35 is repeatedly executed. In this case, the CPU 122 continues the continuous heating by the second heater 102 corresponding to the second set temperature started in S33. When the second detected temperature is equal to or higher than the second set temperature (S35: Yes), the CPU 122 starts intermittent heating by the second heater 102 corresponding to the second set temperature (S37). Accordingly, power having a voltage value corresponding to the second set temperature is intermittently supplied from the power supply 128 to the second heater 102 (see FIG. 11B). That is, in S37, the CPU 122 switches the heating in the second heater 102 from continuous heating corresponding to the second set temperature (see S33) to intermittent heating corresponding to the second set temperature.

  After executing S37, the CPU 122 determines whether or not the first detected temperature is equal to or lower than the first lower limit temperature (S39). In S39, the CPU 122 acquires the temperature information output from the first temperature detection unit 111 via the connection I / F 130. Then, the CPU 122 compares the first detected temperature detected by the acquired temperature information with the first lower limit temperature, and determines the magnitude relationship. The first lower limit temperature is 95% of the first set temperature, as described above with reference to S23 of FIG. For example, the CPU 122 acquires the first lower limit temperature from the process of the first heat treatment with the same head unit 60 as the processing target. Since the second set temperature is equal to the first set temperature, the CPU 122 can also acquire the first lower limit temperature based on the second set temperature. In this case, for example, the CPU 122 acquires a value indicating a ratio to the first set temperature for setting the first lower limit temperature from the storage unit 124, and acquires the second set temperature stored in the RAM 126 in S31 or S47 described later. The first lower limit temperature is calculated from the value indicating the ratio obtained. As described above, the value indicating the ratio is stored in the storage unit 124 in a state registered in the first heat treatment program. You may make it register the value which shows the ratio mentioned above in the program of the 2nd heat processing memorize | stored in the memory | storage part 124. FIG. The CPU 122 stores the first lower limit temperature in the RAM 126. In S23 of FIG. 9, the first lower limit temperature stored in the RAM 126 may be used here.

  When the first detected temperature is higher than the first lower limit temperature (S39: No), the CPU 122 shifts the process to S51. When the first detected temperature is equal to or lower than the first lower limit temperature (S39: Yes), the CPU 122 updates the heating temperature in the second heater 102 to the third set temperature (S41). The third set temperature is a temperature that is higher than the second set temperature by a predetermined amount. For example, the third set temperature is a temperature that is about 10% higher than the second set temperature. When the second set temperature is 50 ° C, the third set temperature is 55 ° C. The temperature that is the difference from the second set temperature is appropriately set in consideration of various conditions. The value indicating the above-described ratio that specifies the temperature that is the difference from the second set temperature is stored in the storage unit 124 in a state registered in the second heat treatment program, for example. The CPU 122 acquires the value indicating the ratio described above from the storage unit 124, and calculates the third set temperature from the second set temperature stored in the RAM 126 in S31 or S47 described later and the value indicating the acquired ratio. The temperature that is the difference from the second set temperature may be specified by a value (for example, 5 ° C.) that directly indicates this temperature. The CPU 122 sets the second set temperature stored in the RAM 126 as the third set temperature. Subsequently, the CPU 122 starts continuous heating by the second heater 102 corresponding to the third set temperature (S43). Accordingly, power having a voltage value corresponding to the third set temperature is continuously supplied from the power supply 128 to the second heater 102 (see FIG. 11A). That is, in S43, the CPU 122 switches the heating in the second heater 102 from intermittent heating corresponding to the second set temperature (see S37 or S49 described later) to continuous heating corresponding to the third set temperature.

  Next, the CPU 122 determines whether or not the second detected temperature detected by the temperature information from the second temperature detecting unit 112 is equal to or higher than the third set temperature (S45). In S <b> 45, the CPU 122 obtains the temperature information output from the second temperature detection unit 112 via the connection I / F 130. Then, the CPU 122 compares the second detected temperature detected from the acquired temperature information with the third set temperature stored in the RAM 126 in S41, and determines the magnitude relationship.

  When the second detected temperature is lower than the third set temperature (S45: No), the CPU 122 detects the second detected temperature detected by the temperature information from the second temperature detector 112 sequentially acquired via the connection I / F 130. Based on the above, S45 is repeatedly executed. In this case, the CPU 122 continues the continuous heating by the second heater 102 corresponding to the third set temperature started in S43. When the second detected temperature is equal to or higher than the third set temperature (S45: Yes), the CPU 122 updates the heating temperature in the second heater 102 to the second set temperature (S47). The CPU 122 sets the third set temperature stored in the RAM 126 as the second set temperature. Subsequently, the CPU 122 starts intermittent heating by the second heater 102 corresponding to the second set temperature (S49). Accordingly, power having a voltage value corresponding to the second set temperature is intermittently supplied from the power supply 128 to the second heater 102 (see FIG. 11B). That is, in S49, the CPU 122 switches the heating in the second heater 102 from continuous heating corresponding to the third set temperature (see S43) to intermittent heating corresponding to the second set temperature. Thereafter, the CPU 122 shifts the process to S51.

  In S51, the CPU 122 determines whether or not the second detected temperature is equal to or lower than the second lower limit temperature. In S <b> 51, the CPU 122 obtains the temperature information output from the second temperature detection unit 112 via the connection I / F 130. Then, the CPU 122 compares the second detected temperature detected by the acquired temperature information with the second lower limit temperature, and determines the magnitude relationship. The second lower limit temperature is, for example, 95% of the second set temperature in S31. The value indicating the ratio to the second set temperature for setting the second lower limit temperature is stored in the storage unit 124 in a state registered in the second heat treatment program, for example. CPU122 acquires the value which shows the ratio mentioned above from the memory | storage part 124, and calculates 2nd minimum temperature from the value which shows the 2nd preset temperature memorize | stored in RAM126 by S31 or S47, and the acquired ratio. The CPU 122 stores the second lower limit temperature in the RAM 126. In addition, you may make it register the value which shows directly the temperature with respect to 2nd preset temperature which sets 2nd minimum temperature or 2nd minimum temperature in the program of 2nd heat processing.

  In this embodiment, since the second set temperature is equal to the first set temperature, the second lower limit temperature is equal to the first lower limit temperature in S23 or S39 of FIG. In S51, the temperature stored in the RAM 126 in S23 or S39 in FIG. 9 may be used as a temperature (second lower limit temperature) as a criterion. The ratio relating to the second lower limit temperature may be a value different from 95%, similarly to the first lower limit temperature. In this case, the ratio relating to the second lower limit temperature may be a value different from the ratio relating to the first lower limit temperature. Which value is set is appropriately set in consideration of various conditions.

  When 2nd detection temperature is higher than 2nd minimum temperature (S51: No), CPU122 returns a process to S39, and performs the process after S39. When the second detected temperature is equal to or lower than the second lower limit temperature (S51: Yes), the CPU 122 returns the process to S33 and executes the processes after S33. In S33 to be re-executed, the CPU 122 switches the heating in the second heater 102 from the intermittent heating corresponding to the second set temperature (see S37 or S49) to the continuous heating corresponding to the second set temperature. After executing S51, the CPU 122 uses the first lower limit temperature stored in the RAM 126 in S39 to be re-executed, and uses the second lower limit temperature stored in the RAM 126 in S51 to be re-executed.

<Effect of this embodiment>
According to this embodiment, the following effects can be obtained.

  (1) The inkjet head 31 is formed of a plurality of head units 60 (see FIG. 3). The head unit 60 includes a second tank 62, a plurality of connection portions 63, a nozzle plate 70, a plurality of flow path modules 80, a frame 90, a cover 100, a first heater 101, and a second heater 102. The 1st temperature detection part 111, the 2nd temperature detection part 112, and the 3rd temperature detection part 113 are provided (refer FIGS. 4-8). The second tank 62 is provided above the plurality of flow path modules 80 covered with the cover 100, and the second tank 62 and the plurality of flow path modules 80 are connected via a plurality of connection portions 63 (see FIG. 4, see FIGS. 7 and 8. The nozzle plate 70 and the plurality of flow path modules 80 are attached to the frame 90 and connected via the frame 90 (see FIGS. 5 to 7). The first heater 101 is provided on the frame 90, and the second heater 102 is provided on the second tank 62 (see FIGS. 4 and 6). The first temperature detection unit 111 is provided on the nozzle plate 70, the second temperature detection unit 112 is provided on the second tank 62, and the third temperature detection unit 113 is provided on the cover 100 (see FIG. 7).

  Therefore, the second tank 62 is heated by the second heater 102, the ultraviolet curable ink stored in the second tank 62 is warmed, and the plurality of flow path modules 80 connecting the warmed ultraviolet curable ink to the nozzles 32. Can flow into each. The head unit 60 is formed by the nozzle plate 70, the plurality of flow path modules 80, and the frame 90, and the frame 90 is provided with the first heater 101 to heat the frame 90, whereby the nozzle plate 70 and the plurality of flow path modules 80 are formed. Can be warmed. Since the nozzle plate 70 is also warmed, heat conduction from the plurality of flow path modules 80 to the nozzle plate 70 side can be suppressed. The cover 100 can improve the heat retention of the plurality of flow path modules 80. The ultraviolet curable ink before flowing from the nozzle 32 through the ink flow path 81 in the flow path module 80 can be warmed. The ultraviolet curable ink discharged from the nozzle 32 can be set to a temperature suitable for discharge. The ultraviolet curable ink supplied to the head unit 60 is set to a temperature at which ejection failure does not occur, and an image of suitable quality can be recorded.

  The second tank 62 can be arranged compactly. The ultraviolet curable ink can be supplied from one second tank 62 to the plurality of flow path modules 80. Compared to a configuration in which a tank corresponding to the second tank 62 is provided for each of the plurality of flow path modules 80, a simple head unit 60 can be obtained. Since the nozzle plate 70 and the plurality of flow path modules 80 are connected via the frame 90, it is not necessary to directly connect them with, for example, an adhesive or a screw. The plurality of flow path modules 80 can be replaced individually. For example, when the flow path module 80A out of the flow path modules 80A, 80B, 80D, 80E, 80F, 80G fails, the failed flow path module 80A is removed from the frame 90, and a new flow path module 80A is attached to the frame 90. Only the flow channel module 80A can be exchanged by an operation such as attachment. When the flow path modules 80A and 80F fail, the flow path modules 80A and 80F are removed by removing the failed flow path modules 80A and 80F from the frame 90 and attaching new flow path modules 80A and 80F to the frame 90. Can only be exchanged. It is possible to obtain a head unit 60 that can cope with a large amount of ink consumption and forms a small inkjet head 31 with excellent maintainability in the event of a failure. The small size of the inkjet recording apparatus 10 can be realized by the small inkjet head 31.

  (2) Two first heaters 101 are provided on the frame 90 in a non-contact state with both the nozzle plate 70 and the plurality of flow path modules 80 (see FIG. 7). At that time, there is a gap AS between one of the two first heaters 101 and the flow path module 80A and between the other first heater 101 and the flow path module 80G. Each was formed (see FIG. 7). Therefore, heat from the first heater 101 can be conducted to the frame 90 in direct contact. The nozzle plate 70 and the plurality of flow path modules 80 can be indirectly heated through the frame 90. By forming the gap AS between the first heater 101 and the flow path modules 80A and 80G, the flow path modules 80A and 80G can be insulated from the heat from the first heater 101. The heat from each first heater 101 is not directly conducted to the flow path modules 80A and 80G, and the occurrence of a state in which the temperature of the flow path modules 80A and 80G approaching the first heater 101 becomes high can be suppressed. it can.

  (3) In the first heating process (see FIG. 9), based on the first detected temperature and the third detected temperature detected by the temperature information from the first temperature detecting unit 111 and the third temperature detecting unit 113 (FIG. 9). S15, S17, and S23), and the heating of the frame 90 by the first heater 101 was appropriately controlled (see S13, S19, and S21 in FIG. 9). Therefore, the temperature of the ultraviolet curable ink that is supplied to the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G and is discharged from the nozzle 32 is set to the first set temperature of the first heater 101 (see S11 in FIG. 9). ) Or an equivalent temperature. By starting the continuous heating corresponding to the first set temperature in S13 of FIG. 9, the temperature of the ultraviolet curable ink supplied to the flow path module 80 can be raised smoothly. By starting intermittent heating corresponding to the first set temperature in S19 of FIG. 9, the ultraviolet curable ink that has reached the first set temperature is held at the first set temperature or a temperature equivalent thereto, or the first The temperature of the ultraviolet curable ink that has become higher than the set temperature can be returned to the first set temperature or a temperature equivalent thereto. In a state where the third detected temperature is higher than the fourth set temperature (see S17: No in FIG. 9) and it is estimated that the heat insulation inside the cover 100 provided with the plurality of flow path modules 80 is secured. By stopping the heating in S21, the power consumption required for the heating can be suppressed.

  (4) In the second heat treatment (see FIG. 10), based on the first detected temperature and the second detected temperature detected by the temperature information from the first temperature detecting unit 111 and the second temperature detecting unit 112 (FIG. 10). S35, S39, S45 and S51), and heating of the second tank 62 by the second heater 102 was appropriately controlled (see S33, S37, S43 and S49 in FIG. 9). Therefore, the temperature of the ultraviolet curable ink stored in the second tank 62 and supplied to the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G is set to each set temperature of the second heater 102 (S31 in FIG. 10). , S41 and S47) or an equivalent temperature. By starting the continuous heating corresponding to the second set temperature in S33 of FIG. 10, the ultraviolet curing before being stored in the second tank 62 and supplied to the flow path modules 80A, 80B, 80D, 80E, 80F, 80G. The temperature of the mold ink can be raised smoothly. By starting intermittent heating in S37 of FIG. 10, the ultraviolet curable ink that has reached the second set temperature is maintained at the second set temperature or a temperature equivalent thereto, or becomes higher than the second set temperature. The temperature of the ultraviolet curable ink can be returned to the second set temperature or a temperature equivalent thereto. UV curing before discharge in the flow path module 80 which has become the first lower limit value or less by starting continuous heating corresponding to the third set temperature (third set temperature> second set temperature) in S43 of FIG. The temperature of the mold ink can be raised smoothly. By starting indirect heating corresponding to the second set temperature in S49 of FIG. 10, the temperature of the ultraviolet curable ink that has become the third set temperature or higher can be returned to the second set temperature or a temperature equivalent thereto. .

<Modification>
This embodiment can also be performed as follows. Some configurations of the modifications shown below can be appropriately combined and employed. Hereinafter, points different from the above will be described, and description of similar points will be omitted as appropriate.

  (1) In the above, the recording unit 30 including the inkjet heads 31K, 31M, 31Y, and 31C formed by the plurality of head units 60 and the irradiation unit 38 are reciprocated in the short direction by the moving unit 40 to record an image. The inkjet recording apparatus 10 to be performed has been described as an example (see FIGS. 1 and 3). The head unit 60 (see FIG. 4) can also be employed when the recording unit of the inkjet recording apparatus includes a line-type inkjet head. In the line-type inkjet head, nozzles 32 that discharge ultraviolet curable ink of each color are arranged in the short direction. For example, in a line-type inkjet head, the nozzle 32 is formed in a range equal to or larger than the width W1 (see FIG. 1) of the recording medium 14 in the short direction.

  For example, a line-type inkjet head is formed by arranging a plurality of groups of head units 60 arranged in the short direction in the longitudinal direction. A first unit row by a plurality of head units 60 arranged in the short direction on one side in the longitudinal direction (for example, upstream in the transport direction), and short on the other side in the longitudinal direction (for example, downstream in the transport direction). The second unit row by the plurality of head units 60 arranged in the hand direction is arranged in a state shifted by a predetermined amount in the short direction. Such an arrangement is for eliminating the region in the short direction where the nozzle 32 is not present, as described above. In an ink jet recording apparatus including a recording unit using a line type ink jet head, the moving unit 40 and the support unit 46 are omitted. The conveyance of the recording medium 14 by the conveyance unit 20 is continuously performed. The irradiation unit is provided downstream of the recording unit in the transport direction. The ultraviolet rays irradiated from the irradiation unit are applied to the ink dots by the ultraviolet curable ink of each color landed on the recording surface 15 of the recording medium 14 conveyed to the position where the irradiation unit is provided by the conveyance unit 20.

  (2) In the above description, the two first heaters 101 are provided on the predetermined side surfaces of the openings 92 and 93 of the frame 90 (see FIG. 6). The first heater may be attached to the frame with a different structure. For example, the first heater may be embedded in the frame. In this case, the first heater is, for example, a rod-shaped metal heater, and a mounting hole corresponding to the rod-shaped first heater is formed in the frame. The first heater is provided in this mounting hole. The number of first heaters may be appropriately set in consideration of various conditions. The type of the second heater and the attachment of the second heater to the second tank 62 may be different from the above mode (see FIG. 4).

  (3) In the above description, the first temperature detection unit 111 is provided on the nozzle plate 70. The first temperature detection unit 111 may be provided at a predetermined position of any one of the flow path modules 80A, 80B, 80D, 80E, 80F, and 80G. For example, the first temperature detection unit 111 is provided at a predetermined position of the flow path module 80 that is opposite to the discharge surface 35 in the vertical direction. In this case, the first temperature detection unit 111 detects the temperature of the flow path module 80 heated indirectly through the frame 90. Further, the first temperature detection unit 111 may be provided at a predetermined position of the frame 90. For example, the first temperature detection unit 111 is provided at a predetermined position of a portion of the frame 90 that separates the openings 92 and 93 that are opposite to the nozzle plate 70 in the vertical direction. In this case, the first temperature detection unit 111 detects the temperature of the frame 90 heated by the first heater 101.

  (4) In the above, the flow path module 80 included in one head unit 60 is formed by separate flow path modules 80A, 80B, 80D, 80E, 80F, and 80G (see FIGS. 5 and 6). ). The number of flow path modules for one head unit may be different from six. For example, one flow path module may be used for one head unit. In this case, one opening is formed in the frame corresponding to one channel module. In addition, it is good also as two flow path modules with respect to one head unit. When a plurality of flow path modules are used, the number of openings is appropriately determined in consideration of various conditions.

  (5) In the above, the heating in S13 of the first heat treatment (see FIG. 9) was set as continuous heating (first set temperature), and the heating in S19 was set as intermittent heating (first set temperature). Both the heating in S13 and S19 may be continuous heating or intermittent heating. In this case, the voltage value of the power supplied to the first heater 101 is set higher in S13 than in S19. Further, the heating in S33 of the second heat treatment (see FIG. 10) is set as continuous heating (second set temperature), the heating in S37 and S49 is set as intermittent heating (second set temperature), and the heating in S43 is continuously performed. Heating (third set temperature) was used. The heating in S33, S37, S43 and S49 may all be continuous heating or intermittent heating. In this case, the voltage value of the electric power supplied to the second heater 102 is set to be the highest in S43. The voltage value at S33 is set higher than S37 and S49. The voltage values in S37 and S49 are the same.

  (6) In the above description, when the first detected temperature is the same as the first set temperature in S15 of the first heat treatment (see FIG. 9), the determination is affirmed (S15: Yes). S15 may be determined based on whether or not the first detected temperature is higher than the first set temperature. If the first detected temperature is equal to the first set temperature, the determination may be negative (S15: No). In S17 (see FIG. 9), when the third detected temperature is the same as the fourth set temperature, the determination is affirmed (S17: Yes). S17 may be determined based on whether or not the third detected temperature is lower than the fourth set temperature. If the third detected temperature is equal to the fourth set temperature, the determination may be negative (S17: No). In S23 (see FIG. 9), when the first detected temperature is the same as the first lower limit temperature, the determination is affirmed (S23: Yes). S23 may be determined based on whether or not the first detected temperature is lower than the first lower limit temperature. If the first detected temperature is equal to the first lower limit temperature, the determination may be negative (S23: No).

  In S35 of the second heat treatment (see FIG. 10), when the second detected temperature is the same as the second set temperature, the determination is affirmed (S35: Yes). S35 may be determined based on whether or not the second detected temperature is higher than the second set temperature. If the second detected temperature is equal to the second set temperature, the determination may be negative (S35: No). In S39 (see FIG. 10), when the first detected temperature is the same as the first lower limit temperature, the determination is affirmed (S39: Yes). S39 may be determined based on whether or not the first detected temperature is lower than the first lower limit temperature. If the first detected temperature is equal to the first lower limit temperature, the determination may be negative (S39: No). In S45 (see FIG. 10), when the second detected temperature is the same as the third set temperature, the determination is affirmed (S45: Yes). S45 may be determined based on whether or not the second detected temperature is higher than the third set temperature, and if the second detected temperature and the third set temperature are equal, the determination may be negative (S45: No). In S51 (see FIG. 10), when the second detected temperature is the same as the second lower limit temperature, the determination is affirmed (S51: Yes). S51 may be determined based on whether or not the second detected temperature is lower than the second lower limit temperature, and if the second detected temperature and the second lower limit temperature are equal, the determination may be negative (S51: No).

  (7) In the above, after starting continuous heating by the second heater 102 corresponding to the second set temperature in S33 of the second heat treatment (see FIG. 10), the second detected temperature is set to the second set temperature in S35. It was decided to determine whether this was the case. In the second heating process, a process similar to S39 may be executed after S31 and S33, or after S31 or S33. That is, the second heat treatment may be as shown in FIG. In the second heating process shown in FIG. 12, S32 is added as a process after the execution of S31 and S34 is added as a process after the execution of S33 with respect to the second heating process shown in FIG. In the second heat treatment shown in FIG. 12, in order to clarify the correspondence with the second heat treatment shown in FIG. 10, the same step numbers are assigned to the common processes in the two types of second heat treatment. . In the second heat treatment shown in FIG. 12, the processes having the same step numbers as those of the second heat treatment shown in FIG. 10 are executed as described above.

  In S32 and S34 of the second heat treatment shown in FIG. 12, the CPU 122 obtains the first detected temperature and the first lower limit temperature, respectively, as described above with reference to S39, and the first detected temperature is the first lower limit temperature. It is determined whether or not: When the first detected temperature is higher than the first lower limit temperature and S32 is negative (S32: No), the CPU 122 shifts the process to S33. When S51 is affirmed (S51: Yes), the CPU 122 returns the process to S32. If the first detected temperature is higher than the first lower limit temperature and S34 is negative (S34: No), the CPU 122 proceeds to S35. When S35 is denied (S35: No), the CPU 122 returns the process to S34. When the first detected temperature is equal to or lower than the first lower limit temperature and S32 or S34 is affirmed (S32 or S34: Yes), the CPU 122 shifts the process to S41. In the second heat treatment shown in FIG. 12, either S32 or S34 may be omitted.

DESCRIPTION OF SYMBOLS 10 Inkjet recording device, 14 Recording medium, 15 Recording surface, 20 Conveying part 30 Recording part, 31, 31K, 31M, 31Y, 31C Inkjet head 32, 32A, 32B, 32D, 32E, 32F, 32G Nozzle 33, 33A, 33B , 33D, 33E, 33F, 33G Nozzle group 34 Carriage, 35 Discharge surface, 38 Irradiation part 40 Moving part, 41, 42 Pulley, 43 Timing belt, 46 Support part 50, 50K, 50M, 50Y, 50C First tank 51, 51K, 51M, 51Y, 51C Supply tube 60 Head unit, 62 Second tank 63, 63A, 63B, 63D, 63E, 63F, 63G Connection part 70 Nozzle plate, 71 Positioning hole 80, 80A, 80B, 80D, 80E, 80F , 80G channel module 81 Ink flow path, 82 Branch portion, 83 Drive element 84A, 84B, 84D, 84E, 84F, 84G Positioning hole 85A, 85B, 85D, 85E, 85F, 85G Mounting hole 90 Frame, 91 Positioning pin, 92, 93 Opening 94A, 94B, 94D, 94E, 94F, 94G Positioning pins 95A, 95B, 95D, 95E, 95F, 95G Screw holes, 96 Screws 100 Cover, 101 First heater, 102 Second heater 111 First temperature detection unit, 112 First Two temperature detection unit, 113 Third temperature detection unit 120 Control device, 122 CPU, 124 Storage unit, 126 RAM
128 power supply, 130 connection interface (connection I / F)
AS gap, W1 width

Claims (10)

A head unit for forming an inkjet head of an inkjet recording apparatus that ejects ink of a predetermined color,
A second tank for storing the ink supplied from the first tank of the inkjet recording apparatus for storing the ink;
A nozzle plate formed with a plurality of nozzles for ejecting the ink;
The ink that is connected to the plurality of nozzles formed on the nozzle plate and that flows the ink supplied from the second tank to each of the plurality of nozzles, and is connected to each of the plurality of nozzles. A flow path module provided with a plurality of drive elements for ejecting the ink from the nozzles, provided corresponding to each of the plurality of nozzles in each tributary part of the flow path;
Connecting the second tank and the flow channel module, a connection portion through which the ink supplied from the second tank to the flow channel module flows,
The nozzle plate is attached, the flow channel module is detachably attached, and the frame connecting the nozzle plate and the flow channel module;
A first heater provided in the frame;
And a second heater provided in the second tank. The first heater is
Provided in contact with the frame and in a non-contact state with the nozzle plate and the flow path module;
The head unit according to claim 1, wherein a gap is formed between the flow path module and the first heater in a state where the nozzle plate and the flow path module are attached to the frame.   The head unit according to claim 1, wherein the second tank is provided above the flow path module.   The head unit according to any one of claims 1 to 3, wherein the head unit includes a cover that covers the flow path module attached to the frame. The channel module is
Of the plurality of nozzles formed on the nozzle plate, the ink connected to the plurality of first nozzles forming the first nozzle group and supplied from the second tank to each first nozzle of the first nozzle group A first ink channel that is a first portion of the ink channel is formed, and each of the plurality of first nozzles is connected to each branch portion of the first ink channel that is connected to the plurality of first nozzles. A first flow path module provided with a plurality of first drive elements included in the plurality of drive elements that discharge the ink from the first nozzle,
Of the plurality of nozzles formed on the nozzle plate, the ink connected to the plurality of second nozzles forming the second nozzle group and supplied from the second tank to each second nozzle of the second nozzle group The second ink flow path, which is the second part of the ink flow path, is formed, and each of the plurality of second nozzles is connected to each branch portion of the second ink flow path connected to the plurality of second nozzles. A second flow path module including a plurality of second drive elements included in the plurality of drive elements, each of which is provided corresponding to each of the plurality of drive elements, and discharges the ink from the second nozzle.
The connecting portion is
Connecting the second tank and the first flow path module, a first connection portion through which the ink supplied from the second tank to the first flow path module flows;
Connecting the second tank and the second flow path module, and a second connection portion through which the ink supplied from the second tank to the second flow path module flows,
The first flow channel module and the second flow channel module are detachably attached to the frame in a state where they are adjacent to each other,
The head unit according to any one of claims 1 to 4, wherein the frame connects the nozzle plate to the first flow path module and the second flow path module. A first tank for storing ink of a predetermined color;
An ink jet head formed by arranging a plurality of head units that discharge the ink and include a first heater, a second heater, a first temperature detection unit, and a second temperature detection unit;
A controller that controls heating by the first heater and heating by the second heater;
The head unit is
A second tank for storing the ink supplied from the first tank;
A nozzle plate formed with a plurality of nozzles for ejecting the ink;
The ink that is connected to the plurality of nozzles formed on the nozzle plate and that flows the ink supplied from the second tank to each of the plurality of nozzles, and is connected to each of the plurality of nozzles. A flow path module provided with a plurality of drive elements for ejecting the ink from the nozzles, provided corresponding to each of the plurality of nozzles in each tributary part of the flow path;
Connecting the second tank and the flow channel module, a connection portion through which the ink supplied from the second tank to the flow channel module flows,
The nozzle plate is attached, the flow channel module is detachably attached, and the frame connects the nozzle plate and the flow channel module.
The first heater is provided on the frame,
The second heater is provided in the second tank,
The first temperature detection unit is provided in the nozzle plate, the flow path module or the frame,
The second temperature detection unit is provided in the second tank,
The controller is
When the first detected temperature detected by the temperature information from the first temperature detection unit is lower than the first set temperature, the heating by the first heater corresponding to the first set temperature is controlled,
When the second detected temperature detected by the temperature information from the second temperature detection unit is lower than the second set temperature, the heating by the second heater corresponding to the second set temperature is controlled,
In a state in which heating by the second heater corresponding to the second set temperature is controlled or in a state in which heating by the second heater corresponding to the second set temperature is not controlled, the first detected temperature is An inkjet recording apparatus that controls heating by the second heater corresponding to a third set temperature higher than the second set temperature when lower than a first lower limit temperature lower than the first set temperature.   The ink jet recording apparatus according to claim 6, wherein the control unit controls heating by the second heater corresponding to the second set temperature when the second detected temperature is higher than the third set temperature. The controller is
When the second detected temperature is lower than the second set temperature, the continuous heating by the second heater corresponding to the second set temperature is controlled,
The inkjet recording apparatus according to claim 6 or 7, wherein when the second detected temperature is higher than the second set temperature, intermittent heating by the second heater corresponding to the second set temperature is controlled. The controller is
If the first detected temperature is lower than the first lower limit temperature, control the continuous heating by the second heater corresponding to the third set temperature,
The inkjet according to any one of claims 6 to 8, wherein when the second detected temperature is higher than the third set temperature, intermittent heating by the second heater corresponding to the second set temperature is controlled. Recording device. The head unit is
A cover for covering the flow path module attached to the frame;
A third temperature detector provided on the cover,
The controller is
When the first detected temperature is lower than the first set temperature, the continuous heating by the first heater corresponding to the first set temperature is controlled,
When the first detected temperature is higher than the first set temperature and the third detected temperature detected by the temperature information from the third temperature detection unit is lower than the fourth set temperature, the first set temperature corresponds to the first set temperature. Control intermittent heating by the first heater,
The heating stop by the first heater is controlled when the first detected temperature is higher than the first set temperature and the third detected temperature is higher than the fourth set temperature. 2. An ink jet recording apparatus according to item 1.

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