JP2015085660A - Washing device for ink jet head and method for washing ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for washing an ink jet head by which preferable washing for a nozzle part can be achieved in an ink jet head having a circulation flow passage structure.SOLUTION: When a nozzle part is washed by use of: a cap part (14) in which a cleaning fluid for immersion of a nozzle face (277) of an ink jet head (200) is stored; a cleaning liquid supply parts (15, 16, 17) for supplying the cleaning liquid to the cap part; a first flow passage (30) which is connected to a circulation port (256A) of the ink jet head; a first pump (22) provided in the first flow passage; a second flow passage (30) which is connected to a supply port (252A) of the ink jet head; a second pump (32) provided in the second flow passage; and the cleaning liquid stored in the cap part, the cleaning liquid stored in the cap part is fed to the first flow passage from a nozzle opening via a circulation flow passage and the circulation port, and is fed from the supply port to the nozzle part via a supply flow passage.

Description

  The present invention relates to an inkjet head cleaning device and an inkjet head cleaning method, and more particularly to an inkjet head cleaning technique having a circulation channel structure in which a supply channel and a circulation channel are provided.

  In the ink jet head, foreign matters such as dried liquid (ink) and paper dust may adhere to the nozzle portion. Stability in the ejection direction is reduced due to adhesion of foreign matter to the nozzle portion. In order to use the inkjet head stably for a long period of time, it is necessary to remove foreign matters from the nozzle portion.

  Patent Document 1 describes a droplet discharge device having a cleaning function. The droplet discharge device described in the document includes an ultrasonic vibrator in the cap, and the cap is covered with a nozzle (discharge nozzle) in a state where the cap is filled with a cleaning liquid, and ultrasonic waves are oscillated from the ultrasonic vibrator. The nozzle and the nozzle plate are washed.

  FIG. 4 of the same document uses the structure of the ink supply system of the ink jet head to fill the inside of the ink jet head (flow path) with the cleaning liquid from the ink supply port of the ink jet head (connection portion of the connection pipe (12)). The configuration is illustrated.

  Patent Document 2 describes an inkjet head cleaning device. In the inkjet head cleaning apparatus described in the same document, the inkjet head is immersed in a cleaning liquid that is ultrasonically vibrated in a head immersion container, sucked from an ink supply port, and the cleaning liquid is circulated from a nozzle to a flow path. The nozzle and the ink flow path are cleaned by pulling up from the head immersion container and spraying a cleaning liquid from the nozzle.

JP 2006-347000 A JP 2004-358667 A

  However, as in the configuration described in FIG. 4 of Patent Document 1, if the cleaning liquid is flowed from the ink supply port of the ink jet head through the ink jet head flow toward the nozzle, the ink is removed from the ink jet head flow path. The foreign matter is concentrated on the nozzle. Further, the foreign matter may adhere to the inner wall of the nozzle, which may further deteriorate the stability in the ejection direction.

  On the other hand, in the configuration described in Patent Document 2, the cleaning liquid is circulated from the nozzle to the flow path of the ink jet head. When the ink is supplied, the foreign matter caught in the flow path moves to the nozzle, and the foreign matter that has moved to the nozzle may cause an ejection failure.

  In the case where a filter is provided at the ink supply port of the ink jet head, foreign matter that has flowed from the nozzle when the cleaning liquid is circulated from the nozzle adheres to the filter. When ink is supplied (circulated) after cleaning, the foreign matter adhering to the filter moves to the nozzle, and the foreign matter that has moved to the nozzle may cause ejection abnormality.

  Patent Documents 1 and 2 describe the cleaning of nozzles in an inkjet head having a circulation channel structure provided with a supply channel for supplying ink to the nozzle unit and a circulation channel for circulating ink from the nozzle unit. Not a thing.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inkjet head cleaning apparatus and an inkjet head cleaning method in which cleaning of a preferable nozzle portion is realized in an inkjet head having a circulation channel structure. To do.

  In order to achieve the above object, a nozzle surface in which a nozzle opening is formed, a nozzle part including the nozzle opening, a circulation channel communicating with the nozzle part, a circulation port communicating with the circulation channel, and supplying liquid to the nozzle part An ink jet head cleaning apparatus for cleaning an ink jet head having a supply channel, a supply port communicating with the supply channel, a cap portion for storing a cleaning liquid for immersing the nozzle surface of the ink jet head, and circulation of the ink jet head A first flow path connected to the opening, a first pump provided in the first flow path, a cleaning liquid storage section for storing the cleaning liquid, and a second flow path connected to the supply port of the inkjet head. When the nozzle part is cleaned using the second flow path to which the liquid is supplied, the second pump provided in the second flow path, and the cleaning liquid stored in the cap part, the first pump The cleaning liquid prepared and stored in the cap part is sent from the nozzle opening to the first flow path through the circulation flow path and the circulation opening, and the second pump is operated to pass the supply flow from the second flow path to the supply flow path and the supply flow path. And an ink jet head cleaning device including a pump control unit that sends a cleaning liquid to the nozzle unit.

  According to the present invention, the flow of the cleaning liquid from the nozzle part to the circulation port through the circulation flow path and the flow of the cleaning liquid from the supply port to the nozzle part through the supply flow path are present in the nozzle part. Foreign matter is discharged to the first channel through the circulation channel and the circulation port. In addition, the flow of the cleaning liquid from the supply port to the nozzle unit prevents foreign matter existing in the nozzle unit from moving to the supply flow path and the supply port, thereby preventing occurrence of abnormal discharge due to remaining foreign matter.

1 is an overall configuration diagram of an inkjet head cleaning device according to a first embodiment of the present invention. The block diagram which shows schematic structure of the control system in the inkjet head cleaning apparatus shown in FIG. The perspective view which shows the structural example of the inkjet head in which the inkjet head cleaning apparatus shown in FIG. 1 is used. Explanatory drawing of the nozzle arrangement of the inkjet head shown in FIG. Sectional drawing which shows the internal structure of the inkjet head shown in FIG. Plane perspective view of the nozzle surface of a multi-head configured using the inkjet head shown in FIG. The flowchart which shows the flow of the inkjet head cleaning method which concerns on 1st Embodiment of this invention. The whole block diagram of the ink-jet head cleaning device concerning a 2nd embodiment of the present invention. The block diagram which shows schematic structure of the control system in the inkjet head cleaning apparatus shown in FIG. The flowchart which shows the flow of the inkjet head cleaning method which concerns on 2nd Embodiment of this invention. Explanatory drawing which shows the example of a connection of the gas supply apparatus applied to the inkjet head cleaning apparatus which concerns on 3rd Embodiment of this invention. Explanatory drawing which shows the other connection example of the gas supply apparatus applied to the inkjet head cleaning apparatus which concerns on 3rd Embodiment of this invention. Explanatory drawing schematically showing the drying process by heating The block diagram which shows schematic structure of the control system in the inkjet head cleaning apparatus which concerns on 3rd Embodiment of this invention. The flowchart which shows the flow of the inkjet head cleaning method which concerns on 3rd Embodiment of this invention. Explanatory drawing of other modes of liquid feeding using a pump Explanatory drawing of the inkjet head cleaning method which concerns on 4th Embodiment of this invention. Explanatory drawing showing an example of the mounting structure of the cleaning device a: Schematic diagram showing a state in which a moisturizing cap is attached to a multi-head; b: Schematic diagram showing a state in which a cleaning cap is attached to an inkjet head. Explanatory drawing which shows the other example of the cap for washing | cleaning

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
(Overall configuration of inkjet head cleaning device)
FIG. 1 is an overall configuration diagram of an inkjet head cleaning device according to a first embodiment of the present invention. The inkjet head cleaning apparatus 10 shown in the figure includes a cap portion 14 that stores a cleaning liquid 12 that immerses the nozzle surface 277 of the inkjet head 200, a first flow path 20 that is connected to a circulation port 256A of the inkjet head 200, a first The first pump 22 provided in the flow path 20, the first pressure gauge 23 provided in the first flow path 20 (between the first pump 22 and the circulation port 256 </ b> A), and the first pressure gauge 23 connected to the supply port 252 </ b> A of the inkjet head 200. 2 flow path 30, a second pump 32 provided in the second flow path 30, and a second pressure gauge 31 provided in the second flow path 30 (between the second pump 32 and the supply port 252A). Composed.

  The cap unit 14 communicates with a cleaning liquid tank 16 (an example of a cleaning liquid supply unit, a cleaning liquid storage unit) via a third flow path 15 (an example of a cleaning liquid supply unit). When the third pump 17 (an example of the cleaning liquid supply unit) provided in the third flow path 15 is operated, the cleaning liquid is supplied from the cleaning liquid tank 16 to the cap unit 14.

  In the third flow path 15 (between the cleaning liquid tank 16 and the third pump 17), a filter 18 that captures foreign matters mixed in the cleaning liquid is provided. The arrow line illustrated on the lower side of the third pump 17 in FIG. 1 indicates the liquid feeding direction of the cleaning liquid.

  A joint 20A having a structure connectable to the circulation port 256A is provided at one end of the first channel 20 connected to the circulation port 256A of the inkjet head 200, and the other end of the first channel 20 is provided. Is connected to the waste liquid tank 24.

  When the first pump 22 is operated, the cleaning liquid stored in the cap portion 14 is discharged from the nozzle opening (not shown in FIG. 1 and indicated by reference numeral 280 in FIG. 4) of the inkjet head 200 (not shown in FIG. 1). In FIG. 5, the reference numeral 281 is attached to the figure and is shown).

  The cleaning liquid supplied from the nozzle unit to the ink jet head 200 is sent to the circulation port 256A via a circulation channel (not shown in FIG. 1 and indicated by reference numeral 226 in FIG. 5) and discharged from the circulation port 256A. The liquid is sent to the waste liquid tank 24 through the first flow path 20.

  A joint 30A having a structure connectable to the supply port 252A is provided at one end of the second flow channel 30 connected to the supply port 252A of the inkjet head 200, and the other end of the second flow channel 30 is provided. Is connected to the cleaning liquid tank 16. Between the second pump 32 and the cleaning liquid tank 16 in the second flow path 30, a filter 34 that captures foreign matters mixed in the cleaning liquid is provided.

  When the second pump 32 is operated, the cleaning liquid is sent from the cleaning liquid tank 16 to the internal flow path (supply flow path) of the inkjet head 200 via the filter 34, the second pump 32, and the joint 30A.

  The arrow line shown on the upper side of the first pump 22 and the arrow line shown on the upper side of the second pump 32 indicate the feeding direction of the cleaning liquid by the operation of the first pump 22 and the second pump 32, respectively. The first pressure gauge 23 provided in the first flow path 20 functions as a first pressure measurement unit that measures the pressure of the first flow path 20, and the second pressure gauge 31 provided in the second flow path 30 It functions as a second pressure measuring unit that measures the pressure of the two flow paths 30.

  The details of the internal flow path structure of the inkjet head 200 shown in FIG. 1 will be described later. Reference numeral 232 shown in FIG. 1 is an ink supply chamber, reference numeral 232A is a filter on the ink supply side, reference numeral 236 is an ink circulation chamber, reference numeral 236A. Is a filter on the ink circulation side, and reference numeral 233 is a partition wall separating the ink supply chamber and the ink circulation chamber.

  The filter 236A has a hole (not shown) through which foreign matter discharged from the circulation port 256A passes. The hole provided in the filter 236A exceeds the area (size) of the filter mesh and has an opening area corresponding to the size of the assumed foreign matter. As the planar shape of the hole provided in the filter 236A, various shapes such as a circle and a rectangle can be applied.

  The inkjet head cleaning device 10 includes a fixing member (not shown) that fixes the inkjet head 200. The fixing member may be integrated with the cap portion 14 or may be a member different from the cap portion 14.

  When the inkjet head 200 is fixed to the fixing member, the joint 20A of the first flow path 20 is attached to the circulation port 256A of the inkjet head 200, and the joint 30A of the second flow path 30 is attached to the supply port 252A of the inkjet head 200. The inkjet head 200 can be cleaned.

  An inkjet head 200 in which the inkjet head cleaning apparatus 10 shown in FIG. 1 is used is a head structure constituting a full-line multihead having a structure in which a plurality of nozzles are arranged over a length corresponding to the entire width of a recording medium. .

  The inkjet head to which the inkjet head cleaning apparatus 10 shown in this example is applied is not limited to the above example. For example, it can be applied to a serial head.

  The ink jet head 200 illustrated in FIG. 1 has a circulation channel structure including a supply port 252A for supplying liquid (ink) and a circulation port 256A for circulating (collecting) the liquid. Although the detailed structure of the inkjet head 200 will be described later, the supply port 252A communicates with the nozzle portion via the internal flow path (supply flow path) of the inkjet head 200, and the circulation port 256A is the internal flow path ( It communicates with the nozzle part via a circulation channel.

  Here, the “internal flow path” of the inkjet head 200 includes the supply flow path and the circulation flow path described above, and a groove through which a liquid passes, such as a pressure chamber (shown with reference numeral 218 in FIG. 6) described later. , Recesses, holes and the like.

  The inkjet head 200 may be a full-line multi-head configured by arranging a plurality of inkjet heads 200. A “full-line multihead” has a structure in which a plurality of nozzles are arranged over a length corresponding to the entire width of a sheet (shown with reference symbol P in FIG. 6). The liquid can be ejected to the entire surface of the paper by moving the ink only once.

  “Full width of paper” is the length of paper in a direction (X direction in FIG. 6) orthogonal to the relative movement direction (Y direction in FIG. 6) between the paper and the inkjet head. Here, the term “orthogonal” in the present specification includes the case of intersecting at an angle of substantially 90 ° among the modes of intersecting at an angle of less than 90 ° or greater than 90 °. A mode in which similar operational effects are generated is included.

(Description of control system)
FIG. 2 is a block diagram showing a schematic configuration of a control system in the inkjet head cleaning apparatus 10 shown in FIG. As shown in the figure, in the inkjet head cleaning apparatus 10, each part of the apparatus is comprehensively controlled by a system control unit 50.

  The system control unit 50 includes an arithmetic device (processor), a memory, and peripheral circuits thereof.

  Based on the command signal (pressure set value) sent from the system control unit 50, the measured value of the first pressure gauge 23, and the measured value of the second pressure gauge 31, the pump control unit 52 2 The pump 32 controls the operation (on / off, rotation speed, etc.). In addition, the operation (ON / OFF, rotation speed, etc.) of the third pump 17 is controlled to maintain a constant liquid level (water level) of the cleaning liquid in the cap unit 14.

  For example, when the cleaning liquid is supplied from the cap portion 14 to the internal flow path of the ink jet head 200 through the nozzle opening (see FIG. 4) of the ink jet head 200, the direction in which the cleaning liquid flows from the ink jet head 200 to the waste liquid tank 24 (see FIG. 1st pump 22 is operated in the direction of the arrow line 1).

  The command signal (pressure set value) sent from the system control unit 50 and the measured value of the first pressure gauge 23 are compared, and the measured value (negative value, details will be described later) of the first pressure gauge 23 is compared with the pressure set value. Is larger (when the absolute value of the measured value of the first pressure gauge 23 is smaller than the absolute value of the command value), the rotation speed of the first pump 22 is increased and the measured value of the first pressure gauge 23 is set to the pressure setting. When the value is smaller than the value (when the absolute value of the measured value of the first pressure gauge 23 is larger than the absolute value of the command value), the rotation speed of the first pump 22 is decreased.

  Further, when the cleaning liquid is supplied from the cleaning liquid tank 16 to the inkjet head 200 via the supply port 252A, the second pump 32 is arranged in the direction in which the cleaning liquid flows from the cleaning liquid tank 16 to the inkjet head 200 (the direction of the arrow line in FIG. 1). To work.

  When the command signal (pressure set value) sent from the system control unit 50 and the measured value of the second pressure gauge 31 are compared, and the measured value (positive value) of the second pressure gauge 31 is larger than the command value When the rotation speed of the second pump 32 is decreased and the measurement value of the second pressure gauge 31 is smaller than the command value, the rotation speed of the second pump 32 is increased.

  Further, when the cleaning liquid is supplied from the cleaning liquid tank 16 to the cap unit 14 via the third flow path 15, the third direction is the third direction in the direction in which the cleaning liquid flows from the cleaning liquid tank 16 to the cap unit 14 (the direction of the arrow line in FIG. 1). The pump 17 is operated.

  The temperature adjustment unit 54 functions as a heating unit that heats the cleaning liquid. That is, the heater includes a heater and a heater control circuit (driver), and maintains the temperature of the cleaning liquid at a preset temperature based on a command signal sent from the system control unit 50.

  The sensor 56 illustrated in FIG. 2 includes a temperature sensor that detects the temperature of the cleaning liquid. The detection result of the temperature sensor (cleaning liquid temperature information) is provided to the system control unit 50. The system control unit 50 sends a command signal to the temperature adjustment unit 54 based on the temperature information of the cleaning liquid provided from the temperature sensor.

  In general, when the temperature of the cleaning liquid is increased, the solubility of the solidified ink is increased, so that the cleaning period can be shortened and the cleaning effect can be improved. The heater for heating the cleaning liquid may be provided in the cap portion 14 and the cleaning liquid tank 16, or may be provided in the second flow path 30 and the third flow path 15. A configuration in which a plurality of heaters are provided and temperature distribution does not occur in the cleaning liquid in the apparatus is preferable.

  The temperature sensor is a position that is not directly affected by the heating by the heater, and it is preferable to arrange the temperature sensor in the vicinity of the heater because the occurrence of control variations due to the influence of the environmental temperature or the like can be suppressed.

  The sensor 56 includes various sensors arranged in each part of the apparatus in addition to the temperature sensor described above. For example, a temperature sensor that detects the temperature of the cleaning liquid, a sensor that detects the water level (remaining amount) of the cleaning liquid in the cap unit 14, a sensor that detects the water level (remaining amount) of the cleaning liquid in the cleaning liquid tank 16, and fixing the inkjet head 200 And a position sensor for detecting a fixed position.

  The ultrasonic vibration generating unit 58 (ultrasonic vibration applying unit) is a unit that applies ultrasonic vibration to the cleaning liquid stored in the cap unit 14 or the cleaning liquid in the inkjet head 200 and generates ultrasonic vibration. An ultrasonic transducer and a drive circuit (driver circuit) for the ultrasonic transducer are configured.

  For example, an ultrasonic vibrator can be disposed on the outer periphery of the cap unit 14 and the cap unit 14 can be ultrasonically vibrated to impart ultrasonic vibration to the cleaning liquid in the cap unit 14. Further, an ultrasonic vibrator may be arranged inside the cap unit 14 and the cleaning liquid in the cap unit 14 may be directly ultrasonically vibrated.

  By using the ultrasonically vibrated cleaning liquid, it is possible to improve the cleaning effect and shorten the cleaning period. The frequency and output of the ultrasonic wave are in a range in which a load (stress) is not applied to components constituting the ink jet head 200 such as the nozzle surface 277 (see FIG. 1), and a higher cleaning effect is obtained. .

  When the inkjet head 200 includes a piezoelectric element (an example of an ultrasonic vibration applying unit) as a means for generating an ejection force, the piezoelectric element can be operated to apply ultrasonic vibration to the cleaning liquid in the inkjet head 200.

  The ultrasonic vibration generating unit 58 in the aspect of generating ultrasonic vibration using a piezoelectric element includes a drive circuit (driver circuit) for the piezoelectric element. The drive circuit for the piezoelectric element includes an oscillation circuit, an amplifier circuit, peripheral circuits thereof, a memory, and the like.

  The display unit 60 is a display unit that displays various information (error information, various parameter setting information, status information (progress status) during the cleaning process, etc.) of the inkjet head cleaning device 10, and includes a display device, a display driver, Memory etc. are included.

  The operation unit 62 is information input means by an operator, and information input from the operation unit 62 is sent to the system control unit 50. The system control unit 50 sends a command signal to each part of the apparatus based on information input from the operation unit 62. Examples of the operation unit 62 include a keyboard, a mouse, and a joystick. The display unit 60 and the operation unit 62 may be integrated with each other using a touch panel display.

  The inkjet head cleaning apparatus 10 includes a parameter storage unit 64 that stores various settings such as system parameters, a program storage unit 66 that stores programs used in each unit of the apparatus, and a memory 68 that stores various information. .

  When the inkjet head cleaning device 10 executes the cleaning process of the inkjet head 200, the program is read from the program storage unit 66 and various setting values are read from the parameter storage unit 64.

  The inkjet head cleaning device 10 includes a timer 59 as an operation period measuring unit that measures the operation period of the first pump 22 and the operation period of the second pump 32. In addition, a counter 69 is provided as an execution count measuring unit that measures the number of executions (repetition count) of a series of steps described later.

  The timer 59 and the counter 69 may be incorporated in a processor that constitutes the system control unit 50.

(Description of inkjet head)
Next, an inkjet head in which the inkjet head cleaning apparatus 10 shown in this example is used will be described.

  3 is a perspective view (including a partial cross-sectional view) showing an example of the structure of the inkjet head 200, FIG. 4 is an explanatory view of the nozzle arrangement of the inkjet head 200, and FIG. 5 is a sectional view showing the internal structure of the inkjet head 200. 6 is a perspective plan view of the nozzle surface 277 of the multi-head 201 configured using the inkjet head 200. FIG.

  As shown in FIG. 3, the inkjet head 200 includes an ink supply chamber 232, an ink circulation chamber 236, and the like on the opposite side of the nozzle surface 277 of the nozzle plate 275 (the upper side when the nozzle surface is the lower side in FIG. 3). An ink supply unit is included.

  When the inkjet head 200 (multi-head 201, see FIG. 6) is operated, the ink supply chamber 232 is connected to an ink tank (not shown) via a supply line 252 and the ink circulation chamber 236 is a circulation line. It is connected to a recovery tank (not shown) via 256.

  Although the number of nozzle openings 280 is omitted in FIG. 4, a plurality of nozzle openings 280 are formed on the nozzle surface 277 of the nozzle plate 275 of one inkjet head 200 by a two-dimensional nozzle arrangement. .

  That is, the inkjet head 200 has an end face on the long side along the V direction having an inclination of the angle β with respect to the X direction, and a short side of the short side along the W direction having an inclination of the angle α with respect to the Y direction. It has a parallelogram plane shape having end faces, and a plurality of nozzle openings 280 are arranged in a matrix in the row direction along the V direction and the column direction along the W direction.

  The arrangement of the nozzle openings 280 is not limited to the mode illustrated in FIG. 4, and a plurality of nozzle openings 280 are arranged along the row direction along the X direction and the column direction obliquely intersecting the X direction. May be.

  That is, the matrix arrangement of the nozzle openings 280 (nozzle portion 281; see FIG. 6) is the arrangement interval (inter-nozzle pitch) of the nozzle openings 280 in the projected nozzle row in which the nozzle openings 280 arranged in the X direction are projected. A uniform arrangement.

  In FIG. 5, reference numeral 214 denotes an ink supply path, 218 denotes a pressure chamber (liquid chamber), 216 denotes an individual supply path that connects each pressure chamber 218 and the ink supply path 214, and 220 denotes a nozzle connected from the pressure chamber 218 to the nozzle opening 280. The communication path 226 is a circulation individual flow path that connects the nozzle communication path 220 and the circulation common flow path 228.

  A vibration plate 266 is provided on the side opposite to the nozzle surface 277 (upper side in FIG. 5) of the flow channel structure 210 constituting these flow channel portions (214, 216, 218, 220, 226, 228). A piezoelectric element 230 having a laminated structure of a lower electrode (common electrode) 265, a piezoelectric layer 231, and an upper electrode (individual electrode) 264 is disposed on the vibration plate 266 via an adhesive layer 267.

  The upper electrode 264 is an individual electrode patterned corresponding to the shape of each pressure chamber 218, and a piezoelectric element 230 is provided for each pressure chamber 218.

  The ink supply path 214 is connected to the ink supply chamber 232 described with reference to FIG. 3, and ink is supplied from the ink supply path to the pressure chamber 218 via the individual supply path 216. By applying a driving voltage to the upper electrode 264 of the piezoelectric element 230 provided in the corresponding pressure chamber 218 in accordance with the image signal of the image to be drawn, the piezoelectric element 230 and the diaphragm 266 are deformed and the pressure chamber 218 is deformed. The ink volume is changed, and ink is ejected from the nozzle opening 280 through the nozzle communication path 220 due to the pressure change accompanying this.

  By controlling the driving of the piezoelectric element 230 corresponding to each nozzle opening 280 based on the dot arrangement data generated from the image information, ink droplets can be ejected from the nozzle opening 280. Recording a desired image on the paper by controlling the ink ejection timing from each nozzle opening 280 according to the transport speed while transporting the paper P (see FIG. 6) in the Y direction at a constant speed. Can do.

  Although not shown, the pressure chamber 218 provided corresponding to each nozzle opening 280 has a substantially square planar shape, and the outlet to the nozzle opening 280 is provided at one of the diagonal corners. The other side is provided with a supply ink inlet (individual supply path) 216.

  The shape of the pressure chamber is not limited to a square. The planar shape of the pressure chamber may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon and other polygons, a circle, and an ellipse.

  The “supply channel” of the inkjet head 200 described above includes the ink supply channel 214, the pressure chamber 218, the nozzle communication channel 220 shown in FIG. 5, and the ink supply chamber 232 shown in FIG. 3.

  A circulation outlet (not shown) is formed in the nozzle portion 281 including the nozzle opening 280 and the nozzle communication path 220, and the nozzle portion 281 communicates with the circulation individual flow path 226 via the circulation outlet.

  Of the ink in the nozzle part 281, ink that is not used for ejection is collected (circulated) to the circulation common channel 228 via the circulation individual channel 226.

  The circulation common flow path 228 is connected to the ink circulation chamber 236 described with reference to FIG. 5, and the ink is always collected to the circulation common flow path 228 through the circulation individual flow path 226, thereby non-ejection (non-drive). At this time, thickening of the ink in the nozzle portion is prevented.

  The “circulation flow path” of the inkjet head 200 described above includes the circulation individual flow path 226, the circulation common flow path 228 shown in FIG. 5, and the ink circulation chamber 236 shown in FIG.

  The nozzle openings 280 (nozzle portions 281) may be arranged in a single row in the width direction of the paper P or in a two-row staggered arrangement. As a method for discharging the liquid from the nozzle opening 280, other discharge methods such as a thermal method and an electrostatic method can be applied.

  The multi-head 201 shown in FIG. 6 has a structure in which a plurality of inkjet heads 200 are arranged in a line along the width direction (X direction) of the paper P. A branch number (an integer added after “-” (hyphen)) attached to the ink-jet head 200 represents the i-th (an integer from 1 to n) head module.

  A plurality of nozzle openings 280 shown in FIG. 4 are arranged in a matrix on the nozzle surface 277 of each inkjet head 200.

The multi-head 201 illustrated in FIG. 6 is a full-line inkjet head (single-pass / page-wide head) in which a plurality of nozzle openings are arranged over a length corresponding to the entire width L _{max of the} paper P.

  In the cleaning process by the inkjet head cleaning apparatus 10 shown in this example, if the liquid supply channel and the circulation channel are provided, the width direction of the paper P of the short serial head less than the width of the paper P is used. The serial head for printing on the entire surface of the paper P may be applied by combining the scanning of the paper P and the intermittent conveyance of the paper P in the direction orthogonal to the width direction of the paper P.

(Explanation of flowchart)
FIG. 7 is a flowchart showing the flow of the inkjet head cleaning method according to the first embodiment of the present invention. The flowchart described below is applied to the inkjet head cleaning apparatus 10 shown in FIG.

  In cleaning the inkjet head 200, the inkjet head 200 is removed from the multi-head 201 (see FIG. 6). In the inkjet head 200, the supply port 252A (see FIG. 1) and the circulation port 256A are connected to the supply line 252 (see FIG. 3) and the circulation line 256 of the multi-head 201 by a joint (connector). The connection between the 252A and the circulation port 256A and the supply line 252 and the circulation line 256 is released.

  The ink-jet head 200 removed from the multi-head 201 is in a state where ink has entered.

  Next, the connection between the electric circuit of the inkjet head 200 and the drive circuit board is released. The electric circuit of the inkjet head 200 is bonded to the drive substrate via a flexible substrate. The flexible board is removed from the drive circuit board (or the flexible board is removed from the inkjet head 200), and the electrical circuit of the inkjet head 200 and the drive circuit board are disconnected.

  In the aspect in which the connector connected to the connector mounted on the drive circuit board is attached to the flexible board, the cover is attached to the connector mounted on the flexible board, so that the inkjet board 200 is cleaned with the flexible board. Ink or the like can be prevented from adhering to the mounted connector.

  It is possible to install the inkjet head cleaning device 10 at the installation location of the inkjet recording apparatus on which the multi-head 201 is mounted, and to clean the inkjet head 200 removed from the multi-head 201 at the installation location of the apparatus.

  On the other hand, when the inkjet head 200 is cleaned at a dedicated cleaning location (cleaning factory), there is a case where the cleaning device cannot be placed at the location where the inkjet head is installed and there is no restriction on the size of the cleaning device, which may be efficient. . However, when the inkjet head 200 is transported to a cleaning factory, it is necessary to select a packaging and transport method that takes into account the prevention of deterioration of the state of the inkjet head 200 being transported.

  For example, the inkjet head 200 is placed in a container in which a moisturizing state is maintained (a moisturizing liquid is placed) to prevent deterioration of the inkjet head 200 due to drying, or by using a buffering agent to vibrate the inkjet head 200 due to vibration. It may be possible to prevent failure.

  In addition, the container in which the inkjet head 200 is accommodated during transportation is provided with a humidity sensor to monitor the environmental humidity of the inkjet head 200 being transported, and the impact on the container in which the inkjet head 200 is accommodated during transportation. It is conceivable to provide an impact sensor (shock sensor) to measure and monitor the impact applied to the inkjet head 200 during transportation.

  In addition, a protective cover is attached to the nozzle surface 277 to prevent the nozzle surface 277 from being damaged or damaged during transportation, use of a tube with a valve, attachment of a clip to the tube, attachment of a plug to the tip of the tube. It is conceivable to prevent ink leakage due to the above.

  When the cleaning method (cleaning process) of the inkjet head 200 is started (step S10 in FIG. 7), the ink in the internal flow path of the inkjet head 200 is replaced with the cleaning liquid (replacement step: step S12). Specifically, the inkjet head 200 is attached to the inkjet head cleaning apparatus 10 (see FIG. 1) (the inkjet head 200 is fixed using a fixing holding member that fixes and holds the inkjet head 200), and the inkjet head 200 is circulated. The joint 20A of the first flow path 20 is attached to the port 256A, the joint 30A of the second flow path 30 is attached to the supply port 252A, and the third pump 17 is operated to supply the cleaning liquid from the cleaning liquid tank 16 to the cap unit 14. Then, the nozzle surface 277 of the inkjet head 200 is immersed in the cleaning liquid.

  Alternatively, the cleaning liquid may be supplied to the cap unit 14 in advance, and the inkjet head 200 may be attached to the inkjet head cleaning device 10 in a state in which the cap unit 14 is filled with the cleaning liquid.

  Then, the first pump 22 is operated so that the cleaning liquid is supplied from the nozzle unit 281 (see FIG. 5) to the internal flow path of the inkjet head 200, and the cleaning liquid is directed from the nozzle unit 281 to the circulation port 256A via the circulation flow path. A flow is created (first cleaning liquid feeding step). Further, the second pump 32 is operated to create a flow of cleaning liquid from the supply port 252A to the nozzle portion 281 through the supply flow path (second cleaning liquid feeding step).

  The flow of the cleaning liquid from the nozzle unit 281 to the circulation port 256A and the flow of the cleaning liquid from the supply port 252A to the nozzle unit 281 cause the ink in the supply channel of the inkjet head 200 and the ink in the circulation channel to move to the circulation port 256A. Thus, the ink is discharged from the circulation port 256A to the outside of the inkjet head 200. Then, the ink in the supply channel and the ink in the circulation channel of the inkjet head 200 are replaced with the cleaning liquid.

  The pressure set value and operation period of the first pump 22 and the pressure set value and operation period of the second pump 32 are the flow resistance of the internal flow path of the ink jet head 200 and the volume of cleaning liquid contained in the ink jet head 200 (ink jet The volume of the internal flow path of the head 200), the state of the ink jet head 200, the physical properties of the cleaning liquid, the damage to the ink jet head 200, and the like are appropriately determined.

  When the pressure setting value of the first pump 22 is relatively increased, the operation period of the first pump 22 can be relatively shortened. Similarly, when the pressure setting value of the second pump 32 is relatively increased, the operation period of the second pump 32 can be relatively shortened.

  In this example, the pressure setting value of the first pump 22 in the replacement step is minus 25 kilopascals, the operation period of the first pump 22 is 3 minutes, the pressure setting value of the second pump 32 is 20 kilopascals, The operation period is 3 minutes.

  Here, “plus (positive)” of the pressure setting value means the direction of the pressure that causes the liquid to flow into the ink jet head 200, and “minus (negative)” of the pressure setting value causes the ink to be discharged from the ink jet head 200. It means the direction of pressure. That is, with reference to the inkjet head 200, the direction of the pressure for flowing the liquid into the inkjet head 200 is “plus”, and the direction of the pressure for discharging the liquid from the inkjet head 200 is “minus”.

  As described above, since a hole is formed in the filter 236A provided in the ink circulation chamber 236, the flow path resistance value from the nozzle portion (shown with reference numeral 281 in FIG. 5) to the circulation port 256A. Is less than the flow path resistance value from the supply port 252A to the nozzle portion.

  Therefore, by setting the absolute value of the pressure setting value of the first pump 22 to be equal to or larger than the absolute value of the pressure setting value of the second pump 32, the volume of the cleaning liquid discharged from the circulation port 256A per unit time can be increased. Since the volume of ink flowing in from the supply port 252A is exceeded, the volume of the cleaning liquid flowing into the inkjet head 200 from the supply port 252A per unit time is subtracted from the ink discharged from the circulation port 256A per unit time. A volume of cleaning liquid is sucked into the interior (nozzle part) of the ink jet head from the cap part 14 through a nozzle opening (shown with reference numeral 280 in FIG. 5) per unit time.

  Further, the absolute value of the pressure set value of the first pump 22 is set to a value exceeding the absolute value of the pressure set value of the second pump 32, so that the absolute value of the pressure set value of the first pump 22 and the second pump 32 are set. Compared with the case where the absolute value of the pressure setting value is the same, the volume per unit time of the cleaning liquid sucked into the ink jet head 200 from the nozzle section can be increased, and the ink in the nozzle section can be efficiently cleaned. It is possible to obtain a high cleaning effect in cleaning the nozzle part.

  Furthermore, by relatively increasing the value obtained by subtracting the absolute value of the pressure setting value of the second pump 32 from the absolute value of the pressure setting value of the first pump 22, the ink jet head 200 can be moved from the nozzle unit per unit time. The volume of the cleaning liquid sucked into the inside can be relatively increased.

  In this example, the absolute value of the pressure setting value of the first pump 22 is 1.25 times the absolute value of the pressure setting value of the second pump 32. When the pressure difference between the pressure of the liquid discharged from the inkjet head 200 (the pressure setting value of the first pump 22) and the pressure of the liquid flowing into the inkjet head 200 (the pressure setting value of the second pump 32) is relatively small In addition, since the amount of liquid sucked from the nozzle portion is relatively small, from the viewpoint of securing a certain amount of liquid pressure to be discharged from the ink jet head 200 and the amount of liquid sucked from the nozzle portion, the ink jet head The pressure difference from the pressure of the liquid flowing into the 200 needs to be increased to some extent.

  Therefore, from the viewpoint of efficient suction of the cleaning liquid from the nozzle unit, and from the viewpoint of the flow rate of the cleaning liquid passing through the internal flow path of the inkjet head 200 being a certain flow rate or more suitable for cleaning, the pressure setting value of the first pump 22 Is preferably more than 1 time and not more than 3 times the absolute value of the pressure setting value of the second pump 32.

  In the replacement step, when the cleaning liquid in the cap part 14 decreases and becomes equal to or lower than a predetermined lower limit value, the third pump 17 is operated to supply the cleaning liquid from the cleaning liquid tank 16 to the cap part 14.

  The cleaning liquid preferably has higher foreign matter removal performance (for example, performance for dissolving the ink solidified product). However, if aggregation or the like occurs when the cleaning liquid with high foreign matter removal performance comes into contact with the ink, the concentration of the buffer liquid (a liquid that does not cause aggregation when contacted with the ink, for example, the concentration of the cleaning liquid is lowered. (Buffer solution replacement step), and the buffer solution is replaced with the cleaning solution (cleaning solution replacement step).

  When the ink in the internal flow path of the inkjet head 200 is replaced with the cleaning liquid in the replacement step (step S12), the second pump 32 is stopped and the nozzle portion 281 is cleaned (nozzle portion cleaning step: step S14). ).

  In the nozzle part cleaning step, the foreign matter attached to the nozzle part 281 is removed by the flow of the cleaning liquid from the nozzle part 281 toward the circulation port 256A by operating the first pump 22. The pressure setting value and operation period of the first pump 22 in the nozzle cleaning process depend on the flow path resistance of the internal flow path of the inkjet head 200, the volume of the internal flow path of the inkjet head 200, and the state of the inkjet head (degree of contamination). Set as appropriate. Moreover, the ultrasonic vibration addition process which adds ultrasonic vibration to a nozzle part washing | cleaning process washing | cleaning liquid may be included.

  In this example, the pressure setting value of the first pump 22 in the nozzle part cleaning step is set to be minus 50 kilopascals or more and minus 20 kilopascals or less. The set value of the operation period of the first pump 22 is 1 minute or more and 10 minutes or less. In particular, when the ejection state of the inkjet head 200 is poor (if it is dirty), the pressure setting value of the first pump 22 is adjusted as appropriate within a range of minus 100 kilopascals or more and less than minus 50 kilopascals.

  However, when the pressure setting value of the first pump 22 is set to minus 50 kilopascals or less, the damage given to the ink jet head becomes large. Therefore, the operation period of the first pump 22 is set to be shorter. When the pressure setting value of the first pump 22 is set to minus 100 kilopascals, the operation period of the first pump 22 is set to 30 seconds or less.

  In this way, the pressure set value and the operation period of the first pump 22 are set according to the discharge state of the inkjet head.

  In the nozzle part cleaning process, when the cleaning liquid in the cap part 14 decreases and falls below a predetermined lower limit value, the third pump 17 is operated to supply the cleaning liquid from the cleaning liquid tank 16 to the cap part 14.

  Next, an ink solidified substance dissolving step (step S16) for dissolving the ink solidified substance is executed. In the ink solidified substance dissolving step, the first pump 22 and the second pump 32 are stopped to stop the flow of the cleaning liquid, and the ink solidified substance adhering to the nozzle portion 281 and the circulation flow path (supply flow path) is dissolved in the cleaning liquid. .

  In this example, since the second pump 32 is stopped in the nozzle part cleaning process (step S14), the ink solidified substance dissolving process is performed on the supply channel while the nozzle part cleaning process is being performed on the nozzle part 281. (Step S16) is executed.

  The execution period of the ink solidified substance dissolving step is set to be relatively long when the nozzle portion 281 is dirty, and is set to be relatively short when the nozzle portion 281 is slightly dirty. Further, it is preferable to set the execution period of the ink solidified substance dissolving step in consideration of the degree of contamination of the circulation channel and the supply channel.

  The execution period of the ink solidified product dissolution step can be set to several minutes to about one day (24 hours). In this example, the execution period of the ink solidified substance dissolving step for the nozzle portion 281 and the circulation channel is set to 5 minutes.

  Next, a foreign matter discharging step (step S18) is performed. In the foreign matter discharging step, the first pump 22 and the second pump 32 are operated to discharge the foreign matter removed from the nozzle portion 281, the supply flow path, and the circulation flow path from the circulation port 256 </ b> A.

  In the foreign matter discharging step, foreign matters (substances dissolved in the cleaning liquid and substances floating in the cleaning liquid) that have already been taken into the cleaning liquid are moved to the circulation port 256A by the flow of the cleaning liquid. The pressure setting value of the second pump 32 can be set to be not less than the pressure setting value of the first pump 22 and not more than the pressure setting value of the second pump 32 in the replacement step.

  In this example, the pressure setting value of the first pump 22 in the foreign matter discharging step is minus 25 kilopascals (the same setting value as the pressure setting value of the first pump 22 in the replacement step), and the pressure setting value of the second pump 32 in the foreign matter discharging step. The value is 20 kilopascals (the same set value as the pressure set value of the second pump 32 in the replacement process).

  Further, the operation period of the first pump 22 and the operation period of the second pump 32 in the foreign matter discharging step are set according to the volume of the cleaning liquid stored in the inkjet head 200. That is, in the ink solidified substance dissolving step, all the cleaning liquid stored in the nozzle portion 281 and the internal flow path of the ink jet head 200 is discharged, so that the foreign matter removed in the nozzle portion cleaning step and the ink solidified substance dissolving step remove the cleaning liquid. The ink dissolved in the ink can be discharged to the outside of the inkjet head 200.

  In this example, the operation period of the first pump 22 is set to 5 minutes, and the operation period of the second pump 32 is set to 5 minutes. The operation period of the second pump 32 may be equal to or less than the operation period of the first pump 22 (the second pump 32 may be stopped during the operation of the first pump 22).

  When the foreign matter discharging step is executed, the number of processings in a series of steps of the nozzle portion cleaning step (step S14), the ink solidified material dissolving step (step S16), and the foreign matter discharging step (step S18) is set in advance. It is determined whether or not the number of times has been reached (process number determination step: step S20).

  If it is determined in step S20 that the preset number of times is not reached (No determination), the process proceeds to step S14, and the nozzle part cleaning step, the ink solidified substance dissolving step, and the foreign matter are reached until the preset number of times is reached. A series of steps of the discharging step is executed.

  On the other hand, if it is determined in step S20 that the preset number of times has been reached (YES determination), the process proceeds to step S22, and the cleaning process of the inkjet head 200 is terminated.

  An embodiment including a step (pre-inspection step) of confirming the state of the inkjet head 200 before performing the cleaning process is preferable. According to the aspect including the pre-inspection step, it is possible to set cleaning conditions suitable for the state before the inkjet head 200 is cleaned.

  As an example of the pre-inspection process, a print inspection (inspection of the ejection state of the inkjet head 200) can be given. By grasping the discharge state of the inkjet head 200 before the cleaning process, it is possible to optimize the settings of the pressure setting value, the operation period, the pressure setting value, the operation period, and the like of the first pump 22. is there.

  In the print inspection, an inspection drive voltage supply unit that supplies an inspection drive voltage to the inkjet head 200, an inspection ink receptor that receives ink ejected from the inkjet head 200, and ink that adheres to the inspection ink receptor ( A print inspection apparatus including an ink measurement unit that measures the position, shape, etc. of dots, lines, etc. is applied.

  As an inspection method applicable to the pre-inspection process, observation of the nozzle surface 277 using an optical microscope can be given. In the inkjet head in which the nozzle plate 275 (see FIG. 5) is formed of silicon, the nozzle portion 281 using an infrared microscope and observation of the internal flow path can be mentioned.

  Furthermore, when the nozzle plate 275 is formed of a material that transmits X-rays, observation of the nozzle portion 281 of the inkjet head 200 and the internal flow path using X-rays can be given.

  When the number of nozzles in which ejection abnormality has occurred in the inkjet head 200 is relatively large, the pressure setting value of the first pump 22 is relatively small, the pressure setting value of the second pump 32 is relatively large, The operation period of the first pump 22 and the operation period of the second pump 32 are set relatively long.

  On the other hand, when the number of nozzles in which ejection abnormality has occurred in the inkjet head 200 is relatively small, the pressure setting value of the first pump 22 is set relatively large and the pressure setting value of the second pump 32 is set relatively small. The operation period of the first pump 22 and the operation period of the second pump 32 are set relatively short.

  An embodiment including a step (post-inspection step) for confirming the state of the inkjet head 200 after the cleaning treatment is preferable. By comparing the inspection result of the pre-inspection process and the inspection result of the post-inspection process, it can be determined whether the cleaning is sufficient or the setting of the cleaning conditions is appropriate.

(Explanation of effects)
According to the inkjet head cleaning device 10 and the inkjet head cleaning method configured as described above, the circulation port that includes the circulation channel that communicates with the nozzle portion 281 and communicates with the nozzle portion 281 via the circulation channel. When cleaning the nozzle portion 281 of the inkjet head 200 having a structure including 256A, the cleaning liquid is allowed to flow from the nozzle portion 281 (nozzle opening 280) to the circulation port 256A via the circulation channel, and the cleaning solution is discharged from the circulation port 256A. Therefore, even if foreign matter remains in the circulation flow path, the circulation flow path from the nozzle portion 281 to the circulation opening 256A in the use state of the inkjet head 200 (the state in which ink is ejected from the nozzle opening 280). Since a flow of ink is generated, foreign matter remaining in the circulation flow path returns to the nozzle unit 281. There is no.

  Therefore, the occurrence of abnormal discharge due to the movement of foreign matter remaining in the circulation channel to the nozzle portion 281 is avoided.

  By using the cleaning liquid that is ultrasonically vibrated, the cleaning efficiency can be improved, and the time required for the cleaning process can be shortened. After the cleaning liquid is supplied to the cap unit 14, ultrasonic vibration may be applied to the cleaning liquid of the cap unit 14. After the cleaning liquid is supplied into the inkjet head 200, the piezoelectric element 230 (see FIG. 5), ultrasonic vibration may be applied to the cleaning liquid in the inkjet head 200.

  The period during which ultrasonic vibration is applied to the cleaning liquid can be any period from when the cleaning liquid is supplied to the cap unit 14 or the inkjet head 200 until the cleaning liquid is discharged.

  In general, the higher the temperature of the cleaning liquid, the higher the ability of the cleaning liquid to dissolve the solidified ink, so that a higher cleaning effect can be obtained. Therefore, it is preferable to raise the temperature of the cleaning liquid as long as it does not affect the member with which the cleaning liquid comes into contact.

  By removing in advance the dirt (ink, etc.) adhering to the outer surface (nozzle surface 277, etc.) of the ink jet head 200, the dirt adhering to the outer surface of the ink jet head 200 is mixed into the cleaning liquid, and the dirt of the cleaning liquid becomes nozzle It is prevented from entering the portion 281 (the internal flow path of the inkjet head 200).

  Further, in order to maintain the normal state of the cleaning liquid in the cap unit 14, the cleaning liquid is supplied to the cap unit 14 through the filter 18. The cap unit 14 and the inkjet head 200 (nozzle surface 277) overflow the cleaning liquid from the cap unit 14. The distance between the cap portion 14 and the ink jet head 200 (nozzle surface 277) is preferably adjusted by adjusting the distance between the cap portion 14) and the like.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment described below, the same or similar parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Moreover, the structure of the inkjet head cleaning device 10 according to the first embodiment can be applied to the structure that is not described in the following description.

(Description of overall configuration)
FIG. 8 is an overall configuration diagram of an inkjet head cleaning device 10A according to the second embodiment. The inkjet head cleaning apparatus 10A shown in the figure is a pure water tank 70 (an example of a replacement liquid supply unit) that stores pure water that functions as a replacement liquid for the cleaning liquid, with respect to the inkjet head cleaning apparatus 10 shown in FIG. A switching valve 72 (switching unit) provided in the second channel 30, a fourth channel 74 communicating with the cleaning liquid tank 16, and a fifth channel 76 communicating with the pure water tank 70 (an example of a replacement liquid supply unit) ) Is added.

  Further, the third flow path 15 is connected to the second flow path 30. A switching valve 72 is attached to the other end of the second flow path 30, and the filter 34 is disposed between the connection portion with the third flow path 15 and the switching valve 72. The filter 34 also serves as a filter for the second flow path 30 and the third flow path 15.

  As the switching valve 72, a three-way valve in which a port to be communicated is switched based on a control signal is applied. In the switching valve 72, the other end of the second flow path 30 is connected to the common port 72A, one end of the fourth flow path 74 is connected to the first port 70B, and the fifth flow path 76 is connected to the second port 72C. Are connected at one end. The switching valve 72 functions as a means for switching between communication between the second flow path 30 and the fourth flow path 74 or communication between the second flow path 30 and the fifth flow path 76.

  When the second flow path 30 and the fourth flow path 74 are communicated, the cleaning liquid is supplied from the cleaning liquid tank 16 to the second flow path 30, and when the second flow path 30 and the fifth flow path 76 are communicated, Pure water is supplied from the pure water tank 70 to the two flow paths 30.

(Description of control system)
FIG. 9 is a block diagram showing a schematic configuration of a control system in the inkjet head cleaning apparatus 10A shown in FIG. In the control system of the inkjet head cleaning apparatus 10A shown in FIG. 9, a valve control unit 78 is added to the control system of the inkjet head cleaning apparatus 10 shown in FIG.

  The valve control unit 78 controls the operation of the switching valve 72 based on a command signal sent from the system control unit 50. That is, when the cleaning liquid is supplied from the supply port 252A of the inkjet head 200 and the nozzle opening 280 (see FIG. 5) to the internal channel of the inkjet head 200 via the second channel 30 (see FIG. 8), the common When the port 72A and the first port 70B are communicated and pure water is supplied to the internal flow path of the inkjet head 200, the common port 72A and the second port 72C are communicated.

(Explanation of flowchart)
FIG. 10 is a flowchart showing the flow of the inkjet head cleaning method according to the second embodiment. In the flowchart shown in FIG. 10, a replacement liquid replacement step (step S24) is added after the processing number confirmation step (step S20) and before the end step (step S22) with respect to the flowchart shown in FIG. ing.

  If the inkjet head 200 is attached to the multi-head 201 in a state where the cleaning liquid remains in the nozzle portion 281 and the internal flow path of the inkjet head 200, the cleaning liquid flows out to the inkjet recording apparatus on which the multi-head 201 is mounted.

  If there is a problem with the outflow of the cleaning liquid into the ink jet recording apparatus (for example, the conveyance unit that conveys the recording medium), there is no problem even if the cleaning liquid flows out into the ink jet recording apparatus (the member to which the cleaning liquid adheres is damaged) The cleaning liquid is replaced with a replacement liquid, such as pure water or ink, which is a liquid having a property of preventing the generation of liquid.

  In addition, when a cleaning liquid is mixed in the ink of the ink jet recording apparatus, ink ejection may be affected by a change in ink color or a change in physical property value. The cleaning liquid is replaced with a replacement liquid that is a liquid that does not cause such a problem.

  That is, if it is determined in step S20 of FIG. 10 that the series of processing times has reached the set number of times (YES determination), the process proceeds to step S24 (substitution liquid replacement step). In step S24, the switching valve 72 (see FIG. 8) is operated to connect the fifth flow path 76 and the second flow path 30, and the second pump 32 and the third pump 17 are operated to operate the pure water tank 70. The pure water is supplied from the nozzle portion 281 (see FIG. 5) of the inkjet head 200 to the internal flow path.

  Further, the first pump 22 is operated to discharge the nozzle portion 281 of the inkjet head 200 and the cleaning liquid in the internal flow path to the waste liquid tank 24. When the first pump 22, the second pump 32, and the third pump 17 are operated for a certain period of time, the nozzle portion 281 of the inkjet head cleaning device 10 and the cleaning liquid in the internal flow path are replaced with pure water.

  The operating conditions (pressure set value, operating period) of the first pump 22 and the operating conditions of the second pump 32 are based on the flow path resistance of the internal flow path of the inkjet head 200 and the volume of the internal flow path of the inkjet head 200. It is decided. In this example, the pressure setting value of the first pump 22 is set to minus 25 kilopascals, and the pressure setting value of the second pump 32 is set to 20 kilopascals.

  The operation period of the first pump 22 and the operation period of the second pump 32 are set as follows. First, the first pump 22 and the second pump 32 are operated for 5 minutes. Next, the second pump 32 is stopped and only the first pump 22 is operated for 5 minutes.

  Next, the first pump 22 and the second pump 32 are operated for 5 minutes, the second pump 32 is stopped, and only the first pump 22 is operated for 5 minutes. Then, the stop of the 2nd pump 32 is maintained and the 1st pump 22 is stopped for 5 minutes. The stagnation part of pure water is diffused during a period when the first pump 22 and the second pump 32 are stopped.

  Thereafter, the first pump 22 and the second pump 32 are operated for 5 minutes, the second pump 32 is stopped, only the first pump 22 is operated for 5 minutes, and the first pump 22 and the second pump 32 are operated for 5 minutes. The first pump 22 and the second pump 32 are stopped by operating.

  When the replacement liquid replacement step is completed and the cleaning liquid for the nozzle portion 281 and the internal flow path of the ink jet head 200 is replaced with pure water, the ink jet head cleaning process is ended (step S22).

  In the replacement liquid replacement step, when the deionized water in the cap unit 14 decreases and falls below a predetermined lower limit value, the third pump 17 is operated to supply deionized water from the deionized water tank 70 to the cap unit 14. The

  In this example, pure water is exemplified as the replacement liquid for the cleaning liquid. However, the replacement liquid may be any liquid that does not cause a problem even if it flows out of the ink jet recording apparatus, such as ink or a solvent component of the ink.

(Explanation of effects)
According to the inkjet head cleaning device 10A and the inkjet head cleaning method according to the second embodiment, the cleaning liquid is replaced with a replacement liquid such as pure water after the cleaning using the cleaning liquid. After being attached to the multi-head 201 and mounted on the ink jet recording apparatus, it is possible to prevent the cleaning liquid from flowing into the apparatus, which causes a problem if it flows into the apparatus. Further, no problem occurs even if the replacement liquid flows out into the apparatus.

[Third Embodiment]
(Description of overall configuration)
Next, a third embodiment of the present invention will be described. FIG. 11 is an explanatory view showing a connection example of a gas supply device (an example of a drying unit) applied to the inkjet head cleaning device according to the third embodiment, and FIG. 12 is an explanatory view showing another connection example of the gas supply device. FIG. 13 is an explanatory view schematically showing a drying process by heating.

  In the third embodiment described below, the same or similar parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted. In addition, in the following description, the description omitted is the configuration of the inkjet head cleaning device 10 (inkjet head cleaning method) according to the first embodiment or the inkjet head cleaning device 10A (inkjet head cleaning method) according to the second embodiment. ) Is applicable.

  In the inkjet head cleaning apparatus 10B (inkjet head cleaning method) according to the third embodiment, a drying process is performed on the nozzle portion 281 (see FIG. 5) and the internal flow path of the inkjet head 200.

  The inkjet head cleaning device 10B shown in FIG. 11 has a gas supply device 80, a gas supply device 80, and a gas supply device for connecting the gas supply device 80 and the inkjet head 200 (supply port 252A), in addition to the configuration for cleaning the inkjet head 200 using a cleaning liquid. A flow path 82, a gas discharge flow path 84 connected to the circulation port 256A of the inkjet head 200, a gas discharge pump 86 provided in the gas discharge flow path 84, and a third pressure gauge 85 are provided.

  Although not shown in FIG. 11, the inkjet head cleaning device 10 </ b> B is configured to clean the nozzle portion 281 and the internal flow path of the inkjet head 200 using the cleaning liquid shown in FIG. 1 or 8. .

  When cleaning with the cleaning liquid is performed and the cleaning liquid is replaced with the replacement liquid, the replacement liquid is discharged from the inkjet head 200, and the cap unit 14, the first flow path 20, and the second flow path 30 are removed from the inkjet head 200. It is.

  A gas supply channel 82 (joint 82A) is attached to the supply port 252A of the inkjet head 200, a gas discharge channel 84 (joint 84A) is attached to the circulation port 256A of the inkjet head 200, and a gas supply cap 90 is brought into close contact with the nozzle surface 277.

  The gas supply device 80 is operated to send gas to the gas supply flow path 82, and the gas discharge pump 86 is operated to perform negative pressure (negative pressure based on the pressure of the nozzle portion 281 of the inkjet head 200 and the internal flow path). When the gas is generated, the gas sent out from the gas supply device 80 is supplied from the supply port 252A to the nozzle part 281 and the internal flow path of the ink jet head 200, and is supplied to the nozzle part 281 and the internal flow path of the ink jet head 200. The gas thus discharged is discharged to the outside of the inkjet head 200 via the circulation port 256 </ b> A and the gas discharge channel 84.

  The arrow line illustrated on the upper side of the gas supply flow path 82 in FIG. 11 and the arrow line illustrated on the upper side of the gas discharge flow path 84 represent the gas flow direction.

  With the gas sent out from the gas supply device 80, the moisture in the nozzle part 281 of the inkjet head 200 and the internal flow path is removed. Examples of the gas supplied from the gas supply device 80 to the inkjet head 200 include dry air (dry gas) and nitrogen.

  An example of the gas supply device 80 that supplies dry air includes a configuration including a drying unit that dries (dehumidifies) air (atmosphere), a blower fan, and a delivery port. Examples of the gas supply device 80 for supplying nitrogen include a configuration including a nitrogen tank in which nitrogen is stored, a blower fan, a sending port, and a louver for adjusting the wind direction.

(Description of other aspects)
The inkjet head cleaning device 10C shown in FIG. 12 supplies gas from the nozzle surface 277 (nozzle opening 280 (see FIG. 5)) to the nozzle portion 281 of the inkjet head 200 and the internal flow path, and supplies the supply port 252A and the circulation port. It has the structure which discharges gas from 256A.

  That is, in the inkjet head cleaning device 10C shown in FIG. 12, one end of the gas supply channel 82B is connected to the gas supply device 80, and the gas supply cap 90 is connected to the other end of the gas supply channel 82B. . A pressure pump 86A and a fourth pressure gauge 85A are provided in the gas supply channel 82B.

  A first gas discharge channel 84B (joint 84D) is connected to the circulation port 256A of the inkjet head 200, and a second gas discharge channel 84C (joint 84E) is connected to the supply port 252A of the inkjet head 200.

  When the pressurization pump 86A is operated, a gas flow in the direction indicated by the arrow line is generated in the gas supply channel 82B, the first gas discharge channel 84B, and the second gas discharge channel 84C. The gas sent out from the gas supply device 80 is supplied from the nozzle surface 277 (nozzle opening 280 (see FIG. 5)) to the nozzle portion 281 of the inkjet head 200 and the internal flow path, and the nozzle portion 281 of the inkjet head 200, and The gas is discharged from the internal flow path through the circulation port 256A (first gas discharge flow channel 84B) and the supply port 252A (second gas supply flow channel 82C).

  Combining the configuration of the inkjet head cleaning device 10B shown in FIG. 11 and the configuration of the inkjet head cleaning device 10C shown in FIG. 12, the flow of gas from the supply port 252A to the circulation port 256A, and the circulation port 256A from the nozzle portion 281 It is possible to adopt a configuration that selectively generates a gas flow to (supply port 252A).

  When the configuration of the inkjet head cleaning device 10B shown in FIG. 11 and the configuration of the inkjet head cleaning device 10C shown in FIG. 12 are combined, the first gas discharge channel 84B is branched from the gas discharge channel 84, and the first A control valve (shown with reference numeral 98 in FIG. 14) is attached to the one gas discharge channel 84B.

  A second gas discharge channel 84C is branched from the gas supply channel 82, and a control valve (shown with reference numeral 98 in FIG. 14) is attached to the second gas discharge channel 84C.

  As long as the first flow path 20 and the first pump 22 shown in FIGS. 1 and 8 can use both the cleaning liquid and the gas, the first flow path 20 and the first flow path shown in FIGS. The pump 22 and the like can also be used as the gas discharge channel 84 and the gas discharge pump 86 shown in FIG.

  In the embodiment in which the first flow path 20 and the first pump 22 shown in FIGS. 1 and 8 are combined with the gas discharge flow path 84 and the gas discharge pump 86 shown in FIG. 11, the second flow path 30 is branched. The third flow path 15 is branched and connected to the gas supply device 80.

(Description of drying treatment by heating)
Next, the drying process by heating with respect to the inkjet head 200 after cleaning using the cleaning liquid will be described.

  As shown in FIG. 13, the inkjet head 200 is placed in an oven 92 (an example of a replacement liquid supply unit, a heating device), and heat treatment is performed on the inkjet head 200, so that a nozzle portion 281 (see FIG. 5) and the internal flow path is dried.

  The drying conditions (temperature, relative humidity, operation period, etc.) of the oven 92 are appropriately determined in consideration of the drying state of the inkjet head 200. The drying conditions of the oven 92 in this example are a temperature of 40 ° C., a relative humidity of 10% (RH) or less, and an operation period of 24 hours.

(Description of other drying processes)
In addition to the drying process using gas and the drying process by heating, the inkjet head 200 can be vacuum-dried by setting the internal pressure of the chamber to less than atmospheric pressure (reduced pressure (vacuum) state). Moreover, it is also possible to combine a plurality of different drying processes as appropriate to form a series of drying processes.

(Description of control system)
FIG. 14 is a block diagram showing a schematic configuration of a control system of the inkjet head cleaning apparatuses 10B and 10C according to the third embodiment. 14, parts that are the same as or similar to those in FIGS. 2 and 9 are given the same reference numerals, and descriptions thereof are omitted.

  As shown in FIG. 14, the operation of the drying device 94 is controlled based on a command signal from the system control unit 50. 14 includes the gas supply device 80 shown in FIGS. 11 and 12, the oven 92 shown in FIG. 13, and a vacuum chamber (not shown).

  The pump 96 shown in FIG. 14 includes the first pump 22, the second pump 32, the third pump 17, the gas discharge pump 86 shown in FIG. 11, and the pressurizing pump 86A shown in FIG. included.

  Further, the valve 98 shown in FIG. 14 is a switching valve 72 shown in FIG. 8, the configuration of the inkjet head cleaning device 10B shown in FIG. 11, and the configuration of the configuration of the inkjet head cleaning device 10C shown in FIG. A control valve (not shown) attached to the first gas discharge channel 84B and the second gas supply channel 82C is included.

(Explanation of flowchart)
FIG. 15 is a flowchart of the inkjet head cleaning method according to the third embodiment. 15, parts that are the same as or similar to those in FIGS. 7 and 10 are given the same reference numerals, and descriptions thereof are omitted.

  In the flowchart shown in FIG. 15, a drying step (step S26) is added after the replacement liquid replacement step (step S24) in FIG. 10 and before the end step (step S22).

  In step S24, when the cleaning liquid is replaced with pure water, a drying process is performed. In the drying process, first, gas is supplied from the supply port 252A (see FIG. 11), and the pure water accommodated in the internal flow path of the inkjet head 200 is discharged from the circulation port 256A.

  The pressure set value of the gas discharge pump 86 when discharging pure water accommodated in the internal flow path of the inkjet head 200 is 30 kilopascals, and the operation period of the gas discharge pump 86 is 5 minutes.

  Next, gas is supplied from the nozzle surface 277 (see FIG. 12), and pure water stored in the nozzle portion 281 (see FIG. 5) is discharged from the circulation port 256A. The pressure setting value of the pressurizing pump 86A when discharging pure water stored in the nozzle unit 281 is 30 kilopascals, and the operating period of the pressurizing pump 86A is 5 minutes.

  Next, gas is supplied to the nozzle portion 281. The pressure set value of the pressurizing pump 86A when gas is supplied to the nozzle unit 281 is 30 kilopascals, and the operating period of the pressurizing pump 86A is 20 minutes.

  Thereafter, the supply of gas to the nozzle portion 281 of the inkjet head 200 is continued, and further, gas is supplied from the supply port 252A of the inkjet head 200 to the internal flow path. When the gas is supplied from the supply port 252A to the internal flow path, the pressure setting value of the gas discharge pump 86 and the pressure setting value of the pressure pump 86A are 30 kilopascals, the operation period of the gas discharge pump 86, the pressure pump The operating period of 86A is 60 minutes.

  After the drying process using gas, the inkjet head 200 is put in an oven 92 (see FIG. 13), and a drying process is performed by heating. When the series of drying processes is completed, the process proceeds to step S22, and the cleaning process for the inkjet head 200 is completed.

(Explanation of effects)
According to the inkjet head cleaning apparatuses 10B and 10C and the inkjet head cleaning method according to the third embodiment, the cleaning liquid is dried by drying the nozzle portion 281 and the internal flow path of the inkjet head 200 after the cleaning process using the cleaning liquid. The inkjet head 200 after the used cleaning process can be stored for a long period of time.

[Description of other modes of liquid feeding using a pump]
FIG. 16 is an explanatory diagram of another aspect of liquid feeding using a pump. Liquid feeding by a pump (such as the first pump 22 shown in FIG. 1) is configured to allow liquid to pass through the pump, and a direct pump is used. On the other hand, in the configuration shown in FIG. 16, the inside of the cleaning liquid tank 16 is pressurized using the pump 32A (the configuration corresponding to the second pump 32 and the third pump 17 in FIG. 1) (the cleaning liquid passes through the pump 32A). The cleaning liquid is sent out from the cleaning liquid tank 16.

  FIG. 16 illustrates an example in which the second pressure gauge 31 is disposed in the second flow path 30, but the second pressure gauge 31 may be disposed between the pump 32 </ b> A and the cleaning liquid tank 16. .

  When the cleaning liquid is sent from the cleaning liquid tank 16 to the second flow path 30, the control valve 33 is opened, and when the cleaning liquid is sent from the cleaning liquid tank 16 to the third flow path 15, the control valve 19 is opened.

  The pressurization method of the pump 32A shown in FIG. 16 can be applied as appropriate to the flow path to which the tank is connected.

[Fourth Embodiment]
(Description of overall configuration)
Next, a fourth embodiment of the present invention will be described. FIG. 17 is an explanatory diagram of an inkjet head cleaning method (apparatus) according to the fourth embodiment. In FIG. 17, the same reference numerals are given to the portions shown in FIG. 1 to FIG. In FIG. 17, a part of the inkjet head 200 is not shown.

  In the inkjet head cleaning method described below, cleaning of the inkjet head 200 constituting the multihead 201 is performed in a state where the multihead 201 is mounted on an inkjet recording apparatus (not shown).

  In the multi-head 201 shown in FIG. 17, the supply pipe 252 of the inkjet head 200 is connected to the supply pipe 202, and the circulation pipe 256 is connected to the recovery pipe 203. The ink jet head 200 can be detached from the supply line 252 and the circulation line 256.

  The supply pipe line 252 and the circulation pipe line 256 have a structure capable of closing the connection portion with the ink jet head 200, and can prevent ink leakage when the ink jet head 200 is removed. When removing the inkjet head 200, the circulation of the ink is stopped.

  The ink jet head 200 to be cleaned has the supply pipe 252 and the circulation pipe 256 removed, and an ink jet head cleaning device (see FIGS. 1 and 8, etc.) is attached to perform the cleaning process.

  Since the inkjet head cleaning apparatus and method (except for heat drying using the oven 92 illustrated in FIG. 13 and vacuum drying not illustrated) shown in the first to third embodiments are applied to the cleaning process, The description is omitted here.

  In the case of having a structure for attaching the cleaning device to the position of the supply line 252 and the circulation line 256 indicated by the one-dot broken line with the reference numeral 204 in FIG. 17, without removing the inkjet head 200 from the multi-head 201, The inkjet head 200 can be cleaned.

  FIG. 18 is an explanatory diagram showing an example of an attachment structure to the ink jet head cleaning device provided in the supply conduit 252 and the circulation conduit 256. The attachment structure to the inkjet head cleaning apparatus shown in the figure includes a branch pipe 252B and a valve 252C attached to the supply pipe 252, a branch pipe 256B and a valve 256C attached to the circulation pipe 256.

  For example, when the inkjet head cleaning device 10 of FIG. 1 is attached, the valves 252C and 256C of FIG. 18 are closed, the second flow path 30 of FIG. 1 is connected to the branch pipe 252B, and the branch pipe 256B of FIG. The first flow path 20 is connected.

  FIG. 19A is a schematic view showing a state in which the moisture retention cap 206 is attached to the multi-head 201, and FIG. 19B is a schematic view showing a state in which the cleaning cap 207 is attached to the inkjet head 200. FIG.

  FIG. 20 is a schematic diagram showing a state where the cleaning cap 207 applied to the multi-head to which the cleaning cap 207 shown in FIG.

  The cleaning process of the inkjet head 200 is executed before executing the printing process, waiting for the printing process, changing the setup, and after executing the printing process. Then, as shown in FIG. 19A, the multi-head 201 is provided with a moisture retention cap 206.

  Therefore, when the cleaning process of the inkjet head 200 is executed, the moisture retention cap 206 is removed from the multi-head 201, and the cleaning cap 207 shown in FIG. 19B is attached to the nozzle surface 277 of the inkjet head 200.

  On the other hand, a moisturizing cap 208 is attached to the nozzle surface 277 of the inkjet head 200 that is not to be cleaned. Instead of the moisturizing cap 208, a sheet having durability against ink may be attached to the nozzle surface 277 of the inkjet head 200. For example, a polyimide sheet can be used as a sheet having durability against ink.

  When removing the moisturizing cap 206 from the multihead 201, the multihead 201 may be moved, or the moisturizing cap 206 may be moved.

  FIG. 20 is an explanatory diagram of another aspect of the cleaning cap. The cleaning cap 207 </ b> A shown in the drawing has a narrow interval between the adjacent inkjet heads 200 in the multi-head 201, and it is difficult to attach a cleaning cap having a shape (size) protruding outward from the outer periphery of the nozzle surface. used.

  The cleaning cap 207 </ b> A shown in FIG. 20 has a shape (size) stored inside the nozzle surface 277. A soft material (for example, silicone rubber having high chemical resistance) that does not damage the nozzle surface 277 is applied to a portion (for example, an edge portion) that contacts the nozzle surface 277 of the cleaning cap 207A.

  The inkjet head cleaning apparatus and method shown in this example can also be applied to an apparatus including a plurality of multi-heads 201 (for example, multi-heads for each color).

  Since the apparatus cannot be operated during the cleaning process, it is necessary to prevent the inkjet head 200 (multi-head 201) from drying. Therefore, it is preferable to shorten the processing period by shortening the processing period by increasing the pressure setting value of the pump or omitting the drying process.

[Description of cleaning solution]
The cleaning liquid applied to the inkjet head cleaning apparatus and method shown in this example contains a water-soluble organic solvent, a basic compound, and other additives. Specific examples of the cleaning liquid include the following compositions.

Diethylene glycol monobutyl ether: 25.0 mass percent Diethylene glycol: 10.0 mass percent Imidazole: 0.5 mass percent Benzotriazole: 0.2 mass percent Colloidal silica: 0.2 mass percent Ion-exchanged water: balance In addition, it shows in this example The cleaning liquid applied to the inkjet head cleaning apparatus and method is not limited to the above example, and the substance contained corresponding to the ink used can be changed, added, or deleted. When the cleaning liquid is changed, conditions and parameters applied to the cleaning process are changed as appropriate.

  In the present specification, cleaning of the inkjet head 200 for graphic use is exemplified. However, in addition to the inkjet head (multihead) for graphic use, cleaning of an industrial inkjet head that discharges functional liquid (metal ink, etc.) is also possible. Also, the present invention can be applied.

  The inkjet head cleaning apparatus and method described above can be appropriately changed, added, or deleted without departing from the spirit of the present invention. Moreover, it is also possible to combine each embodiment mentioned above suitably.

[Invention disclosed in this specification]
As will be understood from the description of the embodiments of the invention described in detail above, the present specification includes disclosure of various technical ideas including at least the invention described below.

  (First aspect): Nozzle surface in which nozzle openings are formed, a nozzle portion including nozzle openings, a circulation channel communicating with the nozzle portion, a circulation port communicating with the circulation channel, and a supply for supplying liquid to the nozzle portion An inkjet head cleaning apparatus for cleaning an inkjet head having a supply port connected to a flow path and a supply flow path, wherein a cap for storing a cleaning solution for immersing the nozzle surface of the inkjet head, and a circulation port of the inkjet head A first flow path to be connected, a first pump provided in the first flow path, a cleaning liquid storage section in which the cleaning liquid is stored, and a second flow path connected to the supply port of the inkjet head. When the nozzle portion is cleaned using the second flow path, the second pump provided in the second flow path, and the cleaning liquid stored in the cap section, the first pump is operated to activate the key. The cleaning liquid stored in the nozzle part is sent from the nozzle opening to the first flow path through the circulation flow path and the circulation opening, and the second pump is operated to pass the nozzle from the second flow path through the supply opening and the supply flow path. An ink jet head cleaning apparatus comprising: a pump control unit that sends cleaning liquid to the unit.

  According to the first aspect, the flow of the cleaning liquid from the nozzle part to the circulation port through the circulation flow path and the flow of the cleaning liquid from the supply port to the nozzle part through the supply flow path are present in the nozzle part. Foreign matter to be discharged is discharged to the first flow path through the circulation flow path and the circulation port. In addition, the flow of the cleaning liquid from the supply port to the nozzle unit prevents foreign matter existing in the nozzle unit from moving to the supply flow path and the supply port, thereby preventing occurrence of abnormal discharge due to remaining foreign matter.

  In the first aspect, an aspect including an detaching step of removing the inkjet head from the apparatus and an attaching step of attaching the inkjet head to the apparatus is possible.

  (Second aspect): In the inkjet head cleaning device according to the first aspect, a replacement liquid supply unit that supplies a replacement liquid to the cap part, and a cleaning liquid is supplied from the cleaning liquid supply part to the cap part, or a replacement liquid is supplied to the cap part. And a switching unit that selectively switches whether the replacement liquid is supplied from the supply unit.

  According to the second aspect, by replacing the cleaning liquid in the nozzle portion with the replacement liquid after cleaning with the cleaning liquid, the cleaning liquid is prevented from flowing into the apparatus when the inkjet head after the cleaning process is mounted on the apparatus. The

  (Third Aspect): The inkjet head cleaning apparatus according to the first aspect or the second aspect includes a drying unit that performs a drying process on the inkjet head.

  According to the 3rd aspect, the inkjet head after washing | cleaning can be preserve | saved for a long term by performing a drying process to the inkjet head after washing | cleaning.

  (Fourth aspect): In the inkjet head cleaning device according to the third aspect, the drying unit includes a gas supply device that supplies gas from the nozzle unit, a gas discharge channel that is connected to the circulation port, and a gas discharge channel. And a gas discharge pump control unit that controls the gas discharge pump to generate a gas flow from the nozzle unit to the circulation port.

  According to the 4th aspect, drying of a nozzle part is accelerated | stimulated by the flow of gas by supplying gas to a nozzle part.

  The gas discharge channel of the fourth aspect can be used also as the first channel of the first aspect. Moreover, the gas discharge pump of the 4th aspect can be combined with the 1st pump of the 1st aspect. Furthermore, the gas discharge pump control unit of the fourth aspect can also be used as the pump control unit of the first aspect.

  (5th aspect): The inkjet head washing | cleaning apparatus as described in a 3rd aspect or a 4th aspect is equipped with the heating apparatus which heats and dries an inkjet head.

  According to the fifth aspect, it is possible to dry the internal flow path including the supply flow path, the nozzle part, and the circulation flow path of the ink jet head collectively by performing a drying process by heating.

  (Sixth aspect): The inkjet head cleaning apparatus according to any one of the first to fifth aspects includes an ultrasonic vibration applying unit that ultrasonically vibrates the cleaning liquid.

  According to the sixth aspect, it is possible to improve the cleaning effect by applying ultrasonic vibration to the cleaning liquid.

  (Seventh aspect): In the inkjet head cleaning device according to the sixth aspect, the ultrasonic vibration applying unit includes an ultrasonic vibration element that ultrasonically vibrates the cleaning liquid in the cap unit.

  According to the 7th aspect, the cleaning effect from a nozzle part to a circulation port can be improved by providing an ultrasonic vibration to the cleaning liquid in a cap part.

  (Eighth aspect): In the ink jet head cleaning apparatus according to the sixth aspect or the seventh aspect, the ultrasonic vibration applying unit supplies a driving voltage to the piezoelectric element included in the ink jet head, thereby A drive voltage supply unit for vibrating is provided.

  According to the eighth aspect, since the ultrasonic vibration is applied to the cleaning liquid for the internal flow path of the inkjet head using the piezoelectric element provided in the inkjet head, the cleaning effect of the internal flow path of the inkjet head is expected to be improved. .

  Further, it is possible to apply ultrasonic vibration to the cleaning liquid without separately preparing a device for generating ultrasonic vibration.

  (Ninth aspect): Nozzle surface in which nozzle openings are formed, a nozzle portion including nozzle openings, a circulation channel communicating with the nozzle portion, a circulation port communicating with the circulation channel, and a supply for supplying liquid to the nozzle portion An ink-jet head cleaning method for cleaning an ink-jet head having a supply port communicated with a flow path and a supply flow path, wherein the cleaning liquid is supplied to a cap portion that immerses the nozzle surface of the ink-jet head; The first liquid provided in the first flow path connected to the circulation port of the inkjet head is operated, and the cleaning liquid stored in the cap portion is sent from the nozzle portion to the first flow path through the circulation flow path and the circulation port. The first cleaning liquid feeding step and the cleaning liquid supplied to the second flow path by operating the second pump provided in the second flow path connected to the supply port of the inkjet head are the supply ports. An inkjet head cleaning method comprising a second cleaning liquid flowing step is sent to the nozzle portion through the al supply channel, a.

  According to the ninth aspect, the flow of the cleaning liquid from the nozzle part to the circulation port through the circulation flow path and the flow of the cleaning liquid from the supply port to the nozzle part through the supply flow path are present in the nozzle part. Foreign matter to be discharged is discharged to the first flow path through the circulation flow path and the circulation port. In addition, the flow of the cleaning liquid from the supply port to the nozzle unit prevents foreign matter existing in the nozzle unit from moving to the supply flow path and the supply port, thereby preventing occurrence of abnormal discharge due to remaining foreign matter.

  In a ninth aspect, an aspect includes a replacement liquid supply step of supplying a replacement liquid to the cap portion, and a switching step of selectively switching between supplying the cleaning liquid to the cap portion or supplying the replacement liquid to the cap portion. preferable.

  In the ninth aspect, an aspect including a drying step of performing a drying process on the inkjet head is preferable.

  In the ninth aspect, it is preferable that the drying step includes an air flow generation step for generating a gas flow from the nozzle portion to the circulation port.

  In the ninth aspect, an aspect including a heating step of heating and drying the inkjet head is preferable.

  (Tenth aspect): The inkjet head cleaning method according to the ninth aspect includes an ultrasonic vibration applying step of ultrasonically vibrating the cleaning liquid in the first cleaning liquid feeding step or the second cleaning liquid feeding step.

  According to the tenth aspect, it is possible to improve the cleaning effect by applying ultrasonic vibration to the cleaning liquid.

  In the tenth aspect, the ultrasonic vibration applying step is preferably an aspect in which the cleaning liquid in the cap portion is ultrasonically vibrated.

  In the tenth aspect, the ultrasonic vibration applying step is preferably an aspect in which the piezoelectric element is ultrasonically vibrated by supplying a driving voltage to the piezoelectric element included in the inkjet head.

  (Eleventh aspect): In the inkjet head cleaning method according to the ninth aspect or the tenth aspect, a cleaning process is performed on the inkjet head mounted on the apparatus.

  According to the eleventh aspect, it is not necessary to remove the inkjet head when the inkjet head is subjected to a cleaning process.

  (Twelfth aspect): In the ink jet head cleaning method according to the ninth aspect or the tenth aspect, a cleaning process is performed on the ink jet head removed from the apparatus.

  According to the twelfth aspect, since the cleaning process is performed on the ink-jet head removed from the apparatus, restrictions on the place where the cleaning process is performed are alleviated.

  DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C, 10D ... Inkjet head washing | cleaning apparatus, 14 ... Cap part, 15 ... 3rd flow path, 16 ... Cleaning liquid tank, 17 ... 3rd pump, 20 ... 1st flow path, 22 ... 1st pump 30 ... second flow path, 32 ... second pump, 50 ... system control unit, 52 ... pump control unit, 58 ... ultrasonic vibration generating unit, 70 ... pure water tank, 72 ... switching valve, 76 ... fifth flow Path, 78 ... valve control unit, 80 ... gas supply device, 82, 82A ... gas supply flow path, 84, 84B, 84C ... gas discharge flow path, 86 ... gas discharge pump, 86A ... pressure pump, 92 ... oven, 94 ... Drying device

Claims (12)

Nozzle surface in which a nozzle opening is formed, a nozzle portion including the nozzle opening, a circulation channel communicating with the nozzle unit, a circulation port communicating with the circulation channel, and a supply channel for supplying liquid to the nozzle unit An inkjet head cleaning device for cleaning an inkjet head having a supply port communicating with the supply flow path,
A cap portion for storing a cleaning liquid for immersing the nozzle surface of the inkjet head;
A first flow path connected to the circulation port of the inkjet head;
A first pump provided in the first flow path;
A cleaning liquid reservoir for storing the cleaning liquid;
A second flow path connected to the supply port of the inkjet head, and a second flow path to which the cleaning liquid is supplied;
A second pump provided in the second flow path;
When cleaning the nozzle part using the cleaning liquid stored in the cap part, the first pump is operated to allow the cleaning liquid stored in the cap part to pass from the nozzle opening to the circulation channel and the circulation port. A pump controller that sends the cleaning liquid from the second flow path to the nozzle section via the supply port and the supply flow path by sending the first pump through the first flow path and operating the second pump;
An inkjet head cleaning device comprising: A replacement liquid supply section for supplying a replacement liquid to the cap section;
A switching unit that selectively switches between supplying the cleaning liquid from the cleaning liquid supply unit to the cap unit or supplying the replacement liquid from the replacement liquid supply unit to the cap unit;
An inkjet head cleaning apparatus according to claim 1, comprising:   The inkjet head cleaning apparatus according to claim 1, further comprising a drying unit that performs a drying process on the inkjet head. The drying unit includes a gas supply device that supplies gas from the nozzle unit,
A gas discharge passage connected to the circulation port;
A gas discharge pump provided in the gas discharge flow path;
A gas discharge pump control unit that controls the gas discharge pump to generate a gas flow from the nozzle unit to the circulation port;
An inkjet head cleaning apparatus according to claim 3, comprising:   The inkjet head cleaning apparatus according to claim 3, wherein the drying unit includes a heating device that heats and dries the inkjet head.   The inkjet head cleaning apparatus according to claim 1, further comprising an ultrasonic vibration applying unit that ultrasonically vibrates the cleaning liquid.   The inkjet head cleaning apparatus according to claim 6, wherein the ultrasonic vibration applying unit includes an ultrasonic vibration element that ultrasonically vibrates the cleaning liquid in the cap unit.   The inkjet head according to claim 6, wherein the ultrasonic vibration applying unit includes a drive voltage supply unit that supplies a drive voltage to a piezoelectric element included in the inkjet head and causes the piezoelectric element to vibrate ultrasonically. Cleaning device. Nozzle surface in which a nozzle opening is formed, a nozzle portion including the nozzle opening, a circulation channel communicating with the nozzle unit, a circulation port communicating with the circulation channel, and a supply channel for supplying liquid to the nozzle unit An inkjet head cleaning method for cleaning an inkjet head having a supply port communicating with the supply channel,
A first cleaning liquid supply step in which a cleaning liquid is supplied to a cap portion that immerses the nozzle surface of the inkjet head;
A first pump provided in a first flow path connected to the circulation port of the inkjet head is operated to allow the cleaning liquid stored in the cap portion to flow from the nozzle portion through the circulation flow channel and the circulation port. A first cleaning liquid feeding step to be sent to one flow path;
The second pump provided in the second flow path connected to the supply port of the inkjet head is operated to supply the cleaning liquid supplied to the second flow path from the supply port to the nozzle portion via the supply flow path. A second cleaning liquid feeding process to be sent;
An inkjet head cleaning method comprising:   The inkjet head cleaning method according to claim 9, further comprising an ultrasonic vibration applying step of ultrasonically vibrating the cleaning liquid in the first cleaning liquid feeding process or the second cleaning liquid feeding process.   The inkjet head cleaning method according to claim 9 or 10, wherein a cleaning process is performed on the inkjet head mounted on the apparatus.   The inkjet head cleaning method according to claim 9 or 10, wherein a cleaning process is performed on the inkjet head removed from the apparatus.

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