JP2017196794A - Washing device of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve proper cleaning by preventing ink from being dried and stuck in a liquid discharge path from a cap to a waste liquid tank.SOLUTION: A washing device of a printer includes: a head cap 201 which is detachably provided in an ink jet head 31 and covers the ink jet head in the state where a nozzle is sealed from the outer air in the attached state; a liquid feeding path 206 which supplies washing liquid L2 into the head cap 201; a liquid discharge path 207 which discharges waste liquid stored in the head cap 201; a suction/discharge pump 205 which feeds the washing liquid L2 to the head cap 201 through the liquid feeding path 206 and discharges the waste liquid from the head cap 201 through the liquid feeding path 206; a switching part 210 which selectively connects the liquid feeding path 206 or the liquid discharge path 207 to the head cap 201; and a washing control part 70b which switches the liquid feeding direction by the suction/discharge pump 205 to the head cap 201 direction or waste liquid direction in accordance with selection of the path by the switching part 210.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cleaning device for a printing apparatus that performs printing on printing paper by discharging ink with an inkjet head.

  In general, an inkjet printing apparatus to which an inkjet method is applied prints images, characters, and the like by ejecting ink from a nozzle of an inkjet head toward printing paper based on print data such as image information and character information. In addition, since print data can be printed in color on printing paper using multicolor inks, it is widely used for home use and business use.

  In such an ink jet printing apparatus, a pump is driven from the ink jet head for the purpose of preventing unnecessary matter remaining on or adhering to the ink jet head surface and ink thickened near the nozzle to prevent nozzle clogging. A cleaning process for forcibly discharging ink is performed.

  The ink discharged by cleaning the inkjet head may be dried and fixed in the waste liquid tube from the head cap to the waste liquid tank. In addition, if ink is fixed to the edge of the cap, the sealing performance cannot be secured when the inkjet head is covered with the head cap, and the inside of the nozzle dries, and the sealing performance deteriorates, causing air leakage during ink suction. There was a risk that air bubbles would be mixed into the nozzle. Furthermore, if the ink adheres to the waste liquid tube, the flow path resistance increases and insufficient suction occurs.If the ink is completely clogged, the pressure in the path increases and flows back to the cap side. End up.

  Conventionally, there is a technique disclosed in Patent Document 1 as a technique for preventing or eliminating such ink drying and sticking in a waste liquid tube. In the technique disclosed in Patent Document 1, a recording head storage container that covers and seals the entire nozzle surface is provided to store the nozzle surface in a sealed manner. At this time, the recording head storage container is filled with the cleaning liquid, and the entire nozzle surface of the recording head is stored in the cleaning liquid.

JP 2013-176898 A

  However, in the ink jet printing apparatus described in Patent Document 1, since there is only one path for supplying the cleaning liquid and discharging the waste ink generated by the cleaning, the cleaning liquid collected after use becomes contaminated with the waste ink, and the cleaning is not performed. As the number of times increases, the ink discharged by the cleaning operation of the ink jet head dries and adheres in the drainage path such as a waste tube, and there is a problem that proper cleaning cannot be performed.

  The present invention has been made in view of the above problems, and prevents the ink discharged by the cleaning operation of the ink-jet head from drying and adhering in the drainage path from the cap to the waste liquid tank. An object of the present invention is to provide a cleaning device for a printing apparatus that can realize cleaning.

In order to achieve the above object, a first feature of a printing apparatus cleaning apparatus according to the present invention is a printing apparatus cleaning apparatus having an inkjet head for discharging ink from a nozzle to a printing medium,
A head cap that is detachably provided on the inkjet head and covers the nozzle in a sealed state from the outside air when attached;
A liquid supply path for supplying a cleaning liquid into the head cap;
A drainage path for discharging waste liquid stored in the head cap;
Sucking and discharging means for delivering the cleaning liquid to the head cap through the liquid supply path and discharging the waste liquid from the head cap through the liquid discharge path;
Switching means for selectively connecting the liquid supply path or the drainage path to the head cap;
And a control unit that switches the liquid feeding direction by the suction / discharge unit to the head cap direction or the waste liquid direction in accordance with selection of a path by the switching unit.

  A second feature of the cleaning device according to the present invention is that the control means supplies the cleaning liquid to the suction / discharge means toward the head cap while the switching means connects the liquid supply path to the head cap. The delivery start and the delivery stop of the suction / exhaust means are controlled according to the delivered flow rate.

The third feature of the cleaning apparatus according to the present invention is further provided with a measuring unit that is disposed in the head cap and measures the amount or quality of water in the head cap.
The control means causes the suction / discharge means to send out the cleaning liquid in the direction of the head cap while the switching means connects the liquid supply path to the head cap, and according to the measurement result of the measurement means, the suction / discharge It is to control the start and stop of sending of the means.

According to a fourth aspect of the cleaning apparatus of the present invention, the switching unit has a function of closing a connection path from the liquid supply path to the head cap,
The control means causes the suction / discharge means to send out the cleaning liquid in the direction of the head cap, stops the delivery by the suction / discharge means while the cleaning liquid is filled in the connection path, and connects the connection by the switching means. The purpose is to control the path to be blocked.

A fifth feature of the cleaning apparatus according to the present invention is that the switching means is
With respect to the connection path from the liquid supply path or the drainage path to the head cap, the liquid supply path and the drainage path are arranged at connection points,
A joint channel that interconnects the connection path, the liquid feeding path, and the drainage path;
Comprising three closing valves provided at connection points of the connection path, the liquid supply path and the drainage path to the combined flow path,
By opening one closing valve of the liquid feeding path or the drainage path and closing the other closing valve of the liquid feeding path or the drainage path, and opening the closing valve of the connection path, Selectively connecting the liquid path or the drainage path to the connection path;
By closing all the stop valves, the connection path, the liquid supply path, and the drainage path are closed.

A sixth feature of the cleaning apparatus according to the present invention is that the measurement means is provided on a bottom surface in the head cap, and generates ultrasonic waves upward from the bottom surface.
Detecting means for detecting the reflected wave of the generated ultrasonic wave,
The control means measures the amount of water based on the arrival time of the reflected wave, measures the water quality based on the amount of attenuation of the amplitude of the reflected wave, and starts sending and receiving the intake / exhaust means according to these measurement results. The purpose is to control the sending stop.

  According to the first feature of the ink jet printing apparatus according to the present invention, the cleaning liquid is supplied to the head cap side while the liquid feeding path is connected to the head cap, or the drain path is connected to the head cap. In addition to cleaning the inkjet head by switching the liquid feeding direction by the suction / discharge means according to the selection of the path by the switching means, such as discharging the waste liquid to the drain side, the waste liquid tank in the head cap and from the head cap The drainage path up to can also be cleaned. As a result, the ink discharged by the head cleaning operation is prevented from drying and adhering in the drainage path from the cap to the wastewater tank, and it is avoided that insufficient suction or backflow occurs and proper cleaning cannot be performed. can do.

  According to the second feature of the cleaning apparatus of the present invention, when supplying the cleaning liquid from the liquid supply path toward the head cap, by controlling the start and stop of the discharge of the suction / discharge means according to the flow rate sent, for example, In addition to ink suction when cleaning the inkjet head, the cleaning liquid is repeatedly sucked and discharged several times to rinse the path, the cleaning liquid supplied into the head cap is overflowed, and the head cap and the upper edge are cleaned, etc. Various cleaning methods can be performed.

  According to the third feature of the cleaning apparatus according to the present invention, by using the measuring means for measuring the water amount or the water quality in the head cap, it is not affected by the change in the flow rate due to the contamination or deterioration of the liquid feeding path. The various cleaning methods described above can be performed with higher accuracy.

  This measurement means includes a method for detecting reflected waves of ultrasonic waves, liquid level detection by a laser displacement meter, dirt detection by the amount of light received by a transmission sensor, liquid level / dirt detection by change in dielectric constant, float sensor Various methods such as liquid level detection using a (magnet) and liquid level detection using a weight sensor (pressure sensitive) can be employed.

  According to the fourth feature of the cleaning device of the present invention, the connection path is closed while the connection path is filled with the cleaning liquid, so that the connection path that is also a waste liquid path is filled with the cleaning liquid for a long time. The ink remaining in the path can be prevented from drying and sticking for a long time.

  According to the fifth feature of the cleaning apparatus of the present invention, each shut-off valve is appropriately opened or closed at the connection point where the liquid supply path and the drainage path are connected to the connection path to the head cap. As a result, the various cleaning methods described above can be implemented, and the connection path can be blocked for the long-term storage described above.

  As a mechanism of this shut-off valve, a substantially L-shaped connection path that can selectively connect either the liquid supply path or the drain path to the connection path is rotated in a watertight state in the combined flow path. Provided inside the rotating body, and by changing the rotation angle of this rotating body with a motor, etc., either the liquid supply path or the drainage path is selectively connected to the connection path, or all paths are blocked. A so-called three-way cock can be employed. Further, as another mechanism of the closing valve, three closing valves may be electronically controlled as electromagnetic valves.

  According to the sixth feature of the cleaning apparatus of the present invention, as the measuring means, an ultrasonic wave is generated from the bottom surface in the head cap toward the upper water surface, and the reflected wave is detected. The amount and quality of the cleaning liquid in the head cap are measured based on the arrival time and the amplitude attenuation amount, and the start and stop of the cleaning liquid are controlled. Thereby, both the amount of water and water quality can be detected collectively with a simple detection structure.

  According to this feature, an overflow condition is detected when the reflected wave is temporally saturated while the cleaning liquid is being sent out, or path contamination is detected due to a change in the amplitude of the reflected wave at the time of rinsing by sending the cleaning liquid. Or by generating strong ultrasonic waves to stir the inside of the cap to scrape ink stains, or by generating stronger ultrasonic waves, the cleaning liquid can be ejected above the liquid level, and the inkjet head and nozzle guard Various operations such as cleaning the gap can be performed.

1 is a configuration diagram illustrating a configuration of an inkjet printing apparatus according to a first embodiment of the present invention. It is a block diagram which shows the inkjet head and maintenance unit which concern on 1st Embodiment. It is a block diagram which shows the switching part which concerns on 1st Embodiment. (A)-(c) is a block diagram which shows the switching part which concerns on 1st Embodiment. It is the figure which showed the function structure of the inkjet printing apparatus which concerns on 1st Embodiment. (A) And (b) is explanatory drawing which showed the connection state of each path | route which concerns on 1st Embodiment. (A) is explanatory drawing which showed the state at the time of the cap washing | cleaning process which concerns on 1st Embodiment, The same figure (b) is explanatory drawing which showed the state at the time of a long-term storage process. It is the flowchart which showed the whole process sequence of the maintenance process in the inkjet printing apparatus which concerns on 1st Embodiment. It is the flowchart which showed the process sequence of the cleaning process which concerns on 1st Embodiment. It is the flowchart which showed the process sequence of the path | route cleaning process which concerns on 1st Embodiment. It is the flowchart which showed the process sequence of the long-term storage process which concerns on 1st Embodiment. It is a block diagram which shows the measurement part which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In one embodiment of the present invention, line-type image formation is provided in which a plurality of inkjet heads each having a large number of nozzles are provided, and black or color ink is ejected from each inkjet head and printing is performed on a printing sheet line by line. The apparatus will be described as an example.

(Overall configuration of inkjet printing apparatus)
The structure of the inkjet printing apparatus 1 which is one Embodiment of this invention is demonstrated in detail. FIG. 1 is a configuration diagram illustrating a configuration of an inkjet printing apparatus 1 according to an embodiment of the present invention. FIG. 2 is a configuration diagram illustrating configurations of an inkjet head 31 and a maintenance unit 200.
As shown in FIG. 1, the inkjet printing apparatus 1 includes a side paper feed unit 10, an internal paper feed unit 20, a printing unit 30, a paper discharge unit 40, and a reversing unit 50.

  The side paper feeding unit 10 includes a paper feeding table 11 on which the printing paper W is stacked, and a primary paper feeding unit 12 that conveys only the uppermost printing paper W from the paper feeding table 11 onto the paper feeding conveyance path FR. And a secondary paper feeding unit 14 for carrying the printing paper W conveyed by the primary paper feeding unit 12 onto the circulation conveyance path CR.

  The internal paper feed unit 20 includes a paper feed tray 21a on which the print papers W are stacked, and a primary paper feed unit 22a that transports only the uppermost print paper W from the paper feed tray 21a onto the paper feed transport path FR. The printing paper W is laminated, the primary paper supply unit 22b that conveys only the uppermost printing paper W from the paper feeding base 21b onto the paper feeding conveyance path FR, and the printing paper W. Sheet feeding table 21c, a primary sheet feeding unit 22c that conveys only the uppermost printing sheet W from the sheet feeding table 21c onto the sheet feeding conveyance path FR, and a sheet feeding table 21d on which the printing sheets W are stacked. And a primary paper feed section 22d for transporting only the uppermost printing paper W from the paper feed tray 21d onto the paper feed transport path FR.

In this way, the printing paper W is conveyed from the side paper feeding unit 10 and the internal paper feeding unit 20 to the secondary paper feeding unit 14, and further, the printing paper W is also conveyed from the reversing unit 50 described later.
Therefore, in front of the secondary paper feeding unit 14 in the transport direction, the transport path of the fed printing paper W and the path through which the paper on which one side is printed are circulated and merged are merged A point exists. Based on this merging point, the path on the paper feed mechanism side is referred to as a paper feed conveyance path FR, and the other path is referred to as a circulation conveyance path CR.

  The printing unit 30 is provided on a paper transport unit 133 that transports the print paper W on the circulation transport path CR, and an upper portion of the paper transport unit 133. C (cyan), M (magenta), Y (yellow), K A plurality of ink jet heads 31 arranged in a staggered manner for each (black) ink color, and a maintenance unit 200 that performs a cleaning process of the ink jet heads 31 are provided.

  The inkjet head 31 is a member that discharges ink from the nozzles to the print medium, and is arranged in parallel with the print paper W on the paper transport unit 133 on the lower surface side of the recording head main body 32 as shown in FIG. A nozzle surface is provided. On this nozzle surface, a nozzle plate 33 is formed in which a plurality of nozzles for ejecting certain ink droplets downward according to image data are formed. Although details of the recording head main body 32 are not shown, an ink chamber for supplying ink to each nozzle and an ejection mechanism using, for example, a piezoelectric element are provided.

  The paper transport unit 133 includes an annular platen belt 132, and the printing paper W fed by the secondary paper feed unit 14 is placed on the platen belt 132 by a suction fan 131 (described later) installed in the platen belt 132. The ink is sucked by the ink, and is printed in line units by the ink ejected from the inkjet head 31 while being transported on the transport path at a predetermined transport speed.

The printing paper W printed by the printing unit 30 is conveyed on the circulation conveyance path CR in the housing by a conveyance roller or the like disposed on the circulation conveyance path CR. A switching mechanism 43 is provided on the circulation conveyance path CR to switch between guiding the printing paper W conveyed on the circulation conveyance path CR to the paper discharge unit 40 or recirculating it on the circulation conveyance path CR. Yes.
The switching mechanism 43 switches the printing paper W in order to guide it to one of a paper discharge unit 40 and a reversing unit 50 described later.

  When a predetermined time has elapsed after printing of the printing paper W, it is necessary to remove unnecessary materials such as dry ink on the surface of the inkjet head. Therefore, a maintenance unit 200 that performs a cleaning process of the inkjet head 31 is disposed below the paper transport unit 133 for the purpose of removing unnecessary materials. During the cleaning process, the paper transport unit 133 moves in the X1 direction and the maintenance unit 200 moves in the Y1 direction, so that the maintenance unit 200 approaches the ink jet head 31 and the head cap 201 is further lifted to perform ink jetting. The head 31 is mounted and a cleaning process is executed.

  The paper discharge unit 40 includes a tray-shaped paper discharge table 41 protruding from the casing of the inkjet printing apparatus 1 and a pair of paper discharge rollers 42 that guide the print paper W to the paper discharge table 41. Then, the printing paper W guided to the paper discharge unit 40 by the switching mechanism 43 is conveyed to the paper discharge table 41 by the paper discharge roller 42, and is stacked on the paper discharge table 41 with the printing surface facing down.

  The reversing unit 50 reverses the printing paper W, and the reversing unit 51 conveys the printing paper W from the circulation conveyance path CR to the reversing table 51 or conveys the printing paper W from the reversing table 51 onto the circulation conveyance path CR. And a roller 52.

  The printing paper W guided to the reversing unit 50 by the switching mechanism 43 is transported from the circulation transport path CR to the reversing table 51 by the reversing roller 52, and is transported from the reversing table 51 to the circulation transport path CR after a predetermined time. Thus, the front and back are reversed with respect to the circulation conveyance path CR. The printing paper W whose front and back are reversed is conveyed toward the printing unit 30 on the circulation conveyance path CR by a plurality of rollers such as a conveyance roller 53 provided on the circulation conveyance path CR.

(Configuration of maintenance unit 200)
Next, the configuration of the maintenance unit 200 will be described. 3 and 4 are configuration diagrams illustrating the switching unit according to the first embodiment. As shown in FIG. 2, the maintenance unit 200 switches between a pan 200a, a head cap 201 provided on the pan 200a, an air release valve 203, an intake / exhaust pump 205, a cleaning liquid tank 208, and a waste liquid tank 209. Part 210.

  Among these, at least the head cap 201 is provided for each inkjet head 31. However, the suction / discharge pump 205, the cleaning liquid tank 208, the waste liquid tank 209, the air release valve 203, and the switching unit 210 are provided for each of the plurality of caps 111 when each operation can be made common for each inkjet head 31. It is good also as a structure. Hereinafter, for convenience of explanation, an example of a configuration in which one inkjet head 31 is provided for each will be described.

The pan 200a has a box shape that opens upward, and includes a bottom surface that is substantially parallel to the nozzle surface, and serves as a tray for the leaked ink.
The head cap 201 is a member that is detachably attached to the ink-jet head 31 and covers the nozzle in a sealed state from the outside air in the mounted state. The head cap 201 is formed in a box shape opened upward, and covers the nozzle surface from below to seal the region of the nozzle surface including all the nozzles included in one inkjet head 31 from below. The opening end of the head cap 201 is provided with a sealing member made of an elastic body or a flexible body for forming a liquid-tight and air-tight seal by being elastically pressed by the nozzle plate 33 over the entire circumference. Yes.

  The head cap 201 is provided with cap driving means for moving up and down in order to selectively switch the vertical position of the head cap 201. The cap driving means includes, for example, appropriate mechanical, electromagnetic, and fluid raising / lowering means. The head cap 201 is moved up and down in the vertical direction with respect to the inkjet head 31, and the head cap 201 seals the nozzle surface. The state to stop and the state to release the sealing can be switched. Note that the inkjet head 31 side may be moved up and down with respect to the head cap 201.

  On the lower surface of the head cap 201, an air introduction pipe 202 for opening the suction space from the head cap 201 to the atmosphere is provided. The atmosphere introduction pipe 202 has one end connected to the head cap 201 and the other end communicating with the atmosphere. An air release valve 203 is provided in the middle of the air introduction pipe 202. The atmosphere release valve 203 opens and closes the opening of the atmosphere introduction pipe 202 that communicates with the atmosphere, and can be selected between an open state and a closed state under the control of the control unit 70. When the atmosphere release valve 203 is opened, the head cap 201 is opened to the atmosphere. Although the structure of the air release valve 203 is not particularly limited, for example, an electromagnetic valve or the like can be employed.

A connection path 204 is connected to the lower surface of the head cap 201. The connection path 204 is a pipe that supplies the cleaning liquid L <b> 2 to the head cap 201 or discharges the waste liquid in the head cap 201 to the waste liquid tank 209.
The head cap 201 communicates with the cleaning liquid tank 208 via the connection path 204 and a liquid supply path 206 described later, and communicates with the waste liquid tank 209 via the connection path 204 and a liquid discharge path 207 described later.

  The cleaning liquid tank 208 is a tank that stores the cleaning liquid L2 supplied into the head cap 201. The cleaning liquid L2 in the cleaning liquid tank 208 is supplied into the head cap 201 through the liquid supply path 206 and the connection path 204. A liquid supply path 206 is connected to the cleaning liquid tank 208. The liquid supply path 206 is a pipe for supplying the cleaning liquid L <b> 2 into the head cap 201.

  The waste liquid tank 209 is a tank that stores the waste liquid L1 discharged from the head cap 201. The waste liquid is discharged from the head cap 201 into the waste liquid tank 209 via the drain path 207 and the connection path 204. A drainage path 207 is connected to the waste liquid tank 209. The drainage path 207 is a pipe for discharging the waste liquid stored in the head cap 201.

  In the present embodiment, each of the connection path 204, the liquid supply path 206, and the drainage path 207 is the liquid supply path 206 with respect to the connection path 204 from the liquid supply path 206 or the drainage path 207 to the head cap 201. And the connection point P1 to which the drainage path 207 is connected is formed and connected to each other.

  A switching unit 210 is formed at the connection point P1. As shown in FIG. 3, the switching unit 210 is a so-called joint channel 211 that interconnects the connection path 204, the liquid supply path 206, and the drainage path 207, and the so-called all-paths can be closed inside the joint path 211. The three-way cock 212 is configured.

  As a mechanism of the switching unit 210, the connection path 212 a of the three-way cock 212 is provided inside the rotating body 213 that is rotated in a watertight state in the combined flow path 211, and the rotation angle of the rotating body 213 is changed by a motor or the like. Thus, three stop valves are formed at connection points of the connection path 204, the liquid supply path 206, and the drainage path 207 with respect to the combined flow path 211.

  As shown in FIGS. 4A and 4B, the switching unit 210 rotates and opens one closing valve of the liquid feeding path 206 or the drainage path 207 and the other of the liquid feeding path 206 or the drainage path 207. The liquid supply path 206 or the drainage path 207 is selectively connected to the connection path 204 by closing the closed valve and opening the connection path 204. Moreover, as shown in FIG.4 (c), the connection path | route 204, the liquid feeding path | route 206, and the drainage path | route 207 are obstruct | occluded by rotating so that all the closing valves may be closed.

  As the switching unit 210, a substantially L-shaped connection path that can selectively connect either the liquid supply path 206 or the drainage path 207 to the connection path 204 may be used. As a mechanism of the valve, three closing valves may be electronically controlled as electromagnetic valves.

  The suction / discharge pump 205 sends the cleaning liquid L2 to the head cap 201 through the liquid feeding path 206 and discharges the waste liquid from the head cap 201 through the liquid feeding path 206. A suction / discharge pump 205 is provided in the connection path 204. As the suction / discharge pump 205, a fluid pump having an appropriate configuration, such as a tube pump, can be used. In the present embodiment, the suction amount can be varied under the control of the control unit 70.

Furthermore, the maintenance unit 200 is provided with a purge pump 35 that supplies air into the inkjet head in order to pressurize the interior of the inkjet head and discharge ink from the nozzles. The discharge of ink from the inkjet head by the pressure of the purge pump 35 is called a purge operation.
When the ink is discharged from the inkjet head by this purge operation, the ink is stored inside the head cap 201, and the nozzle is immersed in the stored ink.

(Functional configuration of inkjet printing apparatus 1)
Next, the functional configuration of the inkjet printing apparatus 1 according to the present embodiment will be described. FIG. 5 is a diagram illustrating a functional configuration of the inkjet printing apparatus 1 according to the present embodiment, and FIGS. 6A and 6B are explanatory diagrams illustrating connection states of respective paths according to the first embodiment. It is. FIG. 7A is an explanatory diagram showing a state during cap cleaning processing according to the first embodiment, and FIG. 7B is an explanatory diagram showing a state during long-term storage processing.

  As shown in FIG. 5, the inkjet printing apparatus 1 includes an external interface unit 71, a unit driving unit 139, a paper transport unit 133, a maintenance unit 200, a printing unit 30, an operation unit 60, and a control unit 70. It has. Among these configurations, the paper transport unit 133, the maintenance unit 200, and the printing unit 30 have been described above, and a description thereof will be omitted.

The unit driving unit 139 drives the paper transport unit 133 and the maintenance unit 200 based on an instruction from the control unit 70.
The external interface unit 71 is an interface device for connecting to the terminal 100 via the network 9 and supplies, for example, print data transmitted from the terminal 100 to the control unit 70. The measuring unit 72 is a device that measures time.

  The operation unit 60 includes a display / input panel (not shown), a start key for starting reading and printing, a stop key for stopping reading and printing, and a numeric keypad for inputting the number of prints (whichever And an operation signal based on a user operation is supplied to the control unit 70.

  The display / input panel of the operation unit 60 includes a pressure-sensitive or electrostatic transparent touch panel disposed on the front surface and a liquid crystal display panel disposed on the back surface of the touch panel for displaying various display screens (none of which are shown). ). The user touches the surface of the touch panel directly with his / her finger while looking at the display screen of the liquid crystal display panel, and sets a standby time for automatically starting the cleaning process and a button for executing the cleaning process. In order to prevent the ink jet head from drying, the paper transport unit 133 is automatically moved to the standby position, and further, the standby position movement setting time for moving the maintenance unit 200 to the maintenance position, and the cleaning setting for executing the cleaning process. Various buttons such as a setting button for setting time can be pressed.

  The control unit 70 performs central control of the inkjet printing apparatus 1 and controls the side paper feed unit 10, the internal paper feed unit 20, the printing unit 30, the paper discharge unit 40, and the reversing unit 50. Moreover, the control part 70 is provided with the drive control part 70a and the washing | cleaning control part 70b on the function.

  When executing the cleaning process, when the maintenance preparation is not completed, the drive control unit 70a moves the paper transport unit 133 to the standby position and moves the maintenance unit 200 to the maintenance position. In addition, when the cleaning process is completed, the drive control unit 70a moves the maintenance unit 200 to the standby position and moves the paper transport unit 133 to the printing position.

  The cleaning control unit 70b performs the path cleaning process and the cap cleaning process by switching the liquid feeding direction by the suction / discharge pump 205 to the head cap direction or the waste liquid direction according to the selection of the path by the switching unit 210. The path cleaning process is for cleaning the path from the head cap to the waste liquid tank 209, and the cap cleaning process is for cleaning the edge of the cap.

  As the path cleaning process and the cap cleaning process, the cleaning control unit 70b is configured so that the switching unit 210 connects the liquid supply path 206 to the head cap 201 as shown in FIG. ), The suction / discharge pump 205 is caused to send the cleaning liquid L2 toward the head cap 201. At this time, in the path cleaning process, an amount of cleaning liquid that fills the head cap 201 with the cleaning liquid L2 is sent out. On the other hand, in the cap cleaning process, as shown in FIG. 7A, an amount of cleaning liquid overflowing from the upper surface of the head cap 201 is sent out.

  In addition, as shown in FIG. 4B, the cleaning control unit 70b is configured so that the suction / discharge pump as shown in FIG. 6B while the switching unit 210 connects the drainage path 207 to the head cap 201. In 205, the waste liquid L1 is sent in the direction of the waste liquid tank 209.

  In addition, the cleaning control unit 70b performs control so that the connection path 204 is filled with the cleaning liquid L2 during long-term storage. Specifically, the cleaning control unit 70b causes the suction / discharge pump 205 to send the cleaning liquid L2 in the direction of the head cap 201, and while the connection path 204 is filled with the cleaning liquid L2, stops the pumping by the suction / discharge pump 205, As shown in FIG. 4C, the switching unit 210 controls the connection path 204 to be closed, and as shown in FIG. 7B, the state in which the cleaning liquid L2 is filled in the connection path 204 is maintained. Let

The cleaning control unit 70b controls the start and stop of delivery of the suction / discharge pump 205 according to the delivered flow rate. In this embodiment, the drive time of the suction / exhaust pump 205 is measured by the measuring unit 72, and the start and stop of delivery of the suction / exhaust pump 205 are controlled by the measurement time. (Operation during maintenance processing)
Next, the operation | movement at the time of the maintenance process of the inkjet printing apparatus 1 provided with the above structure is demonstrated.

(1) Overall processing First, overall processing during maintenance processing will be described. FIG. 8 is a flowchart showing an overall processing procedure of maintenance processing in the inkjet printing apparatus 1 according to the present embodiment. As shown in the figure, the control unit 70 determines whether or not a maintenance process is requested (step S101). The request for the maintenance process can be performed manually by a user who is supplied with an operation signal for requesting the execution of the cleaning process from the operation unit 60, or can be automatically performed. In the case of being automatic, it includes the elapse of a predetermined time, printing a predetermined number of times, or detection of a dirt sensor.

When it is determined that the maintenance process is not requested (“N” in S101), the process waits until an operation signal for requesting the execution of the cleaning process is supplied.
When an operation signal for requesting execution of the maintenance process is supplied, the drive control unit 70a of the control unit 70 moves the paper transport unit 133 to the standby position (step S102). Specifically, the drive control unit 70a controls the unit drive unit 139 so as to move the paper transport unit 133 in the X1 direction shown in FIG.

  Next, the drive control unit 70a of the control unit 70 moves the maintenance unit 200 to the maintenance position (step S103). Specifically, the drive control unit 70a controls the unit drive unit 139 to move the maintenance unit 200 in the Y1 direction illustrated in FIG. As a result, the maintenance unit 200 approaches the inkjet head 31, and the head cap 201 is further raised by the drive system (not shown) and attached to the inkjet head 31.

  In this state, the cleaning control unit 70b executes a cleaning process for the head cap 201 (S104). Thereafter, the drive controller 70a lowers the head cap 201 to release the sealed state of the inkjet head 31, and controls the unit driver 139 so that the maintenance unit 200 moves in the Y2 direction shown in FIG. Then, it is separated from the inkjet head 31 (S105).

  Thereafter, the cleaning control unit 70b executes a path cleaning process (S106) and a cap cleaning process (S107). Furthermore, the control unit 70 determines whether a long-term storage process is requested (step S108). The request for long-term storage processing is automatic when triggered by a user manual operation to which an operation signal for requesting execution of long-term storage processing is supplied from the operation unit 60 or when the main power of the inkjet printing apparatus 1 is turned off. There is a case.

  When the long-term storage process is requested, the operation path cleaning process is executed (S111), the cap cleaning process is executed, and a standby state is entered. On the other hand, when the long-term storage process is not requested, the drive control unit 70a moves the maintenance unit 200 to the standby position (step S109). Specifically, the drive control unit 70a controls the unit drive unit 139 to move the maintenance unit 200 in the Y2 direction illustrated in FIG. Further, the drive control unit 70a moves the paper transport unit 133 to the printing position (step S110). Specifically, the drive control unit 70a controls the unit drive unit 139 to move the paper transport unit 133 in the X2 direction shown in FIG.

(2) Cleaning Process Next, the cleaning process in step S104 included in the above-described maintenance process will be described. FIG. 9 is a flowchart showing a processing procedure of the cleaning process according to the present embodiment.

  In the cleaning process, the cleaning control unit 70b drives the switching unit 210 to connect the drainage path 207 to the head cap 201 (S201). Next, the cleaning control unit 70b switches the liquid feeding direction by the suction / discharge pump 205 to the waste liquid direction (S202).

  Then, the cleaning control unit 70b performs a normal cleaning operation (S203). The normal cleaning operation includes a suction operation, an empty suction operation, a wipe operation, and a spit operation. The suction operation is an operation in which the air release valve 203 is closed and the suction / discharge pump 205 is driven to forcibly discharge ink from the inkjet head. The idle suction operation is an operation of operating the intake / exhaust pump 205 in the low speed mode with the atmosphere release valve 203 opened. The wiping operation is an operation in which the wiping means is brought into sliding contact with the periphery of the ejection port of the inkjet head 31. The spit operation is a preliminary discharge operation that discharges ink and removes thickened ink or the like from the nozzles.

(3) Path cleaning process and cap cleaning process Next, the path cleaning process and the cap cleaning process in step S104 will be described. FIG. 10 is a flowchart showing the procedure of the route cleaning process according to the present embodiment. Here, the route cleaning process and the cap cleaning process are different from each other only in that the amount of water for sending the cleaning liquid L2 in the direction of the head cap 201 is different.

  First, the cleaning control unit 70b rotates the switching unit 210 (S301) to connect the liquid feeding path 206 to the head cap 201. Next, the cleaning control unit 70b switches the liquid feeding direction by the suction / discharge pump 205 to the head cap direction (S302).

  Then, as shown in FIG. 6A, the cleaning control unit 70b drives the suction / discharge pump 205 while the switching unit 210 connects the liquid supply path 206 to the head cap 201, and moves toward the head cap 201. The cleaning liquid L2 is sent out (S303). Thereafter, the cleaning control unit 70b determines whether or not a predetermined amount of water has been fed (S304). In the present embodiment, the cleaning control unit 70b measures the time during which the suction / discharge pump 205 is driven and the cleaning liquid is sent out by the measuring unit 72, and the amount of water is determined by the driving time that is the measurement result. In the path cleaning process, it is determined whether or not the time t1 is reached so that the cleaning liquid L2 fills the head cap 201. On the other hand, in the cap cleaning process, it is determined whether or not the time t2 at which the cleaning liquid L2 overflows from the head cap 201 has been reached. The time t1 and the time t2 are recorded in advance in a memory or the like in the control unit 70.

  When the time t1 or the time t2 is not reached (“N” in S304), the suction / discharge pump 205 is driven to continue sending the cleaning liquid. When the time t1 or the time t2 is reached (“Y” in S304), the suction / discharge pump 205 is stopped and the delivery of the cleaning liquid is stopped (S305).

The cleaning control unit 70b rotates the switching unit 210, connects the drainage path 207 to the head cap 201 (S306), and switches the liquid feeding direction by the suction / discharge pump 205 to the waste liquid direction (S307). Then, the cleaning control unit 70b drives the suction / discharge pump 205 while the switching unit 210 connects the drainage path 207 to the head cap 201, and the waste liquid stored in the head cap 201 is discharged. (S308).
Thereafter, the cleaning control unit 70b determines whether or not the path cleaning process has been executed a predetermined number of times (S309), and the processes from step S301 to step 308 are repeatedly executed until the predetermined number of times is reached. After executing the predetermined number of times, the route cleaning process is terminated.

(4) Long-Term Storage Process Next, the long-term storage process in step S104 will be described. FIG. 11 is a flowchart showing a processing procedure of long-term storage processing according to the present embodiment.

First, the drive control unit 70a controls the unit driving unit 139 so that the maintenance unit 200 moves in the Y1 direction shown in FIG. 1 to bring the maintenance unit 200 close to the inkjet head 31, and then the inkjet head 31. The head cap 201 is attached to the head (S401).
The cleaning control unit 70b rotates the switching unit 210 (S402), and connects the liquid feeding path 206 to the head cap 201. Next, the cleaning control unit 70b switches the liquid feeding direction by the suction / discharge pump 205 to the head cap direction (S403).

  Then, as shown in FIG. 6A, the cleaning control unit 70b drives the suction / discharge pump 205 while the switching unit 210 connects the liquid supply path 206 to the head cap 201, and moves toward the head cap 201. The cleaning liquid L2 is sent out (S404). Thereafter, the cleaning control unit 70b determines whether or not a predetermined amount of water has been fed according to the measurement result by the measurement unit 72 (S405). Here, the cleaning control unit 70b determines whether or not it has reached a time t3 for sending out an amount of water to the extent that the cleaning liquid L2 rises beyond the edge of the head cap 201. This time t3 is set to be not less than time t1 and less than time t2. The suction / discharge pump 205 is driven to send out the cleaning liquid. The time t3 is recorded in advance in a memory or the like in the control unit 70.

  If the time t3 has not been reached (“N” in S405), the suction / discharge pump 205 is driven to continue sending the cleaning liquid. When the time t3 has been reached (“Y” in S405), while the cleaning fluid L2 is filled in the connection path 204, the driving of the suction / discharge pump 205 is stopped and the delivery of the cleaning fluid is stopped (S305).

  Thereafter, as shown in FIG. 4C, the cleaning control unit 70b closes the connection path 204 by rotating the switching unit 210 and closing all the stop valves. In this state, the head cap 201 is brought into close contact with the inkjet head 31 to seal the nozzle surface.

(Action / Effect)
According to the present embodiment, the cleaning liquid L 2 is supplied to the head cap 201 side while the liquid supply path 206 is connected to the head cap 201, and the liquid is discharged while the liquid discharge path 207 is connected to the head cap 201. In addition to cleaning the inkjet head 31, the inside of the head cap 201 and the head cap 201 can be switched by switching the liquid feeding direction by the suction / discharge pump 205 according to the selection of the path by the switching unit 210 such as discharging the waste liquid to the liquid side. The drainage path 207 up to the waste liquid tank can also be cleaned. As a result, the ink discharged by the head cleaning operation is prevented from drying and adhering in the drainage path 207 from the cap to the waste liquid tank, and insufficient suction or backflow occurs, preventing proper cleaning. It can be avoided.

  In addition, according to the present embodiment, when supplying the cleaning liquid L2 from the liquid supply path 206 toward the head cap 201, the ink jet head 31 is controlled by controlling the start and stop of the suction / discharge pump 205 according to the supplied flow rate. In addition to ink suction at the time of cleaning, the cleaning liquid L2 is repeated several times to rinse the path, the cleaning liquid L2 supplied into the head cap 201 is overflowed, and the head cap 201 and the upper edge are cleaned, etc. Various cleaning methods can be performed.

  According to the present embodiment, the connection path 204 is closed while the connection path 204 is filled with the cleaning liquid L2, thereby maintaining the state in which the connection path 204, which is also a waste liquid path, is filled with the cleaning liquid L2 for a long period of time. It is possible to prevent the ink remaining in the path from drying and sticking for a long time.

  In addition, according to the present embodiment, the three-way cock that can block all the paths at the connection point P1 where the liquid supply path 206 and the drainage path 207 are connected to the connection path 204 leading to the head cap 201. By adopting it, the various cleaning methods described above can be implemented by appropriately opening or closing each closing valve of each route, and the connection route 204 can be closed for the long-term storage described above.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The gist of the present embodiment is to measure the amount of water in the head cap 201 by detecting the reflected wave of the generated ultrasonic wave. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the functions and the like are the same unless otherwise specified, and the description thereof is omitted.

(Configuration of measurement unit)
The present embodiment includes a measurement unit 220 that drives an ultrasonic wave generating element that is a piezoelectric element to generate an ultrasonic wave and detects a reflected wave of the generated ultrasonic wave. More specifically, the measuring unit 220 is provided on the bottom surface of the head cap 201 and applies a predetermined voltage to the ultrasonic wave generating element from the drive system circuit to drive the ultrasonic wave generating element so that the ultrasonic wave is superposed upward from the bottom surface. While generating sound waves, switching between driving and detection on the drive system circuit side, observing the voltage generated at the ultrasonic wave generation element due to piezoelectric element vibration due to the reflected wave from the liquid surface, arrival time of reflected wave and attenuation of amplitude Is detected.

  The measuring unit 220 detects an overflow state when the reflected wave is temporally saturated while the cleaning liquid L2 is being sent out, or causes a path due to a change in the amplitude of the reflected wave at the time of rinsing cleaning by sending the cleaning liquid L2. Detect dirt.

  Specifically, in the overflow detection, first, the time of the reflected wave is measured while feeding the cleaning liquid. Then, when the time change is saturated before and after the assumed time Tr = L / C (L: height of cap, C: sound speed), it is determined as an overflow state. Then, the liquid feeding is stopped after a predetermined washing time Tw continues to flow. The cleaning time Tw is set in advance according to the cleaning power. At this time, if the estimated time Tr is not reached even if the liquid is supplied for a certain period of time, it is determined that a significant flow path clogging has occurred, and the cleaning control unit 70b operates the information that stops the liquid supply and prompts the user to confirm. Display on the unit 60.

  In the path contamination detection, first, the amplitude of the reflected wave is measured at a periodic contamination check timing or a rinsing operation during cleaning. Here, when there are many ink components, the ultrasonic waves are attenuated by viscosity and pigment, and the amplitude is reduced. Therefore, the cleaning and rinsing operations are repeated until the amplitude of the cleaning liquid alone is approached. The relationship between the degree of contamination and the amplitude is preliminarily tabulated and stored in a memory or the like according to the mixing ratio of ink and cleaning liquid.

The cleaning control unit 70b controls the start and stop of delivery of the cleaning liquid L2 by measuring the amount and quality of the cleaning liquid L2 in the head cap 201 based on the arrival time of the reflected wave and the attenuation amount of the amplitude.
Specifically, the cleaning control unit 70b causes the suction / discharge pump 205 to send the cleaning liquid L2 toward the head cap 201 while the switching unit 210 connects the liquid supply path 206 to the head cap 201. According to the measurement result, the start and stop of delivery of the suction / exhaust pump 205 are controlled.

  Note that the ultrasonic wave generating element of the measuring unit 220 generates stronger ultrasonic waves to stir the inside of the cap and scrape ink stains, or generate stronger ultrasonic waves to remove the cleaning liquid L2 from the liquid surface. The gap between the inkjet head 31 and the nozzle guard can be cleaned by discharging upward.

  Further, the above-described overflow detection operation and path dirt detection operation may be executed in combination. That is, during the overflow detection, the path contamination may also be detected to determine the cleaning time Tw. In this case, control is performed so that the cleaning liquid L2 that continues to flow until the amplitude increases continues to flow. On the other hand, at the time of cleaning the path dirt, the liquid level position may also be detected, and the liquid feeding may be controlled to be stopped on the upper surface of the head cap.

  Note that bubbles may be generated inside the head cap 201 during cleaning, and normal reflected waves may not be observed due to the bubbles (bubbles). In that case, the cleaning liquid L2 can continue to flow until the waveform returns to normal, and control can be performed to eliminate the return bubble. If the waveform does not return to normal even after a certain period of time, information prompting the user to confirm is displayed.

(Example of change)
In the above embodiment, the method of detecting the reflected wave of the ultrasonic wave is adopted as the measurement unit for detecting the position of the liquid level and the water quality, but the present invention is not limited to this, and the liquid level detection by the laser displacement meter. Adopt various methods such as contamination detection by the amount of light received by the transmission type sensor, liquid level / dirt detection by change of dielectric constant, liquid level detection by float sensor (magnet), liquid level detection by weight sensor (pressure sensitive) Can do.

  In the above-described embodiment, the printing apparatus that forms an image by ejecting ink from the inkjet head onto the printing medium of the paper medium conveyed on the conveyance path is described as an example. However, the present invention is not limited to this. For example, the present invention can also be applied to an image forming apparatus intended for a base material of a building material or a decorative surface of a humidity-controlled building material containing a porous material made of calcium silicate or the like. As an apparatus for forming an image on such a building material, it is relatively moved with respect to a table-like flat bed unit that holds a printing medium made of the building material or the like and a building material placed and fixed on the flat bed. There is a type having a shuttle base unit, and even in a printing apparatus of such a type, the present invention can be applied to maintenance of an inkjet head provided in the shuttle base unit.

(Action / Effect)
According to the present embodiment, by using the measuring unit 220 that measures the amount of water or the quality of water in the head cap 201, the above-described various types can be performed without being affected by changes in the flow rate due to contamination or deterioration of the liquid feeding path 206. The cleaning method can be performed with higher accuracy.

  According to the present embodiment, the measuring unit 220 is configured to generate ultrasonic waves from the inner bottom surface of the head cap 201 toward the upper water surface and detect the reflected waves, thereby reducing the arrival time and amplitude of the reflected waves. Based on the amount, the amount and quality of the cleaning liquid L2 in the head cap 201 are measured to control the start and stop of the cleaning liquid L2. Thereby, both the amount of water and water quality can be detected collectively with a simple detection structure.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 9 ... Network 10 ... Side paper feeding part 20 ... Internal paper feeding part 30 ... Printing part 31 ... Inkjet head 32 ... Recording head main body 33 ... Nozzle plate 40 ... Paper discharge part 50 ... Reversing part 51 ... Reversing stand 52 ... Reversing roller 53 ... Conveying roller 60 ... Operation unit 70 ... Control unit 70a ... Driving control unit 70b ... Cleaning control unit 71 ... External interface unit 72 ... Measurement unit 111 ... Cap 115 ... Air release valve 131 ... Suction fan 132 ... Platen Belt 133 ... Paper transport unit 139 ... Unit drive section 200 ... Maintenance unit 200a ... Pan 201 ... Head cap 202 ... Atmospheric introduction pipe 203 ... Atmospheric release valve 204 ... Connection path 205 ... Suction / discharge pump 206 ... Liquid feed path 207 ... Drain path 208 ... Cleaning liquid tank 209 ... Waste Tank 210 ... switching unit 211 ... combined channel 212 ... three-way stopcock 212a ... coupling passage 213 ... rotary member 220 ... measurement unit

Claims (6)

A cleaning device for a printing apparatus having an inkjet head for discharging ink from a nozzle to a printing medium,
A head cap that is detachably provided on the inkjet head and covers the nozzle in a sealed state from the outside air when attached;
A liquid supply path for supplying a cleaning liquid into the head cap;
A drainage path for discharging waste liquid stored in the head cap;
Sucking and discharging means for delivering the cleaning liquid to the head cap through the liquid supply path and discharging the waste liquid from the head cap through the liquid discharge path;
Switching means for selectively connecting the liquid supply path or the drainage path to the head cap;
A cleaning device for a printing apparatus, comprising: a control unit that switches a liquid feeding direction by the suction / discharge unit to the head cap direction or the waste liquid direction in accordance with selection of a path by the switching unit.   The control means causes the suction / discharge means to send the cleaning liquid in the direction of the head cap while the switching means connects the liquid supply path to the head cap, and according to the flow rate sent, the suction / discharge means The printing apparatus cleaning apparatus according to claim 1, wherein the start and stop of the delivery are controlled. A measuring means arranged in the head cap and measuring the amount or quality of water in the head cap;
The control means causes the suction / discharge means to send out the cleaning liquid in the direction of the head cap while the switching means connects the liquid supply path to the head cap, and according to the measurement result of the measurement means, the suction / discharge The printing apparatus cleaning apparatus according to claim 1, wherein the start and stop of delivery of the means are controlled. The switching means has a function of closing a connection path from the liquid feeding path to the head cap,
The control means causes the suction / discharge means to send out the cleaning liquid in the direction of the head cap, stops the delivery by the suction / discharge means while the cleaning liquid is filled in the connection path, and connects the connection by the switching means. The cleaning apparatus for a printing apparatus according to claim 1, wherein the path is controlled to be closed. The switching means is
With respect to the connection path from the liquid supply path or the drainage path to the head cap, the liquid supply path and the drainage path are arranged at connection points,
A joint channel that interconnects the connection path, the liquid feeding path, and the drainage path;
Comprising three closing valves provided at connection points of the connection path, the liquid supply path and the drainage path to the combined flow path,
By opening one closing valve of the liquid feeding path or the drainage path and closing the other closing valve of the liquid feeding path or the drainage path, and opening the closing valve of the connection path, Selectively connecting the liquid path or the drainage path to the connection path;
The printing apparatus cleaning apparatus according to claim 1, wherein the connection path, the liquid supply path, and the drainage path are closed by closing all the stop valves. The measurement means is provided on the bottom surface in the head cap, and generates ultrasonic waves upward from the bottom surface; and
Detecting means for detecting the reflected wave of the generated ultrasonic wave,
The control means measures the amount of water based on the arrival time of the reflected wave, measures the water quality based on the amount of attenuation of the amplitude of the reflected wave, and starts sending and receiving the intake / exhaust means according to these measurement results. The printing apparatus cleaning apparatus according to claim 3, wherein the stoppage of the feeding is controlled.

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