JP2008221620A - Fluid jet device, and cleaning method of fluid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jet device which can improve the success rate of cleaning, and to provide a cleaning method of the fluid jet device. <P>SOLUTION: The fluid jet device carries out non-boiling cleaning which includes the pressure reduction step (steps S13 and S14) of pressure-reducing the downstream side from a choke valve in an ink supply passage by driving of a suction pump while the choke valve is closed, and the discharge step (steps S15 and S16) of discharging an ink from a recording head by opening the choke valve in the case where the size of a negative pressure generated at the downstream side from the choke valve in the ink supply passage by the pressure reduction step reaches a valve opening threshold value preliminarily set as a size of the negative pressure before the ink in the ink supply passage becomes a boiling state after opening of the choke valve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus and a cleaning method for the fluid ejecting apparatus.

  Generally, an ink jet printer (hereinafter simply referred to as “printer”) is known as a fluid ejecting apparatus that ejects ink (fluid) from a nozzle of a recording head (fluid ejecting head) to a target. In such a printer, an ink cartridge (fluid storage means) for storing ink is detachably mounted, and ink supplied from the ink cartridge via an ink supply path (fluid supply path) is recorded on a paper (target). ) Is executed by jetting the ink. Further, in order to reduce the ejection failure of the recording head ink during printing, such a printer performs cleaning such as so-called choke cleaning that forcibly discharges thickened ink or bubbles from the nozzles of the recording head. It has become so.

In this choke cleaning, a choke valve (open / close valve) provided on the ink supply path is closed, and a negative pressure is generated in the print head by suction from the nozzle forming surface side of the print head with a suction pump (suction means). The bubbles present in the recording head are expanded. Then, by driving a pressurizing pump for pressurizing the inside of the ink cartridge, the choke valve on the ink supply path is forcibly opened, and ink is allowed to flow from the ink cartridge into the recording head at once. As a result, highly viscous ink and expanded bubbles in the recording head are discharged together with the ink from each nozzle formed in the recording head (for example, Patent Document 1).
JP 2006-205687 A

  By the way, when the chalk cleaning as described above is executed, the bubbles contained in the ink in the ink supply path before the cleaning are discharged together with the ink. On the other hand, a part of the air dissolved in the ink is deposited by the boiling phenomenon due to the pressure reduction in the ink supply path at the time of chalk cleaning, and fine bubbles are newly generated in the ink in the ink supply path. was there. When ink ejection is started by the recording head in a state where the fine bubbles are included in the ink in the ink supply path, there is a risk that ink ejection failure occurs due to the fine bubbles being ejected from the nozzles. was there. That is, there is a possibility that the chalk cleaning that should have been executed to suppress the ink ejection failure may fail.

  SUMMARY An advantage of some aspects of the invention is to provide a fluid ejecting apparatus and a fluid ejecting apparatus cleaning method capable of improving a cleaning success rate.

  In order to achieve the above object, according to the cleaning method for a fluid ejecting apparatus of the present invention, the fluid guided from the fluid storing means to the fluid ejecting head side through the fluid supply path is sucked from the nozzle formed in the fluid ejecting head. When suctioning and discharging by means of driving means, the downstream side of the on-off valve in the fluid supply path is depressurized while the on-off valve provided in the fluid supply path is closed, and then the on-off valve is opened. A fluid ejecting apparatus cleaning method for discharging fluid from the fluid ejecting head by causing the valve to close to the on-off valve in the fluid supply path by driving the suction means with the on-off valve closed. A pressure reducing step for reducing the pressure on the downstream side, and the magnitude of the negative pressure generated downstream of the on / off valve in the fluid supply path by the pressure reducing step is After the valve, when the valve opening threshold set in advance as the magnitude of the negative pressure before the fluid in the fluid supply path reaches the boiling state is reached, the on-off valve is opened and the fluid ejecting head removes the fluid from the fluid ejecting head. And a non-boiling cleaning having a discharge step for discharging the water.

  According to the present invention, the negative pressure on the downstream side of the on-off valve in the fluid supply path becomes large enough to bring the fluid in the fluid supply path to a boiling state after the on-off valve is opened. Is opened. Therefore, when non-boiling cleaning in which the fluid is discharged from the fluid ejecting head based on the driving of the suction means is performed, it is avoided that the fluid flowing in the fluid supply path boils and gas is deposited, and the subsequent fluid It is possible to suppress fluid ejection failure during fluid ejection by the ejection head. Therefore, the success rate of cleaning can be improved.

  In the fluid ejecting apparatus cleaning method of the present invention, the fluid ejecting apparatus includes a downstream side of the on-off valve in the fluid supply path after the suction unit starts driving with the on-off valve closed. Storage means for storing in advance the elapsed time when the magnitude of the negative pressure reaches the valve opening threshold value as the valve opening permission time is provided, and in the discharge step, in the fluid supply path by execution of the pressure reducing step When the elapsed time from the start of pressure reduction downstream of the opening / closing valve reaches the valve opening permission time, the opening / closing valve is opened to discharge the fluid from the fluid ejecting head.

  According to the present invention, when the elapsed time from the start of the driving of the suction means with the opening / closing valve closed reaches the opening permission time, the negative pressure on the downstream side of the opening / closing valve in the fluid supply path is reduced. It is determined that the pressure level has reached the valve opening threshold, and the on-off valve is opened to discharge the fluid from the fluid ejecting head. That is, since the on-off valve can be opened at an accurate timing without providing a separate sensor for detecting negative pressure downstream of the on-off valve in the fluid supply path, the on-off valve is opened. In this case, it can be avoided that the fluid in the fluid supply path boils and fine bubbles are precipitated from the fluid.

  In the fluid ejection device cleaning method of the present invention, the fluid ejection device is provided with pressure detection means for detecting a negative pressure downstream of the on-off valve in the fluid supply path, and in the discharging step, When the magnitude of the negative pressure detected by the pressure detecting means by the execution of the pressure reducing step reaches the valve opening threshold, the on-off valve is opened to discharge the fluid from the fluid ejecting head. .

  According to the present invention, the negative pressure downstream of the on-off valve in the fluid supply path is detected by the pressure detecting means, and the on-off valve is opened when the detected negative pressure reaches the valve opening threshold. The fluid is ejected from the fluid ejecting head. Therefore, at the time of non-boiling cleaning, the negative pressure on the downstream side of the on-off valve in the fluid supply path is actually measured to open the on-off valve, so that when the on-off valve is opened, It is possible to avoid boiling of the fluid and precipitation of fine bubbles from the fluid.

  In the fluid ejection device cleaning method of the present invention, the fluid ejection device may be configured to supply the fluid when the magnitude of the negative pressure downstream of the on-off valve in the fluid supply path reaches the valve opening threshold. Negative pressure maintaining means for maintaining the magnitude of negative pressure downstream of the on-off valve in the passage at the valve opening threshold is provided, and in the discharging step, the negative pressure maintaining means causes the negative pressure maintaining means to The on-off valve is opened to discharge the fluid from the fluid ejecting head in a state where the magnitude of the negative pressure downstream of the on-off valve is maintained at the valve opening threshold.

  According to the present invention, even if the pressure on the downstream side of the on-off valve in the fluid supply path is reduced by driving the suction means, the negative pressure on the downstream side of the on-off valve in the fluid supply path is driven by the negative pressure maintaining means. By doing so, the valve opening threshold is maintained. Therefore, when the on-off valve is opened during the non-boiling cleaning, it is possible to avoid the fluid in the fluid supply path from boiling and the fine bubbles from depositing from the fluid.

  In the cleaning method for a fluid ejection device of the present invention, the downstream side of the fluid supply path with respect to the on / off valve is depressurized in a state in which the on / off valve is closed, and the downstream side of the on / off valve in the fluid supply path is provided. When the negative pressure becomes large enough to cause the fluid in the fluid supply path to boil, the boiling control is performed to open the on-off valve and discharge the fluid from the fluid ejecting head. The non-boiling cleaning is performed after the permissible cleaning.

  According to the present invention, the non-boiling cleaning is performed after the boiling permissible cleaning that allows the fluid in the fluid supply path to boil during cleaning. For this reason, the fine bubbles generated by boiling the fluid in the fluid supply path during the boiling permissible cleaning are discharged together with the fluid from the fluid ejecting head by the non-boiling cleaning.

  In the cleaning method for a fluid ejecting apparatus according to the present invention, the normal cleaning for discharging the fluid from the fluid ejecting head is performed by driving the suction means while the open / close valve is maintained open. The non-boiling cleaning is performed after the execution.

  According to the present invention, since the suction force for sucking the fluid in the fluid supply path from the fluid ejecting head side is weaker in the normal cleaning than in the non-boiling cleaning, the bubbles existing in the fluid supply path from before the cleaning. May not be reliably discharged from the fluid ejecting head. Therefore, by performing the non-boiling cleaning after executing the normal cleaning, the bubbles existing in the fluid supply path before the cleaning are surely discharged together with the fluid from the fluid ejecting head.

  The fluid ejecting apparatus according to the present invention includes a fluid storing unit that stores a fluid, a fluid ejecting head that ejects a fluid supplied from the fluid storing unit via a fluid supply path, from a nozzle, and a midway of the fluid supplying path. An on-off valve, fluid receiving means that contacts the fluid ejecting head in a state in which fluid can be sucked from the nozzle, and exerting suction force in a state where the fluid receiving means is in contact with the fluid ejecting head A suction means for sucking fluid from the nozzle of the fluid ejecting head and discharging the fluid into the fluid receiving means, and the downstream side of the on-off valve in the fluid supply path with the on-off valve closed. In the fluid ejecting apparatus that discharges the fluid from the fluid ejecting head into the fluid receiving means by reducing the pressure by the suction means and then opening the on-off valve. The negative pressure on the downstream side of the on-off valve in the fluid supply path after the decompression of the fluid supply path on the downstream side of the on-off valve in the fluid supply path by the suction means is started with the on-off valve closed. However, after the opening / closing valve is opened, the elapsed time until the valve opening threshold set in advance as the magnitude of the negative pressure before the fluid in the fluid supply path is in a boiling state is preliminarily set as the valve opening permission time. A storage means for storing and opening the on-off valve when an elapsed time from the start of pressure reduction downstream of the on-off valve in the fluid supply path by the suction means reaches the valve opening permission time And an opening / closing valve control means.

  According to the present invention, when the elapsed time from the start of the driving of the suction means with the opening / closing valve closed reaches the opening permission time, the negative pressure on the downstream side of the opening / closing valve in the fluid supply path is reduced. It is determined that the pressure has reached the valve opening threshold, and the on-off valve is opened to eject fluid from the fluid ejecting head. That is, since the on-off valve can be opened at an accurate timing without providing a separate sensor for detecting negative pressure downstream of the on-off valve in the fluid supply path, the on-off valve is opened. In this case, it can be avoided that the fluid in the fluid supply path boils and fine bubbles are precipitated from the fluid. Therefore, the success rate of cleaning can be improved.

  The fluid ejecting apparatus according to the present invention includes a fluid storing unit that stores a fluid, a fluid ejecting head that ejects a fluid supplied from the fluid storing unit via a fluid supply path, from a nozzle, and a midway of the fluid supplying path. An on-off valve, fluid receiving means that contacts the fluid ejecting head in a state in which fluid can be sucked from the nozzle, and exerting suction force in a state where the fluid receiving means is in contact with the fluid ejecting head A suction means for sucking fluid from the nozzle of the fluid ejecting head and discharging the fluid into the fluid receiving means, and the downstream side of the on-off valve in the fluid supply path with the on-off valve closed. In the fluid ejecting apparatus that discharges the fluid from the fluid ejecting head into the fluid receiving means by reducing the pressure by the suction means and then opening the on-off valve. Pressure detecting means for detecting a negative pressure downstream of the on-off valve in the fluid supply path, and the magnitude of the negative pressure detected by the pressure detecting means is determined after the opening of the on-off valve. On-off valve control means is further provided for opening the on-off valve when a predetermined valve opening threshold is reached as the magnitude of the negative pressure before the fluid in the boiling state.

  According to the present invention, the negative pressure downstream of the on-off valve in the fluid supply path is detected by the pressure detecting means, and the on-off valve is opened when the detected negative pressure reaches the valve opening threshold. The fluid is ejected from the fluid ejecting head. Therefore, in order to measure the negative pressure on the downstream side of the on-off valve in the fluid supply path and to open the on-off valve, the fluid in the fluid supply path boils when the on-off valve is opened, It can be avoided that bubbles are deposited from the fluid. Therefore, the success rate of cleaning can be improved.

  The fluid ejecting apparatus according to the present invention includes a fluid storing unit that stores a fluid, a fluid ejecting head that ejects a fluid supplied from the fluid storing unit via a fluid supply path, from a nozzle, and a midway of the fluid supplying path. An on-off valve, fluid receiving means that contacts the fluid ejecting head in a state in which fluid can be sucked from the nozzle, and exerting suction force in a state where the fluid receiving means is in contact with the fluid ejecting head A suction means for sucking fluid from the nozzle of the fluid ejecting head and discharging the fluid into the fluid receiving means, and the downstream side of the on-off valve in the fluid supply path with the on-off valve closed. In the fluid ejecting apparatus that discharges the fluid from the fluid ejecting head into the fluid receiving means by reducing the pressure by the suction means and then opening the on-off valve. The magnitude of the negative pressure downstream of the on-off valve in the fluid supply path is set in advance as the magnitude of the negative pressure before the fluid in the fluid supply path becomes boiling after the on-off valve is opened. A negative pressure maintaining means for maintaining the magnitude of the negative pressure downstream of the on-off valve in the fluid supply path at the valve opening threshold when the valve opening threshold is reached, and the negative pressure maintaining means On-off valve control means for opening the on-off valve when the magnitude of the negative pressure downstream of the on-off valve in the fluid supply path is maintained at the valve opening threshold.

  According to the present invention, even if the pressure on the downstream side of the on-off valve in the fluid supply path is reduced by driving the suction means, the negative pressure on the downstream side of the on-off valve in the fluid supply path is driven by the negative pressure maintaining means. By doing so, the valve opening threshold is maintained. Therefore, when the on-off valve is opened, it is possible to avoid the fluid in the fluid supply path from boiling and the fine bubbles from being precipitated from the fluid. Therefore, the success rate of cleaning can be improved.

(First embodiment)
Hereinafter, a first embodiment in which a fluid ejecting apparatus and a fluid ejecting apparatus cleaning method of the present invention are embodied will be described with reference to FIGS. 1 to 6. In the following description of the present specification, when referring to “front-rear direction”, “left-right direction”, and “up-down direction”, the front-rear direction (sub-scanning direction) and the left-right direction (main scanning) indicated by arrows in FIG. Direction) and vertical direction (gravity direction).

  As shown in FIG. 1, an ink jet printer 11 as a liquid ejecting apparatus includes a frame 12 having a rectangular shape in plan view. A platen 13 is installed in the frame 12 so as to extend in the left-right direction, and a sheet P as a target is fed along the front-rear direction on the platen 13 by a paper feed mechanism (not shown). It has become. Further, a rod-shaped guide shaft 14 is installed in the frame 12 in parallel with the longitudinal direction (left-right direction) of the platen 13.

  A carriage 15 is supported on the guide shaft 14 in a state where the carriage 15 can reciprocate in the axial direction (left-right direction) of the guide shaft 14. The carriage 15 is connected to a carriage motor 17 provided on the back surface of the frame 12 via an endless timing belt 16 stretched between a pair of pulleys 16 a provided on the inner surface of the rear wall of the frame 12.

  A recording head 18 as a fluid ejecting head is mounted on the lower surface side of the carriage 15 facing the platen 13. On the carriage 15, a plurality (four in this embodiment) of valve units 19 that supply ink as temporarily stored fluid to the recording head 18 are provided. As shown in FIG. 2, the lower surface of the recording head 18 is a nozzle forming surface 18a in which a plurality of nozzles 20 (only one is shown in FIG. 2) are opened. Then, printing is performed by ejecting ink droplets onto the paper P fed from the nozzles 20 onto the platen 13.

  As shown in FIG. 1, a cartridge holder 21 is provided at the right end in the frame 12, and a plurality of ink cartridges 22 as fluid storage means are detachably attached to the cartridge holder 21 (in this embodiment, four). Pieces) are installed. Each ink cartridge 22 includes a rectangular box-like case 23 as shown in FIG. Each case 23 accommodates a bag-like ink pack 24 made of a flexible film, and each ink cartridge 22 is filled with ink of a different color. Yes. When each ink cartridge 22 is mounted in the cartridge holder 21, it is connected to the upstream end of the ink tube 25A constituting the ink supply path (liquid supply path) 25, thereby passing through the ink tube 25A. Thus, each valve unit 19 on the carriage 15 is connected to each other.

  As shown in FIGS. 1 and 2, on the carriage 15, corresponding to each ink tube 25 </ b> A, the ink tube 25 </ b> A is opened and closed at an intermediate position between the ink cartridge 22 and the valve unit 19. A choke valve 47 is provided as a valve. These choke valves 47 are opened and closed by a differential pressure between the pressure of the ink upstream of the choke valve 47 in the ink tube 25A and the pressure of the ink downstream of the choke valve 47 in the ink tube 25A. It has become.

  As shown in FIG. 1, a pressurizing unit 26 is mounted on the right end of the frame 12 above the cartridge holder 21. The pressurizing unit 26 is a device that pressurizes pressurized air as a pressurized gas into the ink cartridge 22 through an air supply path 27, and includes a pressurizing pump 28, an air pressure sensor 29, and an air release valve 30. ing. The air pressure sensor 29 is a sensor for detecting the pressure of the pressurized air flowing through the air supply path 27.

  The air supply path 27 is branched into the same number (four in this embodiment) as the number of ink cartridges 22 with a distributor 31 disposed downstream of the atmosphere release valve 30 as a boundary. The branched air supply paths 27 are connected to the corresponding ink cartridges 22 at the respective leading ends (downstream ends) and communicate with the case 23 of the ink cartridge 22. Therefore, when the pressurizing pump 28 of the pressurizing unit 26 is driven, the pressurized air pumped from the pressurizing pump 28 is introduced into the case 23 of each ink cartridge 22 via the air supply path 27. It has become so. Each ink pack 24 is crushed by the pressure (ie, air pressure) of the pressurized air fed into each case 23, and the ink in each ink pack 24 is transferred to each ink supply path 25 (ink tube 25A). ) Through the recording head 18 side.

  As shown in FIG. 2, each ink pack 24 provided in the case 23 of the ink cartridge 22 can lead out ink into each ink tube 25A. A space between the case 23 and the ink pack 24 is a pressure chamber 32, and pressurized air pumped from the pressure pump 28 through the air supply path 27 is introduced into the pressure chamber 32. It has come to be.

  As shown in FIG. 1, a home position serving as a retraction position of the recording head 18 is provided between the cartridge holder 21 and the platen 13 near the right end in the frame 12. A maintenance unit 33 for performing various types of maintenance such as cleaning is disposed below the home position. As shown in FIG. 2, the maintenance unit 33 includes nozzles on the nozzle formation surface 18 a of the recording head 18 (specifically, areas in which the openings (also referred to as “nozzle openings”) of the nozzles 20 are formed). A cap (fluid receiving means) 34 made of a synthetic resin having a bottomed square box shape with an open upper side capable of abutting so as to surround 20 openings is provided.

  The cap 34 can be moved up and down by driving an elevating device (not shown). The cap 34 is lifted while the carriage 15 is moved to the home position, so that the upper end of the cap 34 is the recording head 18. The nozzle forming surface 18a is in close contact with each other, and is in contact with the recording head 18 so as to surround each nozzle 20 opening. The state in which the cap 34 is in contact with the recording head 18 so that the upper end is in close contact with the nozzle forming surface 18a is also referred to as “contact state” hereinafter.

  A discharge port 35 is formed through the bottom wall portion of the cap 34, and a discharge tube 36 is connected to the discharge port 35. A suction pump 37 (for example, a tube pump) as a suction means is provided in the middle portion of the discharge tube 36. Further, the tip (downstream end) of the discharge tube 36 is connected to a waste ink tank 38. The maintenance unit 33 can perform so-called choke cleaning using the choke valves 47 on the carriage 15 when the suction pump 37 is driven.

  As shown in FIGS. 3A and 3B, each choke valve 47 includes a base material 40 made of synthetic resin, and one side surface of each base material 40 (upper surface in FIGS. 3A and 3B). Each is formed with a recess 41. Introduced paths 42 penetrating and formed in the base material 40 are respectively opened at the bottom surfaces of the recesses 41, and the introduced paths 42 communicate with the ink tubes 25A connected to the ink cartridges 22, respectively. ing. Further, a protrusion 43 is formed on the bottom surface of each recess 41, and a discharge path 44 is opened on the top surface of each protrusion 43. The discharge paths 44 are formed through the base material 40 and communicate with the recording head 18 side.

  In addition, a flexible film 45 is fixed to one side surface of each base material 40 in a state where a slack is provided on the concave portion 41 side, and each concave portion 41 is sealed by each film 45. Yes. And the pressure chamber 46 enclosed by the airtight state by the inner surface of each recessed part 41 and each film 45 is each formed. Therefore, when ink is supplied to each valve unit 19 from the ink tube 25 </ b> A, the ink flows into the pressure chambers 46 via the introduction paths 42.

  When the amount of ink flowing into each pressure chamber 46 increases, each film 45 is separated from each protrusion 43 as shown in FIG. When the amount of ink in each pressure chamber 46 further increases and the pressure received from the ink increases, each film 45 swells to one side (the upper side in FIGS. 3A and 3B). become. Therefore, in the present embodiment, the recess 41, the protrusion 43, the film 45, and the like constitute a choke valve 47 as an on-off valve. Further, the introduction path 42, the recess 41 and the discharge path 44 together with the ink tube 25A constitute the ink supply path 25.

Next, chalk cleaning will be described below with reference to FIGS.
When performing chalk cleaning, as shown in FIG. 2, the cap 34 is lifted and brought into contact with the recording head 18, whereby the space in the cap is formed by the nozzle forming surface 18 a of the recording head 18 and the inner surface of the cap 34. Is formed. When the suction pump 37 is driven in this state, air and ink in the cap inner space are sucked into the waste ink tank 38 on the downstream side via the discharge tube 36. As a result, the inner space of the cap is in a negative pressure state with respect to the atmospheric pressure, and this negative pressure acts on each nozzle 20 of the recording head 18, and the ink in the recording head 18 is transferred from each nozzle 20 to the inside of the cap 34. To be discharged. In the following description, the negative pressure with respect to the atmospheric pressure is simply referred to as “negative pressure”.

  Further, when the suction pump 37 is driven, ink in each valve unit 19 and choke valve 47 as well as in the recording head 18 is sucked. As a result, the ink in the pressure chamber 46 in each choke valve 47 is discharged downstream from each discharge path 44, whereby the ink in each pressure chamber 46 decreases. When the drive of the suction pump 37 is continued, each film 45 is displaced to each protrusion 43 side (lower side in FIGS. 3A and 3B) as the ink in each pressure chamber 46 decreases, As shown in FIG. 3B, each film 45 comes into contact with each projection 43 and each discharge path 44 is closed. If the driving of the suction pump 37 is further continued, the pressure on the downstream side from the inlet of each discharge passage 44 is further reduced.

  When the negative pressure downstream from the inlet of each discharge passage 44 is accumulated, the pressurizing pump 28 is driven. Then, ink is supplied from each ink cartridge 22 into each choke valve 47 and introduced into each pressure chamber 46. Thereafter, as the amount of ink delivered to each pressure chamber 46 increases, when the ink pressure becomes greater than the negative pressure, the direction in which each film 45 moves away from each protrusion 43 (in FIG. ), And each discharge passage 44 is opened.

  As a result, the ink flows into each discharge path 44 where the negative pressure is accumulated, and the thickened ink and bubbles staying downstream from the respective ink tubes 25A and the respective pressure chambers 46 have an increased flow velocity. The ink is forcibly discharged from each nozzle 20 of the recording head 18 together with the ink. In this way, so-called chalk cleaning is performed. The ink discharged from each nozzle 20 of the recording head 18 is discharged to the waste ink tank 38 via the cap 34 and the discharge tube 36.

Next, the electrical configuration of the ink jet printer 11 will be described with reference to FIG.
As shown in FIG. 4, the ink jet printer 11 includes a control device 50 that controls the entire printer 11. An air pressure sensor 29 of the pressurizing unit 26 and the like are electrically connected to the input side interface of the control device 50. On the other hand, a paper feed motor, a carriage motor 17, a recording head 18, a pressure pump 28, a suction pump 37, and the like (not shown) are electrically connected to the output side interface of the control device 50. Then, the control device 50 controls the driving of the paper feed motor, the carriage motor 17, the recording head 18, the pressurizing pump 28, the suction pump 37, and the like according to an input signal from the air pressure sensor 29 and the like. It has become.

  In the control device 50, a CPU 51, a ROM 52, a RAM 53, a timer 54, an ASIC (Application Specific Integrated Circuit) 55, and the like are provided. The ROM 52 has various control programs (such as ink filling processing described later) for controlling the ink jet printer 11 and various threshold values (a first elapsed time threshold value, a second elapsed time threshold value, a third elapsed time threshold value described later). Etc. are stored in advance. The RAM 53 stores various information that can be appropriately rewritten while the ink jet printer 11 is being driven. The timer 54 is configured by a counter that performs counting processing based on a clock signal from a clock circuit.

  Next, among the control processing routines executed by the control device 50 of the present embodiment, the ink filling processing routine executed when the ink cartridge 22 is mounted on the ink jet printer 11 is shown in the flowchart shown in FIG. This will be described below based on the timing chart shown in FIG.

  The control device 50 executes an ink filling process routine when the ink cartridge 22 is mounted on the cartridge holder 21. In this ink filling process routine, the control device 50 starts normal cleaning (step S10). Specifically, the control device 50 causes the cap 34 to come into contact with the recording head 18 located at the home position by driving the elevating device, starts driving the pressure pump 28, and then starts driving the suction pump 37. . For this reason, in normal cleaning, ink flows into each choke valve 47 via each ink tube 25A by driving the pressurizing pump 28 simultaneously with the start of the cleaning, so that the open state of each choke valve 47 is maintained. Is done.

  And the control apparatus 50 calculates | requires 1st elapsed time T1 after the process of step S10 was performed from the time which the timer 54 has measured, and this 1st elapsed time T1 was set to the 1st elapsed time threshold value preset. It is determined whether or not KT1 or more (step S11). The first elapsed time threshold value KT1 is set so that the ink in each ink cartridge 22 passes through each ink supply path 25 through the recording head 18 by performing normal cleaning even when there is no ink in each ink supply path 25. The time required to reach the nozzles 20 and be discharged into the cap 34 is set in advance by experimentation or simulation.

  When the determination result in step S11 is negative (T1 <KT1), the control device 50 repeatedly executes the determination process in step S11 until the determination result in step S11 becomes a positive determination. On the other hand, when the determination result in step S11 is affirmative (T1 ≧ KT1), the control device 50 stops the normal cleaning by stopping the driving of the pressurizing pump 28 and the suction pump 37 (step S12).

  Subsequently, the control device 50 starts to perform choke cleaning (specifically, non-boiling cleaning described later) by starting the drive of the suction pump 37 with the cap 34 kept in contact with the recording head 18. (Step S13). During non-boiling cleaning, the suction pump 37 is driven at a predetermined speed set in advance.

  And the control apparatus 50 calculates | requires 2nd elapsed time T2 after the process of step S13 was performed from the time which the timer 54 has measured, and this 2nd elapsed time T2 was preset 2nd elapsed time threshold value. It is determined whether or not KT2 has been reached (step S14).

  Here, when the suction pump 37 is driven in a state where the cap 34 is in contact with the recording head 18, the drive of the pressurizing pump 28 is stopped, so that the pressure chambers of the respective choke valves 47 communicating with the cap 34 are stopped. Each choke valve 47 is closed by reducing the pressure of each 46. When the suction pump 37 is further driven, as shown in FIG. 6, the downstream side (discharge path 44) of the choke valve 47 in each ink supply path 25 is depressurized as the cap 34 is depressurized. When the negative pressure NP in the cap 34 (or in the discharge passage 44) exceeds the boiling threshold NPng (for example, “−90 KPa”), each ink supply is performed when each choke valve 47 is opened thereafter. There is a risk that the ink flowing in the path 25 toward the recording head 18 will be in a boiling state. There is a risk that fine bubbles will be deposited from the ink thus boiled.

  Therefore, in the present embodiment, even if the negative pressure NP is generated in the cap 34 by the processing in step S13, the negative pressure value is set to such a magnitude that the ink does not boil when each choke valve 47 is subsequently opened. A corresponding valve opening threshold value KNP (for example, “−80 KPa”) is detected in advance by experiments or simulations. And the time when the magnitude | size of the negative pressure NP in the cap 34 reaches | attains the magnitude | size of the valve opening threshold value KNP after the drive of the suction pump 37 was started by execution of the process of step S13 was measured, and this measurement was carried out. The time is set and stored in the ROM 52 as the second elapsed time threshold (valve opening permission time) KT2. Therefore, in the present embodiment, the ROM 52 also stores as a storage unit.

  If the determination result in step S14 is negative (T2 <KT2), the control device 50 repeatedly executes the determination process in step S14 until the determination result in step S14 becomes a positive determination. On the other hand, when the determination result in step S14 is affirmative (T2 ≧ KT2), the control device 50 starts driving the pressurizing pump 28 to open each choke valve 47 (step S15). Therefore, in this embodiment, the control apparatus 50 functions as a valve opening control means.

  Subsequently, the control device 50 obtains the third elapsed time T3 from the time when the process of step S15 is executed from the time measured by the timer 54, and the third elapsed time T3 is greater than the second elapsed time threshold KT2. It is determined whether or not the third elapsed time threshold value KT3 set to be longer is reached (step S16). The third elapsed time threshold value KT3 is a time period for setting the period for opening the choke valves 47 and discharging the ink from the nozzles 20 of the recording head 18 into the cap 34. It is set in advance.

  When the determination result in step S16 is negative (T3 <KT3), the control device 50 repeatedly executes the determination process in step S16 until the determination result in step S16 becomes a positive determination. On the other hand, when the determination result in step S16 is affirmative (T3 ≧ KT3), the control device 50 stops driving the pressurizing pump 28 and the suction pump 37 and stops non-boiling cleaning (step S17). Thereafter, the control device 50 ends the ink filling process routine.

  That is, in the ink filling process routine of this embodiment, after the normal cleaning is performed, the non-boiling cleaning in which the non-boiling state of the ink flowing in each ink supply path 25 is maintained (steps S13, S14, S15, S16, Each process of S17 is equivalent). In this non-boiling cleaning, steps S13 and S14 correspond to pressure reducing steps for reducing the pressure downstream of the choke valve 47 in each ink supply path 25 (that is, the discharge path 44). Further, in steps S15 and S16, ink is discharged from the nozzles 20 of the recording head 18 into the cap 34 by opening the choke valves 47 before the negative pressure NP in the cap 34 reaches the boiling threshold value NPng. This corresponds to the discharging step.

Next, the operation when the ink cartridge 22 is mounted on the ink jet printer 11 of this embodiment will be described below.
When each ink cartridge 22 is mounted on the cartridge holder 21, normal cleaning in which the pressure pump 28 and the suction pump 37 are driven with the cap 34 in contact with the recording head 18 is executed. Then, the ink in each ink cartridge 22 flows into each choke valve 47 via each ink tube 25 </ b> A and reaches each nozzle 20 of the recording head 18. Then, the ink is discharged from the nozzles 20 of the recording head 18 into the cap 34.

  At this time, the negative pressure NP generated in the cap 34 by driving the suction pump 37 is about “−60 KPa”. Therefore, each nozzle 20 of the recording head 18 is sufficiently filled with ink, but in each ink supply path 25 (particularly in each choke valve 47 or valve unit 19 having a complicated structure). In some cases, bubbles may remain without being sufficiently filled with ink.

  Therefore, in the present embodiment, after the normal cleaning is performed, non-boiling cleaning is performed in which ink is discharged from the nozzles 20 of the recording head 18 into the cap 34 with a suction force stronger than the normal cleaning. In this non-boiling cleaning, only the suction pump 37 is driven to generate a negative pressure NP in the cap 34, and ink is discharged from the nozzles 20 of the recording head 18 into the cap 34 by this negative pressure NP. . At this time, since the pressure pump 28 is not driven, the downstream side of the choke valve 47 in each ink supply path 25 is in a negative pressure state, and as a result, each choke valve 47 is in a closed state.

  When the suction pump 37 is further driven with the choke valves 47 closed as described above, the inside of the cap 34 is further decompressed. When the second elapsed time T2 after the start of the non-boiling cleaning starts (that is, when the suction pump 37 starts driving) reaches the second elapsed time threshold value KT2, the magnitude of the negative pressure NP in the cap 34 Is determined to have reached the valve opening threshold value KNP, and the pressurizing pump 28 starts to be driven.

  Then, ink flows into each choke valve 47 from each ink cartridge 22 via each ink tube 25A, and each choke valve 47 is opened by the pressure of the ink. As a result, the ink flowing in each ink tube 25 </ b> A is supplied to the recording head 18 through each choke valve 47 and the valve unit 19, and is discharged from each nozzle 20 of the recording head 18. At this time, the flow rate of ink in each ink supply path 25 during non-boiling cleaning is faster than the flow rate of ink during normal cleaning. Therefore, bubbles that could not be discharged from the ink supply paths 25 during normal cleaning are discharged together with ink from the nozzles 20 of the recording head 18 together with the ink. Moreover, since the magnitude of the negative pressure NP in the cap 34 does not exceed the magnitude of the boiling threshold value NPng, the ink flowing in each ink supply path 25 boiles during the non-boiling cleaning, and fine bubbles are newly deposited. There is no end to it.

Therefore, in this embodiment, the following effects can be obtained.
(1) At the time of non-boiling cleaning, the negative pressure NP on the downstream side of the choke valve (open / close valve) 47 in each ink supply path (fluid supply path) 25 is reduced in the ink supply path 25 after the choke valve 47 is opened. Each choke valve 47 is opened before the ink (fluid) reaches a boiling state. Therefore, the boiling of the ink flowing in each ink supply path 25 from the ink cartridge (fluid storage means) 22 side toward the recording head (fluid ejection head) 18 is avoided. That is, when non-boiling cleaning is performed, it is avoided that the ink flowing in each ink supply path 25 boils and gas is deposited, and the occurrence of ink ejection failure during subsequent printing is suppressed. . Therefore, the success rate of cleaning can be improved.

  (2) In this embodiment, the time from when the suction pump (suction means) 37 is started until the negative pressure NP in the cap (fluid receiving means) 34 reaches the valve opening threshold value KNP is the second elapsed time threshold value. (Valve opening permission time) KT2 is preset. Therefore, at the time of non-boiling cleaning, when the second elapsed time T2 after the drive of the suction pump 37 reaches the second elapsed time threshold value KT2, the magnitude of the negative pressure NP in the cap 34 is the valve opening threshold value KNP. It is determined that Each choke valve (open / close valve) 47 is opened to discharge ink (fluid) from each nozzle 20 of the recording head (fluid ejecting head) 18. In other words, each choke valve 47 can be opened at an accurate timing without providing a separate sensor or the like for detecting the negative pressure NP in the cap 34. Therefore, when each choke valve 47 is opened. It can be avoided that the ink flowing in each ink supply path 25 boils and fine bubbles are precipitated from the ink.

(3) In normal cleaning, since the magnitude of the negative pressure NP generated in the cap (fluid receiving means) 34 is smaller than that at the time of non-boiling cleaning, each ink supply path (fluid supply path) 25 Therefore, there is a possibility that the bubbles cannot be completely discharged together with the ink from each nozzle 20 of the recording head (fluid ejecting head) 18. Therefore, in the present embodiment, non-boiling cleaning is executed after execution of normal cleaning when the ink cartridge 22 is mounted. Therefore, the bubbles contained in the ink in each ink supply path 25 before execution of non-boiling cleaning can be reliably discharged from each nozzle 20 of the recording head 18 by execution of non-boiling cleaning.
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment in that a sensor for detecting a negative pressure in the cap 34 is provided and the contents of the ink filling process routine are provided. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. Shall.

  As shown in FIG. 7, a communication port 60 that allows the inside of the cap 34 to communicate with the outside is formed through the bottom wall portion of the cap 34 of the present embodiment separately from the discharge port 35. The upper end of the tube 61 is connected. A pressure sensor 62 for detecting the pressure (negative pressure NP) in the cap 34 is provided at the lower end of the detection tube 61. The pressure sensor 62 is electrically connected to the control device 50, and the control device 50 detects the negative pressure NP in the cap 34 based on the magnitude of the signal input from the pressure sensor 62. . Therefore, in the present embodiment, the pressure sensor 62 and the control device 50 constitute a pressure detection unit.

Next, the ink filling process routine executed by the control device 50 of the present embodiment will be described below based on the flowchart shown in FIG. 8 and the timing chart shown in FIG.
The control device 50 executes an ink filling process routine when the ink cartridge 22 is mounted on the cartridge holder 21. In this ink filling process routine, the control device 50 resets the cleaning count K to “0 (zero)” (step S20). The number of times of cleaning K indicates the number of times that the boiling allowable cleaning described later is continuously executed when the ink filling process routine is executed.

  Subsequently, the control device 50 performs boiling permissible cleaning which is a kind of chalk cleaning (step S21). Specifically, the control device 50 starts driving the suction pump 37 in a state where the cap 34 is brought into contact with the recording head 18 located at the home position by driving the lifting device. And the control apparatus 50 calculates | requires the elapsed time after the drive of the suction pump 37 started from the time which the timer 54 has measured, and the elapsed time is set to the boiling allowable time Tng (refer FIG. 9) set beforehand. It is determined whether it has been reached. As shown in FIG. 9, the permissible boiling time Tng is the time when the negative pressure NP in the cap 34 reaches the boiling threshold NPng based on the driving of the suction pump 37. It is set in advance by simulation or the like. Then, when the elapsed time since the driving of the suction pump 37 reaches the boiling allowable time Tng, the control device 50 drives the pressurizing pump 28.

  Subsequently, the control device 50 obtains the fourth elapsed time T4 from when the suction pump 37 starts to be driven from the time measured by the timer 54, and the fourth elapsed time T4 is longer than the allowable boiling time Tng. It is determined whether or not it is equal to or greater than the fourth elapsed time threshold value KT4 set to (step S22). The fourth elapsed time threshold value KT4 is a time for setting the execution time of the boiling permissible cleaning, and is set in advance by experiment, simulation, or the like. When the determination result of step S22 is negative (T4 <KT4), the control device 50 repeatedly executes the determination process of step S22 until the determination result of step S22 becomes a positive determination.

  On the other hand, when the determination result in step S22 is affirmative (T4 ≧ KT4), the control device 50 stops the boiling permissible cleaning by stopping the driving of the pressurizing pump 28 and the suction pump 37 (step S23). . Then, the control device 50 increments the cleaning number K by “1” (step S24). Subsequently, the control device 50 determines whether or not the cleaning number K incremented in step S24 has reached a predetermined number KK (for example, “3”) set in advance (step S25).

  When the determination result in step S25 is negative (K <KK), the control device 50 proceeds to step S21 described above. That is, in the present embodiment, when the ink cartridge 22 is mounted on the cartridge holder 21, the boiling permissible cleaning is continuously executed for a predetermined number of times KK. On the other hand, if the determination result in step S25 is affirmative (K = KK), the control device 50 starts driving the suction pump 37 with the cap 34 kept in contact with the recording head 18, thereby making the non-operation. The execution of boiling cleaning is started (step S26).

  Subsequently, the control device 50 detects the negative pressure NP in the cap 34 based on the signal input from the pressure sensor 62, and determines whether or not the negative pressure NP is equal to or lower than the valve opening threshold KNP (step S27). ). If this determination result is a negative determination (NP> KNP), the control device 50 determines that the inside of the cap 34 still needs to be depressurized, and the determination of step S27 is continued until the determination result of step S27 becomes a positive determination. Repeat the process. Therefore, in this embodiment, steps S26 and S27 correspond to a pressure reduction step.

  On the other hand, if the determination result of step S27 is affirmative (NP ≦ KNP), the control device 50 starts driving the pressurizing pump 28 to open each choke valve 47 (step S28). That is, in the present embodiment, as shown in FIG. 9, when the non-boiling cleaning is performed, the negative pressure NP in the cap 34 (that is, the downstream side of the choke valve 47 in each ink supply path 25) is measured, When the magnitude of the negative pressure NP reaches the magnitude of the valve opening threshold value KNP, each choke valve 47 is opened. Subsequently, the control device 50 sequentially executes steps S29 and S30 corresponding to steps S16 and S17, and ends the ink filling process routine. Therefore, in this embodiment, steps S29 and S30 correspond to the discharge step.

  As described above, when the ink cartridge 22 is mounted on the cartridge holder 21, the boiling allowable cleaning is executed a predetermined number of times KK. In this boiling permissible cleaning, each choke valve 47 is opened after the negative pressure NP in the cap 34 reaches the boiling threshold NPng, so that it exists in each ink supply path 25 before the cleaning is performed. Air (bubbles) is reliably discharged from each nozzle 20 of the recording head 18 together with the ink. However, immediately after each choke valve 47 is opened, the ink flowing in each ink supply path 25 is in a boiling state, and fine bubbles may be deposited from the ink.

  Therefore, in the present embodiment, the non-boiling cleaning is performed after the boiling allowable cleaning is performed a predetermined number of times KK. As a result, the fine bubbles deposited from the ink flowing in each ink supply path 25 in the boiling permissible cleaning are discharged from each nozzle 20 of the recording head 18 together with the ink by executing the non-boiling cleaning. Therefore, bubbles (including fine bubbles) are rarely included in the ink in each ink supply path 25 after the completion of the ink filling process routine. Therefore, ink ejection failure when printing on the paper P after the ink filling process routine is satisfactorily suppressed.

Therefore, in this embodiment, in addition to the effect (1) of the first embodiment, the following effects can be obtained.
(4) The negative pressure NP in the cap (fluid receiving means) 34 that has a negative pressure comparable to that on the downstream side of the choke valve (open / close valve) 47 in each ink supply path (fluid supply path) 25 is It is detected based on the signal. In the non-boiling cleaning, when the detected negative pressure NP reaches the valve opening threshold value KNP, the pressurizing pump 28 is driven to open the choke valves 47 respectively. Flows in each ink supply path 25 and is discharged from each nozzle 20 of the recording head (fluid ejecting head) 18. That is, the negative pressure NP in the cap 34 is measured, and the timing for opening each choke valve 47 based on the actual measurement result is set. Therefore, in the non-boiling cleaning, each ink is used when each choke valve 47 is opened. It can be avoided that the ink flowing in the supply path 25 boils and fine bubbles are deposited from the ink.

(5) In the boiling permissible cleaning, the ink flowing to the recording head (fluid ejecting head) 18 side in each ink supply path (fluid supply path) 25 may boil and fine bubbles may precipitate from the ink. . Therefore, in this embodiment, after the boiling permissible cleaning is executed, non-boiling cleaning is performed in which fine bubbles are not deposited from the ink after cleaning. Therefore, the fine bubbles generated by boiling the ink flowing in each ink supply path 25 at the time of boiling allowable cleaning can be discharged together with the ink from each nozzle 20 of the recording head 18 by non-boiling cleaning.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. Note that the third embodiment is different from the second embodiment in that a regulator is provided to keep the negative pressure in the cap 34 constant, and the contents of the ink filling processing routine. Therefore, in the following description, portions different from those of the second embodiment will be mainly described, and the same or corresponding member configurations as those of the second embodiment are denoted by the same reference numerals and redundant description is omitted. Shall.

  As shown in FIG. 10, the upper end of the detection tube 61 is connected to the communication port 60 formed through the bottom wall portion of the cap 34 of the present embodiment, and the cap 34 is connected to the lower end of the detection tube 61. A regulator 70 is provided as a negative pressure holding means that is driven when the internal pressure (negative pressure NP) exceeds a certain pressure. Then, as shown in FIG. 11, when the negative pressure NP in the cap 34 reaches the valve opening threshold KNP, the regulator 70 is driven to cap air from the regulator 70. The negative pressure NP in the cap 34 is maintained at the valve opening threshold value KNP.

Next, the ink filling process routine executed by the control device 50 of the present embodiment will be described below based on the timing chart shown in FIG.
The control device 50 executes an ink filling process routine when the ink cartridge 22 is mounted on the cartridge holder 21. In this ink filling process routine, the control device 50 sequentially executes the processes corresponding to steps S20, S21, S22, S23, S24, and S25, and then drives the suction pump 37 to perform non-boiling cleaning. Start execution. Then, the control device 50 adds the choke valves 47 to open when the fifth elapsed time from the start of the driving of the suction pump 37 becomes equal to or greater than a preset fifth elapsed time threshold value KT5. The drive of the pressure pump 28 is started.

  Note that the fifth elapsed time threshold value KT5 is determined when the regulator 70 is driven because the negative pressure NP in the cap 34 reaches the valve opening threshold value KNP based on the driving of the suction pump 37. It is a time set so that each choke valve 47 is opened in the state where The fifth elapsed time threshold value KT5 is set in advance to be longer than the second elapsed time threshold value KT2 and shorter than the third elapsed time threshold value KT3.

  Then, the control device 50 stops the driving of the pressurization pump 28 and the suction pump 37 when the third elapsed time T3 from the start of the driving of the suction pump 37 becomes equal to or greater than the third elapsed time threshold value KT3. To finish non-boiling cleaning. Thereafter, the control device 50 ends the ink filling process routine.

Therefore, in this embodiment, in addition to the effects (1) and (5) of the first and second embodiments, the following effects can be obtained.
(6) During non-boiling cleaning, the suction pump (suction means) 37 is driven to depressurize the ink supply paths (fluid supply paths) 25 downstream of the choke valves (open / close valves) 47 (that is, in the caps 34). Even so, the negative pressure NP in the cap 34 is maintained at the valve opening threshold value KNP when the regulator (negative pressure maintaining means) 70 is driven. Therefore, the negative pressure NP in the cap 34 does not become so large that the ink (fluid) flowing in each ink supply path 25 after the choke valve 47 is opened becomes a boiling state. Therefore, when each choke valve 47 is opened at the time of non-boiling cleaning, it is possible to avoid that the ink flowing in each ink supply path 25 boils and fine bubbles are deposited from the ink.

In addition, you may change each said embodiment into another embodiment as follows.
In the first embodiment described above, boiling cleaning may be executed instead of normal cleaning.

In the second embodiment, normal cleaning may be executed instead of boiling permissible cleaning.
In each of the above embodiments, the non-boiling cleaning may be performed a plurality of times instead of performing the normal cleaning or the boiling permissible cleaning.

  In each of the above embodiments, in the non-boiling cleaning, since the suction pump 37 is driven at a predetermined speed set in advance, the third elapsed time T3 after the drive of the suction pump 37 is started is the third elapsed time. The operation stops when the threshold value KT3 is exceeded. However, the non-boiling cleaning detects the number of rotations of a motor (not shown) that is a drive source of the suction pump 37, and stops when the detected number of rotations exceeds a preset number of rotations. May be. For example, when a stepping motor is used as a driving source, the number of steps of the pulse voltage supplied to the stepping motor is counted, and when the number of steps reaches a predetermined number of steps, the non-boiling cleaning is stopped. Also good.

  In each of the above embodiments, an on-off valve (for example, an electromagnetic valve) that opens and closes based on a control command from the control device 50 may be provided instead of the choke valve 47 that opens and closes due to pressure fluctuation in each ink supply path 25. . In this case, when performing the non-boiling cleaning, the suction pump 37 is driven after each on-off valve is closed, and the inside of the cap 34 is depressurized. Then, when the magnitude of the negative pressure NP in the cap 34 reaches the magnitude of the valve opening threshold KNP, the opening / closing valve is opened and the driving of the pressurizing pump 28 is started, whereby each ink supply path 25 is started. The ink is caused to flow toward the recording head 18 and the ink supplied into the recording head 18 is discharged into the cap 34. Even if comprised in this way, the effect equivalent to said each embodiment can be acquired.

  In addition, when an opening / closing valve that opens and closes based on a control command from the control device 50 is provided in the ink supply path 25, the pressurizing pump 28 may not be driven during cleaning. In this case, the cleaning is executed by the suction force exerted by the suction pump 37.

  In each of the above-described embodiments, the ink filling process routine may be executed only when the ink cartridge 22 is mounted on the ink jet printer 11 for the first time (that is, when ink is initially filled).

  In each of the above embodiments, the cap 34 is configured so that ink is sucked from each nozzle 20 of the recording head 18 when the suction pump 37 is driven with a part of the cap 34 in contact with the recording head 18. I just need it. For example, the cap 34 may be configured such that the opening thereof can come into contact with the side surface of the recording head 18 so as to be fitted outside.

  In each of the above-described embodiments, the fluid ejecting apparatus is configured so that the recording head 18 has an overall shape corresponding to the length in the width direction (left-right direction) of the paper P in the direction intersecting the conveyance direction (front-back direction) of the paper P. A so-called full line type printer may be embodied.

  In each of the above embodiments, the fluid ejecting apparatus is embodied in the ink jet printer 11. However, the present invention is not limited to this, and fluid other than ink (liquid or liquid in which particles of functional material are dispersed or mixed in the liquid) Body, and fluid bodies such as gels) may be embodied in a fluid ejecting apparatus that ejects or discharges the body. For example, a liquid material ejecting apparatus that ejects a liquid material that is dispersed or dissolved in materials such as electrode materials and color materials (pixel materials) used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. Further, a liquid ejecting apparatus that ejects a bio-organic matter used for biochip manufacturing, or a liquid ejecting apparatus that ejects a liquid that is used as a precision pipette and serves as a sample may be used. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate, a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, and a fluid ejecting apparatus that ejects a fluid such as a gel (for example, a physical gel) It may be. The present invention can be applied to any one of these fluid ejecting apparatuses. In the present specification, the term “fluid” is a concept that does not include a fluid consisting only of a gas and a fluid consisting only of a granular material (including a granular material and a powder). , Organic solvents, solutions, liquid resins, liquid metals (including metal melts), liquids, fluids, and the like.

1 is a schematic plan view of an ink jet printer according to a first embodiment. FIG. 2 is a schematic diagram illustrating an ink supply system of an ink jet printer. (A) is a schematic sectional drawing which shows the valve opening state of a choke valve, (b) is a schematic sectional drawing which shows the valve closing state of a choke valve. The block circuit diagram which shows an electric structure. 6 is a flowchart for explaining an ink filling process routine according to the first embodiment; The timing chart explaining the change of the negative pressure in a cap in a 1st embodiment. The schematic sectional drawing which shows the cap of 2nd Embodiment. 9 is a flowchart illustrating an ink filling process routine according to the second embodiment. The timing chart explaining the change of the negative pressure in a cap in a 2nd embodiment. The schematic sectional drawing which shows the cap of 3rd Embodiment. The timing chart explaining the change of the negative pressure in a cap in a 3rd embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer (fluid ejecting apparatus), 18 ... Recording head (fluid ejecting head), 20 ... Nozzle, 22 ... Ink cartridge (fluid storage means), 25 ... Ink supply path (fluid supply path), 34 ... Cap ( Fluid receiving means), 37 ... suction pump (suction means), 47 ... choke valve (open / close valve), 50 ... control device (pressure detection means, open / close valve control means), 52 ... ROM (storage means), 62 ... pressure sensor (Pressure detection means), 70 ... regulator (negative pressure maintaining means), KNP ... valve opening threshold, KT2 ... second elapsed time threshold (valve opening permission time), NP ... negative pressure, T2 ... second elapsed time.

Claims (9)

Provided in the fluid supply path when the fluid guided from the fluid storage means to the fluid ejection head side is sucked and discharged from the nozzle formed in the fluid ejection head by driving the suction means. Cleaning the fluid ejecting apparatus that discharges the fluid from the fluid ejecting head by opening the on-off valve after the downstream side of the on-off valve in the fluid supply path is depressurized with the on-off valve closed. A method,
A depressurizing step of depressurizing the downstream side of the on-off valve in the fluid supply path by driving the suction means with the on-off valve closed; and
The magnitude of the negative pressure generated downstream of the on-off valve in the fluid supply path by the pressure reducing step is that the negative pressure before the fluid in the fluid supply path becomes boiling after the on-off valve is opened. A non-boiling cleaning having a discharging step of opening the on-off valve and discharging the fluid from the fluid ejecting head when a predetermined valve opening threshold value is reached as a magnitude of How to clean the device. In the fluid ejecting apparatus, a negative pressure magnitude downstream of the on-off valve in the fluid supply path after the suction means starts driving with the on-off valve closed is the valve opening threshold. A storage means for storing in advance the elapsed time at the time of reaching the valve opening permission time is provided,
In the discharge step, the opening / closing valve is opened when an elapsed time from the start of pressure reduction downstream of the opening / closing valve in the fluid supply path by the execution of the pressure reducing step reaches the valve opening permission time. The method of cleaning a fluid ejecting apparatus according to claim 1, wherein a fluid is discharged from the fluid ejecting head using a valve. The fluid ejection device is provided with a pressure detection means for detecting a negative pressure downstream of the on-off valve in the fluid supply path,
In the discharging step, when the magnitude of the negative pressure detected by the pressure detecting means by the execution of the pressure reducing step reaches the valve opening threshold value, the on-off valve is opened and fluid is discharged from the fluid ejecting head. The method for cleaning a fluid ejecting apparatus according to claim 1, wherein the fluid ejecting apparatus is discharged. The fluid ejection device includes a negative pressure downstream of the on-off valve in the fluid supply path when the magnitude of negative pressure on the downstream side of the on-off valve in the fluid supply path reaches the valve opening threshold. Negative pressure maintaining means for maintaining the pressure level at the valve opening threshold is provided,
In the discharging step, the open / close valve is opened while the negative pressure maintaining means maintains the open pressure threshold value of the downstream side of the open / close valve in the fluid supply path at the valve opening threshold. The method of cleaning a fluid ejecting apparatus according to claim 1, wherein fluid is discharged from the fluid ejecting head. In the state where the on-off valve is closed, the downstream side of the on-off valve in the fluid supply path is depressurized, and the negative pressure on the downstream side of the on-off valve in the fluid supply path is reduced to the fluid in the fluid supply path. When the size of the liquid becomes boiling, the permissible boiling cleaning is performed to open the on-off valve and discharge the fluid from the fluid ejecting head, and the non-boiling cleaning is performed after the boiling permissible cleaning is performed. The method for cleaning a fluid ejection device according to any one of claims 1 to 4, wherein the cleaning method is performed. A normal cleaning for discharging the fluid from the fluid ejecting head by driving the suction means in a state where the open / close valve is maintained is performed, and the non-boiling cleaning is performed after the normal cleaning is performed. The cleaning method of the fluid ejecting apparatus according to any one of claims 1 to 4. A fluid storage means for storing fluid, a fluid ejection head for ejecting fluid supplied from the fluid storage means via a fluid supply path from a nozzle, an on-off valve provided in the middle of the fluid supply path, and the nozzle A fluid receiving means that comes into contact with the fluid ejecting head in a state in which fluid can be sucked, and a suction force that is exerted in a state in which the fluid receiving means is brought into contact with the fluid ejecting head, from the nozzle of the fluid ejecting head Suction means for sucking fluid and discharging it into the fluid receiving means, with the on-off valve being closed, the downstream side of the on-off valve in the fluid supply path is depressurized by the suction means, and thereafter In the fluid ejecting apparatus, the fluid is discharged from the fluid ejecting head into the fluid receiving means by opening the on-off valve.
The negative pressure on the downstream side of the on-off valve in the fluid supply path after the decompression of the fluid supply path on the downstream side of the on-off valve in the fluid supply path by the suction means is started with the on-off valve closed. However, after the opening of the on-off valve, the elapsed time when the valve opening threshold set in advance as the magnitude of the negative pressure before the fluid in the fluid supply path is in a boiling state is set as the valve opening permission time. Storage means for storing in advance;
An opening / closing valve control means for opening the opening / closing valve when an elapsed time from the start of pressure reduction downstream of the opening / closing valve in the fluid supply path by the suction means reaches the opening permission time; A fluid ejection device further comprising: A fluid storage means for storing fluid, a fluid ejection head for ejecting fluid supplied from the fluid storage means via a fluid supply path from a nozzle, an on-off valve provided in the middle of the fluid supply path, and the nozzle A fluid receiving means that comes into contact with the fluid ejecting head in a state in which fluid can be sucked, and a suction force that is exerted in a state in which the fluid receiving means is brought into contact with the fluid ejecting head, from the nozzle of the fluid ejecting head. Suction means for sucking fluid and discharging it into the fluid receiving means, with the on-off valve being closed, the downstream side of the on-off valve in the fluid supply path is depressurized by the suction means, and thereafter In the fluid ejecting apparatus, the fluid is discharged from the fluid ejecting head into the fluid receiving means by opening the on-off valve.
Pressure detecting means for detecting a negative pressure downstream of the on-off valve in the fluid supply path;
The valve opening threshold value set in advance as the magnitude of the negative pressure detected by the pressure detecting means is the magnitude of the negative pressure before the fluid in the fluid supply path is brought into a boiling state after the opening / closing valve is opened. An on-off valve control means for opening the on-off valve when the pressure reaches the fluid injection device. A fluid storage means for storing fluid, a fluid ejection head for ejecting fluid supplied from the fluid storage means via a fluid supply path from a nozzle, an on-off valve provided in the middle of the fluid supply path, and the nozzle A fluid receiving means that comes into contact with the fluid ejecting head in a state in which fluid can be sucked, and a suction force that is exerted in a state in which the fluid receiving means is brought into contact with the fluid ejecting head, from the nozzle of the fluid ejecting head. Suction means for sucking fluid and discharging it into the fluid receiving means, with the on-off valve being closed, the downstream side of the on-off valve in the fluid supply path is depressurized by the suction means, and thereafter In the fluid ejecting apparatus, the fluid is discharged from the fluid ejecting head into the fluid receiving means by opening the on-off valve.
The magnitude of the negative pressure downstream of the on-off valve in the fluid supply path is set in advance as the magnitude of the negative pressure before the fluid in the fluid supply path becomes boiling after the on-off valve is opened. Negative pressure maintaining means for maintaining a negative pressure magnitude downstream of the on-off valve in the fluid supply path at the valve opening threshold when the valve opening threshold is reached;
Open / close valve control means for opening the open / close valve when the negative pressure maintaining means maintains the open pressure threshold value of the negative pressure downstream of the open / close valve in the fluid supply path. A fluid ejection device further provided.

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