JP2007276439A - Liquid ejection device and cleaning method for liquid ejection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection device capable of suppressing the occurrence of poor liquid ejection from a liquid ejection head even when plural kinds of cleaning patterns to which different liquid suction forces from inside the liquid ejection head are imparted, and a cleaning method for the liquid ejection device. <P>SOLUTION: When a cleaning mechanism performs cleaning, a control part selects a cleaning pattern to be applied to the cleaning from among plural kinds of cleaning patterns to which different suction flow velocities of ink from inside the liquid ejection head are imparted so as to enable the cleaning based on the selected cleaning pattern to be executed. When the selected cleaning pattern is a medium cleaning pattern or a strong cleaning pattern, the control part enables an EEPROM to store starting-point time information T when the cleaning is finished. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus such as an ink jet printer, and a liquid ejecting apparatus cleaning method for cleaning a liquid ejecting head provided in the liquid ejecting apparatus.

  In general, as a liquid ejecting apparatus that ejects liquid from a recording head as a liquid ejecting head to a target, an ink jet printer that ejects ink (liquid) onto a recording sheet (target) (hereinafter simply referred to as “printer”). )It has been known. The printer includes a recording head mounted on a carriage that reciprocates along the main scanning direction, and a recording paper conveyance mechanism that conveys the recording paper in the sub-scanning direction. The recording head is supplied from within the cartridge. Nozzles for ejecting ink toward the recording paper are formed (for example, Patent Document 1).

  The printer described in Patent Document 1 includes a cap that can seal the nozzle formation surface of the recording head. When the suction pump is driven with the cap sealing the nozzle formation surface, the recording head is cleaned by the suction action of the suction pump. As a result of the cleaning being performed, the thickened ink and air bubbles are removed from the inside of the recording head. As a result, ink ejection failure (ejection failure) during printing is suppressed. Incidentally, the types of cleaning performed in this printer include manual cleaning that is performed based on the operation of a switch (cleaning start means) by an operator, timer cleaning that is performed at predetermined intervals, There are various cleanings such as replacement cleaning performed at the time of cartridge replacement. Note that timer cleaning refers to cleaning that is performed after a predetermined time has elapsed from the time indicated by the time information stored in time information storage means (for example, EEPROM: Electronically Erasable and Programmable Read Only Memory).

In the printer described in Patent Document 1, when any one of the above cleanings is performed, time information at the end of the cleaning is stored in the time information storage unit. This time information is starting time information indicating the time that is the starting point of the elapsed time until the next timer cleaning is executed, and is always updated to the time information at the end of cleaning each time cleaning is executed. Is done. For this reason, in the printer described in Patent Document 1, the timer cleaning is not performed immediately after the cleaning other than the timer cleaning is performed, so that the timer cleaning is not performed more than necessary and the ink is unnecessary. Consumption is controlled.
JP 2000-289229 A

  By the way, in each of the above-described cleanings, a plurality of types of cleaning patterns may be set recently that have different suction forces of ink from the recording head by the suction pump even when the same type of cleaning is performed. For example, in timer cleaning, a weak pattern having the smallest ink suction force, a medium pattern having a medium ink suction force, and a strong pattern having the largest ink suction force are set. Normally, when bubbles are generated in the recording head, when the medium pattern and the strong pattern are executed, the bubbles in the recording head are surely removed by the cleaning. On the other hand, when the weak pattern is executed, there is a difference in the suction force of the ink from the recording head in each cleaning pattern, such as removing thickened ink and foreign matter in the vicinity of the nozzle opening.

  However, in the printer described in Patent Document 1, the starting point time information stored in the time information storage unit is the time when the cleaning based on the weak pattern ends even when the weak pattern cleaning as described above is executed. The information is updated, and measurement of the elapsed time from the update time until the next timer cleaning is executed again has been started. Therefore, if manual cleaning and replacement cleaning are not performed after that, the period until the next timer cleaning is performed becomes long. Therefore, when bubbles remain in the recording head, the bubbles are removed with time. There was a risk of becoming larger. As a result, there has been a problem that the flow of ink in the recording head is hindered by such a large bubble, and ink ejection failure occurs during printing.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide liquid ejection even when a plurality of types of cleaning patterns having different liquid suction forces from the liquid ejection head are set. An object of the present invention is to provide a liquid ejecting apparatus and a liquid ejecting apparatus cleaning method capable of suppressing the occurrence of defective ejection of liquid from a head.

  In order to achieve the above object, a liquid ejecting apparatus of the invention includes a cleaning unit that performs cleaning of the liquid ejecting head by sucking liquid from a nozzle formed on a nozzle forming surface of the liquid ejecting head. A liquid ejecting apparatus that performs at least one type of cleaning including timer cleaning that is executed every elapse of a predetermined time set in advance by a cleaning unit, wherein the liquid is related to a cleaning pattern in cleaning performed by the cleaning unit. A pattern storage means for storing a plurality of types of cleaning patterns having a difference in the suction force of the liquid from the ejection head, and a time that is a starting point for counting the elapsed time until the next timer cleaning is executed by the cleaning means. Time information that stores the starting time information A memory selection means, a pattern selection means for selecting a cleaning pattern in the cleaning from the cleaning patterns stored in the pattern storage means when the cleaning means performs cleaning, and the pattern selection means selects the cleaning pattern. The cleaning unit is controlled so that cleaning based on the cleaning pattern is executed, and the selected cleaning pattern is configured so that the suction force of the liquid from the nozzle of the liquid ejecting head among the cleaning patterns is relative. Control means for storing time information at the time of completion of cleaning based on the cleaning pattern as the starting time information in the time information storage means when the cleaning pattern has a large setting.

  According to the present invention, the time at which the cleaning ends is performed only when the cleaning is performed based on the cleaning pattern that is set with a relatively large suction force of the liquid from the liquid ejecting head among the plurality of types of cleaning patterns. Information is stored as starting time information in the time information storage means. That is, when cleaning based on a cleaning pattern (so-called weak pattern) in which the liquid suction force from the liquid ejecting head is relatively small is executed, the starting time information stored in the time information storage unit is updated. It will never be done. Therefore, even if cleaning other than timer cleaning is not performed once after the cleaning based on such a weak pattern is completed, the time information storage unit stores the above-mentioned weak pattern without updating at the end of the cleaning of the weak pattern. Timer cleaning is reliably executed after a predetermined time has elapsed from the time indicated by the starting time information. By executing the timer cleaning, it is possible to suppress the bubble from growing greatly in the liquid ejecting head, and as a result, it is possible to suppress the occurrence of liquid ejection failure during printing. Therefore, even when a plurality of types of cleaning patterns having different liquid suction forces from the liquid ejecting head are set, it is possible to suppress the occurrence of defective liquid ejection from the liquid ejecting head.

  In the liquid ejecting apparatus according to the aspect of the invention, the cleaning unit may include a sealing unit that can seal a nozzle forming surface of the liquid ejecting head, and the nozzle formation in a state where the sealing unit seals the nozzle forming surface. And suction means driven to suck liquid from the nozzles on the surface.

  According to the present invention, the cleaning is executed by driving the suction unit in a state where the nozzle forming surface is sealed by the sealing unit. Therefore, the liquid is reliably sucked from the liquid jet head based on the negative pressure generated by the suction force of the suction means.

  In the liquid ejecting apparatus according to the aspect of the invention, the cleaning unit may include manual cleaning that is performed when the cleaning start unit that gives an opportunity to start cleaning is operated, and start time information that is stored in the time information storage unit. Timer cleaning that is performed after the predetermined time has elapsed from the time and replacement cleaning that is performed when the liquid storage unit that stores the liquid to be supplied to the nozzles of the liquid ejecting head is attached or detached can be performed.

  According to the present invention, manual cleaning and replacement cleaning can be performed in addition to timer cleaning. For this reason, even before a predetermined time has elapsed since the last cleaning, cleaning other than timer cleaning can be performed as necessary.

In the liquid ejecting apparatus according to the aspect of the invention, the pattern selection unit may select a cleaning pattern that is different from the cleaning pattern that was previously executed.
According to the present invention, when performing the next cleaning, cleaning based on a cleaning pattern other than the cleaning pattern in the previous cleaning is performed from among a plurality of cleaning patterns. Accordingly, when cleaning is performed a plurality of times, bubbles do not remain without being removed from the liquid ejecting head, while unnecessary liquid is sucked from the liquid ejecting head. There is no longer any consumption.

  In the liquid ejecting apparatus according to the aspect of the invention, each of the cleaning patterns may correspond to the suction force of the liquid from the liquid ejecting head, the suction speed of the liquid from the liquid ejecting head, and the unit time of the liquid from the liquid ejecting head. Is set based on one of the suction amount and the total suction amount of the liquid from the liquid jet head at the time of cleaning.

  In general, the difference in the suction force of the liquid from the liquid ejecting head can be rephrased as a difference in the ability to discharge bubbles from the liquid ejecting head. In this regard, in the present invention, when each cleaning pattern is set based on the speed of the suction flow rate of the liquid from the liquid ejecting head, cleaning based on the cleaning pattern having a relatively high suction flow rate is executed. Sometimes, it becomes possible to discharge bubbles together with the liquid from the liquid ejecting head. In addition, when each cleaning pattern is set based on the suction amount per unit time of the liquid from the liquid ejecting head, cleaning based on the cleaning pattern having a relatively large suction amount per unit time was performed. Sometimes, it becomes possible to discharge bubbles together with the liquid from the liquid ejecting head. In addition, when each cleaning pattern is set based on the total liquid suction amount from the liquid ejecting head at the time of cleaning, cleaning is performed based on the cleaning pattern having a relatively large total liquid suction amount at the time of cleaning. When this is done, the bubbles can be discharged together with the liquid from the liquid ejecting head.

  On the other hand, the cleaning method for a liquid ejecting apparatus according to the present invention includes at least timer cleaning that is performed every elapse of a predetermined time with respect to cleaning that sucks liquid from a nozzle formed on a nozzle forming surface of a liquid ejecting head. A method of cleaning a liquid ejecting apparatus that performs one type of cleaning, wherein when the cleaning is performed, a cleaning pattern applied in the cleaning is different from the liquid suction force from the liquid ejecting head. The cleaning pattern is selected from a plurality of types of cleaning patterns, and cleaning based on the selected cleaning pattern is performed, and the selected cleaning pattern includes a suction force of liquid from the nozzle of the liquid ejecting head among the cleaning patterns. Is relatively large When a cleaning pattern was to run the timer cleaning from time showing time information when the cleaning end after a predetermined time elapses.

  According to the present invention, the time at which the cleaning ends is performed only when the cleaning is performed based on the cleaning pattern that is set with a relatively large suction force of the liquid from the liquid ejecting head among the plurality of types of cleaning patterns. Information is stored as starting time information in the time information storage means. That is, when cleaning based on a cleaning pattern (so-called weak pattern) in which the liquid suction force from the liquid ejecting head is relatively small is executed, the starting time information stored in the time information storage unit is updated. It will never be done. Therefore, even if cleaning other than timer cleaning is not performed once after the cleaning based on such a weak pattern is completed, the time information storage unit stores the above-mentioned weak pattern without updating at the end of the cleaning of the weak pattern. Timer cleaning is reliably executed after a predetermined time has elapsed from the time indicated by the starting time information. By executing the timer cleaning, it is possible to suppress the bubble from growing greatly in the liquid ejecting head, and as a result, it is possible to suppress the occurrence of liquid ejection failure during printing. Therefore, even when a plurality of types of cleaning patterns having different liquid suction forces from the liquid ejecting head are set, it is possible to suppress the occurrence of defective liquid ejection from the liquid ejecting head.

  Hereinafter, an embodiment in which the present invention is embodied in an ink jet printer will be described with reference to FIGS. In the following description of the present specification, the terms “front-rear direction”, “left-right direction”, and “up-down direction” indicate the front-rear direction, the left-right direction, and the up-down direction indicated by arrows in FIG. .

  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 extending in the left-right direction is provided in the frame 12, and the recording paper P is fed onto the platen 13 by a paper feed mechanism configured to have a paper feed motor 14 outside the frame 12. It has become so. A rod-shaped guide member 15 is installed above the platen 13 in the frame 12 in parallel with the longitudinal direction (left-right direction) of the platen 13.

  A carriage 16 is supported on the guide member 15 such that the carriage 16 can reciprocate in the axial direction (left-right direction) with respect to the guide member 15. The carriage 16 is linked to a carriage motor 18 via a timing belt 17 stretched between a pair of pulleys 17 a provided on the rear surface in the frame 12. The carriage 16 is reciprocated along the guide member 15 by driving the carriage motor 18.

  A recording head 19 as a liquid ejecting head is mounted on the lower surface of the carriage 16, and the lower surface of the recording head 19 includes a plurality of nozzles 20 (only four are shown in FIG. 2) as shown in FIG. 2. The nozzle forming surface 19a is formed. A cartridge 21 as a liquid storage unit is detachably mounted on the carriage 16 above the recording head 19, and ink as a liquid is accommodated in the cartridge 21 so as to be supplied to the recording head 19. ing.

  The ink in the cartridge 21 is supplied from the cartridge 21 to the recording head 19 by driving a piezoelectric element (not shown) provided in the recording head 19, and is fed onto the platen 13 from each nozzle 20 of the recording head 19. The recording paper P is discharged (jetted). That is, printing is performed on the recording paper P. Also, a cleaning mechanism (cleaning means) 23 for cleaning the nozzle forming surface 19a of the recording head 19 at the time of non-printing is provided near the home position region provided in the non-printing region located at the right end portion in the frame 12. It has been.

Next, the cleaning mechanism 23 will be described with reference to FIG.
As shown in FIG. 2, the cleaning mechanism 23 includes a cap (sealing means) 24 having a bottomed square box shape, and an elevating device 25 for moving the cap 24 in the vertical direction. When the carriage 16 is moved to the home position area, the cleaning mechanism 23 raises the cap 24 by the lifting device 25 so that the nozzle formation surface 19 a (each nozzle 20) of the recording head 19 is moved by the cap 24. It is designed to be sealed. Further, a protrusion 27 projects downward from the bottom wall of the cap 24, and a discharge path 27 a for discharging ink from the cap 24 extends along the vertical direction in the protrusion 27. Is formed through.

  An upper end portion 29 a of a discharge tube 29 made of a flexible material is connected to the protrusion 27, and a lower end portion 29 b of the discharge tube 29 is inserted into the waste ink tank 30. A suction pump 31 is disposed in the middle of the discharge tube 29 between the cap 24 and the waste ink tank 30. When the suction pump 31 is driven, ink is sucked from each nozzle 20 of the recording head 19 and flows in the discharge tube 29, and is discharged into the waste ink tank 30 from the lower end portion 29 b of the discharge tube 29. It has become so. In the waste ink tank 30, a waste ink absorbing material 32 made of a porous member is accommodated.

Next, the electrical configuration of the ink jet printer 11 will be described with reference to FIG.
As shown in FIG. 3, the ink jet printer 11 includes a control unit 40 as a control unit, and the control switch 40 is operated by an operation switch (operation switch operated to give an opportunity to start cleaning by the cleaning mechanism 23). Cleaning start means) SW is electrically connected. The operation switch SW is configured to output an operation signal that triggers the start of cleaning to the control unit 40 when operated by a user, for example. Further, the paper feed motor 14, the carriage motor 18, the lifting device 25, the suction pump 31, and the like are electrically connected to the control unit 40. The motors 14 and 18, the lifting device 25, the suction pump 31, and the like are controlled by the control unit 40 in their driving states. Further, the control unit 40 is connected in a communicable state with a host computer 50 as an external device.

  The host computer 50 includes a main body 51, an input device 52 such as a keyboard and a mouse, and a display unit 53. In the main body 51, a printer driver 54 as a computer program is constructed by a program and a CPU (not shown). The printer driver 54 executes processing for converting image data and document data into print data, processing for attaching setting information such as the number of paper sheets and paper size to the print data, and the like. The print data converted by the printer driver 54 is transmitted from the host computer 50 to the ink jet printer 11 and received by the interface 41 of the ink jet printer 11. The control unit 40 performs drive control of the paper feed motor 14 and the carriage motor 18 in order to perform printing on the recording paper P based on the received print data.

  In the control unit 40, an interface 41, a CPU 42, a ROM 43, a RAM 44, an EEPROM (Electronically Erasable and Programmable Read Only Memory) 45, an RTC (Real Time Clock) 46, and the like are provided. The ROM 43 stores various control programs for controlling the ink jet printer 11, various information (a table showing each cleaning pattern described later, and a predetermined time), and the like. The RAM 44 stores various information that can be appropriately rewritten while the ink jet printer 11 is being driven.

  The EEPROM 45 stores various types of information (such as starting time information and a cleaning counter described later) that should not be erased even when the ink jet printer 11 is turned off. Therefore, in this embodiment, the control part 40 provided with EEPROM45 functions also as a time information storage means. In addition, the RTC 46 can measure the time while the ink jet printer 11 is powered on, and even when power is supplied from a capacitor (not shown) even after the ink jet printer 11 is powered off. Has been. When the control unit 40 receives time information indicating the current time at the time, for example, when receiving print data from the host computer 50 described above, the control unit 40 counts the time on the RTC 46 based on the received time information. The corrected time is corrected.

Next, the table stored in the ROM 43 will be described with reference to FIG.
The table shown in FIG. 4 shows a plurality of types (seven types in the present embodiment) of cleaning patterns applied in the cleaning performed by the cleaning mechanism 23 of the present embodiment. That is, in the predetermined area of the ROM 43, each cleaning pattern is classified and stored for each type of cleaning (manual cleaning, timer cleaning, replacement cleaning). Therefore, in this embodiment, the control part 40 provided with ROM43 functions also as a pattern memory | storage means.

  Specifically, the manual cleaning is cleaning performed when the operation switch SW is operated, and the ink suction force from the recording head 19 based on the driving of the suction pump 31 (in this embodiment, suction) A plurality of types (three types in the present embodiment) of manual cleaning patterns MCL1, MCL2, and MCL3 are set by providing a difference in flow rate). That is, the first manual cleaning pattern MCL1 is a pattern in which the suction flow rate of ink from the recording head 19 is the slowest among the manual cleaning patterns MCL1 to MCL3. The second manual cleaning pattern MCL2 is a pattern in which the ink suction flow rate from the recording head 19 is medium among the manual cleaning patterns MCL1 to MCL3. The third manual cleaning pattern MCL3 is a pattern in which the ink suction flow velocity from the recording head 19 is the fastest among the manual cleaning patterns MCL1 to MCL3. In the present embodiment, the second manual cleaning pattern MCL2 and the third manual cleaning pattern MCL3 have a relatively fast (high) suction flow velocity (suction force) of ink from the recording head 19 due to the drive of the suction pump 31. ) Set cleaning pattern.

  The timer cleaning is cleaning that is executed after a predetermined time (for example, seven days) has elapsed from the time indicated by the starting time information T (see FIG. 5) stored in the EEPROM 45. In the timer cleaning, a plurality of types (three types in this embodiment) of timer cleaning patterns TCL1 are provided by making a difference in the suction force (suction flow velocity) of the ink from the recording head 19 based on the driving of the suction pump 31. , TCL2 and TCL3 are set. That is, the first timer cleaning pattern TCL1 is a pattern in which the suction flow rate of ink from the recording head 19 is the slowest among the timer cleaning patterns TCL1 to TCL3. The second timer cleaning pattern TCL2 is a pattern in which the ink suction flow rate from the recording head 19 is medium among the timer cleaning patterns TCL1 to TCL3. The third timer cleaning pattern TCL3 is a pattern in which the ink suction flow rate from the recording head 19 is the fastest among the timer cleaning patterns TCL1 to TCL3. In the present embodiment, the second timer cleaning pattern TCL2 and the third timer cleaning pattern TCL3 have a relatively fast (large) suction flow velocity (suction force) of ink from the recording head 19 due to the driving of the suction pump 31. ) Set cleaning pattern.

  Furthermore, the replacement cleaning is performed when the cartridge 21 is attached / detached and replaced, and one type of replacement cleaning pattern CCL is set. The replacement cleaning pattern CCL is set so that ink can be sucked at a flow rate comparable to that of the third manual cleaning pattern MCL3 and the third timer cleaning pattern TCL3 described above. Therefore, in this embodiment, the replacement cleaning pattern CCL is also a cleaning pattern in which the suction flow rate (suction force) of ink from the recording head 19 due to the driving of the suction pump 31 is relatively fast (large). .

  The cleaning patterns MCL1 to MCL3, TCL1 to TCL3, and CCL can be classified into three types according to the difference in the suction flow velocity (suction force) of the ink from the recording head 19 when the cleaning based on each pattern is executed. It is. That is, the first manual cleaning pattern MCL1 and the first timer cleaning pattern TCL1 are classified as weak cleaning patterns because the suction flow rate of ink from the recording head 19 is set low. The second manual cleaning pattern MCL2 and the second timer cleaning pattern TCL2 are classified as medium cleaning patterns because the ink suction flow rate from the recording head 19 is set to a medium level. The third manual cleaning pattern MCL3, the third timer cleaning pattern TCL3, and the replacement cleaning pattern CCL are set to the strong cleaning pattern because the ink suction flow rate from the recording head 19 is the fastest setting.

  When cleaning based on the weak cleaning pattern is executed, the suction force of the ink by driving the suction pump 31 is not so strong. Therefore, if bubbles are generated in the recording head 19, the bubbles are generated. The ink may remain in the cap 24 without being discharged. On the other hand, when the cleaning based on the medium cleaning pattern or the strong cleaning pattern is executed, since the ink suction force by the suction pump 31 is sufficiently strong, even if bubbles are generated in the recording head 19. The bubbles are reliably discharged into the cap 24 together with the ink.

  Next, a cleaning processing routine for causing the cleaning mechanism 23 to perform cleaning among control processing routines executed by the control unit 40 of the present embodiment will be described with reference to FIG.

  Now, the control unit 40 executes a cleaning process routine at predetermined intervals (for example, every 0.1 second). In this cleaning processing routine, the control unit 40 determines whether or not the carriage 16 is located in the home position region (step S10). If this determination result is a negative determination, the control unit 40 determines that the carriage 16 is moving in the left-right direction in the printing area, and ends the cleaning processing routine. On the other hand, when the determination result of step S10 is affirmative, the control unit 40 determines whether or not the cartridge 21 has been replaced (step S11). When the determination result is affirmative, the control unit 40 determines that the cartridge 21 has been attached / detached and the process proceeds to step S20 described later.

  On the other hand, when the determination result of step S11 is negative, the control unit 40 determines whether or not the operation switch SW has been operated (step S12). That is, the control unit 40 determines whether an operation signal from the operation switch SW is input. And when the determination result of step S12 is affirmation determination, the control part 40 transfers the process to step S14 mentioned later. On the other hand, when the determination result in step S12 is negative, the control unit 40 reads the starting time information T from the EEPROM 45 into the RAM 44, reads out the time counted by the RTC 46 into the RAM 44, and reads the starting time information from the EEPROM 45. It is determined whether or not a predetermined time KTTCL set in advance has elapsed from the time indicated by T (step S13). This predetermined time KTTCL is the time from when the cleaning based on the middle cleaning pattern or the strong cleaning pattern is executed until the occurrence of ink ejection failure due to the generation of bubbles in the recording head 19. In advance, it is set by experiment or simulation.

  If the determination result in step S13 is negative, the control unit 40 determines that the elapsed time from the time indicated by the starting time information T stored in the EEPROM 45 has not reached the predetermined time KTTCL, and performs the cleaning process. End the routine. On the other hand, when the determination result of step S13 is affirmative determination, the control unit 40 determines that the elapsed time from the time indicated by the start time information T stored in the EEPROM 45 has reached the predetermined time KTTCL, and performs the process. The process proceeds to step S14.

  In step S14, the control unit 40 reads the cleaning counter KK from the EEPROM 45, and determines whether or not the cleaning counter KK is “1”. The cleaning counter KK is for selecting a cleaning pattern (weak, medium, strong cleaning pattern) to be selected when cleaning is executed. Therefore, in this point, in this embodiment, the control unit 40 also functions as a pattern selection unit. If the determination result in step S14 is affirmative (KK = “1”), the control unit 40 selects a weak cleaning pattern and causes the cleaning mechanism 23 to perform cleaning based on the weak cleaning pattern (step S15). ).

  That is, if the determination result in step S12 is affirmative, the control unit 40 reads the first manual cleaning pattern MCL1 from the ROM 43, and performs a cleaning mechanism to execute manual cleaning based on the first manual cleaning pattern MCL1. 23 is controlled. If the determination result in step S13 is affirmative, the control unit 40 reads the first timer cleaning pattern TCL1 from the ROM 43, and performs a cleaning mechanism to execute timer cleaning based on the first timer cleaning pattern TCL1. 23 is controlled.

  Subsequently, the control unit 40 sets the cleaning counter KK to “2” (step S16). In other words, the control unit 40 selects a medium cleaning pattern that is a cleaning pattern different from the weak cleaning pattern (first timer cleaning pattern TCL1, etc.) in the previous cleaning (the cleaning executed in step S15) in the next cleaning. Then, the cleaning counter KK is set to “2”. Then, the control unit 40 ends the cleaning process routine.

  On the other hand, if the determination result of step S14 is negative (KK ≠ “1”), the control unit 40 determines whether or not the cleaning counter KK is “2” (step S17). If this determination result is a negative determination (KK = “3”), the control unit 40 proceeds to step S20 described later. On the other hand, when the determination result of step S17 is affirmative (KK = “2”), the control unit 40 selects an intermediate cleaning pattern and executes cleaning based on the intermediate cleaning pattern (step S18).

  That is, if the determination result in step S12 is affirmative, the control unit 40 reads the second manual cleaning pattern MCL2 from the ROM 43, and performs a cleaning mechanism to execute manual cleaning based on the second manual cleaning pattern MCL2. 23 is controlled. If the determination result in step S13 is affirmative, the control unit 40 reads the second timer cleaning pattern TCL2 from the ROM 43, and performs a cleaning mechanism to execute timer cleaning based on the second timer cleaning pattern TCL2. 23 is controlled.

  Subsequently, the control unit 40 sets the cleaning counter KK to “3” (step S19). That is, in the next cleaning, the strong cleaning pattern that is a cleaning pattern different from the middle cleaning pattern (second timer cleaning pattern TCL2, etc.) in the previous cleaning (the cleaning executed in step S18) is selected. As shown, the cleaning counter KK is set to “3”. Then, the process proceeds to step S22 described later.

  In step S20, the control unit 40 selects a strong cleaning pattern and executes cleaning based on the strong cleaning pattern (step S20). That is, when the determination result in step S11 is affirmative, the control unit 40 reads the replacement cleaning pattern CCL from the ROM 43 and controls the cleaning mechanism 23 to execute replacement cleaning based on the replacement cleaning pattern CCL. If the determination result in step S12 is affirmative, the third manual cleaning pattern MCL3 is read from the ROM 43, and the cleaning mechanism 23 is controlled to execute manual cleaning based on the third manual cleaning pattern MCL3.

  If the determination result in step S13 is affirmative, the control unit 40 reads the third timer cleaning pattern TCL3 from the ROM 43, and performs a cleaning mechanism to execute timer cleaning based on the third timer cleaning pattern TCL3. 23 is controlled.

  Subsequently, the control unit 40 sets the cleaning counter KK to “1” (step S21). That is, in the next cleaning, the weak cleaning pattern that is a cleaning pattern different from the strong cleaning pattern (the third timer cleaning pattern TCL3, etc.) in the previous cleaning (the cleaning performed in step S20) is selected. Thus, the cleaning counter KK is set to “1”. Then, the process proceeds to step S22 described later.

  In step S22, the control unit 40 determines whether or not the cleaning based on the cleaning pattern set in step S18 or step S20 has been completed. When this determination result is a negative determination, the control unit 40 determines that the cleaning by the cleaning mechanism 23 is still being executed, and repeats the determination process of step S22 until the determination result of step S22 becomes an affirmative determination. Execute. On the other hand, if the determination result in step S22 is affirmative, the control unit 40 receives time information indicating the current time from the host computer 50 side via the interface 41, and uses the received time information as starting time information T. Is stored in a predetermined area of the EEPROM 45 (step S23). Thereafter, the control unit 40 ends the cleaning processing routine.

  Next, a method for cleaning the ink jet printer 11 of the present embodiment will be described below with reference to FIG. It is assumed that the operation switch SW is operated before the predetermined time KTTCL elapses after the cartridge 21 is replaced.

  When the cartridge 21 is replaced with the new cartridge 21 that is sufficiently filled with ink from the old cartridge 21 in which the amount of ink stored is small, the cleaning mechanism 23 performs replacement cleaning based on the replacement cleaning pattern CCL. Execute. That is, the cap 24 that is lifted based on the driving of the lifting device 25 seals the nozzle forming surface 19a of the recording head 19 located in the home position region. In this state, the suction pump 31 is driven, ink is discharged from the recording head 19 into the cap 24, and the discharged ink is discharged into the waste ink tank 30 via the discharge path 27 a and the discharge tube 29. Here, if bubbles are generated in the recording head 19, the replacement cleaning pattern CCL is a strong cleaning pattern, so that the bubbles in the recording head 19 are caused by the suction force of the suction pump 31. The ink is discharged into the cap 24 together with the ink by the flow of the ink.

  Then, as shown in FIG. 6, since the cleaning counter KK is set to “1” and the replacement cleaning pattern CCL is a strong cleaning pattern in the control unit 40, the starting time information stored in the EEPROM 45 is then set. T is updated to start time information T at the end of cleaning based on the replacement cleaning pattern CCL. When the operation switch SW is operated before the predetermined time KTTCL has elapsed from the time indicated by the start time information T newly stored in the EEPROM 45, the cleaning mechanism 23 performs manual cleaning based on the first manual cleaning pattern MCL1. Execute.

  Then, due to the execution of this manual cleaning, deposits (such as ink that has been thickened by evaporation of the solvent) adhering to the vicinity of the openings of the nozzles 20 of the recording head 19 are discharged into the waste ink tank 30 by driving the suction pump 31. Is done. On the other hand, the first manual cleaning pattern MCL1 in the manual cleaning in this case is a weak cleaning pattern. For this reason, when bubbles are generated in the recording head 19, the bubbles flow together with the ink in the recording head 19 due to the slow flow rate of ink in the recording head 19 based on the driving of the suction pump 31. In some cases, the ink may remain in the recording head 19 without being discharged. In the control unit 40, while the cleaning counter KK is set to “2”, the starting point time information T stored in the EEPROM 45 indicates that the first manual cleaning pattern MCL1 is a weak cleaning pattern, so Time information is not updated.

  Then, when the predetermined time KTTCL has elapsed from the time indicated by the starting time information T stored in the EEPROM 45, the cleaning counter KK is set to “2”, so that the cleaning mechanism 23 is based on the second timer cleaning pattern TCL2. Perform timer cleaning. Since the second timer cleaning pattern TCL2 is an intermediate cleaning pattern, in this cleaning, if bubbles are generated in the recording head 19, the ink in the recording head 19 due to the suction force of the suction pump 31 is used. The bubbles are discharged into the cap 24 together with the ink in the recording head 19 by the flow of. Therefore, unlike the case where bubbles have grown greatly in the recording head 19, the fluidity of the ink in the recording head 19 is hindered, and the occurrence of defective ink ejection during printing is well suppressed. Is done. That is, the strong cleaning pattern and the medium cleaning pattern can be referred to as a cleaning pattern having a relatively high bubble discharging property from the recording head 19, while the weak cleaning pattern can be referred to as a cleaning pattern having a relatively low bubble discharging property.

  In the control unit 40, since the cleaning counter KK is set to “3” and the second timer cleaning pattern TCL2 is a middle cleaning pattern, the starting point time information T stored in the EEPROM 45 is the second timer cleaning pattern. Updated to time information at the end of cleaning based on TCL2. If the operation switch SW is operated before the predetermined time KTTCL has elapsed from the time indicated by the starting time information T newly stored in the EEPROM 45, the cleaning counter KK is set to “3”, so that the cleaning mechanism 23 executes cleaning based on the third manual cleaning pattern MCL3. Then, in the control unit 40, the cleaning counter KK is set to “1”, and the starting time information T stored in the EEPROM 45 is updated to the time information at the end of cleaning based on the third manual cleaning pattern MCL3. .

Therefore, in this embodiment, the following effects can be obtained.
(1) Among a plurality of types (seven types in the present embodiment) of cleaning patterns MCL1 to MCL3, TCL1 to TCL3, and CCL, specific cleaning patterns MCL2, MCL3, TCL2, TCL3, and CCL are print heads during the cleaning execution. The ink suction flow velocity (suction force) from 19 is set to be relatively fast (large). When cleaning based on the specific cleaning patterns MCL2, MCL3, TCL2, TCL3, and CCL is executed, time information at the end of the cleaning is stored in the EEPROM (time information storage means) 45 as starting time information T. Is stored (updated). Therefore, even if no cleaning other than the timer cleaning is performed once until the predetermined time KTTCL elapses after the cleaning is completed, the timer cleaning is surely performed after the predetermined time KTTCL elapses. By executing the timer cleaning, it is possible to suppress the bubble from growing large in the recording head (liquid ejecting head) 19, and as a result, ink (liquid) ejection failure (ejection failure) occurs during printing. Is suppressed. Accordingly, even when a plurality of types of cleaning patterns MCL1 to MCL3, TCL1 to TCL3, and CCL having different ink suction flow rates from the inside of the recording head 19 are set, ink ejection failure from the recording head 19 occurs. Can be suppressed.

  (2) Cleaning is executed by driving the suction pump (suction unit) 31 in a state where the nozzle forming surface 19a of the recording head (liquid ejecting head) 19 is sealed by the cap (sealing unit) 24. Therefore, ink (liquid) can be reliably sucked from the recording head 19 based on the negative pressure generated in the cap 24 and the discharge tube 29 by the suction force of the suction pump 31.

  (3) In addition to timer cleaning, manual cleaning and replacement cleaning can be performed. Therefore, even before the predetermined time KTTCL has elapsed since the last cleaning (cleaning based on the medium cleaning pattern or the strong cleaning pattern), cleaning other than the timer cleaning can be performed as necessary.

  (4) When cleaning is performed, the control unit 40 sets the cleaning counter so that the next cleaning (manual cleaning or timer cleaning in the present embodiment) is performed with a cleaning pattern different from the cleaning pattern in the cleaning. Set KK. Therefore, at the next cleaning (manual cleaning or timer cleaning), cleaning based on a cleaning pattern other than the cleaning pattern in the previous cleaning is performed from among a plurality of cleaning patterns. Therefore, when the cleaning is performed a plurality of times, except when the replacement cleaning is continuously performed, bubbles remain in the recording head (liquid ejecting head) 19 without being removed. On the other hand, the ink is not excessively sucked from the recording head 19 and unnecessarily consumed.

The above embodiment may be changed to another embodiment (another example) as follows.
In the above embodiment, each cleaning pattern is a strong, medium, or weak pattern based on the difference in the suction amount per unit time of the ink from the recording head 19 as the difference in the suction force of the ink from the recording head 19. You may make it set. In this case, when the cleaning based on the cleaning pattern having a relatively large suction amount per unit time is executed, the bubbles can be reliably discharged from the recording head 19 together with the ink.

  Each cleaning pattern is set as a strong, medium, or weak pattern based on the difference in the total suction amount of ink from the recording head 19 at the time of cleaning as the difference in the suction force of the ink from the recording head 19. It may be. In this case, when cleaning based on a cleaning pattern with a relatively large total suction amount of ink at the time of cleaning is performed, bubbles can be reliably discharged together with ink from the recording head 19.

  In the above embodiment, the cleaning pattern for replacement cleaning may be set to a plurality of types of weak, medium, and strong by providing a difference in the ink suction flow velocity from the recording head 19. In this case, in the flowchart shown in FIG. 5, when the determination result in step S11 is affirmative, the control unit 40 may shift the process to step S14 instead of step S20.

  In the above embodiment, the timer cleaning patterns TCL1 to TCL3 may be set to a plurality of types (for example, four types) other than the three types by making a difference in the suction flow velocity of ink from the recording head 19. If a plurality of types of cleaning patterns are set for cleaning other than timer cleaning, the timer cleaning pattern may be one type.

  Similarly, the manual cleaning patterns MCL <b> 1 to MCL <b> 3 may be set to a plurality of types (for example, two types) other than the three types by making a difference in the ink suction flow velocity from the recording head 19. If a plurality of types of cleaning patterns are set for cleaning other than manual cleaning, the number of manual cleaning patterns may be one.

In the above embodiment, the manual cleaning patterns MCL1 to MCL3 need not be set.
In the above embodiment, the liquid ejecting apparatus is embodied as the ink jet printer 11, but for example, it is embodied in a liquid ejecting apparatus used for manufacturing a color filter such as a liquid crystal display or pixel formation such as an organic EL display. Also good.

1 is a schematic perspective view of an ink jet printer according to an embodiment. The schematic diagram of the cleaning mechanism in this embodiment. The block circuit diagram which shows the electric constitution in this embodiment. A table showing each cleaning pattern. The flowchart which shows a cleaning process routine. 6 is a timing chart for explaining the timing at which the cleaning counter and the starting time information are updated in the EEPROM.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer (liquid ejecting apparatus), 19 ... Recording head (liquid ejecting head), 19a ... Nozzle formation surface, 20 ... Nozzle, 21 ... Cartridge (liquid storage means), 23 ... Cleaning mechanism (cleaning means), 24 ... cap (sealing means), 31 ... suction pump (suction means), 40 ... control unit (pattern storage means, time information storage means, pattern selection means, control means), 50 ... host computer (external device), KTTCL ... Predetermined time, MCL1 to MCL3, TCL1 to TCL3, CCL ... cleaning pattern, SW ... operation switch (cleaning start means), T ... start time information.

Claims (6)

A timer that performs cleaning of the liquid ejecting head by sucking liquid from a nozzle formed on a nozzle forming surface of the liquid ejecting head, and is a timer that is executed every predetermined time set in advance by the cleaning means A liquid ejecting apparatus in which at least one type of cleaning including cleaning is performed,
A pattern storage unit that stores a plurality of types of cleaning patterns having a difference in the suction force of the liquid from the liquid ejecting head with respect to the cleaning pattern in the cleaning performed by the cleaning unit;
Time information storage means for storing start time information indicating a time that is a starting point of counting elapsed time until the next timer cleaning is performed by the cleaning means;
A pattern selection means for selecting a cleaning pattern in the cleaning from the cleaning patterns stored in the pattern storage means when the cleaning means performs cleaning;
The cleaning unit is controlled so that cleaning based on the cleaning pattern selected by the pattern selection unit is executed, and the selected cleaning pattern is transmitted from the nozzle of the liquid ejecting head among the cleaning patterns. A control unit that stores time information at the end of cleaning based on the cleaning pattern as the starting time information in the time information storage unit when the cleaning pattern has a relatively large suction force. Injection device. The cleaning unit includes a sealing unit capable of sealing the nozzle forming surface of the liquid jet head, and sucks liquid from the nozzle on the nozzle forming surface in a state where the sealing unit seals the nozzle forming surface. The liquid ejecting apparatus according to claim 1, further comprising a suction unit that is driven for the purpose. The cleaning means is executed after the predetermined time has elapsed from the time indicated by the manual time cleaning performed when the cleaning start means for giving an opportunity to start cleaning is operated and the starting time information stored in the time information storage means. 3. The liquid according to claim 1, wherein the timer cleaning that is performed and the replacement cleaning that is performed when the liquid storage unit that stores the liquid to be supplied into the liquid ejecting head is attached and detached are executable. Injection device. 4. The liquid ejecting apparatus according to claim 1, wherein the pattern selection unit selects a cleaning pattern that is different from a cleaning pattern of a cleaning performed last time. Each of the cleaning patterns corresponds to the suction force of the liquid from the liquid ejecting head, the suction speed of the liquid from the liquid ejecting head, the suction amount of the liquid from the liquid ejecting head per unit time, and at the time of cleaning The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is set based on any one of a total suction amount of liquid from the liquid ejecting head. A cleaning method for a liquid ejecting apparatus that performs at least one type of cleaning including timer cleaning that is performed every predetermined time that has been set in advance, with regard to cleaning that sucks liquid from nozzles formed on a nozzle formation surface of a liquid ejecting head Because
When performing the cleaning, a cleaning pattern applied in the cleaning is selected from a plurality of types of cleaning patterns having a difference in the suction force of the liquid from the liquid ejecting head, and the selected cleaning pattern If the selected cleaning pattern is a cleaning pattern in which the suction force of the liquid from the nozzles of the liquid ejecting head is relatively large among the cleaning patterns, the cleaning pattern is selected. A cleaning method for a liquid ejecting apparatus, wherein the timer cleaning is executed after a predetermined time has elapsed from the time indicated by the time information at the end.

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