JP2009190229A - Liquid delivery device and control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To favorably maintain humidity in a capping means, while restraining a liquid from being replenished to the capping means. <P>SOLUTION: A waste liquid (ink) is stored in a reservoir tank 52 under a closed state thereof, by cleaning of sucking forcibly the ink inside of a nozzle, as shown in (a), and an evaporation amount of the ink from an opening part 42a is calculated under the condition where a cap 42 releases sealing of a printing head 23 in printing or the like. The waste liquid is returned from the reservoir tank 52 to the cap 42, based on the evaporation amount and a tank residual amount in the reservoir tank 52, as shown in (b). The waste liquid stored in the reservoir tank 52 is thereby prevented from being evaporated, and a prescribed humid state is kept thereby in the cap 42. Consequently, the humidity in the cap 42 is maintained favorably while restraining the moisturizing ink not related to the printing from being consumed wastefully. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid ejection apparatus that ejects liquid onto a target to form dots and a control method therefor.

Conventionally, this type of liquid ejecting apparatus has a recording head in which a plurality of nozzles are formed and a sponge that absorbs ink at the bottom, and a rectangular frame-shaped upper surface abuts the recording head to seal the nozzles. A cap, an ink retaining portion communicating with the cap via the first tube, a waste liquid tank communicating with the ink retaining portion via the second tube, and a tube pump for discharging the ink from the ink retaining portion to the waste liquid tank. (For example, see Patent Document 1). In this liquid ejection device, when the nozzle is sealed, the second tube is crushed by a tube pump and the communication between the ink retaining part and the waste liquid tank is interrupted, thereby using the ink in the ink retaining part communicating with the cap. The inside is moisturized.
JP 2004-291357 A

  However, in the liquid ejecting apparatus described above, since the ink retaining portion communicates with the cap via the first tube, the ink in the ink retaining portion evaporates from the cap that is opened while the nozzle is unsealed. End up. For this reason, in order to maintain moisture retention in the cap, the cap must be replenished relatively frequently, and consumption of ink unrelated to printing increases.

  The main purpose of the liquid ejection apparatus and the control method thereof according to the present invention is to keep the moisture of the capping means better while suppressing the consumption of the liquid for moisturizing.

  The present invention adopts the following means in order to achieve the above-mentioned object.

The liquid ejection device of the present invention is
A liquid ejection apparatus that ejects liquid to a target to form dots,
An ejection head in which nozzles for ejecting liquid are formed;
A moisturizing capping means for sealing the nozzle by contacting an opening with the discharge head, and opening the opening contacting the discharge head to release the sealing of the nozzle;
Storage means for storing liquid in a sealed state;
The liquid stored in the storage means can be supplied to the capping means, and the liquid in the nozzle is sucked and stored through the capping means in a state where the capping means seals the nozzle. Liquid supply means capable of being supplied to the means;
The evaporation amount of the liquid evaporated from the opening is calculated in a state where the capping unit releases the sealing of the nozzle, and a predetermined wet state of the capping unit is maintained based on the calculated evaporation amount. And a control means for controlling the liquid supply means.

  In the liquid discharge apparatus of the present invention, the liquid is stored in a sealed state by the storage means, and the evaporation amount of the liquid evaporated from the opening of the capping means in a state where the capping means releases the nozzle sealing is calculated. Then, the liquid supply unit is controlled based on the calculated evaporation amount so that the predetermined wet state of the capping unit is maintained. Thereby, evaporation of the liquid stored in the storage unit can be prevented and a predetermined wet state of the capping unit can be maintained. Therefore, it is possible to keep the moisture of the capping means better while suppressing the consumption of the moisture retaining liquid.

  In such a liquid ejection apparatus according to the present invention, the control unit calculates the storage amount of the storage unit, and the calculated storage amount is not insufficient with respect to the liquid amount to be supplied to the capping unit based on the evaporation amount. Sometimes the liquid supply means is controlled so that the amount of liquid is supplied from the storage means to the capping means, and when the calculated storage amount is insufficient with respect to the liquid amount to be supplied, the capping means It may be a means for controlling the liquid supply means so that the liquid in the nozzle is sucked in a state where the nozzle is sealed. By so doing, it is possible to replenish the storage means with liquid as necessary while maintaining the wet state of the capping means. In this aspect of the liquid ejection apparatus of the present invention, the control means is configured such that when the calculated storage amount is insufficient with respect to the liquid amount to be supplied, and when the insufficient liquid amount is equal to or less than a predetermined amount, the storage means The liquid supply means is controlled so that the liquid is supplied from the nozzle to the capping means, and the discharge head is controlled so that the liquid corresponding to the shortage is discharged from the nozzle to the capping means. Good. In this way, the timing for sucking the liquid in the nozzle can be delayed.

  In the liquid ejection apparatus according to the aspect of the invention, the control unit may supply a liquid amount of liquid to be supplied to the capping unit from the storage unit to the capping unit at a timing immediately before the capping unit seals the nozzle. It is good also as a means to control the said liquid supply means. In this way, it is possible to prevent the liquid supplied to the capping means from evaporating before sealing the nozzle.

  Furthermore, in the liquid ejection apparatus of the present invention, the control means may be means for controlling the liquid supply means so that a liquid having a liquid amount corresponding to the calculated evaporation amount is supplied to the capping means. . In this way, the liquid can be supplied to the capping means without excess or deficiency, and a constant wet state can be maintained.

  In the liquid ejection apparatus according to the present invention, the capping unit includes a timing unit capable of timing the sealing release time during which the nozzle is released from sealing. The control unit includes the timed sealing release time. It may be a means for calculating the evaporation amount based on the above. In this way, the evaporation amount can be calculated with high accuracy. In this case, the time measuring means is a means for starting time measurement of the sealing release time when a dot formation instruction is given to the target and ending the time measurement when the dot formation is completed. Also good.

  In the liquid ejection apparatus of the present invention, the storage means may be a means having a pressure valve that automatically discharges liquid when a pressure equal to or higher than a predetermined pressure is reached. If it carries out like this, it can prevent that the liquid overflows the capping means exceeding the maximum quantity which can be stored by the storage means.

  Furthermore, in the liquid ejection apparatus of the present invention, the capping unit may be a unit having an absorbent material that impregnates the liquid in the opening. By so doing, it is possible to prevent the liquid from being scattered when the liquid is supplied from the storage means to the capping means.

The control method of the liquid ejection apparatus according to the present invention includes an ejection head in which nozzles for ejecting liquid are formed, and an opening in which the opening is in contact with the ejection head to seal the nozzle and in contact with the ejection head A capping means for moisturizing to release the nozzle and releasing the sealing of the nozzle; a storage means for storing the liquid in a sealed state; and the capping means capable of supplying the liquid stored in the storage means to the capping means. A liquid supply means capable of sucking the liquid in the nozzle and supplying it to the storage means through the capping means in a state where the nozzle is sealed, A method of controlling a liquid ejection device for forming
The evaporation amount of the liquid evaporated from the opening is calculated in a state where the capping unit releases the sealing of the nozzle, and a predetermined wet state of the capping unit is maintained based on the calculated evaporation amount. The gist is to control the liquid supply means.

  According to the control method of the liquid ejection apparatus of the present invention, the liquid is stored in a sealed state by the storage means, and the liquid evaporates from the opening of the capping means in a state where the capping means releases the nozzle sealing. The liquid supply means is controlled so that a predetermined wet state of the capping means is maintained based on the calculated evaporation amount. Thereby, evaporation of the liquid stored in the storage unit can be prevented and a predetermined wet state of the capping unit can be maintained. Therefore, it is possible to keep the moisture of the capping means better while suppressing the consumption of the moisture retaining liquid. In this method of controlling the liquid ejection device, various aspects of the liquid ejection device of the present invention described above may be added, and steps for realizing the functions of the liquid ejection device described above may be added. May be.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of the configuration of an ink jet printer 20 which is an embodiment of the liquid ejection apparatus of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of a capping device 40.

  As shown in FIG. 1, the ink jet printer 20 of the present embodiment is attached to a carriage belt 32 and a paper feed roller 35 that is driven by a drive motor 33 to convey the paper P onto the platen 36 from the back to the front in the figure. A carriage 22 that is driven by a carriage motor 34 to reciprocate in the left-right direction (main scanning direction) along the guide 28, and mounted on the carriage 22 is yellow (Y), magenta (M), cyan (C), and black ( K) an ink cartridge 26 that individually stores ink of each color, a print head 24 in which a nozzle 23 that pressurizes each ink supplied from each ink cartridge 26 to eject ink droplets is formed, and the right end of the platen 36 A surface (hereinafter referred to as a nozzle formation surface) on which the nozzle 23 of the print head 24 is formed is sealed. In addition, a capping device 40 that performs cleaning by sucking ink in the nozzles 23 as needed, a controller 70 that controls the entire device, and various instructions from the user, as well as notifying the user of various information. The operation panel 80 is provided. A linear encoder 25 that detects the position of the carriage 22 is disposed on the rear surface of the carriage 22, and the position of the carriage 22 is managed using the linear encoder 25. The print head 24 can adopt a method of applying pressure to the piezoelectric element to deform the piezoelectric element and pressurizing the ink, and can also apply a voltage to the heating resistor (for example, a heater). It is also possible to employ a method in which the ink is pressurized with bubbles generated by heating the ink.

  As shown in FIG. 2, the capping device 40 includes a substantially rectangular parallelepiped cap 42 in which an opening 42 a is formed at an upper portion and a sponge 41 as an ink absorber for absorbing ink is disposed therein, and a bottom portion of the cap 42. The tube pump 50 attached to the stretchable tube 51 connected to the bottom, the air release valve 46 attached to the stretchable tube 45 connected to the bottom of the cap 42, and the contact between the cap 42 and the print head 24. An elevating device 48 for elevating and lowering the cap 42 to perform contact and release, and a retractable reserve tank 52 that communicates with the cap 42 via the tube 51 and stores waste liquid (ink) from the cap 42 in a sealed state. And a pressure valve 54 attached to a stretchable tube 53 connected to the bottom of the reserve tank 52. The capping device 40 seals the nozzle formation surface in a state where the print head 24 is moved to a position on the capping device 40 (hereinafter, this position is referred to as a home position) during a printing pause, and the ink in the nozzles 23 is discharged. It is used to suppress thickening (drying) or to perform flushing that ejects ink at a predetermined timing regardless of print data.

  The tube pump 50 includes a main body 50a that rotates forward (direction (1) in the figure) or reverse (direction (2) in the figure) by a motor (not shown), and a pair of rotating rollers 50b provided on the outer peripheral side of the main body 50a. A pump case 50c that suppresses movement of the tube 51 wound around the main body 50a to the outside is provided. When the tube pump 50 is driven forward, the rotation roller 50b rotates while crushing the tube 51 with the pump case 50c in accordance with the forward drive of the main body 50a, and the ink and air in the crushed tube 51 are rotated. Is discharged to the downstream (reserve tank 52) side and negative pressure is generated on the upstream (cap 42) side when the crushed portion is restored. On the other hand, when the tube pump 50 is driven in reverse, the rotating roller 50b rotates while crushing the tube 51 with the pump case 50c as the main body 50a is driven in reverse, and the ink and air in the crushed tube 51 are removed. A negative pressure is generated on the downstream side (reserve tank 52 side) when the portion discharged and crushed to the upstream side (cap 42 side) is restored. The state of the process performed by driving the tube pump 50 is shown in FIG. As shown in FIG. 3A, when the tube pump 50 is driven to rotate forward in a state where the cap 42 seals the nozzle formation surface and the atmosphere release valve 46 is closed, the tube 42 is formed by the print head 24 and the cap 42. A cleaning process for forcibly sucking the ink in the nozzle 23 by setting the internal space to a negative pressure can be performed. Of the ink sucked at this time, the portion absorbed by the sponge 41 wets the inside of the cap 42, and the portion not absorbed by the sponge 41 is discharged and stored in the reserve tank 52 by the forward rotation driving of the tube pump 50. . Further, as shown in FIG. 3B, when the tube pump 50 is driven in reverse, the cap 51 is formed by sucking the waste liquid (ink) stored in the reserve tank 52 with a negative pressure in the tube 51 on the reserve tank 52 side. The waste liquid returning process to return to 42 can be performed. The waste liquid returned at this time is absorbed by the sponge 41 and wets the cap 42. Note that when the waste liquid returning process is being performed, the reserve tank 52 slightly contracts. Further, since at least one of the pair of rotating rollers 50b of the tube pump 50 always crushes the tube 50, the waste liquid in the reserve tank 52 does not evaporate even when the opening 42a of the cap 42 is open. . In addition, the reserve tank 52 includes a pressure valve 54 below and can discharge waste liquid to a waste liquid recovery tank (not shown) via the tube 53, so that the maximum amount that can be stored is not exceeded.

  The controller 70 is configured as a microprocessor centered on the CPU 72, and can write and erase data such as a ROM 73 that stores processing programs, a RAM 74 that temporarily stores data, and a tank remaining amount R of the reserve tank 52. A flash memory 75, an interface (I / F) 76 for exchanging information with an external device, a timer 77 for executing a timing process in response to a timing command, and an input / output port (not shown) are provided. A position detection signal from the linear encoder 25, an operation signal from the operation panel 80, an on / off signal from the power switch 82, and the like are input to the controller 70 via an input port (not shown), and a print job is output from the user PC 90. Etc. are input via the I / F 76. The controller 70 also shows a control signal to the print head 24, a control signal to the drive motor 33, a control signal to the carriage motor 34, a control signal to the lifting device 48, a display command signal to the operation panel 80, and the like. In addition to the output port, print status information and the like are output to the user PC 90 via the I / F 76.

  The operation of the ink jet printer 20 of the embodiment configured in this way will be described. FIG. 4 is a flowchart illustrating an example of a main routine executed by the CPU 72 of the controller 70. This routine is executed every predetermined timing (for example, every several milliseconds) after the power of the inkjet printer 20 is turned on.

  When the main routine is executed, the CPU 72 first determines whether or not it is a cleaning timing (step S100). Here, the cleaning timing includes a timing immediately after the replacement of the ink cartridge is completed or when a cleaning request generated when the user instructs cleaning from the operation driver 60 or the printer driver installed in the user PC 90 is used. Yes, it is determined whether or not this timing is met. If it is determined in step S100 that it is the cleaning timing, the cleaning processing routine illustrated in FIG. 5 is executed (step S200), and this routine is terminated. Hereinafter, the description of the main routine will be interrupted, and the cleaning process routine of FIG. 5 will be described.

  When the cleaning process routine is executed, the CPU 72 first executes a cleaning process (step S210). In the cleaning process, the tube pump 50 is driven to rotate forward in a state where the cap 42 seals the nozzle forming surface and the air release valve 46 is closed, and the internal space formed by the print head 24 and the cap 42 is set to a negative pressure. Then, the ink in the nozzle 23 is forcibly sucked. Note that the driving time of the tube pump 50 is set to a predetermined time that is obtained in advance through experiments or the like and stored in the ROM 73 as a time required for cleaning. By this cleaning process for a predetermined time, ink of a predetermined suction amount Qcl is sucked into the cap 42 from the nozzle 23. When the cleaning process is performed, the tank remaining amount R of the reserve tank 52 registered in the flash memory 75 is updated (step S220). Here, at the timing when the cleaning request from the user is received, it can be considered that the cap 42 seals the nozzle forming surface before the cleaning process, and the sponge 41 sufficiently absorbs the ink. The replacement of the ink cartridge normally does not require much time, so it can be considered that the sponge 41 sufficiently absorbs the ink immediately after the replacement. Therefore, considering only the balance of the ink amount, the ink of the suction amount Qcl sucked from the nozzle 23 to the cap 42 is discharged to the reserve tank 52 without being absorbed by the sponge 41. Therefore, a value (R + Qcl) obtained by adding the suction amount Qcl to the tank remaining amount R already registered is updated as the tank remaining amount R. Since the ink is not stored in the reserve tank 52 at the time of shipment, the default value of the tank remaining amount R is set to 0. When the tank remaining amount R is updated, it is determined whether or not the updated tank remaining amount R exceeds the maximum amount Rmax that can be stored in the reserve tank 52 (step S230). Here, since the reserve tank 52 includes the pressure valve 54, the ink is automatically discharged when the storage amount is likely to exceed the maximum amount Rmax. Therefore, when the updated tank remaining amount R exceeds the maximum amount Rmax, the tank remaining amount R is corrected to the maximum amount Rmax (step S240), and this routine is terminated. On the other hand, when the maximum amount Rmax is not exceeded, this routine is ended as it is.

  Returning to the main routine of FIG. 4, if it is not the cleaning timing in step S100, it is determined whether or not there is a print request (step S300). Here, the print request is generated when the user instructs printing from the printer driver installed in the user PC 90. If there is no print request, this routine is terminated as it is. If there is a print request, the print processing routine illustrated in FIG. 6 is executed (step S400), and this routine is terminated. Hereinafter, the print processing routine of FIG. 6 will be described.

  When the print processing routine is executed, the CPU 72 first releases the sealing of the nozzle forming surface of the cap 42 (step S410). The release of the sealing is performed by controlling the lifting device 48 so that the cap 42 at the position in contact with the nozzle formation surface of the print head 24 is lowered to a predetermined position. When the sealing is released, time measurement by the timer 77 is started (step S420), print data is created based on the print job, and printing processing is started (step S430). In the printing process, the carriage motor 34 controls the drive motor 33 so that the paper P is conveyed in the sub-scanning direction by the conveyance roller 35 and discharges ink from the nozzles 23 of the print head 24 with scanning in the main scanning direction. And the print head 24 are controlled. Then, it is determined whether or not printing is finished (step S440). When printing is finished, the carriage motor 34 is controlled so that the print head 24 moves to the home position (step S450). When the print head 24 moves to the home position, the time measurement by the timer 77 is stopped (step S460), the cap moisturizing process is executed (step S470), and this routine is finished. Here, the cap moisturizing process is performed by a cap moisturizing process routine illustrated in FIG. Hereinafter, the cap moisturizing process routine of FIG. 7 will be described.

  When the cap moisturizing process routine is executed, the CPU 72 first calculates the evaporation amount Qj from the cap 42 based on the time value T of the timer 77 (step S500). Here, the evaporation amount Qj is obtained in advance by experiments or the like as a function of time f (T), and the time value T is calculated as the relationship between the time when the cap 42 is unsealed and the evaporation amount. When given, it was calculated using the function f (T). Next, the replenishment amount Qh is set (step S505). Here, the replenishment amount Qh is the amount of ink to be replenished to the sponge 41 so that the inside of the cap 42 can be maintained in a predetermined wet state. In this embodiment, the evaporation amount Qj is set as it is. When the replenishment amount Qh is set, it is determined whether or not the remaining amount R of the reserve tank 52 is greater than or equal to the replenishment amount Qh (step S510). When the remaining amount R of the tank is equal to or greater than the replenishment amount Qh, the replenishment amount Qh can be returned from the reserve tank 52 to the cap 42. Therefore, the waste liquid return that returns the waste liquid (ink) stored in the reserve tank 52 to the cap 42 Processing is performed (step S515). The waste liquid returning process is performed by dividing the replenishment amount Qh by the discharge capacity per unit time of the tube pump 50 to calculate a necessary drive time, and driving the tube pump 50 in reverse based on the calculated drive time. Subsequently, a value (R−Qh) obtained by subtracting the replenishment amount Qh from the tank remaining amount R registered in the flash memory 75 is updated as the tank remaining amount R (step S520), and the nozzle formation surface is sealed with the cap 42. (Step S555). The nozzle forming surface is sealed by controlling the lifting device 48 so that the cap 42 moves up to a position where the cap 42 is fitted to the print head 24. Then, the value of the timer T is reset (step S585), and this routine is terminated. Thereby, when the tank remaining amount R of the reserve tank 52 is not less than the replenishment amount Qh, the inside of the cap 42 can be moisturized without consuming ink. Further, the waste liquid returned to the cap 42 is absorbed by the sponge 41 and therefore does not scatter in the cap 42.

  On the other hand, when the remaining tank amount R of the reserve tank 52 is less than the replenishment amount Qh in step S510, the difference between the replenishment amount Qh and the remaining tank amount R is calculated as the deficient amount α (step S525). It is determined whether or not the quantity is equal to or less than k (step S530). Here, the predetermined amount k is set as an amount by which ink can be ejected to the cap 42 by flushing from the print head 24. When the shortage amount α is equal to or less than the predetermined amount k, the shortage amount α is set as the flushing amount Qfl in order to compensate for the shortage amount α by flushing (step S535), flushing is performed (step S540), and stored in the reserve tank 52. A waste liquid returning process is performed to return the waste liquid being stored (step S545). Here, the flushing is performed by controlling the print head 24 so that the ink of the flushing amount Qfl set from the nozzle 23 is ejected. Further, at this time, the waste liquid returning process calculates the required driving time by dividing the tank remaining amount R by the discharge capacity per unit time of the tube pump 50, and reversely drives the tube pump 50 based on the calculated driving time. Is done. By this waste liquid returning process, the amount of waste liquid that can be returned from the reserve tank 52 is substantially 0, so the tank remaining amount R registered in the flash memory 75 is cleared (step S550), and the cap 42 is obtained in step S555. In step S585, the value of the timer T is reset, and this routine ends. Thus, even when the remaining amount R of the reserve tank 52 is insufficient with respect to the replenishment amount Qh, when the shortage can be supplemented by flushing, the waste liquid stored in the reserve tank 52 is returned to the cap 42 and the shortage is reduced. Since it is supplemented by flushing, the inside of the cap 42 can be kept moist by simply ejecting a minimum amount of ink from the print head 24.

  When the shortage amount α exceeds the predetermined amount k in step S530, the cap 42 is sealed (step S560), and a cleaning process is performed (step S565). Then, the tank remaining amount R of the reserve tank 52 is updated (step S570). At this time, ink of the suction amount Qcl is sucked into the cap 42 from the nozzle 23 by the cleaning process, and the amount corresponding to the evaporation amount Qj is absorbed by the sponge 42. For this reason, the tank remaining amount R is updated to a value (R + Qcl−Qj) obtained by adding the suction amount Qcl obtained by the cleaning process to the already registered tank remaining amount R and subtracting the evaporation amount Qj. When the tank remaining amount R is updated, it is determined whether or not the updated tank remaining amount R exceeds the maximum amount Rmax that can be stored in the reserve tank 52 (step S575). The maximum amount Rmax is corrected (step S580), the value of the timer T is reset in step S585, and this routine is terminated. On the other hand, when the maximum amount Rmax is not exceeded, the value of the timer T is reset in step S585, and this routine is terminated. As a result, when the remaining amount R of the reserve tank 52 is small, a cleaning process is performed to keep the cap 42 moisturized, and ink can be discharged to the reserve tank 52 to recover the remaining amount R of the tank.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The print head 24 of this embodiment corresponds to the discharge head of the present invention, the capping device 40 corresponds to the capping means, the reserve tank 52 corresponds to the storage means, and the tube pump 50 and the tube 51 correspond to the liquid supply means. The CPU 72 of the controller 70 corresponds to the control means. Further, the timer 77 corresponds to a time measuring means. In the present embodiment, an example of the method for controlling the liquid ejection apparatus of the present invention is also clarified by describing the operation of the inkjet printer 20.

  According to the inkjet printer 20 of the present embodiment described above, the waste liquid (ink) is stored in the sealed reserve tank 52, and the opening 42a is in a state where the cap 42 releases the sealing of the nozzle formation surface. The evaporation amount Qj of the liquid to be evaporated is calculated, and the waste liquid is returned from the reserve tank 52 to the cap 42 on the basis of the evaporation amount Qj and the remaining tank amount R of the reserve tank 52, so that evaporation of the waste liquid from the reserve tank 52 is prevented. And a predetermined wet state in the cap 42 can be maintained. Therefore, it is possible to keep the moisture in the cap 42 better while suppressing consumption of the ink for moisturizing which is not related to printing.

  Further, even when the tank remaining amount R is insufficient, when the flushing can be compensated for by the flushing, the shortage is compensated for, and when the flushing cannot be compensated, the cleaning process is performed. Therefore, the ink can be supplied to the reserve tank 52 at an appropriate timing as needed. it can. Furthermore, since the ink is returned to the cap 42 immediately before the cap 42 seals the nozzle formation surface, it is possible to prevent the ink from evaporating. Since the evaporation amount Qj is set to the replenishment amount Qh as it is, the wet state in the cap 42 can be kept constant. Further, since the evaporation amount Qj is calculated based on the measured value T of the timer 77, it can be calculated with high accuracy. Further, since the reserve tank 52 has the pressure valve 54, it is possible to prevent the ink from overflowing into the cap 42. Furthermore, since the cap 42 has the sponge 41, it is possible to prevent the waste liquid supplied from the reserve tank 52 from scattering.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  In the present embodiment, the tube pump 50 performs the waste liquid returning process and the cleaning process. However, the pump for performing the waste liquid returning process and the pump for performing the cleaning process may be provided separately. Further, the present invention is not limited to the tube type pump, and any type may be used as long as it can perform waste liquid return processing and cleaning processing and can block communication between the cap 42 and the reserve tank 52.

  In the present embodiment, the shortage amount α is compensated by flushing. However, the cleaning process may be performed whenever the remaining amount R of the tank is insufficient with respect to the replenishment amount Qh without performing such flushing.

  In the present embodiment, the evaporation amount Qj is calculated based on the time value T of the timer 77. However, the evaporation amount may be calculated based on the counted number of prints without being limited to the time. Further, the evaporation amount may be calculated in consideration of temperature and humidity.

  In the present embodiment, the evaporation amount Qj is set as the replenishment amount Qh as it is, but is not limited to being set as it is, and the replenishment amount is set by adding or subtracting a predetermined amount to the evaporation amount Qj or multiplying by a coefficient. It is good.

  In the present embodiment, the waste liquid returning process is performed immediately before the cap 42 seals the nozzle formation surface. However, the present invention is not limited to this, and the evaporation amount every predetermined time after the start of printing or the evaporation every printed sheet. The waste liquid returning process may be performed according to the amount.

  In the present embodiment, the evaporation amount before replacing the ink cartridge is not considered, but may be considered. In this case, the evaporation amount may be calculated by measuring the time during which the print head 24 is moving from the home position to the ink cartridge replacement position by the timer 77.

  In the present embodiment, an example in which the liquid ejection apparatus of the present invention is embodied in a printer has been shown. However, the present invention can be applied to any apparatus that ejects liquid onto a target. For example, other liquids or functional materials other than ink can be used. You may embody in the fluid discharge apparatus which discharges the liquid body (dispersion liquid) in which particle | grains are disperse | distributed, the flow body, such as a gel. For example, a liquid discharge device that discharges a liquid in which a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, and a color filter is dissolved, or a liquid material in which the material is dispersed It is good also as a liquid discharge apparatus which discharges the liquid used as a liquid material discharge apparatus which discharges, and a sample used as a precision pipette. Also, a liquid ejection device that ejects a transparent resin liquid such as an ultraviolet curable resin onto a substrate to form a micro hemispherical lens (optical lens) used for an optical communication element or the like, an acid or an alkali to etch the substrate, etc. It is good also as a liquid discharge apparatus which discharges etching liquids, such as a flow body discharge apparatus which discharges gel.

  In the above-described embodiment, the printer is configured to have only the printing function. However, it may be a multi-function printer having a scanner function or a FAX apparatus.

1 is a configuration diagram showing an outline of the configuration of an inkjet printer 20. The block diagram which shows the outline of a structure of the capping apparatus 40. FIG. Explanatory drawing which shows the mode of the process performed by driving the tube pump. The flowchart which shows an example of a main routine. 7 is a flowchart illustrating an example of a cleaning processing routine. 6 is a flowchart illustrating an example of a print processing routine. The flowchart which shows an example of a cap moisturizing process routine.

Explanation of symbols

  20 Inkjet printer, 22 Carriage, 23 Nozzle, 24 Print head, 25 Linear encoder, 26 Ink cartridge, 28 Guide, 32 Carriage motor, 33 Drive motor, 34 Carriage motor, 35 Carrying roller, 36 Platen, 40 Capping device, 41 Sponge, 42 Cap, 42a Opening, 45, 51, 53 Tube, 46 Air release valve, 48 Lifting device, 50 Tube pump, 50a Body, 50b Rotating roller, 50c Pump case, 52 Reserve tank, 54 Pressure valve, 70 Controller 72 CPU, 73 ROM, 74 RAM, 75 flash memory, 76 I / F, 77 timer, 80 operation panel, 82 power switch, 90 user PC.

Claims (10)

A liquid ejection apparatus that ejects liquid to a target to form dots,
An ejection head in which nozzles for ejecting liquid are formed;
A moisturizing capping means for sealing the nozzle by contacting an opening with the discharge head, and opening the opening contacting the discharge head to release the sealing of the nozzle;
Storage means for storing liquid in a sealed state;
The liquid stored in the storage means can be supplied to the capping means, and the liquid in the nozzle is sucked and stored through the capping means in a state where the capping means seals the nozzle. Liquid supply means capable of being supplied to the means;
The evaporation amount of the liquid evaporated from the opening is calculated in a state where the capping unit releases the sealing of the nozzle, and a predetermined wet state of the capping unit is maintained based on the calculated evaporation amount. And a control means for controlling the liquid supply means.   The control unit calculates a storage amount of the storage unit, and when the calculated storage amount is not insufficient with respect to the liquid amount to be supplied to the capping unit based on the evaporation amount, the liquid of the liquid amount is stored in the storage unit. The liquid supply means is controlled to be supplied from the means to the capping means, and the capping means seals the nozzle when the calculated storage amount is insufficient with respect to the liquid amount to be supplied. 2. A liquid ejection apparatus according to claim 1, wherein said liquid supply means is controlled so that the liquid in said nozzle is sucked.   The control means may supply the liquid from the storage means to the capping means when the calculated storage amount is insufficient with respect to the liquid amount to be supplied, and when the insufficient liquid amount is a predetermined amount or less. The liquid ejection apparatus according to claim 2, wherein the liquid ejection unit is a unit that controls the liquid supply unit and controls the ejection head so that the liquid corresponding to the shortage is ejected from the nozzle to the capping unit.   The control means controls the liquid supply means so that a liquid amount of liquid to be supplied to the capping means is supplied from the storage means to the capping means at a timing immediately before the capping means seals the nozzle. The liquid ejection apparatus according to claim 1, which is a means.   5. The liquid ejection according to claim 1, wherein the control unit is a unit that controls the liquid supply unit so that a liquid having a liquid amount corresponding to the calculated evaporation amount is supplied to the capping unit. apparatus. The liquid ejection device according to any one of claims 1 to 5,
A timing means capable of timing the sealing release time during which the capping means releases the sealing of the nozzle;
The liquid ejecting apparatus, wherein the control means is a means for calculating an evaporation amount based on the measured sealing release time.   The time measuring means is means for starting time measurement of the sealing release time when an instruction to form dots on a target is given, and ending time measurement when the dot formation is completed. Liquid ejection device.   8. The liquid ejection apparatus according to claim 1, wherein the storage means is a means having a pressure valve that automatically discharges liquid when a pressure equal to or higher than a predetermined pressure is reached.   9. The liquid ejection apparatus according to claim 1, wherein the capping unit is a unit having an absorbent material impregnated with liquid in the opening. A discharge head in which a nozzle for discharging liquid is formed, and an opening is brought into contact with the discharge head to seal the nozzle, and the opening in contact with the discharge head is opened to release the sealing of the nozzle. A moisturizing capping means, a storage means for storing liquid in a sealed state, and a liquid stored in the storage means can be supplied to the capping means, and the capping means seals the nozzle. And a liquid supply unit capable of sucking the liquid in the nozzle and supplying the liquid to the storage unit via the capping unit, and controlling the liquid discharge apparatus to discharge the liquid to the target to form dots. And
The evaporation amount of the liquid evaporated from the opening is calculated in a state where the capping unit releases the sealing of the nozzle, and a predetermined wet state of the capping unit is maintained based on the calculated evaporation amount. A method for controlling a liquid ejection apparatus for controlling the liquid supply means.

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