JP2016190468A - Liquid discharge device - Google Patents

Abstract

A liquid discharge apparatus capable of realizing an appropriate purge process according to the viscosity of a liquid discharged from a nozzle. A liquid discharge apparatus includes a cartridge mounting portion having a connected portion connected to a cartridge supply portion when the cartridge is mounted, a discharge head having a nozzle for discharging a liquid, and a portion from the connected portion to the nozzle. A purge mechanism that performs a purge process, and a purge control unit that sets a purge amount discharged in the purge process according to an elapsed time from the time of cartridge replacement. The remaining amount acquisition process for acquiring the remaining amount of liquid remaining in the flow path supplied from the cartridge before replacement based on the information on the amount of liquid discharged after replacement from the nozzle, and the remaining amount A resetting process for resetting the purge amount corresponding to the cartridge before replacement to the purge amount corresponding to the cartridge after replacement when it is determined that the predetermined value has been reached; To run. [Selection] Figure 5

Description

  The present invention relates to a liquid ejection apparatus such as an ink jet printer.

  In a general ink jet printer which is an example of a conventional liquid ejecting apparatus, an ink cartridge storing liquid (hereinafter simply referred to as a “cartridge”) is mounted on a cartridge mounting portion, and ink is supplied from the cartridge to the discharge head. Ink is ejected from a plurality of nozzles of the ejection head. It is known that the viscosity of ink increases over time. In order to prevent clogging of nozzles due to thickened ink, ink jet printers are forced to use thickened ink regularly or irregularly. Processing to discharge. Such a maintenance process for discharging the thickened ink is called a purge process.

  Also, the viscosity of the ink in the cartridge tends to increase after the cartridge is opened. For this reason, in the ink jet printer disclosed in Patent Document 1, the amount of ink used in the purge process is changed according to the elapsed time from when the cartridge is replaced, that is, from when the cartridge is first mounted to when the purge process is executed. Control to determine.

JP 2006-192821 A

  By the way, there is a liquid discharge apparatus having a flow path of a certain length from the cartridge to the nozzle of the discharge head. In such a liquid ejection device, the liquid in the cartridge before replacement remains in the flow path even after the cartridge is replaced. When the control of Patent Document 1 is applied to this liquid ejection apparatus, the purge process is executed as a low-viscosity liquid even though the thickened ink of the cartridge before replacement remains in the nozzle. For this reason, an appropriate purge process according to the viscosity of the liquid discharged from the nozzle cannot be realized.

  Therefore, an object of the present invention is to provide a liquid ejection apparatus that can realize an appropriate purge process according to the viscosity of the liquid discharged from the nozzle.

In order to solve the above problem,
The liquid ejection device according to the first aspect of the present invention includes:
A cartridge having a storage chamber for storing the liquid and a supply unit for flowing the liquid in the storage chamber to the outside is replaceably mounted. When the cartridge is mounted, the cartridge is connected to the supply unit to distribute the liquid. A cartridge mounting portion having a connection portion;
An ejection head having a nozzle for ejecting the liquid supplied from the cartridge mounted on the cartridge mounting portion;
A flow path from the connected part to the nozzle;
A purge mechanism for performing a purge process for discharging liquid from the nozzle;
A purge control unit that sets a purge amount, which is a liquid amount discharged from the nozzle in one purge process, in accordance with an elapsed time from the replacement of the cartridge;
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged from the nozzle after replacement, the remaining amount of the liquid supplied from the cartridge before replacement and remaining in the flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, from the first purge amount corresponding to the first elapsed time, which is the elapsed time from the mounting of the cartridge before the replacement, from the mounting of the cartridge after the replacement A reset process for resetting the purge amount to a second purge amount smaller than the first purge amount corresponding to a second elapsed time that is an elapsed time of
Execute.

  According to the above configuration, the purge corresponding to either the pre-replacement cartridge or the post-replacement cartridge according to the remaining amount of liquid in the pre-replacement cartridge remaining in the flow path from the connected part to the nozzle Decide whether to set the amount. Thereby, an appropriate purge process according to the viscosity of the liquid discharged from the nozzle can be realized.

The liquid ejection device according to the second aspect of the present invention includes:
A cartridge having a storage chamber for storing the liquid and a supply unit for flowing the liquid in the storage chamber to the outside is replaceably mounted. When the cartridge is mounted, the cartridge is connected to the supply unit to distribute the liquid. A cartridge mounting portion having a connection portion;
An ejection head having a nozzle for ejecting the liquid supplied from the cartridge mounted on the cartridge mounting portion;
A flow path from the connected part to the nozzle;
A purge mechanism for performing a purge process for discharging liquid from the nozzle;
A purge control unit that sets a purge interval, which is a time interval from the previous purge process to the next purge process, according to an elapsed time from the replacement of the cartridge,
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged from the nozzle after replacement, the remaining amount of the liquid supplied from the cartridge before replacement and remaining in the flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, from the first purge interval corresponding to the first elapsed time, which is the elapsed time from the mounting of the cartridge before the replacement, from the mounting of the cartridge after the replacement A reset process for resetting the purge interval to a second purge interval that is larger than the first purge interval and corresponds to a second elapsed time that is an elapsed time of
Execute.

  According to the above configuration, the purge corresponding to either the pre-replacement cartridge or the post-replacement cartridge according to the remaining amount of liquid in the pre-replacement cartridge remaining in the flow path from the connected part to the nozzle Decide whether to set the interval. Thereby, an appropriate purge process according to the viscosity of the liquid discharged from the nozzle can be realized.

A liquid ejection device according to a third aspect of the present invention includes:
A plurality of cartridges each having a storage chamber for storing liquid and a supply unit for causing the liquid in the storage chamber to flow out are mounted independently and interchangeably, and are connected to the supply unit when the cartridge is mounted. And a cartridge mounting part having a connected part for circulating the liquid,
An ejection head having a plurality of nozzles for ejecting liquids supplied from a plurality of cartridges mounted on the cartridge mounting portion;
A plurality of flow paths from the connected part to the corresponding nozzle;
The amount of liquid discharged from each of the plurality of nozzles in a single purge process, and a common purge amount for the plurality of nozzles is increased as time elapses after replacement of the cartridge. A purge control unit set according to the viscosity;
A purge mechanism for performing a purge process for discharging liquid from the plurality of nozzles based on the purge amount;
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged after replacement, the remaining amount of liquid supplied from the cartridge before replacement and remaining in the corresponding flow path is calculated. Remaining amount acquisition processing to be acquired,
A resetting process for resetting the purge amount with reference to a liquid having the highest viscosity among the liquids discharged from the plurality of nozzles when it is determined that the remaining amount has reached a predetermined value;
Execute.

  According to the above configuration, the resetting process for resetting the purge amount at the timing based on the remaining amount of liquid in the cartridge before replacement remaining in the flow path from the connected part to the nozzle is executed. In the resetting process, the liquid having the highest viscosity among the liquids discharged from the nozzle is used as a reference, so that an appropriate purge process according to the viscosity of the liquid discharged from the nozzle can be realized.

A liquid ejection apparatus according to a fourth aspect of the present invention is
A plurality of cartridges each having a storage chamber for storing liquid and a supply unit for causing the liquid in the storage chamber to flow out are mounted independently and interchangeably, and are connected to the supply unit when the cartridge is mounted. And a cartridge mounting part having a connected part for circulating the liquid,
An ejection head having a plurality of nozzles for ejecting liquids supplied from a plurality of cartridges mounted on the cartridge mounting portion;
A plurality of flow paths from the connected part to the corresponding nozzle;
The purge interval, which is the time interval from the previous purge process performed simultaneously to the plurality of nozzles to the next purge process, is set according to the viscosity of the liquid that increases with the passage of time since the replacement of the cartridge. A purge control unit that is commonly set for a plurality of nozzles;
A purge mechanism for performing a purge process for discharging liquid from the plurality of nozzles based on the purge interval,
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged after replacement, the remaining amount of liquid supplied from the cartridge before replacement and remaining in the corresponding flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, a resetting process is performed in which the purge interval is reset based on a liquid having the highest viscosity among the liquids discharged from the plurality of nozzles. .

  According to the above configuration, the resetting process for resetting the purge interval at the timing based on the remaining amount of liquid in the cartridge before replacement remaining in the flow path from the connected part to the nozzle is executed. In the resetting process, the liquid having the highest viscosity among the liquids discharged from the nozzle is used as a reference, so that an appropriate purge process according to the viscosity of the liquid discharged from the nozzle can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid discharge apparatus which can implement | achieve the appropriate purge process according to the viscosity of the liquid discharged | emitted from a nozzle can be provided.

1 is a schematic plan view illustrating a configuration of an inkjet printer according to a first embodiment. It is a figure which shows the flow path of the liquid from the cartridge in the inkjet printer of FIG. 1 to a nozzle group. It is a figure which shows the structure of the purge mechanism in the inkjet printer of FIG. It is a figure which shows the structure of the control part in the inkjet printer of FIG. 2 is a flowchart showing a flow of a control operation by a purge control unit in the ink jet printer of FIG. 1. FIG. 3 is a schematic diagram showing changes in a range occupied by ink in the cartridge before replacement in the flow path of FIG. 2 and in ink after replacement in order of time series. It is a graph which shows an example of a time-dependent change of the regular purge amount set by the control operation shown in FIG. It is a flowchart which shows the flow of control operation | movement by the purge control part in the inkjet printer which concerns on 2nd Embodiment. It is a graph which shows an example of a time-dependent change of the purge interval set by the control operation | movement shown in FIG. It is a figure which shows the structure of the purge mechanism of the inkjet printer which concerns on 3rd Embodiment. It is a flowchart which shows the flow of control operation | movement by the purge control part in the inkjet printer which concerns on 3rd Embodiment. It is a flowchart which shows the flow of the acquisition process of the separate purge amount in the inkjet printer which concerns on 3rd Embodiment. It is a graph which shows an example of a time-dependent change of the periodic purge amount set by the control operation shown in FIG. It is a flowchart which shows the flow of control operation by the purge control part in the inkjet printer which concerns on 4th Embodiment. It is a flowchart which shows the flow of the acquisition process of the separate purge interval in the inkjet printer which concerns on 4th Embodiment. It is a graph which shows an example of a time-dependent change of the purge interval set by the control operation shown in FIG.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the direction in which the liquid is ejected from the ejection head is defined as the downward direction, and the opposite side is defined as the upward direction.

(First embodiment)
[overall structure]
FIG. 1 is a schematic plan view of an ink jet printer (corresponding to a liquid ejection apparatus of the present invention) 1 according to a first embodiment of the present invention. As shown in FIG. 1, the ink jet printer 1 has a pair of guide rails 2 and 3 arranged substantially parallel to each other, and the carriage unit 10 is supported on the guide rails 2 and 3 so as to be slidable in the left-right direction (scanning direction). Has been. The carriage unit 10 is joined to a timing belt 6 wound around a pair of pulleys 4 and 5, and the timing belt 6 is disposed substantially parallel to the extending direction of the guide rail 3. One pulley 4 is provided with a carriage motor 7 that is driven to rotate in the forward and reverse directions. When the pulley 4 is driven to rotate in the forward and reverse directions, the timing belt 6 reciprocates, and the carriage unit 10 moves to the guide rails 2 and 3. Scanned along. The inkjet printer 1 is provided with a control unit 60 that controls its operation, and the carriage motor 7 is controlled by the control unit 60. In FIG. 1, only a part of the control line between each component controlled by the control unit 60 and the control unit 60 is illustrated, and the others are omitted.

  A cartridge mounting portion 30 is provided in front of the right side of the guide rail 3. Cartridges 20a to 20d storing inks (liquids of the present invention) of four colors (cyan, magenta, yellow, and black) are mounted on the cartridge mounting unit 30 in an interchangeable manner independently of each other. The cartridges 20a to 20d mounted on the cartridge mounting unit 30 are supplied to the carriage unit 10 via the corresponding tubes 35a to 35d. Hereinafter, an arbitrary cartridge is referred to as “cartridge 20”. Similarly, in the following description, a configuration to which a symbol with a to d is added corresponding to each color is represented by a symbol without a to d when an arbitrary configuration is shown.

  The area in which the carriage unit 10 reciprocates has a recording area where image recording is performed on a recording sheet (not shown) as a recording medium, and a maintenance area where image recording is not performed. In the recording area, a platen 8 that supports a recording sheet is disposed below the carriage unit 10. At the time of image recording, the ejection head 12 mounted on the carriage unit 10 reciprocates left and right so as to straddle this recording area. The ejection head 12 is provided with a plurality of nozzles (hereinafter referred to as “nozzle groups”) 13a to 13d corresponding to the inks supplied from the cartridges 20a to 20d.

  Details of the ink flow path P from the cartridges 20a to 20d to the nozzle groups 13a to 13d will be described with reference to FIG. FIG. 2 shows only the ink flow path of the cartridge 20a among the cartridges 20a to 20d. Since the ink flow paths of the cartridges 20a to 20d have the same configuration, descriptions other than the ink flow paths of the cartridge 20a are omitted.

  The cartridge 20a includes a storage chamber 21 that stores ink, and a supply unit 22 that causes the ink in the storage chamber 21 to flow out. The supply unit 22 has a cylindrical outer shape, and protrudes outward from the front wall 23 along the insertion / extraction direction.

  The cartridge mounting portion 30 is provided with four connected portions 31 corresponding to the cartridges 20. The connected part 31 is connected to the supply part 22 of each cartridge 20 when each cartridge 20 is mounted, and distributes ink. Each connected portion 31 includes a holding portion 32 and a sharp cylindrical ink needle 33. The holding part 32 has a wall surface forming a cylindrical space (holding space), and when the cartridge 20 is attached to the cartridge attachment part 30, the supply part 22 is inserted into the holding space. The ink needle 33 is disposed at the center of the holding portion 32 and is formed of a tubular resin needle. The ink needle 33 is provided through the case 34 that forms the housing of the cartridge mounting portion 30, and is one end of the flexible tubes 35 a to 35 d on the outer surface side opposite to the inner surface side on which the cartridge 20 is mounted. Connected to each part.

  When the supply unit 22 is inserted into the holding unit 32, the ink needle 33 is inserted into the ink supply port of the supply unit 22. As a result, the ink stored in the storage chamber 21 can flow out to the outside. That is, the ink in the storage chamber 21 flows into the ink needle 33 from the ink inlet 36 at the end of the ink needle 33 on the cartridge side, and is further supplied to the carriage unit 10 through the tubes 35a to 35d.

  The carriage unit 10 is provided with a joint portion 41 to which the other ends of the tubes 35a to 35d are connected, and four corresponding sub tanks 43a to 43d for temporarily storing the inks supplied through the tubes 35a to 35d. It has been. The carriage unit 10 is provided with supply paths 42a to 42d for supplying ink from the tubes 35a to 35d connected to the joint portion 41 to the corresponding sub tanks 43a to 43d. Each sub tank 43 has an ink inlet 44 and an ink outlet 45. The ink inflow port 44 is located at the downstream end of the supply path 42, from which ink flows into the sub tank 43. However, the tube 35 and the supply path 42 do not need to be separate members. For example, the supply path 42 may be a part of the tube 35, and the ink inlet 44 of the sub tank 43 may be located at the downstream end of the tube 35.

  The ink outlet 45 communicates with the ink inlet 14 of the ejection head 12 via the communication path 46. The ink stored in each sub tank 43 flows out from the ink outlet 45 and is supplied into the ejection head 12 through the communication path 46 and the ink inlet 14. The discharge head 12 has a flow path unit (not shown) and an actuator (not shown). Among these, the flow path unit has a plurality of flow paths that guide the supplied ink of each color to each nozzle group 13 formed on the nozzle formation surface 15 that is the lower surface of the ejection head 12. The actuator is a piezoelectric element that is stacked on the upper surface of the flow path unit and selectively applies the discharge pressure of the ink in the flow path unit toward the nozzle group 13 for each ink color, and is controlled by the control unit 60.

  Returning to FIG. 1, the nozzle cap 51 and the waste ink tray 9 are arranged side by side below the pair of guide rails 2 and 3 in the maintenance area of the area where the carriage unit 10 moves. The nozzle cap 51 is configured to seal each nozzle group 13 of the ejection head 12 during the purge process. The nozzle cap 51 is connected to a suction pump 52 for sucking the space sealed by the nozzle cap 51 with negative pressure. The suction pump 52 is controlled by a purge control unit 61 (see FIG. 3) included in the control unit 60. The waste ink tray 9 receives the ejected ink in a flushing process for ejecting ink from each nozzle group 13 separately from the time of image recording.

  FIG. 3 shows the configuration of the purge mechanism 50. The purge mechanism 50 executes a purge process for forcibly discharging ink from each nozzle group 13. As shown in FIG. 3, in addition to the nozzle cap 51 and the suction pump 52, the purge mechanism 50 includes a switching valve 53 that switches a space sucked by the suction pump 52, and the nozzle cap 51 by moving the nozzle cap 51 up and down. Has a cap operation unit 54 for switching between a capping state in which the nozzle cap 51 is sealed and a uncapping state in which the nozzle cap 51 is not.

  The nozzle cap 51 is a plate-shaped cap body 55 having a substantially rectangular shape in plan view and positioned opposite to the nozzle forming surface on the lower surface of the ejection head 12, and a lip 56 a that rises from the upper surface of the outer periphery of the cap body 55 and is formed in an annular shape. And lips 56b to 56d that partition the space inside the lip 56a into four cap spaces S1 to S4 corresponding to the nozzle groups 13. The cap body 55 is formed with four discharge holes 57a to 57d corresponding to the cap spaces S1 to S4.

  When the suction pump 52 is driven, the air present in one space selected by the switching valve 53 among the cap spaces S1 to S4 and the thickened ink of the nozzle group 13 facing the space are drawn to the suction pump 52. The ink is discharged from the discharge hole 57 and is discharged to a waste ink tank (not shown) through the switching valve 53. Thus, the purge process of this embodiment is performed individually for the nozzle group 13 selected by the switching valve 53 among the nozzle groups 13a to 13d.

  The control unit 60 includes an arithmetic unit such as a CPU that executes various arithmetic processes and a storage unit such as a ROM and a RAM that store various programs or data. As shown in FIG. 4, the control unit 60 includes a discharge control unit 62 that controls the actuator of the discharge head 12, a head position control unit 63 that drives the carriage motor 7, a purge control unit 61 that controls the purge mechanism 50, and the like. In addition, these functional units are constructed by combining hardware such as the CPU and software stored in the ROM or the like. Each functional unit included in the control unit 60 may be configured by a single CPU or a combination of a plurality of CPUs, or a combination of a CPU and an ASIC (Application Specific Integrated Circuit). .

  The purge control unit 61 controls the purge mechanism 50 to execute a purge process. Specifically, when executing the purge process, the purge control unit 61 switches the uncapping state from the capping state by the cap operation unit 54, switches the switching valve 53, and operates the suction pump 52. Further, the purge control unit 61 includes a remaining amount acquisition unit 64 and a resetting unit 65. The remaining amount acquisition unit 64 acquires the remaining amount R of ink supplied from the cartridge before replacement and remaining in the flow path P when the cartridge is replaced. The resetting unit 65 determines whether another cartridge (for example, a cartridge after replacement or another ink color) from a purge amount or a purge interval described later corresponding to a certain cartridge (for example, a cartridge before replacement, a cartridge of a certain ink color). The purge amount or purge interval corresponding to the cartridge or the like is reset. Details of the remaining amount acquisition unit 64 and the resetting unit 65 will be described later.

[Setting the regular purge amount for each nozzle group]
In this embodiment, the purge control unit 61 automatically executes a purge process regardless of whether the inkjet printer 1 is in use. The timing for executing the purge process (including the purge execution date, which is the date for executing the purge process) is determined to be periodically executed based on the elapsed time (including the elapsed days) from the cartridge replacement. ing. Specifically, the purge control unit 61 counts the elapsed time from the cartridge replacement, and executes the purge process when the elapsed time reaches a set time (for example, 30 days). Thereafter, the next purge process is executed when the elapsed time from when the purge process is executed reaches a set time (for example, 30 days). Thus, the purge process in this embodiment is periodically executed so that the time interval from the previous purge process to the next purge process is constant.

  Further, in this embodiment, the purge control unit 61 sets a purge amount (hereinafter referred to as “periodic purge amount”) Qp, which is a liquid amount discharged in one purge process, for each of the nozzle groups 13a to 13d. It is set according to the elapsed time T from the time of cartridge replacement. Here, “one-time purge process” refers to a series of processes performed at the timing of executing the purge process. For example, the operation of discharging a certain amount of ink from the capped nozzle group 13 onto the nozzle cap 51 and discharging the ink on the nozzle cap 51 to the waste ink tank after shifting to the uncapping state is repeated several times. When a fixed amount of ink is discharged from the nozzle group 13, a series of processes repeated a plurality of times is a "single purge process". Then, the purge control unit 61 controls the suction pump 52 and the like so that the set regular purge amount Qp is discharged. Below, the setting method of the regular purge amount Qp in this embodiment is demonstrated.

  First, the relationship between the elapsed time T from the replacement of the cartridge and the appropriate periodic purge amount Qp will be described. In general, the longer the elapsed time T from the replacement of the cartridge, the higher the viscosity of the ink supplied from the cartridge. In particular, the closer to the nozzle group, the more likely it is to come into contact with air, so the viscosity tends to increase. Therefore, by setting the periodic purge amount Qp to a larger value as the elapsed time T becomes longer, an appropriate purge process for discharging ink with high viscosity is realized.

On the other hand, the ink jet printer 1 according to the present embodiment has a flow path P (see FIG. 2) from the ink inlet 36 of the ink needle 33 to the nozzle group 13. In this case, even after the cartridge is replaced, the ink of the cartridge before the replacement (hereinafter referred to as “old ink”) remains in the flow path P for a while. For this reason, in this embodiment, the remaining amount acquisition unit 64 of the purge control unit 61 acquires the remaining amount R of ink that is the amount of old ink remaining in the flow path P for a predetermined period after cartridge replacement. The acquisition process is executed, and the resetting unit 65 of the purge control unit 61 further replaces the cartridge from the periodic purge amount (first purge amount of the present invention) corresponding to the old ink based on the acquired remaining amount R. Resetting processing is executed to reset the periodic purge amount (second purge amount of the present invention) corresponding to the ink (hereinafter referred to as “new ink”). Hereinafter, the control operation of the purge control unit 61 in this embodiment will be described with reference to the flowchart of FIG. In the following description, referred to the elapsed time from the time of mounting the first cartridge and the T ₁ first elapsed time is referred to as a second elapsed time is the elapsed time T ₂ of the from time of mounting the cartridge after replacement .

As shown in FIG. 5, the purge control unit 61 determines whether or not cartridge replacement has been performed (step S11). If the cartridge replacement is determined to have been performed (at step S11 Yes), it starts counting the second elapsed time _{T 2} (step S12). Here, even when the last cartridge replacement, a first count of the elapsed time T ₁ is performed, the count after the count start of the second elapsed time T ₂ is also continued. The elapsed time counting is ended when the remaining ink amount R of the corresponding cartridge becomes equal to or less than a predetermined value (No in step S15 described later).

  Further, the purge control unit 61 starts counting the remaining ink amount R of the old ink remaining in the flow path P (step S13). This remaining ink amount R is obtained by acquiring information related to the amount of ink discharged after cartridge replacement, for example, based on the amount of operation of the actuator of the ejection head 12 and acquiring the amount of ink discharged from the nozzle group 13 after cartridge replacement. It is counted by doing. When the process of step S13 is executed, or when it is determined in step S11 that the cartridge has not been replaced (No in step S11), the process proceeds to step S14.

  In the determination process of step S14, it is determined whether or not the execution date of the determination process corresponds to the date of the purge process performed periodically. For example, it is determined whether or not an elapsed time from when the cartridge after replacement is first mounted or an elapsed time from when the previous purge process was executed has reached a set time.

  If the purge control unit 61 determines in step S14 that it is the purge execution date (Yes in step S14), it acquires the current value of the ink remaining amount R that started counting in step S13, and the ink remaining amount R is It is determined whether it is larger than a predetermined value (step S15). Here, the “predetermined value” is a value that is at least smaller than the volume of the flow path P.

Purge control section 61, when the ink remaining amount R is determined to be greater than the predetermined value (Yes in step S15), and on the basis of the first elapsed time _{T 1,} setting the periodic purge amount Qp (step S16). Specifically, the elapsed time relationship between T and periodic purge amount Qp from cartridge replacement acquires and sets a periodic purge amount Qp at the elapsed time T _1.

On the other hand, the purge control section 61, when the ink remaining amount R is determined to be equal to or smaller than the predetermined value (No at step S15), and based on the _{T 2} second elapsed time, setting a periodic purge amount Qp (step S17). That is, the periodic purge amount corresponding to the old ink is reset from the periodic purge amount corresponding to the old ink. Specifically, the relationship between the elapsed time T and the periodic purge amount Qp from the time of replacement of the cartridge, obtaining and setting a periodic purge amount Qp in the second elapsed time T _2. Note that data indicating the relationship between an arbitrary elapsed time T and an appropriate periodic purge amount Qp at that time is acquired in advance based on ink characteristics and the like, and is stored in a storage unit included in the purge control unit 61. Just keep it. In step S16 and step S17, the data in the storage unit is referred to, and the purge amount Qp at that time may be acquired.

  After step S16 or step S17, the purge control unit 61 performs a purge process to discharge the regular purge amount Qp of ink set in step S16 or step S17 from the nozzle group 13, and then returns to step S11. Moreover, also when the purge control part 61 determines with it not being a purge implementation date by step S14 (No in step S14), it returns to step S11.

  Hereinafter, with reference to FIGS. 6 and 7, the setting method of the periodic purge amount Qp before and after the cartridge replacement by the purge control unit 61 in this embodiment will be described more specifically. 6 and 7 illustrate the ink of the cartridge 20a.

  FIG. 6 is a diagram schematically showing changes in the range occupied by the ink L1 from the first cartridge C1 before replacement and the ink L2 from the second cartridge C2 after replacement in the flow path P in time series. .

The state of t = t ₁ shown in FIG. 6 shows the flow path P when the ink L1 of the first cartridge C1 is used halfway. At this time, the flow path P is filled only with the ink L1. Next, when the first cartridge C1 becomes empty, the first cartridge C1 is removed and the second cartridge C2 is mounted (t = t ₂ ). At this time, the ink L1 remains in the entire area of the flow path P. Thereafter, as the ink is discharged from the ejection head 12, the remaining amount R of the ink L1 in the flow path P decreases, and the proportion of the ink L2 from the second cartridge C2 increases (t = t _{3 to} t ₅ ). Note that t = t ₃ represents a state where the new ink L2 has reached the middle of the tube 35a, t = t ₄ represents a state where the ink L2 has reached the ink inlet 44 of the sub tank 43a, and t = t ₅ Represents a state in which the ink L2 reaches the sub tank 43a and is mixed with the ink L1. Then, at the time of t = _{t 6,} the ink L2 reaches the nozzle groups 13a, the entire area of the flow path P is filled only with ink L2. Note that t = t ₇ represents a state after a little ink is discharged from the time t = t ₆ .

  FIG. 7 is a graph showing a change with time of the periodic purge amount Qp set by the purge control unit 61. In FIG. 7, a thick solid line indicates the periodic purge amount Qp corresponding to an arbitrary time. The thin solid line extending from the thick solid line to the left indicates the periodic purge amount when a new cartridge is installed, based on the viscosity of the ink supplied from the cartridge from the installation to a predetermined timing. Show.

As shown in FIG. 7, even after being exchanged from the first cartridge C1 is t = t ₂ the second cartridge C2, while periodically purge amount Qp is determined on the basis of the first elapsed time T ₁ ( (bold solid line portion of t = t _{2 to} t ₆ ). That is, during this period, as shown in FIG. 6, since the ink L1 supplied from the first cartridge C1 before replacement remains in the flow path P, the periodic purge amount Qp is set in consideration of the viscosity of the ink L1. . Accordingly, for example, it is assumed that t = t ₃ is a periodic purge execution date (Yes in step S14). In this case, the purge control unit 61 determines that the remaining amount R of the ink L1 in the flow path P is greater than a predetermined value (for example, zero) (Yes in step S15), and the first elapsed time T ₁ (= t _3). based on -t _0), it sets a periodic purge amount Qp (step S16). That is, in FIG. 7, the periodic purge amount Qp corresponding to t = t ₃ is acquired on the thick solid line corresponding to the first cartridge C1. Then, a purge process is executed based on the regular purge amount Qp (step S18).

On the other hand, and as a result, it becomes purge execution date at time t = t _7. As shown in FIG. 6, at this time, the ink L1 does not remain in the flow path P, and the flow path P is filled only with the ink L2 supplied from the replaced second cartridge C2. Therefore, the purge control unit 61 determines that the remaining amount R of the ink L1 in the flow path P is not larger than a predetermined value (for example, zero) (No in step S15), and the second elapsed time T ₂ (= t _7). based on -t _2), to set a periodic purge amount Qp (step S17). That is, in FIG. 7, the periodic purge amount Qp corresponding to t = t ₇ is acquired on the thick solid line corresponding to the second cartridge C2. Then, a purge process is executed based on the regular purge amount Qp (step S18).

  As described above, the purge controller 61 responds to the remaining amount R of ink in the cartridge C1 before replacement remaining in the flow path P from the connected portion 31 of the cartridge mounting portion 30 to the nozzle group 13. Thus, it is determined whether to set the purge amount corresponding to the cartridge C1 before replacement or the purge amount corresponding to the cartridge C2 after replacement. Thereby, the purge process according to the viscosity of the ink discharged from the nozzle group 13 can be realized.

In the present embodiment, as shown by the one-dot chain line D1 of t ₄ ~t ₆ 7, which is supplied from the cartridge C2 after the replacement the old ink L1 which is the ink supplied from the first cartridge C1 to the sub-tank 43 While the new ink L2 that is ink is mixed (for example, t = t ₅ ), the periodic purge amount may be set to be smaller than that set based on the first elapsed time T ₁ . In this case, specifically, the purge control section 61, before the new ink L2 reaches the ink inlet 44 is an inlet of the sub-tank 43, obtains and sets a periodic purge amount based on the first elapsed time T ₁ To do. Then, the new ink L2 is after reaching the ink inlet 44, until the ink remaining amount R reaches a predetermined value, obtains and sets a small purge amount than obtained on the basis of the first elapsed time T _1. The purge control unit 61 determines whether or not the new ink L2 has reached the ink inlet 44 that is the inlet of the sub tank 43 based on the remaining amount R of the ink. A determination is made by comparing the volume of the flow path from the inlet 44) to the nozzle group 13 with the ink remaining amount R. Since the viscosity of the liquid in which the old ink L1 and the new ink L2 are mixed is lower than the viscosity of only the old ink L1, an appropriate purge process corresponding to the ink viscosity can be executed even if the periodic purge amount is reduced. . Further, by reducing the periodic purge amount, it is possible to reduce ink consumption in the purge process.

(Second Embodiment)
Next, an ink jet printer (liquid ejecting apparatus) according to a second embodiment of the present invention will be described with reference to FIGS. Note that the ink jet printer of this embodiment differs from the ink jet printer 1 of the first embodiment only in the control operation of the purge control unit 61, and therefore only the control operation of the purge control unit 61 will be described below.

[Purge interval setting for each nozzle group]
In this embodiment, the purge control unit 61 sets a purge interval Ip, which is a time interval from the previous purge process to the next purge process, according to the elapsed time T from the time of cartridge replacement. In this embodiment, the purge control unit 61 controls the purge mechanism 50 so that the purge process is executed with a preset purge amount Qs that is a predetermined fixed value. In this embodiment as well, the purge control unit 61 automatically executes the purge process as in the first embodiment. Hereinafter, a method for setting the purge interval Ip in this embodiment will be described.

  As described above, the longer the elapsed time T from the replacement of the cartridge, the higher the viscosity of the ink supplied from the cartridge. For this reason, by setting the purge interval Ip to a smaller value as the elapsed time T becomes longer, an appropriate purge process is realized that increases the frequency of the purge process as the ink viscosity increases and discharges ink with a high viscosity. Also in this embodiment, the remaining amount acquisition process in which the remaining amount acquisition unit 64 of the purge control unit 61 acquires the remaining ink amount R in consideration of the ink remaining amount R of the old ink remaining in the flow path P. Further, the resetting unit 65 of the purge control unit 61 performs the purge interval corresponding to the new ink from the purge interval corresponding to the old ink (the first purge interval of the present invention) based on the acquired remaining amount R. A resetting process for resetting to (second purge interval of the present invention) is executed. Hereinafter, the control operation of the purge control unit 61 in this embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 8, the purge control unit 61 of this embodiment performs the same control operation as steps S11 to S15 of the first embodiment from step S21 to S25.

Purge control section 61, when the ink remaining amount R is determined to be greater than the predetermined value (Yes in step S25), and on the basis of the first elapsed time _{T 1,} it sets the purge interval Ip (step S26). Specifically, the relationship between the elapsed time T and the purge interval Ip from cartridge replacement acquires and sets the purge interval Ip in T ₁ first elapsed time.

On the other hand, the purge control section 61, when the ink remaining amount R is determined to be equal to or smaller than the predetermined value (No at step S25), and based on the second elapsed time _{T 2,} sets the purge interval Ip (step S27). That is, the purge interval corresponding to the new ink is reset from the purge interval corresponding to the old ink. Specifically, the relationship between the elapsed time T and the purge interval Ip from the time of replacement of the cartridge, to get and set the purge interval Ip in T ₂ second elapsed time. Note that data indicating the relationship between an arbitrary elapsed time T and an appropriate purge interval Ip at that time is acquired in advance based on ink characteristics and stored in a storage unit included in the purge control unit 61. That's fine. In step S26 and step S27, the data in the storage unit is referred to, and the purge interval Ip at that time may be acquired.

  After step S26 or step S27, the purge control unit 61 performs a purge process so as to discharge the set purge amount Qs of ink from the nozzle group 13 (step S28). Further, the purge control unit 61 sets the next purge processing execution date from the purge interval Ip set in step 26 or step S27 (step S29), and then returns to step S21. Moreover, also when the purge control part 61 determines with it not being a purge implementation date by step S24 (No in step S24), it returns to step S21. Note that the process of step S28 may be executed between step S24 and step S25.

  Hereinafter, a method for setting the purge interval Ip before and after the cartridge replacement by the purge control unit 61 in this embodiment will be described more specifically with reference to FIGS. 6 and 9 exemplify the ink of the cartridge 20a among the cartridges 20a to 20d.

  FIG. 9 is a graph showing a change with time of the purge interval Ip set by the purge control unit 61. In FIG. 9, the thick solid line indicates the purge interval Ip corresponding to an arbitrary elapsed time. The thin solid line extending from the thick solid line to the left indicates the purge interval when a new cartridge is installed, based on the viscosity of the ink supplied from the cartridge from the installation to a predetermined timing. ing.

As shown in FIG. 9, even after being exchanged from the first cartridge C1 is t = t ₂ the second cartridge C2, while the purge interval Ip is determined on the basis of the first elapsed time T ₁ (t = Thick solid line portion of t _{2 to} t ₆ ). That is, during this time, as shown in FIG. 6, since the ink L1 supplied from the first cartridge C1 before replacement remains in the flow path P, the purge interval Ip is set in consideration of the viscosity of the ink L1. Accordingly, for example, it is assumed that t = t ₃ is the purge execution date (Yes in step S24). In this case, the purge control unit 61 determines that the remaining amount R of the ink L1 in the flow path P is greater than a predetermined value (for example, zero) (Yes in step S25), and the first elapsed time T ₁ (= t _3). based on -t _0), it sets the purge interval Ip (step S26). In other words, in FIG. 9, the purge interval Ip corresponding to t = t ₃ is acquired on the thick solid line corresponding to the first cartridge C1. Then, the next purge execution date is set based on the purge interval Ip (step S29).

On the other hand, and as a result, it becomes purge execution date at time t = t _7. As shown in FIG. 6, at this time, the ink L1 does not remain in the flow path P, and the flow path P is filled only with the ink L2 supplied from the replaced second cartridge C2. Therefore, the purge control unit 61 determines that the remaining amount R of the ink L1 in the flow path P is not larger than a predetermined value (for example, zero) (No in step S25), and the second elapsed time T ₂ (= t _7). Based on −t ₂ ), the purge interval Ip is set (step S27). That is, speaking in Figure 9, the thick solid line corresponding to the second cartridge C2, to obtain the purge interval Ip corresponding to t = t _7. Then, the next purge execution date is set based on the purge interval Ip (step S29).

  As described above, the purge controller 61 responds to the remaining amount R of ink in the cartridge C1 before replacement remaining in the flow path P from the connected portion 31 of the cartridge mounting portion 30 to the nozzle group 13. Thus, it is determined whether to set the purge interval corresponding to the cartridge C1 before replacement or the purge interval corresponding to the cartridge C2 after replacement. Thereby, the purge process according to the viscosity of the ink discharged from the nozzle group 13 can be realized.

In the present embodiment, as shown by t ₄ ~t dashed line D2 in ₆ in FIG. 9, while the old ink L1 and the new ink L2 in the sub-tank 43 are mixed, if you set on the basis of the first elapsed time T ₁ A larger purge interval may be set. In this case, specifically, the purge control section 61, based on the ink remaining amount R, before the new ink L2 reaches the ink inlet 44 is an inlet of the sub-tank 43, based on the first elapsed time T ₁ To obtain and set the purge interval. Then, the new ink L2 is after reaching the ink inlet 44, until the ink remaining amount R reaches a predetermined value, acquires and sets the larger purge interval than obtained on the basis of the first elapsed time T _1. Since the viscosity of the liquid in which the old ink L1 and the new ink L2 are mixed is lower than the viscosity of only the old ink L1, even if the purge interval is increased, an appropriate purge process according to the viscosity of the ink can be executed. Further, by increasing the purge interval, it is possible to reduce ink consumption in the purge process per certain period.

  In the present embodiment, an example is shown in which the process for setting the purge interval Ip is performed on the purge execution date, but the purge interval Ip may be set at a timing other than the purge execution date. That is, the processes in steps S25, S26, S27, and S29 in FIG. 8 may be performed in a predetermined cycle independently of other processes. For example, the purge interval Ip may be set every day or every hour. By carrying out with a shorter cycle, it is possible to obtain an appropriate purge interval Ip according to the ink remaining amount R in the flow path P.

(Third embodiment)
Next, an ink jet printer (liquid ejecting apparatus) according to a third embodiment of the invention will be described with reference to FIGS. The purge mechanism 70 of the present embodiment is different in configuration from the purge mechanism 50 of the first embodiment and the second embodiment. Further, the control operation of the purge control unit 61 of the present embodiment is also different from the first embodiment and the second embodiment. Therefore, hereinafter, only the configuration of the purge mechanism 70 and the control operation of the purge control unit 61 will be described. Note that, in FIG. 10 showing the configuration of the purge mechanism 70 of this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 10, the nozzle cap 71 rises from the upper surface of the outer peripheral portion of the cap body 75 and the plate-shaped cap body 75 having a substantially square shape in plan view, which is positioned opposite to the nozzle forming surface on the lower surface of the ejection head 12. It has a lip 76a formed in an annular shape, and a lip 76b that partitions a space inside the lip 76a into a cap space S1 facing the nozzle groups 13a to 13c and a cap space S2 facing the nozzle group 13d. The cap body 75 has two discharge holes 77a and 77b corresponding to the two cap spaces S1 and S2, respectively.

  When the cap space S1 is selected by the switching valve 53, the air present in the cap space S1 and the thickened ink of the three nozzle groups 13a to 13c facing the space are drawn by the suction pump 52 and discharged from the discharge hole 77a. And is discharged through a switching valve 53 to a waste ink tank (not shown). In such a purging process, substantially the same amount of thickened ink is discharged from each of the nozzle groups 13a to 13c. Accordingly, the purge control unit 61 controls the purge mechanism 70 by setting one common purge amount for the three nozzle groups 13a to 13c corresponding to the three cartridges 20a to 20c.

[Setting the regular purge amount common to multiple nozzle groups]
Also in this embodiment, similarly to the first embodiment, the purge control unit 61 automatically executes the purge process, and the timing of executing the purge process is based on the elapsed time (including the elapsed days) from the time of cartridge replacement. Stipulated to be executed regularly. That is, in the purge process of this embodiment, the time interval from the previous purge process to the next purge process is constant. Further, the purge control unit 61 of this embodiment sets one common purge amount Qp common to the three nozzle groups 13a to 13c that are simultaneously purged. Below, the setting method of one periodic purge amount Qp common to the nozzle groups 13a-13c in this embodiment is demonstrated.

  In this embodiment, in order to realize an appropriate purge process in any of the three nozzle groups 13a to 13c, the ink having the highest viscosity among the inks ejected from the nozzle groups 13a to 13c is used as a reference. One common periodic purge amount Qp is set. Therefore, in this embodiment, the remaining amount acquisition unit 64 of the purge control unit 61 executes a remaining amount acquisition process of acquiring the ink remaining amount R, and the resetting unit 65 of the purge control unit 61 is acquired. At a timing based on the remaining amount R, a resetting process for resetting the purge amount based on the ink having the highest viscosity among the inks ejected from the nozzle groups 13a to 13c is executed.

In the resetting process, it is necessary to determine a reference ink having the highest viscosity among the inks ejected from the nozzle groups 13a to 13c. As described above, the viscosity of the ink increases with the passage of time from the replacement of the cartridge, but the replacement timing of each of the cartridges 20a to 20c is often different, and the viscosity of the ink with respect to the elapsed time T from the replacement of the cartridge is increased. The rate of increase is often different depending on the type of ink. Therefore, the purge control section 61, in the resetting process, a process to acquire a purge amount Q ₁ to Q ₃ is a purge amount corresponding to the viscosity of the ink corresponding to the nozzle groups 13 a to 13 c, is obtained On the basis of the individual purge amounts Q _{1 to} Q ₃ , a process for determining ink serving as a reference when resetting the periodic purge amount Qp is executed. Hereinafter, the flow of the control operation of the purge control unit 61 of this embodiment when setting one common purge amount Qp common to the nozzle groups 13a to 13c will be described with reference to the flowchart of FIG.

As shown in FIG. 11, the purge control unit 61 of this embodiment performs the same control operation as steps S11 to S14 of the first embodiment from step S31 to S34. However, in these steps S31 to S34, the first and second elapsed times T ₁ and T ₂ and the ink remaining amount R of the old ink remaining in the flow path P are counted separately for each cartridge 20a to 20c. To do.

If the purge control unit 61 determines that the purge execution date is determined in step S34 (Yes in step S34), the purge control unit 61 performs individual processing according to the viscosity of the ink corresponding to each of the nozzle groups 13a to 13c as illustrated in FIG. A process of acquiring the purge amounts Q _{1 to} Q ₃ is performed (step S35).

Based on the acquired three individual purge amounts Q _{1 to} Q ₃ , the purge control unit 61 uses the ink with the highest viscosity among the inks ejected from the three nozzle groups _{13 a to 13} c as a reference purge amount Qp Set. Specifically, the ink corresponding to the maximum purge amount among the acquired three individual purge amounts Q _{1 to} Q ₃ is determined as the ink having the highest viscosity, and the individual purge amount of the ink is determined as the periodic purge amount. Set as Qp (step S36).

  Thereafter, the purge control unit 61 performs a purge process with the periodic purge amount Qp set in step S36 (step S37), and returns to step S31. Moreover, also when the purge control part 61 determines with it not being a purge implementation date by step S34 (No in step S34), it returns to step S31.

Next, the flow of processing for acquiring the individual purge amounts Q _{1 to} Q ₃ corresponding to the ink viscosity corresponding to the nozzle groups _{13 a to 13} c in step S 35 will be described with reference to FIG. As shown in FIG. 12, the purge control unit 61 of the present embodiment sequentially executes the same control operation as steps S <b> 15 to S <b> 17 of the first embodiment for each ink of the cartridges 20 a to 20 c, and the individual purge amount Q the ₁ to Q ₃ is obtained (step S41 to S49). Each of the individual purge amounts Q _{1 to} Q ₃ is the first elapsed time T ₁₁ , T ₂₁ , T ₃₁ from the mounting of the cartridge before replacement that started counting in steps S32 and S33 in FIG. It is obtained from the corresponding values of the second elapsed time T ₁₂ , T ₂₂ , T ₃₂ and the remaining ink amounts R ₁ , R ₂ , R ₃ remaining in the flow path P since the mounting.

FIG. 13 is a graph showing an example of a temporal change in the periodic purge amount Qp set by the purge control unit 61 of the present embodiment. In FIG. 13, a thick solid line indicates the purge amount Qp corresponding to an arbitrary time t, and a broken line, a dotted line, and an alternate long and short dash line indicate individual purge amounts Q _{1 to} Q ₃ corresponding to the arbitrary time t, respectively. Yes. Also, the thin solid line extending to the left from these lines indicates the individual purge amount when a new cartridge is installed and set based on the viscosity of the ink supplied from the cartridge from the installation to a predetermined timing. Is shown. In FIG. 13, t ₈ , t ₁₀ and t ₁₂ are times when the respective cartridges 20a to 20c are replaced, and t ₉ , t ₁₁ and t ₁₃ are flows supplied from the respective cartridges 20a to 20c. This is when the remaining ink amounts R _{1 to} R _{3 of} the old ink remaining in the path P become equal to or less than a predetermined value (for example, zero).

As shown in FIG. 13, the purge control unit 61 of the present embodiment is configured to measure the remaining amount of ink for each of the three cartridges 20 a to 20 c from when the cartridge is replaced until a predetermined value (for example, zero) is reached. After obtaining the individual purge amounts Q _{1 to} Q ₃ based on the first elapsed times T _{11 to} T ₃₁ (not shown in FIG. 13) and the ink remaining amount reaches a predetermined value (for example, zero), The individual purge amounts Q _{1 to} Q ₃ are acquired based on the second elapsed times T _{12 to} T ₃₂ . In addition, when the purge process is performed at an arbitrary time t, the purge control unit 61 according to the present embodiment has a maximum value among the acquired individual purge amounts Q _{1 to} Q ₃ as indicated by a thick solid line in FIG. Is set as the periodic purge amount Qp.

As described above, the purge control unit 61 has the ink remaining amount R of the cartridge C1 before replacement remaining in the flow path P from the connected portion 31 of the cartridge mounting unit 30 to the nozzle groups 13a to 13d. depending on, and determine whether to acquire an amount of purge Q ₁ to Q ₃ corresponding to either the first cartridge C1 and after replacement of the cartridge C2. Thereby, the individual purge amounts Q _{1 to} Q ₃ according to the viscosity of the ink discharged from the nozzle groups _{13 a to 13} d can be acquired. In addition, since the maximum _{one of} the acquired individual purge amounts Q _{1 to} Q ₃ is set as the periodic purge amount Qp, sufficient purge processing is realized for any of the nozzle groups _{13 a to 13} c that are simultaneously purged. Is done.

Also in this embodiment, as in the first embodiment, when the purge control unit 61 acquires each of the individual purge amounts Q _{1 to} Q ₃ , while the old ink L 1 and the new ink L 2 are mixed in the sub tank 43, it may acquire the individual purge amount smaller than setting based on a elapsed time T _1. Accordingly, it is possible to set the purge amount according to the viscosity of the ink discharged in the purge process and reduce the ink consumption amount in the purge process.

(Fourth embodiment)
Next, an inkjet printer (liquid ejection device) according to a fourth embodiment of the invention will be described with reference to FIGS. Since the purge mechanism 70 of this embodiment has the same configuration as that of the third embodiment, one common purge amount is set for the three nozzle groups 13a to 13c, and the nozzle groups 13a to 13c are simultaneously purged. Processing is executed. Further, since this embodiment is different from the third embodiment only in the control operation of the purge control unit 61, only the control operation of the purge control unit 61 will be described below.

[Purge interval common to multiple nozzle groups]
The purge control unit 61 of this embodiment also automatically executes the purge process as in the second embodiment, and from the previous purge process to the next purge process according to the elapsed time T from the time of cartridge replacement. A purge interval Ip that is a time interval is set. The purge control unit 61 of this embodiment sets the purge mechanism 70 so that the purge process is performed with the set purge amount Qs that is a predetermined fixed value for the nozzle groups 13a to 13c that are simultaneously purged. Control. Hereinafter, a method for setting one purge interval Ip common to the nozzle groups 13a to 13c corresponding to the three cartridges 20a to 20c in this embodiment will be described.

  In this embodiment, in order to realize an appropriate purge process in any of the three nozzle groups 13a to 13c, the ink having the highest viscosity among the inks ejected from the nozzle groups 13a to 13c is used as a reference. One common purge interval Ip is set. Therefore, in this embodiment, the remaining amount acquisition unit 64 of the purge control unit 61 executes a remaining amount acquisition process of acquiring the ink remaining amount R, and the resetting unit 65 of the purge control unit 61 is acquired. At a timing based on the remaining ink amount R, a resetting process is executed for resetting the purge interval based on the ink having the highest viscosity among the inks ejected from the nozzle groups 13a to 13c.

In the resetting process, as in the third embodiment, the ink corresponding to each nozzle group 13a to 13c is determined in order to determine the ink with the highest viscosity among the inks ejected from each nozzle group 13a to 13c. It becomes a reference when resetting the purge interval Ip based on the processing for acquiring the individual purge intervals I _{1 to} I ₃ that are purge intervals corresponding to the viscosity of the gas and the acquired individual purge intervals I _{1 to} I ₃ A process for determining ink is executed. Hereinafter, the flow of the control operation of the purge control unit 61 of this embodiment when setting one purge interval Ip common to the nozzle groups 13a to 13c will be described with reference to the flowchart of FIG.

As shown in FIG. 14, the purge control unit 61 of this embodiment performs the same control operation as steps S11 to S14 of the first embodiment from step S51 to S54. However, in these steps S51 to S54, the first and second elapsed times T ₁ and T ₂ and the ink remaining amount R of the old ink remaining in the flow path P are counted separately for each cartridge 20a to 20c. To do.

If the purge control unit 61 determines in step S54 that the purge execution date has been reached (Yes in step S54), the purge control unit 61 performs individual processing according to the viscosity of the ink corresponding to each of the nozzle groups 13a to 13c as shown in FIG. Processing for obtaining the purge intervals I _{1 to} I ₃ is performed (step S55).

Based on the acquired three individual purge intervals I _{1 to} I ₃ , the purge control unit 61 sets the purge interval Ip based on the ink having the highest viscosity among the inks ejected from the three nozzle groups _{13 a to 13} c. Set. Specifically, the ink corresponding to the minimum purge interval among the three acquired individual purge intervals I _{1 to} I ₃ is determined as the ink having the highest viscosity, and the individual purge interval of the ink is determined as the purge interval Ip. (Step S56).

  Thereafter, the purge control unit 61 performs a purge process so as to discharge the set purge amount Qs of ink from the nozzle group 13 (step S57). Further, the purge control unit 61 sets the next purge processing date from the purge interval Ip set in step S56 (step S58), and then returns to step S51. Moreover, also when the purge control part 61 determines with it not being a purge implementation date by step S54 (No in step S54), it returns to step S51. Note that the process of step S57 may be executed between step S54 and step S55.

Next, the flow of processing for obtaining the individual purge intervals I _{1 to} I ₃ corresponding to the viscosity of the ink corresponding to the nozzle groups _{13 a to 13} c in step S 55 will be described with reference to FIG. As shown in FIG. 15, the purge control unit 61 of this embodiment sequentially executes the same control operation as steps S <b> 25 to S <b> 27 of the second embodiment for each ink of the cartridges 20 a to 20 c, and the individual purge interval I the ₁ ~I ₃ acquires (step S61~S69). The individual purge intervals I _{1 to} I ₃ are the first elapsed time T ₁₁ , T ₂₁ , T ₃₁ from the installation of the cartridge before replacement, which starts counting in steps S52 and S53 in FIG. It is acquired from the second elapsed time T ₁₂ , T ₂₂ , T ₃₂ from the time of mounting and the remaining ink amounts R ₁ , R ₂ , R ₃ remaining in the flow path P.

FIG. 16 is a graph showing an example of a change with time of the purge interval Ip set by the purge control unit 61 of the present embodiment. In FIG. 16, a thick solid line indicates a purge interval Ip corresponding to an arbitrary time t, and a broken line, a dotted line, and an alternate long and short dash line indicate individual purge intervals I _{1 to} I ₃ corresponding to an arbitrary time t, respectively. Yes. In addition, a thin solid line extending to the left from these lines indicates an individual purge interval when a new cartridge is installed and set based on the viscosity of ink supplied from the cartridge from the installation to a predetermined timing. Is shown. In FIG. 16, t ₁₄ , t ₁₅ and t ₁₈ are times when the respective cartridges 20a to 20c are replaced, and t ₁₆ , t ₁₇ and t ₁₉ are flows supplied from the respective cartridges 20a to 20c, respectively. This is when the remaining ink amounts R _{1 to} R _{3 of} the old ink remaining in the path P become equal to or less than a predetermined value (for example, zero).

As shown in FIG. 16, the purge control unit 61 of the present embodiment, for each of the three cartridges 20a to 20c, until the remaining amount of ink reaches a predetermined value (for example, zero) after the replacement of the cartridge. After acquiring the individual purge intervals I _{1 to} I ₃ based on the first elapsed times T _{11 to} T ₃₁ (not shown in FIG. 16) and the ink remaining amount reaches a predetermined value (for example, zero), 2 The individual purge intervals I _{1 to} I ₃ are acquired based on the elapsed times T _{12 to} T ₃₂ . In addition, when the purge process is performed at an arbitrary time t, the purge control unit 61 according to the present embodiment has the smallest of the acquired individual purge intervals I _{1 to} I ₃ as indicated by a thick solid line in FIG. Is set as the purge interval Ip.

As described above, the purge control unit 61 has the ink remaining amount R of the cartridge C1 before replacement remaining in the flow path P from the connected portion 31 of the cartridge mounting unit 30 to the nozzle groups 13a to 13d. Accordingly, it is determined whether to acquire the individual purge intervals I _{1 to} I ₃ corresponding to the cartridge C1 before replacement or the cartridge C2 after replacement. Thereby, the individual purge intervals I _{1 to} I ₃ according to the viscosity of the ink discharged from the nozzle groups _{13 a to 13} d can be acquired. Further, since the smallest _{one of} the acquired individual purge intervals I _{1 to} I ₃ is set as the purge interval Ip, sufficient purge processing is realized for any of the nozzle groups 13a to 13c that are simultaneously purged. The

Also in this embodiment, as in the second embodiment, when the purge control unit 61 acquires each of the individual purge intervals I _{1 to} I ₃ , while the old ink L 1 and the new ink L 2 are mixed in the sub tank 43, the purge interval may acquire greater than setting based on a elapsed time T _1. Accordingly, it is possible to set the purge interval according to the viscosity of the ink discharged in the purge process and reduce the ink consumption in the purge process.

  In the present embodiment, an example is shown in which the process for setting the purge interval Ip is performed on the purge execution date, but the purge interval Ip may be set at a timing other than the purge execution date. In other words, the processes in steps S55, S56, and S58 in FIG. 14 may be performed in a predetermined cycle independently of other processes. For example, the purge interval Ip may be set every day or every hour. By carrying out with a shorter cycle, it is possible to obtain an appropriate purge interval Ip according to the ink remaining amount R in the flow path P.

(Other embodiments)
The above-described embodiment is an example in all respects, and should be considered not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  In the above embodiment, an ink jet printer has been described as an example of the liquid ejection apparatus according to the present invention. However, the liquid ejection apparatus according to the present invention may be an apparatus that ejects liquid other than ink. Further, the liquid ejection apparatus according to the present invention is not limited to a serial type printer, but may be a line type printer. The liquid ejection method is not limited to the actuator method, and may be a thermal method, for example.

  Further, the present invention has a flow path of a certain length from the cartridge to the nozzle of the ejection head, so that the liquid in the cartridge before the replacement remains for a predetermined period after the cartridge replacement. It can also be applied to a liquid ejection device. For example, the liquid ejection apparatus according to the present invention is also applied to an ink jet printer in which the cartridge mounting portion is provided on the carriage unit and all of the flow paths from the connected portion to the nozzle are provided on the carriage unit. Is possible. Further, the sub-tank may not be provided in the flow path from the connected part to the nozzle, and a part of the flow path from the connected part to the nozzle may not be a tube.

  In the first and second embodiments, one cartridge may be attached to the cartridge attachment portion. In the above embodiment, the ejection head is provided with a nozzle group composed of a plurality of nozzles corresponding to each ink supplied from the cartridges 20a to 20d. However, the ejection head is provided corresponding to each ink. One nozzle may be provided.

In the above embodiment, as shown in FIGS. 7 and 13, the regular purge amount Qp or the individual purge amounts Q _{1 to} Q ₃ is set so as to continuously increase with the elapsed time T from the time of cartridge replacement. However, the present invention is not limited to this, and for example, the regular purge amount Qp or the individual purge amounts Q _{1 to} Q ₃ may be set to increase stepwise with respect to the elapsed time T. Similarly, the purge interval Ip or the individual purge intervals I _{1 to} I ₃ is not limited to being set to continuously increase with the elapsed time T as shown in FIGS. It may be set to increase stepwise with respect to T.

1 Inkjet printer (liquid ejection device)
12 Discharge heads 13a to 13d Nozzle groups 20a to 20d Cartridge 21 Storage chamber 22 Supply section 30 Cartridge mounting section 31 Connected sections 35a to 35d Tubes 43a to 43d Sub tank 44 Ink inlet (sub tank inlet)
50, 70 Purge mechanism 61 Purge control unit C1 first cartridge (cartridge before replacement)
C2 Second cartridge (cartridge after replacement)
P passage Qp purge amount _Q 1 to Q ₃ separate purge quantity Ip purge interval _I 1 ~I ₃ separate purge interval _{T 1, T 11, T 21} , T 31 first elapsed time _{T 2, T 12, T 22} , T ₃₂ second elapsed time

Claims (17)

A cartridge having a storage chamber for storing the liquid and a supply unit for flowing the liquid in the storage chamber to the outside is replaceably mounted. When the cartridge is mounted, the cartridge is connected to the supply unit to distribute the liquid. A cartridge mounting portion having a connection portion;
An ejection head having a nozzle for ejecting the liquid supplied from the cartridge mounted on the cartridge mounting portion;
A flow path from the connected part to the nozzle;
A purge mechanism for performing a purge process for discharging liquid from the nozzle;
A purge control unit that sets a purge amount, which is a liquid amount discharged from the nozzle in one purge process, in accordance with an elapsed time from the replacement of the cartridge;
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged from the nozzle after replacement, the remaining amount of the liquid supplied from the cartridge before replacement and remaining in the flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, from the first purge amount corresponding to the first elapsed time, which is the elapsed time from the mounting of the cartridge before the replacement, from the mounting of the cartridge after the replacement And a resetting process for resetting the purge amount to a second purge amount that is smaller than the first purge amount and corresponds to a second elapsed time that is an elapsed time. The purge control unit
In the resetting process,
The purge amount is set to the first purge amount corresponding to the first elapsed time from when the replaced cartridge is mounted until the remaining amount reaches a predetermined value,
The liquid ejection apparatus according to claim 1, wherein after the remaining amount reaches a predetermined value, the purge amount is set to the second purge amount corresponding to the second elapsed time. The flow path is provided with a sub-tank for temporarily storing the liquid supplied from the cartridge mounted on the cartridge mounting portion,
The purge control unit
In the resetting process,
Before the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, the purge amount is set to the first purge amount acquired based on the first elapsed time,
After the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, the first purge amount is smaller than that acquired based on the first elapsed time until the remaining amount reaches a predetermined value. The liquid ejection apparatus according to claim 2, wherein the purge amount is set to the first and second purge amounts. The purge control unit periodically executes the purge process so that the time interval from the previous purge process to the next purge process is constant,
The liquid ejecting apparatus according to claim 1, wherein the purge control unit sets the purge amount to increase as the first or second elapsed time increases. A cartridge having a storage chamber for storing the liquid and a supply unit for flowing the liquid in the storage chamber to the outside is replaceably mounted. When the cartridge is mounted, the cartridge is connected to the supply unit to distribute the liquid. A cartridge mounting portion having a connection portion;
An ejection head having a nozzle for ejecting the liquid supplied from the cartridge mounted on the cartridge mounting portion;
A flow path from the connected part to the nozzle;
A purge mechanism for performing a purge process for discharging liquid from the nozzle;
A purge control unit that sets a purge interval, which is a time interval from the previous purge process to the next purge process, according to an elapsed time from the replacement of the cartridge,
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged from the nozzle after replacement, the remaining amount of the liquid supplied from the cartridge before replacement and remaining in the flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, from the first purge interval corresponding to the first elapsed time, which is the elapsed time from the mounting of the cartridge before the replacement, from the mounting of the cartridge after the replacement And a resetting process for resetting the purge interval to a second purge interval that is larger than the first purge interval and corresponds to a second elapsed time that is an elapsed time of the above. The purge control unit
In the resetting process,
The purge interval is set to the first purge interval corresponding to the first elapsed time until the remaining amount reaches a predetermined value after the replacement cartridge is mounted,
The liquid ejection apparatus according to claim 5, wherein after the remaining amount reaches a predetermined value, the purge interval is set to the second purge interval corresponding to the second elapsed time. The flow path is provided with a sub-tank for temporarily storing the liquid supplied from the cartridge mounted on the cartridge mounting portion,
The purge control unit
In the resetting process,
Before the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, the purge interval is set to the first purge interval acquired based on the first elapsed time,
After the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, the first purge interval is larger than the case where the remaining amount reaches a predetermined value than when acquired based on the first elapsed time. The liquid discharge apparatus according to claim 6, wherein the purge interval is set to The purge control unit executes the purge process so that a purge amount that is a liquid amount discharged from the nozzle in one purge process is constant in each purge process,
The liquid ejecting apparatus according to claim 5, wherein the purge control unit sets the purge interval to be shorter as the first or second elapsed time is longer. A plurality of cartridges each having a storage chamber for storing liquid and a supply unit for causing the liquid in the storage chamber to flow out are mounted independently and interchangeably, and are connected to the supply unit when the cartridge is mounted. And a cartridge mounting part having a connected part for circulating the liquid,
An ejection head having a plurality of nozzles for ejecting liquids supplied from a plurality of cartridges mounted on the cartridge mounting portion;
A plurality of flow paths from the connected part to the corresponding nozzle;
The amount of liquid discharged from each of the plurality of nozzles in a single purge process, and a common purge amount for the plurality of nozzles is increased as time elapses after replacement of the cartridge. A purge control unit set according to the viscosity;
A purge mechanism for performing a purge process for discharging liquid from the plurality of nozzles based on the purge amount;
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged after replacement, the remaining amount of liquid supplied from the cartridge before replacement and remaining in the corresponding flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, a resetting process for resetting the purge amount based on a liquid having the highest viscosity among the liquids discharged from the plurality of nozzles is executed. Liquid discharge device. The resetting process includes a process for acquiring an individual purge amount that is a purge amount corresponding to the viscosity of the liquid corresponding to each nozzle, and a reference for resetting the purge amount based on a plurality of the individual purge amounts. A process for determining a liquid,
The purge control unit
In the process of acquiring the individual purge amount,
Until the remaining amount reaches a predetermined value after mounting the cartridge after the replacement, the individual purge amount corresponding to a first elapsed time that is an elapsed time from the mounting of the cartridge before the replacement is acquired,
After the remaining amount reaches a predetermined value, the individual purge amount corresponding to a second elapsed time that is an elapsed time from the mounting of the cartridge after the replacement is acquired,
In the process of determining the reference liquid,
The liquid ejection apparatus according to claim 9, wherein when the remaining amount reaches a predetermined value, a liquid corresponding to a maximum purge amount among the plurality of individual purge amounts is determined as a reference. The flow path is provided with a sub-tank for temporarily storing the liquid supplied from the cartridge mounted on the cartridge mounting portion,
The purge control unit
In the resetting process,
Before the liquid supplied from the replaced cartridge reaches the inlet of the sub tank, the individual purge amount is acquired based on the first elapsed time,
After the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, an individual purge amount smaller than that obtained based on the first elapsed time is acquired until the remaining amount reaches a predetermined value. The liquid ejection device according to claim 10. The purge control unit periodically executes the purge process so that the time interval from the previous purge process to the next purge process is constant,
The liquid ejecting apparatus according to claim 10, wherein the purge control unit acquires a larger value as the individual purge amount as the first or second elapsed time becomes longer. A plurality of cartridges each having a storage chamber for storing liquid and a supply unit for causing the liquid in the storage chamber to flow out are mounted independently and interchangeably, and are connected to the supply unit when the cartridge is mounted. And a cartridge mounting part having a connected part for circulating the liquid,
An ejection head having a plurality of nozzles for ejecting liquids supplied from a plurality of cartridges mounted on the cartridge mounting portion;
A plurality of flow paths from the connected part to the corresponding nozzle;
The purge interval, which is the time interval from the previous purge process performed simultaneously to the plurality of nozzles to the next purge process, is set according to the viscosity of the liquid that increases with the passage of time since the replacement of the cartridge. A purge control unit that is commonly set for a plurality of nozzles;
A purge mechanism for performing a purge process for discharging liquid from the plurality of nozzles based on the purge interval,
The purge control unit
When the cartridge is replaced, based on the information on the amount of liquid discharged after replacement, the remaining amount of liquid supplied from the cartridge before replacement and remaining in the corresponding flow path is calculated. Remaining amount acquisition processing to be acquired,
When it is determined that the remaining amount has reached a predetermined value, a resetting process is performed in which the purge interval is reset based on a liquid having the highest viscosity among the liquids discharged from the plurality of nozzles. Liquid discharge device. The resetting process includes a process for obtaining an individual purge interval that is a purge interval corresponding to the viscosity of the liquid corresponding to each nozzle, and a reference for resetting the purge interval based on a plurality of the individual purge intervals. A process for determining a liquid,
The purge control unit
In the process of acquiring the individual purge interval,
Until the remaining amount reaches a predetermined value after the replacement of the cartridge after the replacement, the individual purge interval corresponding to a first elapsed time that is an elapsed time from the installation of the cartridge before the replacement is acquired,
After the remaining amount reaches a predetermined value, the individual purge interval corresponding to a second elapsed time that is an elapsed time from the mounting of the cartridge after the replacement is acquired,
In the process of determining the reference liquid,
The liquid ejection apparatus according to claim 13, wherein when the remaining amount reaches a predetermined value, a liquid corresponding to a minimum purge interval among the plurality of individual purge intervals is determined as a reference. The flow path is provided with a sub-tank for temporarily storing the liquid supplied from the cartridge mounted on the cartridge mounting portion,
The purge control unit
In the resetting process,
Before the liquid supplied from the replaced cartridge reaches the inlet of the sub tank, the individual purge interval is acquired based on the first elapsed time,
After the liquid supplied from the replaced cartridge reaches the inlet of the sub-tank, an individual purge interval larger than that obtained based on the first elapsed time is acquired until the remaining amount reaches a predetermined value. The liquid ejection device according to claim 14. The purge control unit executes the purge process so that a purge amount that is a liquid amount discharged from the nozzle in one purge process is constant in each purge process,
The liquid ejecting apparatus according to claim 14, wherein the purge control unit acquires a smaller value as the individual purge interval as the first or second elapsed time becomes longer.   The liquid ejection device according to claim 1, wherein a part of the flow path is configured by a tube.

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