JP2011212872A - Liquid ejector control device, liquid ejector, and liquid ejector cleaning method - Google Patents

Abstract

A control device for a liquid ejecting apparatus, a liquid ejecting apparatus, and a cleaning method for the liquid ejecting apparatus that can reliably remove liquid deposits accumulated in a flow path.
In a liquid ejecting apparatus including a liquid ejecting head (10) provided with a circulation channel,
A control device 50 is provided for controlling the ink in the liquid storage unit to a temperature higher than that during normal ink ejection and to circulate the ink in the circulation flow path.
[Selection] Figure 3

Description

The present invention relates to a control apparatus for a liquid ejecting apparatus, a liquid ejecting apparatus, and a cleaning method for the liquid ejecting apparatus, and more particularly to a control apparatus for an ink jet recording apparatus that ejects ink as liquid, an ink jet recording apparatus, and a cleaning method for an ink jet recording apparatus. About.

As an ink jet recording head that is a typical example of a liquid ejecting head mounted on a liquid ejecting apparatus, for example, a flow path forming substrate in which a pressure generating chamber is formed, and a piezoelectric element provided on one surface side of the flow path forming substrate And ejecting ink droplets from the nozzles by applying pressure in the pressure generating chamber by the displacement of the piezoelectric element.

In addition, such an ink jet recording head has a problem that ejection failure such as nozzle clogging occurs due to ink thickening or sedimentation due to a change in ambient environmental temperature. For this reason, there is one that performs a so-called flushing operation that discharges ink having increased viscosity by ejecting ink droplets from nozzles of an ink jet recording head at a predetermined timing, for example, at the start of printing. For example, see Patent Document 1).

Further, for example, there is a pump provided in a circulation path connecting an ink jet recording head and an ink tank, and ink in the ink jet recording head is circulated in the circulation path by this pump at a predetermined timing ( For example, see Patent Document 2).

JP 2001-105613 A JP 2006-088492 A

By performing the flushing operation as described in Patent Document 1, it is possible to suppress the occurrence of liquid droplet ejection defects such as nozzle clogging. Further, as described in Patent Document 2, if the liquid is circulated by a pump or the like, thickening or the like can be suppressed without discharging useless liquid.

However, when sediment has already accumulated in the flow path, the sediment may not be completely removed by flushing or circulation of the liquid by a pump. In particular, when the liquid ejecting apparatus is not used for a long time, it is more difficult to remove the sediment by the above-described flushing or liquid circulation.

It is possible to eliminate sediment by discharging ink more strongly during flushing, but in this case, more liquid is wasted. Moreover, in order to increase the flow rate of the circulation flow path, it is possible to use a pump having a higher pumping capacity, but in this case, the cost for the pump increases.

Such a problem exists not only in the control device of the ink jet recording apparatus but also in the control device of a liquid ejecting apparatus other than ink.

In view of such circumstances, the present invention provides a control device for a liquid ejecting apparatus, a liquid ejecting apparatus, and a cleaning method for the liquid ejecting apparatus that can reliably remove liquid deposits accumulated in a flow path. Objective.

The present invention that solves the above problems includes a liquid ejecting head that ejects liquid from a nozzle opening, a liquid reservoir connected via a liquid channel that supplies liquid to the liquid ejecting head, and a reservoir in the liquid reservoir. A control device for a liquid ejecting apparatus, comprising: a heating means for heating the liquid that is produced;
A control device for a liquid ejecting apparatus, comprising: cleaning control means for controlling the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid when cleaning the liquid flow path. It is in.
In such an aspect, the temperature of the heating means is controlled so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid at the time of cleaning, so that the flow rate of the liquid is increased. Thus, the sediment deposited on the liquid flow path can be surely removed by the increased flow rate.

Here, the liquid channel is a circulation channel having a supply path for supplying the liquid from the liquid reservoir to the liquid ejecting head and a recovery path for recovering the liquid supplied to the liquid ejecting head to the liquid reservoir. A pressure-feeding means provided in the supply path for pumping liquid; a bypass path for communicating upstream and downstream of the pressure-feeding means in the supply path; and a pressure in the liquid storage section by pressurization by the pressure-feeding means. A pressure reducing means for providing a large negative pressure, a first valve provided between a downstream side of the pressure feeding means of the supply path and the bypass path, and opening and closing the supply path, and provided in the recovery path A second valve that opens and closes the recovery path, a third valve that is provided in the bypass path and opens and closes the bypass path, and a valve control means that opens and closes the first valve, the second valve, and the third valve. The valve control means controls the first valve, the second valve, and the third valve at the time of cleaning the circulation flow path to open the supply path and the recovery path and to bypass the bypass. The cleaning control means sets the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal injection for injecting the liquid while the valve control means is in the circulation state. It is preferable to control. Thereby, the temperature of the liquid flowing in the circulation channel becomes higher than the temperature of the liquid at the time of normal injection for ejecting the liquid, and the speed of the liquid flowing in the circulation channel is increased.
The sediment deposited on the circulation channel can be discharged more reliably.

A cap member movably provided so as to contact the ejection surface where the nozzle opening is open; and a suction member that sucks the inside of the cap member; A suction means for sucking liquid is further provided, and the valve control means is in a suction state in which the supply path and the recovery path are closed and the bypass path is opened while the suction member is performing a suction operation. The cleaning control means preferably controls the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal jetting in which the liquid is jetted while the valve control means is in the suction state. Accordingly, when cleaning the liquid ejecting head by suction, the temperature of the liquid is higher than the temperature of the liquid at the time of normal ejecting that ejects the liquid, so that the flow rate of the liquid sucked from the liquid ejecting head is increased. . As a result, the thickened liquid and sediment in the liquid ejecting head can be more reliably removed by suction cleaning.

Another aspect of the invention is a liquid ejecting apparatus including the control device according to the above aspect.
In this aspect, since the liquid sediment deposited in the flow path can be reliably removed, the sediment is prevented from clogging the filter and the nozzle opening, and a liquid ejecting apparatus with improved reliability can be realized. .

According to another aspect of the present invention, there is provided a liquid ejecting head that ejects liquid from a nozzle opening, a liquid reservoir connected via a liquid channel that supplies liquid to the liquid ejecting head, and the liquid reservoir. A cleaning method for a liquid ejecting apparatus comprising a heating means for heating a stored liquid, wherein the temperature of the liquid flow path is set to be higher than that at the time of normal ejection for ejecting the liquid when the liquid flow path is cleaned. In the cleaning method of the liquid ejecting apparatus, the temperature of the heating unit is controlled.
In such an aspect, the temperature of the heating means is controlled so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid at the time of cleaning, so that the flow rate of the liquid is increased. Thus, the sediment deposited on the liquid flow path can be surely removed by the increased flow rate.

1 is a perspective view illustrating a schematic configuration of a recording apparatus according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view illustrating a main part of the recording apparatus according to the first embodiment. FIG. 3 is a block diagram illustrating a control system of the recording apparatus according to the first embodiment. 3 is a flowchart illustrating a cleaning method according to the first embodiment. FIG. 3 is a main part sectional view showing the operation of the recording apparatus of the first embodiment. FIG. 3 is a main part sectional view showing the operation of the recording apparatus of the first embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
<Embodiment 1>
FIG. 1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus that is an example of a liquid ejecting apparatus according to Embodiment 1 of the invention, and FIG. 2 is a cross-sectional view illustrating a main part of the ink jet recording apparatus. .

As illustrated, an ink jet recording apparatus I which is an example of a liquid ejecting apparatus includes an ink jet recording head 10.

An ink jet recording head 10 (hereinafter also referred to as recording head 10) is provided with a nozzle opening 11 for ejecting ink droplets, and a flow path (not shown) communicating with the nozzle opening 11 is connected to the manifold 12 via a filter 15. Communicate. In the manifold 12, an ink introduction path 13 through which ink from the liquid storage unit 20 in which ink is stored is supplied, and an ink that has not been ejected from the nozzle opening 11 in the manifold 12 is collected in the liquid storage unit 20. It is provided so as to communicate with the path 14.

In such a recording head 10, ink from the liquid reservoir 20 is supplied to the manifold 12 via the ink introduction path 13, and the ink filled in the manifold 12 is discharged to the discharge path 14.
The liquid is stored in the liquid storage unit 20.

Further, the recording head 10 is provided with a pressure generating means for generating a pressure change in a flow path communicating with the nozzle opening 11 although not particularly illustrated. An ink droplet is ejected from the nozzle opening 11 by causing a pressure change in the flow path by the pressure generating means. As the pressure generating means, for example, a longitudinal vibration type actuator device in which piezoelectric materials and electrode forming materials are alternately stacked to expand and contract in the axial direction, and electrodes and piezoelectric materials are stacked by film formation and lithography. Examples include those using a flexural vibration type actuator device such as a thin film type and a pressure film type formed by attaching a green sheet. Further, as the pressure generating means, a heating element is arranged in the flow path, and a droplet is discharged from the nozzle opening 11 by a bubble generated by heat generation of the heating element, or static electricity is generated between the diaphragm and the electrode. Examples include those using a so-called electrostatic actuator that is generated and deforms a diaphragm by electrostatic force to discharge droplets from a nozzle opening.

Such a recording head 10 is mounted on a carriage 3, and the carriage 3 is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head 10 is mounted is moved along the carriage shaft 5. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

Further, the ink jet recording apparatus I is provided with a liquid storage unit 20 that is fixed to the apparatus body 4 and stores ink therein. The liquid storage unit 20 includes a supply pipe 22 provided with a supply path 21 for supplying ink to the recording head 10 and a recovery pipe 24 provided with a recovery path 23 for recovering ink from the recording head 10. A circulation channel is connected.

The supply pipe 22 is made of a tubular member such as a flexible tube, and the supply path 21 is provided therein. The supply pipe 22 has one end connected to the liquid storage unit 20 and the other end connected to the recording head 1.
By being connected to the zero ink introduction path 13, the ink in the liquid reservoir 20 is supplied to the manifold 12 via the supply path 21 and the ink introduction path 13.

The collection tube 24 is made of a tubular member such as a flexible tube, and a collection path 23 is provided inside. The recovery tube 24 has one end connected to the liquid storage unit 20 and the other end connected to the recording head 1.
By being connected to the zero discharge path 14, the ink in the manifold 12 is recovered in the liquid storage unit 20 via the discharge path 14 and the recovery path 23.

In the middle of the supply path 21, a pressurizing pump 30 is provided as a pumping unit that pumps the ink in the liquid storage unit 20 to the recording head 10. The ink in the liquid storage unit 20 is supplied to the recording head 10 at a predetermined pressure by the pressure pump 30.

Furthermore, the liquid storage unit 20 is provided with a decompression unit that makes the ink stored therein negative pressure. In this embodiment, the suction pump 31 that sucks the gas in the space in which the ink inside the liquid storage unit 20 is stored and discharges it to the outside is provided as the decompression unit.

Such a suction pump 31 reduces the pressure in the liquid reservoir 20 so as to be a negative pressure larger than the pressure for pressurizing the ink by the pressurizing pump 30. Thus, the suction pump 31
However, by depressurizing the inside of the liquid storage unit 20 with a pressure larger than that of the pressurizing pump 30, the ink pumped by the pressurizing pump 30 does not flow out from the nozzle openings 11 of the recording head 10 and passes through the recovery path 23. And collected in the liquid reservoir 20. Incidentally, when the suction pump 31 that is a decompression unit is not provided in the liquid storage unit 20, the recording head is supplied with the ink fed by the pressurizing pump 30 to the recording head 10 without driving the pressure generating unit. Ink flows out from the ten nozzle openings 11.

Further, the liquid storage unit 20 is provided with a heating unit 35 for heating the ink stored therein. In the present embodiment, as the heating unit 35, a heater for heating the ink inside is provided on the outer surface of the liquid storage unit 20 via the outer surface. Further, the liquid storage unit 20 is provided with a temperature sensor 36 for measuring the temperature of the ink inside. As will be described in detail later, the temperature obtained by the temperature sensor 36 is sent to a cleaning control unit that controls the heating unit 35, and the cleaning control unit heats the ink inside the liquid storage unit 20 to bring it to a predetermined temperature. It is used to adjust how much heat should be applied by means 35.

Further, the supply path 21 is provided with a bypass pipe 26 having a bypass path 25 that communicates the upstream and downstream of the pressurizing pump 30. As will be described in detail later, the bypass path 25 causes the ink in the liquid storage unit 20 to be supplied to the recording head 10 without performing pressurization by the pressurization pump 30 when performing a suction operation for sucking ink from the nozzle openings 11. It is for supply.

In the supply path 21, the recovery path 23, and the bypass path 25, valves 32 to 34 that open and close the respective flow paths are provided. Specifically, a first valve 32 that opens and closes the supply passage 21 is provided on the downstream side of the pressurizing pump 30 in the supply passage 21 and upstream of the junction between the supply passage 21 and the bypass passage 25. The recovery path 23 is provided with a second valve 33 that opens and closes the recovery path 23. Further, the bypass passage 25 is provided with a third valve 34 for opening and closing the bypass passage 25. As will be described in detail later, by controlling the first valve 32, the second valve 33, and the third valve 34, the supply path 21, the recovery path 23, and the bypass path 25 are opened and closed, and the liquid reservoir 20 and Switching is made between a circulation state in which ink is circulated with the recording head 10 and a suction state in which ink is sucked from the nozzle openings 11.

Further, as shown in FIG. 1, in the non-printing area of the ink jet recording apparatus I, suction means 40 that sucks ink, bubbles, and the like in the flow path from the nozzle openings 11 of the recording head 10 is provided.

The suction means 40 includes a cap member 41 that covers the nozzle openings 11 of the recording head 10, and a suction member 43 such as a vacuum pump connected to the cap member 41 via a suction pipe 42.

The suction means 40 having such a configuration causes the cap member 41 to come into contact with the ejection surface of the recording head 10 and causes the suction member 43 to perform a suction operation, thereby setting the inside of the cap member 41 to a negative pressure and the nozzle opening 11. The ink in the flow path is sucked together with the bubbles to perform a suction operation (cleaning operation). Further, at the time of non-printing, the nozzle opening 11 may be sealed by the cap member 41 to suppress drying of the nozzle opening 11.

In addition, since the cap member 41 abuts on the ejection surface where the nozzle opening 11 opens and covers the nozzle opening 11 at a desired timing, the cap member 41 is provided to be movable in the vertical direction in this embodiment. ing. The cap member 41 can be moved by a moving means such as a drive motor or an electromagnet (not shown).

The ink jet recording apparatus I is provided with a control device 50 that controls the operation of the ink jet recording apparatus I.

Here, the control device 50 for controlling such an ink jet recording apparatus I will be described. FIG. 3 is a block diagram showing a control system of the recording apparatus according to the first embodiment of the present invention.

As shown in FIG. 3, in the ink jet recording apparatus I, the recording head 10 serving as a mechanism unit that performs actual printing, and the suction unit 40 that sucks ink from the nozzle openings 11 of the recording head 10.
And a moving means 44 for moving the cap member 41, a first valve 32, a second valve 33 and a third valve 34, and these recording heads 10, suction means 40, first valve 32, second valve 33 and second valve 33. And a control device 50 for controlling the operation of the three valves 34 and the like.

The control device 50 controls printing of the recording head 10 and also controls the cleaning operation of the circulation flow path. Here, the cleaning operation in the present embodiment is (a) the liquid storage unit 20.
Of the ink accumulated in the circulation flow path by heating the ink and circulating the high-temperature ink through the circulation flow path (supply path, recovery path, ink introduction path 13, manifold 12 and discharge path 14 of the recording head 10). (B) heating the ink in the liquid storage unit 20 and discharging the bubbles, sediment, and thickened ink in the ink together with the ink that has become high temperature by suction by the suction means 40. Say. Hereinafter, (a) cleaning is referred to as circulation cleaning, and (b) cleaning is referred to as suction cleaning.

Specifically, the control device 50 includes a print control unit 51, a recording head drive circuit 52, a print position control unit 53, a cleaning control unit 54, and a valve control unit 55.

The print control unit 51 controls the printing operation of the recording head 10, for example, by applying a driving pulse to the piezoelectric element via the recording head driving circuit 52 in response to the input of a printing signal, and the recording head 1.
Ink is discharged from zero.

The print position control means 53 performs positioning in the main scanning direction and the sub-scanning direction such as when the recording head 10 is printing, when not printing, and when performing a suction operation. Specifically, the printing position control means 53 drives the drive motor 6 to move the carriage 3 in the main scanning direction to position the recording head 10 in the main scanning direction, and drives a paper feed motor (not shown) to drive the platen. The recording head 10 is positioned with respect to the recording sheet S in the sub-scanning direction by rotating 8 and moving the recording sheet S in the sub-scanning direction. The printing position control means 53 moves the recording sheet S in the sub-scanning direction while moving the carriage 3 on which the recording head 10 is mounted in the main scanning direction during printing. Further, during non-printing such as during printing standby or cleaning operation, the carriage 3 on which the recording head 10 is mounted is moved to the suction means 40 provided in the non-printing area.

The valve control means 55 controls the first valve 32, the second valve 33, and the third valve 34 provided in each of the supply path 21, the recovery path 23, and the bypass path 25 to supply the supply path 21, the bypass path 25, and The collection path 23 is opened and closed.

Here, the valve control means 55 includes the first valve 32, the second valve 33 and the third valve 34.
By controlling, two states, a circulation state and a suction state, are created.

The circulation state is for circulating ink between the liquid storage unit 20 and the recording head 10. By circulating during printing standby or printing, sedimentation of ink components is suppressed and bubbles contained in the ink are discharged from the recording head 10. Further, as will be described in detail later, circulation cleaning is performed in this circulation state.

In the circulation state, the first valve 32 and the second valve 33 are opened, and the supply path 21 and the recovery path 23 are opened.
To open. Further, the bypass passage 25 is closed by closing the third valve 34. Thereby, the ink in the liquid storage unit 20 is supplied to the recording head 10 by the pressure pump 30 and the ink that is supplied to the recording head 10 and is not discharged from the nozzle openings 11 is supplied to the suction pump 31 of the liquid storage unit 20. The liquid is stored in the liquid storage unit 20 through the recovery path 23 by the suction force.

The suction state is a state that is performed when the suction member 43 sucks ink from the nozzle opening 11.

In the suction state, the first valve 32 and the second valve 33 are closed, and the supply path 21 and the recovery path 2 are closed.
3 is closed. Further, the bypass path 25 is opened by opening the third valve 34. Thus, the ink in the liquid reservoir 20 is recorded via the bypass path 25 by the suction force from the nozzle opening 11 of the suction member 43 without the ink pumped by the pressure pump 30 being supplied to the recording head 10. It is supplied to the head 10. As described above, the ink in the liquid storage unit 20 is supplied to the recording head 10 by the suction force of the suction member 43, so that bubbles and foreign matters staying in the recording head 10 by the suction member 43 are removed from the nozzle opening 11 together with the ink. It can be discharged to the outside.

The cleaning control unit 54 controls the heating unit 35, the suction unit 40, and the valve control unit 55 in order to perform circulation cleaning and suction cleaning.

Specifically, when the circulation cleaning is executed, a signal indicating that the circulation state is set is transmitted to the valve control means 55, and the valve control means makes the circulation state. On the other hand, the heating means 3 is set so that the temperature of the ink in the liquid storage unit 20 becomes higher than the temperature of the ink when the normal ink is ejected.
5 is controlled. Hereinafter, this “temperature higher than the temperature of ink during normal ink ejection” is also referred to as a cleaning temperature. In the present embodiment, “during normal ink ejection” refers to the time when cleaning is not performed, that is, when ink is ejected to the recording sheet S based on a predetermined signal.

Whether or not the ink is at the cleaning temperature by the heating means 35 is determined by the temperature sensor 3.
Judging from the temperature obtained from 6. That is, if the temperature of the ink in the liquid storage unit 20 is equal to or lower than the cleaning temperature, the temperature of the heating unit 35 is increased, and if the temperature is the cleaning temperature, the temperature of the heating unit 35 is maintained, When the temperature is excessively higher than the cleaning temperature, the temperature of the heating means 35 is lowered. The cleaning temperature is preferably a temperature at which the viscosity of the ink is sufficiently lowered and the ink solvent is not excessively evaporated.

In the circulation cleaning, the temperature of the ink circulating through the circulation flow path is set to the cleaning temperature, whereby the viscosity of the ink is lowered. By reducing the viscosity of the ink, the flow rate of the ink flowing through the circulation channel is higher than the speed of the ink flowing through the circulation channel during normal ink ejection.

As described above, in the circulation cleaning, the ink flows through the circulation flow path at a higher flow rate than that at the time of normal ink discharge. The sediment deposited thereon can be discharged more powerfully. This prevents sediment deposited in the circulation flow path from affecting the flow rate of ink during normal ink ejection, and prevents sediment from accumulating on the filter and causing clogging. An improved liquid ejecting apparatus is provided. The sediment discharged by the ink flow velocity is collected by a filter or the like disposed in the liquid storage unit 20.

In addition, because the ink flow rate is improved by heating the ink and lowering the viscosity,
The pressurizing pump 30 can be operated at the same output as that during normal ink ejection. That is, since it is not necessary to provide a high output pump in order to improve the ink flow rate, the energy and cost associated with the pump can be reduced.

Further, the circulation cleaning may be performed at any timing other than during normal ink discharge, but in particular, when the ink jet recording apparatus I has not been used for a long time, that is, the circulation flow. In the case where the ink is not circulating in the path for a long time, it is preferable to perform the printing prior to printing.

When the ink jet recording apparatus I is not used for a long time, the amount of sediment deposited increases, and the ink flowing through the circulation flow path during normal ink ejection can easily discharge the sediment. Although there is a possibility that it cannot be performed, such sediment can be discharged in the circulation cleaning.

For example, the cleaning control unit 54 records the time immediately before turning off the power of the ink jet recording apparatus I in a nonvolatile memory, and when the power is turned on, the time at that time and the time recorded in the memory are Circulating cleaning is performed based on whether or not the non-operation time exceeds a predetermined time. In addition, when the user is given information to perform circulation cleaning,
Circulating cleaning may be performed.

Further, the end timing of the circulation cleaning is performed by referring to table information set in advance in a ROM or the like. The table information includes a circulation cleaning duration and a parameter that affects the amount of sediment deposited in the circulation channel. An example of such a parameter is the non-operating time when the ink jet recording apparatus I was not turned on. For example, the table information is created as follows. A certain time (
Non-operating time T1), circulating cleaning is performed using the ink jet recording apparatus I that has not been turned on, and the time required to confirm that sediment has been discharged (duration T2) is measured. . Several patterns of such non-working time T1 and duration T2 are created and stored as table information in a ROM or the like.

And when carrying out the circulation cleaning, the non-operation time is obtained from the time recorded in the nonvolatile memory as described above, and the continuation time of the circulation cleaning is obtained from the ROM from the non-operation time and the table information, When the duration is reached, the circulation cleaning is finished.

When the suction cleaning is performed, the cleaning control unit 54 sets the temperature of the ink in the liquid storage unit 20 to the cleaning temperature by the heating unit 35, and the valve control unit 5
A signal indicating the suction state is transmitted to 5, and the valve control means 55 causes the suction state. On the other hand, a signal for sucking ink from the recording head 10 is transmitted to the suction means 40, and the ink is sucked from the recording head 10.

Specifically, the cleaning control unit 54 increases the temperature of the heating unit 35 if the temperature of the ink in the liquid storage unit 20 is equal to or lower than the cleaning temperature, and heats the heating if the temperature is the cleaning temperature. If the temperature of the means 35 is maintained and the temperature is excessively higher than the cleaning temperature, the temperature of the heating means 35 is lowered.

Then, the cleaning control unit 54 controls the moving unit 44 at a predetermined timing to bring the cap member 41 into contact with the ejection surface of the recording head 10 to operate the suction member 43, so that the recording head 10 by the suction unit 40 is operated. A suction operation for sucking ink in the vicinity of the nozzle opening 11 is performed. In addition, the cleaning control unit 54 controls the moving unit 44 at a predetermined timing to release the contact state of the cap member 41 with the ejection surface of the recording head 10. Specifically, the cleaning control unit 54 moves the recording head 10 to a position facing the cap member 41 via the printing position control unit 53, and controls the moving unit 44 to move the cap member 41 to the recording head 1.
The suction operation is performed by driving the suction member 43 in contact with the zero discharge surface. When the suction operation ends, the cleaning control unit 54 stops driving the suction member 43 to end the suction operation, and then controls the moving unit 44 to discharge the recording head 10 of the cap member 41. Release the contact state to the surface.

Also in the suction cleaning, by setting the ink temperature to the cleaning temperature, the viscosity of the ink is lowered. As the ink viscosity decreases, the flow rate of the ink sucked by the suction means 40 becomes higher than the ink speed at the time of suction performed without using the ink as the cleaning temperature.

Thus, in suction cleaning, ink is sucked at a high flow rate, so that sediments and thickened ink deposited in the flow path from the filter to the nozzle can be more strongly discharged. Thereby, the nozzle opening 11 is prevented from being clogged with the sediment or the thickened ink, and a liquid ejecting apparatus with improved reliability is provided.

In addition, because the ink flow rate is improved by heating the ink and lowering the viscosity,
Since the suction member 43 does not need to have a high capability in order to improve the ink flow velocity, the energy and cost associated with the suction member 43 can be reduced.

Further, the suction cleaning may be performed at any timing other than during normal ink ejection. In particular, when the ink jet recording apparatus I has not been used for a long time,
That is, when ink remains in the flow path from the filter of the recording head 10 to the nozzle opening 11 and thickened ink remains, it is preferably performed prior to printing.

Here, a cleaning method of the ink jet recording apparatus I will be described. FIG. 4 is a flowchart showing the cleaning method, and FIGS. 5 and 6 are cross-sectional views showing the main parts of the operation of the ink jet recording apparatus.

First, after the power of the ink jet recording apparatus I is turned on, it is determined whether or not circulation cleaning is performed (step S1). This determination is made based on whether or not the non-operating time of the ink jet recording apparatus I exceeds a predetermined time, as described above. If the non-operating time does not exceed the predetermined time (step S1: No), the valve control means 55 is set in a circulating state (step S2), and is ready for printing.

On the other hand, if the non-operation time exceeds the predetermined time (step S1: Yes), the valve control means 55 is in a circulation state to perform circulation cleaning (step S3). And
The cleaning control unit 54 controls the heating unit 35 to set the ink in the liquid storage unit 20 to the cleaning temperature (step S4). In steps S3 to S4, specifically, as described above, the first valve 32 and the second valve are opened and the third valve 34 is closed. As a result, as shown in FIG. 5, the ink in the liquid reservoir 20 is heated by the heating means 35 to become the cleaning temperature, and the ink is pumped by the pressure pump 30 and is supplied to the recording head 10 via the supply path 21. Then, the ink of the recording head 10 is collected in the liquid storage unit 20 by the suction pump 31.

As described in steps S3 to S4, since the ink in the liquid storage unit 20 has been set to the cleaning temperature, the viscosity of the ink is reduced, and the flow rate of the ink circulated through the circulation channel is increased.
Since the ink flow rate is thus increased, the sediment deposited on the circulation flow path and the filter 15 of the recording head can be more strongly discharged together with the ink flow rate.

Next, it is determined whether or not the condition for terminating the circulation cleaning is satisfied (step S5).
). As described above, referring to the table information, the continuation time of the circulation cleaning is obtained from the non-operation time, and the execution time when the circulation cleaning is actually executed is compared with the continuation time. If the execution time has not reached the duration (step S5: No)
), Maintaining the circulation state (step S3), and setting the ink to the cleaning temperature (step S).
4). If the execution time reaches the continuation time (step S5: Yes), the heating of the ink is terminated, and a normal printing can be performed as a circulation state (step S2).

Next, it is determined whether or not the suction operation is started (step S6). When the suction operation is not started (step S6: No), a normal printing can be performed as a circulation state (step S2). When the suction operation is started (step S6; Yes), the valve control means 55
However, the first valve 32, the second valve 33, and the third valve 34 are controlled to be in the suction state (step S7). Then, the cleaning control unit 54 controls the heating unit 35 to set the ink in the liquid storage unit 20 to the cleaning temperature (step S8). Then, the cleaning control means 54 controls the suction means 40 to perform a suction operation (step S9). Specifically, FIG.
As shown, the ink in the liquid storage unit 20 is heated by the heating unit 35 to reach a cleaning temperature, and the cleaning control unit 54 controls the moving unit 44 and the suction member 43 so that the cap member 41 is ejected from the recording head 10. The suction member 43 starts the suction operation. At this time, since the first valve 32, the second valve 33, and the third valve 34 are in the suction state, as the ink is sucked from the nozzle opening 11, the recording head is passed from the liquid storage unit 20 via the bypass 25. 10 is supplied with ink. As a result, the recording head 1
The ink inside 0 is sucked together with bubbles and sediment by the suction member 43. Note that the transition to the suction state by the valve control means 55 and the contact of the cap member 41 with the discharge surface may be reversed in order, or may be performed at the same timing.
Finally, after the suction operation is completed, the circulation state is set (step S10), and the printable state is set.

As described above, according to the present embodiment, the flow rate of the ink flowing through the circulation flow path can be increased by performing the circulation cleaning for circulating the ink heated to the cleaning temperature to the circulation flow path. The sediment deposited on the circulation flow path or the flow path in the recording head 10 can be reliably discharged. Further, in the suction cleaning, since the suction operation is performed in a state where the ink is heated to the cleaning temperature, the flow rate of the ink at the time of suction is increased. This
Sediment and bubbles accumulated in the flow path in the recording head can be reliably discharged.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

For example, in Embodiment 1 described above, cleaning in the ink jet recording apparatus I having a circulation flow path has been described. However, also in an ink jet recording apparatus having a liquid flow path that does not circulate, sediment deposited in the liquid flow path is removed. It is possible to discharge.

For example, a control device for an ink jet recording apparatus including a heating unit that heats ink stored in a liquid storage unit in a liquid storage unit connected via a liquid flow path that supplies ink to the liquid ejecting head is a cleaning device. Sometimes the heating means is controlled to heat the ink to the cleaning temperature. The cleaning in this case is so-called flushing in which ink is ejected from the recording head 10 to the cap member 41 or the like. The cleaning control means of the control device sets the temperature of the ink in the liquid reservoir to the cleaning temperature prior to the flushing. As a result, the viscosity of the ink is lowered, so that the thickened ink is easily discharged into the recording head, and the flow rate of the ink discharged during flushing is increased due to the lower viscosity. Sediment deposited on the road is easily discharged.

Further, the ink jet recording apparatus having such a non-circulating liquid flow path is provided with the suction means 40 as shown in the first embodiment so that the ink in the liquid storage portion is heated to the cleaning temperature at the time of suction cleaning. May be. Even in such an ink jet recording apparatus, the flow rate of the sucked ink becomes high at the time of suction cleaning, so that the sediment in the recording head can be more reliably discharged.

In the ink jet recording apparatus I described above, the ink jet recording head 10 is mounted on the carriage 3 and moved in the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line type recording apparatus in which printing is performed simply by moving a recording sheet S such as paper in the sub-scanning direction.

In each of the above embodiments, an ink jet recording head has been described as an example of a liquid ejecting head, and an ink jet recording apparatus has been described as an example of a liquid ejecting apparatus. However, the present invention covers a wide range of liquid ejecting apparatuses in general. Of course, the present invention can also be applied to a liquid ejecting apparatus that ejects liquid other than ink. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used for manufacturing color filters such as liquid crystal displays, organic EL displays, and FED (
Electrode material ejection head used for electrode formation for field emission display, etc., biochip
Examples thereof include bio-organic ejecting heads used for manufacturing, and the present invention can also be applied to a liquid ejecting apparatus including such a liquid ejecting head.

I ink jet recording apparatus (liquid ejecting apparatus), 10 ink jet recording head (liquid ejecting head), 10 recording head, 11 nozzle opening, 20 liquid reservoir,
21 supply path, 22 supply pipe, 23 recovery path, 24 recovery pipe, 25 bypass path, 26 bypass pipe, 30 pressure pump, 31 suction pump, 32 first valve, 33 second valve, 34 third valve, 35 heating Means, 40 suction means,
41 Cap member, 42 Suction tube, 43 Suction member, 44 Moving means, 50
Control device, 54 cleaning control means

Claims (5)

A liquid ejecting head that ejects liquid from a nozzle opening;
A liquid reservoir connected via a liquid flow path for supplying liquid to the liquid jet head;
A control device of a liquid ejecting apparatus comprising a heating means for heating the liquid stored in the liquid storage section,
A control device for a liquid ejecting apparatus, comprising: cleaning control means for controlling the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid when cleaning the liquid flow path. . In the control apparatus of the liquid ejecting apparatus according to claim 1,
The liquid channel is a circulation channel having a supply path for supplying a liquid from the liquid reservoir to the liquid ejecting head and a recovery path for recovering the liquid supplied to the liquid ejecting head to the liquid reservoir,
A pumping means provided in the supply path to pump the liquid;
A bypass path that communicates the upstream and downstream of the pumping means in the supply path;
A pressure reducing means for causing the pressure in the liquid storage section to be a negative pressure larger than the pressure applied by the pressure feeding means;
A first valve that is provided between the bypass path and the downstream side of the pressure feeding means of the supply path, and opens and closes the supply path;
A second valve provided in the recovery path to open and close the recovery path;
A third valve provided in the bypass path to open and close the bypass path;
Valve control means for opening and closing the first valve, the second valve, and the third valve;
The valve control means controls the first valve, the second valve, and the third valve to clean the circulation flow path, thereby opening the supply path and the recovery path and closing the bypass path. State
The cleaning control means controls the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid while the valve control means is in a circulating state. Control device for injection device. In the control apparatus of the liquid ejecting apparatus according to claim 2,
A cap member movably provided so as to abut the ejection surface where the nozzle opening opens, and a suction member that sucks the inside of the cap member, and the liquid inside the liquid ejecting head is discharged from the nozzle opening. A suction means for sucking;
While the suction member is performing the suction operation, the valve control means closes the supply path and the recovery path and sets the suction state to open the bypass path,
The cleaning control means controls the temperature of the heating means so as to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid while the valve control means is in the suction state. Control device for injection device. A liquid ejecting apparatus comprising the control device according to claim 1. A liquid ejecting head that ejects liquid from a nozzle opening;
A liquid reservoir connected via a liquid flow path for supplying liquid to the liquid jet head;
A liquid ejecting apparatus cleaning method comprising: a heating unit that heats the liquid stored in the liquid storage unit,
A cleaning method for a liquid ejecting apparatus, wherein the temperature of the heating means is controlled to be higher than the temperature of the liquid at the time of normal ejection for ejecting the liquid when cleaning the liquid flow path.

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