JP2003320689A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which can prevent blank dots by avoiding a continuous forced cleaning and preventing an invasion of bubbles into a recording head. <P>SOLUTION: The inkjet recorder has the recording head 1 where nozzle openings 36 are set, a cap member 8 for sealing nozzle openings 36 of the recording head 1, and a pump 9 for cleaning by applying a negative pressure to nozzle openings 36 in a state in which the nozzle openings 36 are sealed by the cap member 8. The cleaning includes a plurality of cleaning modes having different negative pressures at a suction operation time. After the forced cleaning A with the highest negative pressure is carried out, cleanings B, C and D with lower negative pressures than the pressure of the forced cleaning A are carried out before a next forced cleaning A is carried out. Bubbles are thus prevented from passing through a filter 25, and blank dots due to the invasion of bubbles can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a recording head for ejecting ink supplied from an ink cartridge as ink droplets.

[0002]

2. Description of the Related Art An ink jet recording apparatus comprises a recording head mounted on a carriage that reciprocates in a main scanning direction, and recording medium feeding means for intermittently feeding a recording medium such as printing paper in a sub scanning direction. Printing is realized by ejecting ink droplets onto a recording medium while moving the recording head in the main scanning direction.

The recording head pressurizes the ink to a predetermined pressure in the pressure generating chamber and discharges the ink as an ink droplet of a predetermined size from the nozzle opening toward the recording medium based on the pressure. Therefore, it is necessary to maintain a constant ink ejection characteristic from the nozzle opening of the recording head, and if this characteristic fluctuates, the print quality is degraded.

Here, the ink ejection characteristics of the recording head are
It changes due to solidification of ink on the nozzle surface where the nozzle opening is formed, clogging of the nozzle opening due to adhesion of dust, intrusion of bubbles from the nozzle opening, and the like. Therefore, in order to maintain the ink ejection characteristics of the recording head, the ink jet recording apparatus seals the nozzle surface with a cap to prevent drying, and applies a negative pressure to the cap with the nozzle surface sealed. The ink is forcibly sucked from the nozzle opening to be cleaned.

In the above cleaning operation, a plurality of cleaning modes having different ink suction amounts and negative pressures at the time of suction are prepared depending on the difference in the clogging factors to be removed and the degree of clogging, and the appropriate mode is selected. Is running. For example, as long as the minute bubbles that have entered from the nozzle openings are removed, the clogging can be recovered by sucking and removing a small amount of ink near the nozzle openings. On the other hand, when replacing the ink cartridge, it is necessary to remove the air bubbles that have entered the flow path when installing the ink cartridge, so the negative pressure during suction is increased to speed up the ink flow rate.
It is necessary to perform strong cleaning to suck and remove all the ink remaining in the recording head.

[0006]

However, even if the strong cleaning as described above is performed, even relatively large bubbles existing in the ink supply needle upstream of the filter in the flow path are completely sucked and removed. Is difficult.
In the case of strong cleaning, the probability that bubbles in the flow path upstream of the filter will be drawn to the vicinity of the filter and adhere to the filter will increase. If you continue to perform strong cleaning with air bubbles attached to the filter, the air bubbles attached to the filter may pass through the filter and enter the print head, causing serious nozzle problems such as missing dots. .

The present invention has been made in view of such circumstances, and by not performing the powerful cleaning continuously, it is possible to prevent the invasion of air bubbles into the recording head and prevent the occurrence of nozzle trouble. An object is to provide an inkjet recording device.

[0008]

In order to achieve the above object, an ink jet recording apparatus of the present invention comprises a recording head provided with nozzles for ejecting ink droplets, and the nozzle of the recording head is sealed with a cap member. An ink jet recording apparatus comprising: a capping device for cleaning and a suction device for applying a negative pressure to the nozzle while the nozzle is sealed by the cap member to suck and clean the ink in the recording head. The cleaning by the suction device has a plurality of cleaning modes having different negative pressures at the time of suction operation, and after performing the strong cleaning performed at the highest negative pressure, until the next strong cleaning is performed, The gist is that the cleaning is performed at a negative pressure lower than that of the strong cleaning.

That is, the ink jet recording apparatus of the present invention has a plurality of cleaning modes in which the negative pressure during the suction operation is different in the cleaning by the suction device. After performing the strong cleaning performed at the highest negative pressure, the cleaning at a lower negative pressure than the above-described strong cleaning is performed until the next strong cleaning is performed. Therefore, the strong cleaning that is performed in the region where the negative pressure is high and the ink flow velocity is high is not continuously performed, and the cleaning operation in the region where the negative pressure is low and the ink flow velocity is slow continues for a while, so that Even if the bubbles are drawn into the vicinity of the filter, they are prevented from adhering to the filter. Even if air bubbles adhere to the filter, the cleaning operation is performed in the region where the flow velocity is slow after that, so that the air bubbles rarely pass through the filter, resulting in dot omission due to air bubbles entering the print head. The nozzle trouble can be effectively prevented.

In the ink jet recording apparatus of the present invention, the recording head is provided with a flow path valve for opening and closing a flow path of ink supplied from an ink tank,
In the above-mentioned strong cleaning, in the cleaning mode in which the flow path valve is closed and suction is performed to open the flow path valve at a predetermined negative pressure, the flow path valve is closed and sucked to close the flow path valve. The negative pressure in the cap can be made higher than when suctioning without closing. Then, by opening the flow path valve from a high negative pressure state, the ink is rapidly sucked into the cap, and the ink can be discharged at a faster flow rate than when the flow path valve is not closed, so that the clogging can be recovered. It is advantageous.

In the ink jet recording apparatus of the present invention, the cleaning at a negative pressure lower than the above-mentioned strong cleaning is performed in a cleaning mode in which suction is performed without closing the flow path valve, and the flow path valve is not closed. When the ink is sucked, the ink is supplied from the ink tank to some extent even during the suction, so that the negative pressure does not rise as much as when the flow path valve is closed. Therefore, cleaning with a lower negative pressure than that of the strong cleaning is surely executed, and it is possible to effectively prevent nozzle troubles such as dot omission due to air bubble intrusion into the recording head.

In the ink jet recording apparatus of the present invention, for cleaning at a negative pressure lower than the above-mentioned strong cleaning, suction is performed with the flow passage valve closed, and the flow passage valve is moved at a negative pressure lower than the negative pressure for strong cleaning. In the case of the open cleaning mode, cleaning with a negative pressure lower than that of the strong cleaning is executed without fail, and it is possible to effectively prevent nozzle troubles such as dot omission due to air bubble intrusion into the recording head. In addition, it is relatively easy to set a cleaning mode in which the negative pressure is adjusted stepwise as needed, and a fine cleaning mode can be performed according to the clogging factor to be removed and the degree of clogging. become.

In the ink jet recording apparatus of the present invention, when the strong cleaning mode is executed as a cleaning operation when the ink tank is mounted, it is necessary to suck a relatively large amount of ink when the ink tank is mounted. Therefore, strong cleaning can sufficiently discharge the ink to maintain the ejection characteristics. Also, since the ink tank is not mounted so often, the period from one strong cleaning to the next strong cleaning is relatively long, and during that cleaning is performed at a low negative pressure, air bubbles will adhere to the filter. It is possible to effectively prevent the nozzles from passing or passing, and to prevent nozzle troubles such as missing dots.

In the ink jet recording apparatus of the present invention, the strong cleaning mode is executed as a cleaning operation when the ink in the ink tank is initially filled in the recording head, or the ink in which the ink tank is mounted on the carriage. Since the cartridge is a cartridge and the strong cleaning mode is executed as a cleaning operation when replacing the ink cartridge, a relatively large amount of ink needs to be sucked at the time of initial filling or replacement of the ink cartridge. With strong cleaning, the ink can be sufficiently discharged to maintain the ejection characteristics. In addition, since initial filling and ink cartridge replacement are not so frequent, the period from one strong cleaning to the next strong cleaning is relatively long, and cleaning is performed at a low negative pressure during that period, so air bubbles are filtered out. It is possible to effectively prevent the nozzles from adhering to or passing through the nozzles and prevent nozzle troubles such as missing dots.

In the ink jet recording apparatus of the present invention, the strong cleaning mode is executed as one of the cleaning operations performed by a user's instruction, or the strong cleaning mode is automatically set at a predetermined timing. When it is executed as one of the timer cleaning operations that are performed, even in the cleaning operation and the timer cleaning operation that are performed by the user's instruction, a strong operation is performed depending on the clogging factor to be removed and the degree of clogging. Since it may be necessary to perform cleaning, it is possible to sufficiently discharge the ink and recover from clogging by the above-mentioned strong cleaning. Then, once sufficient clogging recovery is performed, it takes a relatively long time until the next clogging required for strong cleaning occurs, so that cleaning with a low negative pressure is performed during that time. Therefore, it is possible to effectively prevent bubbles from adhering to or passing through the filter, and prevent nozzle troubles such as missing dots.

In the present invention, "high negative pressure" refers to a state where the atmospheric pressure of the space sucked for cleaning inside the cap member or the like is low, and "low negative pressure" refers to the high atmospheric pressure of the space. State. The same applies to the following description.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

1 to 3 are views showing an example of the peripheral structure of an ink jet recording apparatus to which the present invention is applied.
This apparatus includes a carriage 3 on which an ink cartridge 2 is mounted and a recording head 1 is mounted.

The carriage 3 is, as shown in FIG.
It is connected to a stepping motor 5 via a timing belt 4, and guided by a guide bar 6 to reciprocate in the paper width direction (main scanning direction) of the recording paper 7. The carriage 3 has a box shape that opens to the upper part, and has a recording paper 7
The nozzle surface of the recording head 1 is mounted so as to be exposed on the surface (the lower surface in this example) opposed to, and the ink cartridge 2 is mounted.

As shown in FIG. 2, in the recording head 1, the ink is supplied from the ink cartridge 2 by being inserted into the supply port 14 at a portion corresponding to the supply port 14 on the lower surface of the ink cartridge 2. A receiving first ink supply needle 13 is provided upright. The ink supplied to the first ink supply needle 13 is filtered by the filter 25 (see FIG. 4) described below and is guided to the nozzle opening 36 (see FIG. 4). In FIG. 2, reference numeral 11 denotes a lid member 1 for pressing the upper portion of the ink cartridge 2 in a state where the ink cartridge 2 is accommodated and covering the opened upper portion of the carriage 3.
1 and 12 are guide holes through which the guide bar 6 is inserted.

The recording head 1 pressurizes the ink to a predetermined pressure in the pressure generating chamber and ejects the ink as an ink droplet of a predetermined size from the nozzle opening 36 toward the recording paper 7 based on the pressure. is there. Then, the recording head 1
The ink is supplied from the ink cartridge 2 to the recording paper 7 by ejecting ink droplets onto the upper surface of the recording paper 7 while moving the carriage 3 back and forth, and by intermittently feeding the recording paper 7, dots and images are printed on the recording paper 7. It is designed to print in a matrix.

As shown in FIG. 3, the recording apparatus is provided with a capping apparatus 15 provided at a home position (a portion near the right end in the drawing) which is a non-printing area in the moving area of the carriage 3, and the capping apparatus. 15
Is provided with a cap member 8 on the upper surface thereof, and moves up and down in conjunction with the movement of the recording head 1 in and out of the home position, and rises when the recording head 1 returns to the home position, and the cap member 8 causes the recording head to move. The nozzle surface of No. 1 is sealed.

The cap member 8 has a rectangular shallow dish shape, and seals the nozzle opening of the recording head 1 during printing suspension to suppress the drying of ink existing in the vicinity of the nozzle opening and increase the ink viscosity. The nozzle opening is prevented and clogging of the nozzle opening is prevented as much as possible. Further, the cap member 8 receives a drive signal irrelevant to print data to the recording head 1 and ejects an ink droplet to eject a thickened ink or the like in the vicinity of the nozzle opening 36 to perform flushing. It also functions as a receiving box.

The inner space of the shallow dish-shaped cap member 8 is connected to a pump device 9 which is a suction device by a flexible tube 16. The pump device 9 is
With the cap member 8 sealing the nozzle surface of the recording head 1, the inside of the cap member 8 is sucked, a negative pressure is applied to the nozzle opening 36 of the recording head 1 to forcibly suck the ink from the nozzle opening 36, and cleaning is performed. It is supposed to do.

The waste ink sucked by the pump device 9 is discharged to the waste liquid tank 19 through the flexible tube 17 and the waste liquid pipe 18. Reference numeral 20 is an ink absorber that absorbs and holds the waste ink stored in the waste liquid tank.

In FIGS. 1 and 3, reference numeral 10 denotes a wiper member for wiping the nozzle surface wet with ink after the cleaning operation to wipe off unnecessary ink and stabilize the meniscus of the nozzle opening 36. Further, in FIG. 3, reference numeral 21 is a guide base for guiding the recording paper 7 being printed, and 22 is an apparatus housing. Note that FIG. 1 shows a state in which the device housing 22 is removed.

FIG. 4 is a diagram schematically showing a sectional structure of the recording head 1. The recording head 1 is attached to a head holder 35 on which a first ink supply needle 13 receiving ink from the ink cartridge 2 is erected, and is attached to the lower surface of the head holder 35 to eject ink droplets from a nozzle opening 36. It is composed of a head body 24.

The head holder 35 filters the second ink supply needle 23 for guiding the ink supplied to the first ink supply needle 13 to the head body 24 and the ink supplied to the second ink supply needle 23. And a filter 25. The first flow path 26 communicates with the first ink supply needle 13 and the second flow path 27 communicates with the second ink supply needle 23. A flow path valve 28 is provided which can block the ink flowing to the head cartridge 24 and open and close the ink flow path supplied from the ink cartridge 2 to the head body 24.

The flow passage valve 28 has a valve seat 30 having an opening communicating with the first flow passage 26 and the second flow passage 27.
And a valve element 29 which is seated on the valve seat 30 and mainly closes the opening of the second flow path 27, and an operating member 31 which applies a pressing force to the valve element 29 to open and close the valve. There is.

The valve element 29 is formed of an elastic material in a disk shape, and its peripheral portion is fitted into the head holder 35 in a liquid-tight manner so that ink flowing from the first flow path 26 to the second flow path 27 leaks. It is designed to prevent it from being taken out. The actuating member 31 is connected to the valve element 29 by a connecting member 34,
The pressing force acting on the actuating member 31 is transmitted to the valve body 29.

In the figure, numeral 32 designates the actuating member 31 as the valve body 2.
9 is a first urging member for urging in the valve opening direction of 9, and 33 is a second urging member for urging the connecting member 34 in the valve closing direction of the valve element 29. In the flow path valve 28, when a pressing force is applied to the operating member 31, the valve body 29 is seated on the valve seat 30 and the ink flowing from the first flow path 26 to the second flow path 27 is shut off. When the pressing force on the member 31 is released, the valve body 29 separates from the valve seat 30 and ink flows from the first flow passage 26 to the second flow passage 27.

At this time, the first urging member 32 for urging the operating member 31 in the valve opening direction of the valve body 29, and the second urging member 33 for urging the connecting member 34 in the valve closing direction of the valve body 29. The first biasing member 32 balances the biasing force so that the first biasing member 32 has a slightly stronger biasing force. Therefore, the actuating member 31 and the connecting member 34 are smoothly slid by the pressing of the actuating member 31, and the opening / closing operation of the flow path valve 28 is smooth, and malfunctions are less likely to occur.

In this recording apparatus, by the opening / closing operation of the flow path valve 28 and the suction operation of the pump device 9,
It is designed to perform strong cleaning by increasing the negative pressure during cleaning.

That is, first, the change in the negative pressure in the cap member 8 when the pump device 9 is operated and the normal cleaning operation is performed with the flow path valve 28 opened is shown in FIG. Shown in curve B. When suction is started, the negative pressure in the cap member 8 gradually rises and the outflow of ink from the nozzle openings 36 begins. Then, after suction is performed for a predetermined time after the negative pressure Pb at which the predetermined flow velocity of the ink in the head main body 24 is obtained, the pump device 9 is performed.
To stop the suction. At this time, the ink in the ink cartridge 2 is supplied to the head body 24 through the first and second flow paths 26 and 27, and the ink in the head body 24 is discharged from the nozzle openings 36.

On the other hand, the curve A of FIG. 5A shows the change in the negative pressure in the cap member 8 when the strong cleaning operation is performed by closing the flow path valve 28. Flow path valve 2
When the pump device 9 is operated to start suction with 8 closed, the negative pressure in the cap member 8 increases, but at this time ink does not flow out from the nozzle opening 36,
The negative pressure rises in a short time as compared with the case of the curve B. Further, since the ink does not flow into the cap member 8, it is possible to suck even a negative pressure higher than that in the case of the curve B.

Then, suction is performed for a predetermined time after the predetermined negative pressure Pa is reached, and then the pump device 9 is stopped to stop the suction. By opening the flow path valve 28 in this state, the ink in the head main body 24 is discharged from the nozzle openings 36. At this time, since the flow path valve 28 is opened all at once from the state where the negative pressure Pa higher than the curve B is maintained, the negative pressure falls more rapidly than in the case of the curve B,
Ink can be discharged at a higher ink flow velocity than in the case of the curve B. As a result, ink is rapidly sucked into the cap member 8, and a strong cleaning effect advantageous for recovery from clogging can be obtained.

FIG. 6 is a block diagram showing the configuration of the control circuit mounted on the recording apparatus.

In the figure, reference numeral 40 denotes a host computer, which has a built-in printer driver 41, and the size of the recording paper 7, selection of monochrome / color printing, and recording mode by input from the input device 42 on the utility of the printer driver 41. Is selected, and data such as fonts and print commands can be input. Also,
It is configured so that a cleaning operation can be executed in response to a cleaning command by an input from the input device 42.

By inputting a print command, print data is sent from the printer driver 41 to the print control means 43. The print control unit 43 also generates bitmap data based on the print data, and causes the head drive unit 44 to generate a drive signal to eject ink droplets from the head main body 24.

The head drive means 44 receives a flushing command signal from the flushing control means 45 and outputs a drive signal for flushing to the head main body 24 in addition to the drive signal based on the print data, and has no relation to printing. The ink can be ejected.

Reference numeral 46 denotes a cleaning control means, and the pump drive means 47 and the flow passage valve opening / closing means 55 are operated by a command from the cleaning control means 46 to operate the pump device 9 or open / close the flow passage valve 28. It is supposed to do. Then, the strong cleaning operation performed by operating the flow path valve 28 and the normal cleaning operation performed without operating the flow path valve 28 are executed.

On the other hand, the cleaning command detecting means 48 is adapted to execute a timer cleaning operation, which will be described later, in response to the cleaning command input on the utility of the printer driver 41. Further, the cleaning command detecting means 48 includes, for example, the cleaning start button 4 arranged on the operation panel of the recording apparatus.
In response to the operation of 9, the manual cleaning operation described later is similarly executed.

From the cleaning command detecting means 48,
A control signal is sent to the print control unit 43, and the cleaning command detection unit 48 receives the cleaning command input on the utility of the printer driver 41 or the operation panel of the recording apparatus. When the arranged cleaning start button 49 is operated, the print control means 43 is activated to print a check pattern for the user to determine the printing state.

The cleaning command detecting means 48 is also provided.
By this, a control signal can be sent to the print history storage means 50, and the print history is reset to zero at this print history storage means 50 at the end of the cleaning operation to obtain the data from the print control means 43. The total print amount printed after the cleaning operation is measured. As a result, when the cleaning command detection unit 48 receives the cleaning command, the print amount after the previous cleaning operation is stored in the print history storage unit 50 is extracted, and this data is supplied to the cleaning mode selection unit 51. It is supposed to be done.

The cleaning mode selecting means 51 is
Upon receiving the print amount data such as the number of printed pages after the execution of the previous cleaning operation, the ROM 52 is accessed to determine the cleaning mode based on the data of the number of printed pages. This determines whether or not to perform the ink suction operation from the head body 24, and when performing the ink suction operation, sends a control signal based on a predetermined cleaning mode to the cleaning control means 46. To do.

In the figure, reference numeral 53 is a wiper member driving means for wiping the nozzle surface by driving the wiper member 10 after the cleaning operation, and 54.
Is a carriage control means for controlling the movement of the carriage 3 during execution of a printing operation.

The recording apparatus has a plurality of cleaning modes with different ink suction amounts.

For example, in the manual cleaning mode executed by the user operating the cleaning start button 49 of the apparatus, the first, second, third and fourth cleaning modes (CL1, CL2, CL3, CL)
A four-step cleaning mode such as 4) is prepared. CL1 to CL2, CL3, CL4 are set so that the ink suction amount increases in sequence, and CL1 to CL2, CL are sequentially set according to the number of cleanings, the print amount from the previous cleaning, the print check result by the user, and the like.
3 and CL4 are switched to perform an optimum cleaning operation.

Further, in the timer cleaning mode which is automatically performed at a predetermined timing such as when the power is turned on after the unused state continues for a certain period, the TC
Three-stage cleaning modes such as L1, TCL2, TCL3, etc. are prepared. TCL1 to TCL2, TCL
3 is set so that the ink suction amount increases in sequence,
TCL1 to TCL2, TCL3 sequentially according to the length of unused period and the result of print check by the user
And the optimum cleaning operation is executed.

Further, when the ink cartridge 2 is replaced, the replacement cartridge is automatically replaced when the ink cartridge 2 is installed, or when the new recording apparatus is used for the first time, the ink cartridge 2 is installed. An initial filling mode is automatically prepared for the purpose of initially filling the head main body 24 with ink. In the replacement cleaning mode and the initial filling mode, CL1 and CL in the manual cleaning mode are used.
2, CL3, CL4, T in timer cleaning mode
The amount of ink to be sucked is set to be larger than that of CL1, TCL2, and TCL3.

In the recording apparatus of the present invention, the most powerful C in the replacement cleaning mode, the initial filling mode, the manual cleaning and the timer cleaning is used.
In the cleaning mode such as L4 or TCL3 in which the amount of ink suction is relatively large, the flow path valve 28 as described above can be used to perform strong cleaning performed at a high negative pressure.

In the recording apparatus of the present invention, after performing the strong cleaning performed with the highest negative pressure among a plurality of cleaning modes having different negative pressures during the suction operation, until the next strong cleaning is performed. During this period, cleaning with a negative pressure lower than that of the above-mentioned strong cleaning is executed. The cleaning mode selection means 51 selects the cleaning mode at this time.

By doing so, the strong cleaning which is performed in the region where the negative pressure is high and the ink flow velocity is fast is not continuously performed, and the cleaning operation in the region where the negative pressure is low and the ink flow velocity is slow is performed for a while. Continue.

Therefore, as shown in FIG. 7, even if the bubbles 37 in the flow path upstream of the filter 25 are once drawn to the vicinity of the filter 25 by the strong cleaning, the bubbles 3
7 is prevented from adhering to the filter 25. Even if the air bubble 25 adheres to the filter 25 by the strong cleaning, the air bubble 37 hardly passes through the filter 25 since the cleaning with a slow flow rate is performed thereafter, and the air bubble into the head main body 24 is almost eliminated. Problems such as missing dots due to intrusion are prevented. In FIG. 7, reference numeral 38 is an ink introduction hole formed at the tip of the second ink supply needle 23.

Explaining a concrete example, for example, in the replacement cleaning mode, when the strong cleaning shown by the curve A in FIG. 5A is executed, a manual cleaning until the next replacement cleaning is executed or In the timer cleaning, cleaning is performed in a region where the negative pressure is low with the flow path valve 28 opened as shown by the curve B in FIG. 5A.

Since a relatively large amount of ink needs to be sucked when the ink cartridge 2 is replaced, it is possible to sufficiently discharge the ink and maintain the ejection characteristics by the above-mentioned strong cleaning. Further, since the ink cartridge 2 is not exchanged very often, the period from one strong cleaning to the next strong cleaning is relatively long, and since cleaning is performed at a low negative pressure during that period, air bubbles adhere to the filter. It is possible to effectively prevent the ink from passing or passing, and to prevent nozzle troubles such as missing dots.

In this example, the cleaning performed at a lower negative pressure than the strong cleaning such as the manual cleaning or the timer cleaning is performed by suctioning without closing the flow path valve 28, as shown by the curve B in FIG. 5 (a). It can be in mode. in this way,
If manual suction or timer cleaning is performed with the flow path valve 28 not closed, ink is supplied from the ink cartridge 2 to some extent even during suction, and thus the negative pressure rises as much as when the flow path valve 28 is closed. Absent. For this reason, the cleaning with a negative pressure lower than that of the strong cleaning is surely executed.

Further, in this example, the amount of ink suction in the manual cleaning CL1, CL2, CL3, CL4 and the timer cleaning TCL1, TCL2, TCL3 can be adjusted by changing the suction time by the pump device 9. .

Alternatively, manual cleaning CL
1, CL2, CL3, CL4 and timer cleaning T
CL1, TCL2, TCL3, and the like, which are cleaned at a lower negative pressure than the above-mentioned strong cleaning, are suctioned with the flow passage valve 28 closed, and the flow passage valve 28 is opened at a negative pressure lower than the negative pressure of the strong cleaning. The cleaning mode can also be set.

That is, as shown by the curves C and D in FIG. 5B, the negative pressure lower than the negative pressure Pa in the strong cleaning shown by the curve A by suctioning with the flow path valve 28 closed. When reaching Pc or Pd, the pump device 9 is stopped to stop the suction, and the flow path valve 28
This is the mode for opening and cleaning. At this time,
By changing the set negative pressures Pc and Pd, the ink suction amount and the ink flow velocity can be adjusted as necessary, and manual cleaning CL1, CL2, CL3, CL4
And timer cleaning TCL1, TCL2, TCL3
It is possible to change the negative pressure according to the cleaning level such as.

The change in the set negative pressure in this case can be adjusted by lengthening or shortening the suction time by the pump device 9. By doing this,
Cleaning with a negative pressure surely lower than that of strong cleaning is executed. It is relatively easy to set a cleaning mode in which the negative pressure is adjusted step by step if necessary, and a fine cleaning mode can be performed according to the clogging factor to be removed and the degree of clogging. .

Explaining the second specific example, for example, in the initial filling mode, the strong cleaning shown by the curve A in FIG. 5A can be executed.
In this case, in the subsequent replacement cleaning, manual cleaning, and timer cleaning, cleaning is performed in a region where the negative pressure is low with the flow path valve 28 opened as shown by the curve B in FIG. 5A. .

Explaining the third specific example, for example, C, which has the largest ink suction amount in manual cleaning, is described.
In L4 and TCL3, which has the largest ink suction amount in timer cleaning, the curve A in FIG.
If you perform the heavy cleaning shown in
In the manual cleaning CL1, CL2, CL3 and the timer cleaning TCL1, TCL2 until the next CL4 or TCL3 is executed, the flow passage valve 28 as shown by the curve B in FIG. Cleaning is performed in a region where the negative pressure is low.

In manual cleaning or timer cleaning, strong CL4 or TCL is performed according to the clogging factor to be removed and the degree of clogging.
In 3, it is possible to sufficiently discharge the ink and recover the clogging. After once performing sufficient clogging recovery, it takes a relatively long time until the next clogging requiring strong cleaning occurs.
Meanwhile, CL1, CL2, CL3 and TCL with low negative pressure
By executing 1 and TCL2, it is possible to prevent nozzle troubles such as missing dots.

Also in this specific example, CL having a low negative pressure is used.
1, CL2, CL3 and TCL1, TCL2 are shown in FIG.
The flow path valve 2 shown by the curves C and D in (b)
With 8 closed, suction can be stopped at a negative pressure Pc or Pd lower than the negative pressure Pa for strong cleaning, and the flow path valve 28 can be opened from that state to perform the cleaning mode. Also at this time, the ink suction amount and the ink flow velocity can be adjusted by changing the set negative pressures Pc and Pd, and the manual cleaning CL1, CL2, C
It is possible to change the negative pressure according to the cleaning level such as L3 and timer cleaning TCL1, TCL2.

Further, in this specific example, the initial filling mode and the exchange cleaning mode can also be executed to perform strong cleaning in which the passage valve 28 is opened and closed with a high negative pressure. Even in this case, immediately after the replacement of the ink cartridge 2 or the initial filling, the ejection characteristics are sufficiently recovered by the strong cleaning, and therefore CL4 and TCL3 having a high negative pressure need to be cleaned for a while after that. Therefore, strong cleaning is not continuously performed.

As described above, the recording apparatus has a plurality of cleaning modes having different negative pressures during the suction operation, and after performing the strong cleaning performed at the highest negative pressure using the flow path valve 28, Until the next strong cleaning, the cleaning with a lower negative pressure than that of the strong cleaning is executed, so that even if air bubbles in the flow path are drawn to the vicinity of the filter 25,
Adhesion to 5 is prevented. Even if bubbles adhere to the filter 25, they rarely pass through the filter 25, and it is possible to effectively prevent nozzle troubles such as dot omission due to bubble intrusion into the recording head 1.

In the above embodiment, an example in which the present invention is applied to a so-called on-carriage type recording apparatus in which the ink cartridge 2 is mounted on the carriage 3 has been described, but the present invention is not limited to this. It can also be applied to a so-called off-carriage type recording apparatus that supplies ink to the recording head 1 from an ink tank such as a pack by a tube.

In the above embodiment, manual cleaning is set at four levels CL1, CL2, CL3 and CL4, and timer cleaning is set at TCL1, TCL2.
Although TCL3 is set in three stages, the number of levels is not limited to this, and it is possible to set the number of levels to be smaller or larger than this.

In the above embodiment, as the ejection element for ejecting ink from the nozzle opening 36 of the head body 24, for example, a longitudinal vibration mode piezoelectric vibrator or a flexural vibration mode piezoelectric vibrator is used. it can. A heating element that heats and vaporizes the ink in the flow path of the head body 24 can also be used.

[0071]

As described above, in the ink jet recording apparatus of the present invention, strong cleaning which is performed in a region where the negative pressure is high and the flow velocity of the ink is high is not continuously performed. Since the cleaning operation of the region in which the flow velocity is slow continues, even if the bubbles in the flow path are drawn to the vicinity of the filter, they are prevented from adhering to the filter. Even if air bubbles adhere to the filter, the cleaning operation is performed in the region where the flow velocity is slow after that, so that the air bubbles rarely pass through the filter, resulting in dot omission due to air bubbles entering the print head. The nozzle trouble can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a peripheral structure of an ink jet recording apparatus of the present invention.

FIG. 2 is an exploded perspective view showing a main part of the ink jet recording apparatus.

FIG. 3 is a diagram showing an internal structure of the ink jet recording apparatus.

FIG. 4 is a diagram schematically showing a cross section of a recording head.

FIG. 5 is a diagram showing a change in negative pressure during a cleaning operation.

FIG. 6 is a block diagram showing a control circuit of the ink jet recording apparatus.

FIG. 7 is a diagram showing an operation of the inkjet recording apparatus.

[Explanation of symbols]

1 recording head 2 ink cartridge 3 carriage 4 Timing belt 5 Stepping motor 6 Guide bar 7 Recording paper 8 Cap member 9 Pump device 10 Wiper member 11 Lid member 12 guide holes 13 First ink supply needle 14 Supply port 15 Capping device 16 Flexible tube 17 Flexible tube 18 Waste pipe 19 Waste liquid tank 20 ink absorber 21 Guide stand 22 Device housing 23 Second ink supply needle 24 head body 25 filters 26 First flow path 27 Second channel 28 flow valve 29 valve 30 seat 31 Actuating member 32 First urging member 33 Second urging member 34 Connection member 35 head holder 36 nozzle openings 37 bubbles 38 Ink introduction hole 40 host computer 41 Printer driver 42 Input device 43 Printing control means 44 Head drive means 45 Flushing control means 46 Cleaning control means 47 Pump drive means 48 Cleaning command detecting means 49 Cleaning start button 50 print history storage means 51 cleaning mode selection means 52 ROM 53 Wiper member driving means 54 Carriage control means 55 Flow valve opening / closing means

Claims (9)

[Claims] 1. A recording head provided with nozzles for ejecting ink droplets, a capping device for sealing the nozzles of the recording head with a cap member, and a nozzle with the nozzle sealed by the cap member. An inkjet recording apparatus having a suction device for sucking ink in a recording head for cleaning by applying a negative pressure, wherein cleaning by the suction device is performed in a plurality of cleaning modes having different negative pressures during suction operation. After performing the strong cleaning performed at the highest negative pressure,
An ink jet recording apparatus, characterized in that it is configured to perform cleaning at a lower negative pressure than the above-mentioned strong cleaning until the next strong cleaning is executed. 2. The recording head is provided with a flow path valve for opening and closing a flow path of ink supplied from an ink tank, and the strong cleaning is performed by suctioning with the flow path valve closed. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is in a cleaning mode in which the flow path valve is opened with a predetermined negative pressure. 3. The ink jet recording apparatus according to claim 2, wherein the cleaning at a negative pressure lower than that of the strong cleaning is a cleaning mode in which suction is performed without closing the flow path valve. 4. The cleaning of a negative pressure lower than the strong cleaning is a cleaning mode in which suction is performed with the flow passage valve closed and the flow passage valve is opened at a negative pressure lower than the negative pressure of the strong cleaning. Item 5. The inkjet recording device according to item 2 or 3. 5. The ink jet recording apparatus according to claim 1, wherein the strong cleaning mode is executed as a cleaning operation when the ink tank is attached. 6. The ink jet recording apparatus according to claim 5, wherein the strong cleaning mode is executed as a cleaning operation when the ink in the ink tank is initially filled in the recording head. 7. The ink jet recording apparatus according to claim 5, wherein the ink tank is an ink cartridge mounted on a carriage, and the strong cleaning mode is executed as a cleaning operation when replacing the ink cartridge. 8. The ink jet recording apparatus according to claim 1, wherein the strong cleaning mode is executed as one of cleaning operations performed by a user's instruction. 9. The ink jet recording apparatus according to claim 1, wherein the strong cleaning mode is executed as one of timer cleaning operations that are automatically performed at a predetermined timing.