JP2001038925A - Ink jet recording apparatus and cleaning control method in the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus capable of achieving the sufficient functional restoration of a recording head. SOLUTION: The suction pumps 10A, 10B connected to the respective suction ports 9e, 9f formed to a capping means 9 are controlled so as to be alternatively driven in such a state that the valve means arranged to the ink flow channel on the upstream side of a recording head 15 is closed. By this constitution, negative pressure alternatively acts on the solidified matter of the nozzle orifice part wherein clogging is generated of the recording head 15 from different directions and the solidified matter receives shaking action to be brought to a state easy to peel from the nozzle orifice part. Since the valve means is opened in such a state the negative pressure from the pumps 10A, 10B is accumulated, a fast flow can be instantly generated in the ink flow channel and, as a result, the function of the recording head can be sufficiently restored.

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 receiving ink from an ink reservoir and discharging ink droplets from nozzle openings based on print data, and more particularly to recording from the ink reservoir. The present invention relates to a cleaning control technique for facilitating discharge of thickened ink and discharge of bubbles in an ink flow path leading to a head.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years, since noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus is generally mounted on a carriage and moves in the width direction of a recording sheet, and an ink jet recording head;
A paper feeder is provided for moving the recording paper in a direction perpendicular to the scanning direction of the recording head, and recording is performed by discharging ink droplets from the recording head onto the recording paper in accordance with print data.

[0003] On the carriage, for example, black,
Equipped with a recording head capable of discharging yellow, cyan, and magenta inks, it is possible to perform full-color printing by changing the discharge ratio of each ink as well as text printing using black ink. Such an ink jet type recording head performs printing by discharging ink pressurized in the pressure generating chamber from the nozzles as ink droplets onto the recording paper, so that the ink viscosity increases due to evaporation of the solvent from the nozzle opening, In addition, there is a problem that printing failure occurs due to solidification of ink, adhesion of dust, and mixing of air bubbles.

[0004] For this purpose, the ink jet recording apparatus is provided with capping means for sealing the nozzle openings of the recording head during non-printing and a wiping member for cleaning the nozzle forming surface as required. This capping means not only functions as a lid for preventing drying of the ink at the nozzle opening described above, but also when the nozzle opening is clogged, the nozzle forming surface is sealed by the capping means, and the suction pump is used. With the negative pressure, the ink is sucked and discharged from the nozzle opening to solve the problem of clogging of the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path.

[0005] Forcible suction and discharge of ink to eliminate clogging of the recording head and mixing of air bubbles into the ink flow path is called a cleaning operation. If you want to resume printing later,
This is executed when the user recognizes a defect in the printing state and operates the cleaning switch, etc., and after sucking and discharging ink from the recording head, the wiping member made of an elastic plate such as rubber is used to clean the nozzle forming surface of the recording head. An operation of wiping is involved.

Also, the recording head is provided with a function of applying a drive signal unrelated to printing to eject ink droplets, which is called a flushing operation, which is performed by a wiping member during a cleaning operation. Recovers an irregular meniscus generated near the nozzle opening of the head by operation, eliminates the occurrence of color mixing due to a slight suction at the nozzle opening of the ink discharged to the capping means during the cleaning operation, and even during printing This is an operation to be executed at regular intervals for the purpose of preventing clogging due to thickening of ink in the nozzle opening where the ejection of ink droplets is small.

[0007]

However, when the above-described cleaning operation is performed, a flow as fast as possible flows into the ink in the ink flow path from, for example, an ink cartridge as an ink storage section to a nozzle opening of a recording head. It is effective to generate the ink, whereby the ink present in the flow path together with the thickened ink can be discharged to some extent, and the solidified ink adhered to the vicinity of the nozzle opening at this time can also be separated. it can. However, in order to increase the flow rate of the ink during the cleaning operation, it is necessary to increase the suction capacity of the pump in order to obtain a large negative pressure.

In general, the suction pump used in this type of recording apparatus is formed in an arc shape in order to realize the operation at a relatively low cost, to ensure operation reliability, and to avoid contamination by ink. A tube pump is used in which the arranged tubes are sequentially crushed to generate a negative pressure.

In such a tube pump, in order to improve the suction capacity of the pump, means for increasing the number of revolutions of the pump, means for increasing the radius of the tubes arranged in an arc, and the like are conceivable. . However, when the number of revolutions of the pump is increased, as in the former case, the number of times the tube is crushed by the roller increases, which causes a problem that the life of the pump is extremely shortened. Therefore, means for improving the suction capacity must be adopted. However, this requires the use of a large pump motor and a large pump drive motor in order to secure the required driving torque with the increase in the size of the pump, which inevitably increases the cost and the size of the entire apparatus. Absent.

Therefore, a valve means which can be opened and closed is arranged in an ink flow path between the ink cartridge and the recording head, and the valve means is closed when suction of ink is started via a capping means in a cleaning operation. After the negative pressure is accumulated in the internal space of the capping means by the operation of the suction pump in the valve state, the valve means is opened to thereby instantaneously increase the flow rate of the ink in the recording head. A recording device has been proposed.

According to this structure, since the ink is discharged into the capping means instantaneously and vigorously by the action of the accumulated negative pressure, the bubbles present in the flow path together with the thickened ink can be discharged. It becomes possible.

However, since the valve means is opened in a state where the driving of the suction pump is stopped, the ink discharged into the capping means remains in a bubbling state, and the ink bubbles are generated in the recording head. There is a problem that the toner adheres to the nozzle forming surface and reenters the nozzle opening. Due to such a phenomenon, not only does the normal operation of ejecting ink droplets from the nozzle openings be hindered, but also the inconvenience that mixed printing is performed by mixing with black ink and three color inks occurs. . In order to suppress this, after the above-described suction operation, a large amount of flushing operation, a re-suction operation of the ink with a reduced negative pressure, and a wiping operation accompanying the operation are required.

On the other hand, even if an attempt is made to forcibly release the ink clogging state at the nozzle opening portion only by the accumulated negative pressure as described above, if the clogging state is relatively strong, the clogging state is recovered. Is often not easy. Therefore, it is necessary to return to a technical solution for increasing the suction capacity of the pump, and to increase the size of the pump and the whole device as described above. Therefore, means for simultaneously solving the above-mentioned problems is desired. I have.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned technical problems, and eliminates clogging of a recording head and discharges bubbles in an ink flow path without increasing the size of the apparatus. An object of the present invention is to provide an ink jet recording apparatus and a cleaning control method in the ink jet recording apparatus which are promoted.

[0015]

In order to achieve the above-mentioned object, a preferred embodiment of the ink jet recording apparatus according to the present invention comprises: an ink reservoir for supplying ink to a recording head; An ink jet recording head that receives ink and ejects ink droplets from nozzle openings based on print data, and seals a nozzle forming surface of the recording head, and receives ink from the recording head by receiving a negative pressure from a suction pump. Capping means having a function of sucking and discharging, and valve means arranged in an ink flow path between the ink storage section and the recording head, and opened in a state where negative pressure is accumulated in the internal space of the capping means. An ink jet recording apparatus comprising: at least two suction ports disposed in the capping unit in a state in which the suction ports are separated from each other; Together, are connected to a suction pump to each of the suction ports, the opening and closing of said valve means disposed on the upstream side of the recording head, the control means for driving selectively drives or simultaneously the suction pump is provided.

[0016] It also has a plurality of ink reservoirs,
The present invention can also be suitably applied to an ink jet type recording apparatus having a plurality of valve means arranged in an ink flow path between each of the ink reservoirs and the recording head.

In another preferred embodiment, the suction pumps are simultaneously driven with the valve means disposed upstream of the recording head closed, and the suction passages from the suction ports to the suction pumps are provided. A configuration including control means for controlling opening and closing of at least one of the valve means may be employed.

In any of the above-described embodiments, when the nozzle forming surface of the recording head is sealed by the capping means, it corresponds to both ends of the nozzle row that ejects the ink that is most easily thickened. It is preferable to adopt a configuration in which suction ports are provided at the bottom of the capping means with a space therebetween.

In a preferred aspect of the cleaning control method in the ink jet type recording apparatus according to the present invention, an ink storage section for supplying ink to a recording head and a nozzle receiving ink from the ink storage section based on print data are provided. An ink jet recording head that discharges ink droplets from an opening, a capping unit that seals a nozzle forming surface of the recording head, and has a function of sucking and discharging ink from the recording head under a negative pressure from a suction pump; A cleaning control method in an ink jet type recording apparatus comprising: a valve unit disposed in an ink flow path between the ink storage unit and the recording head and opened in a state where negative pressure is accumulated in an internal space of the capping unit. The capping means further comprises at least two suction ports separated from each other. A suction pump is connected to each suction port, and a simultaneous driving step of simultaneously driving each suction pump with the valve means opened is provided. In the driven state, the valve closing step of closing the valve means, the alternative driving step of selectively driving each suction pump with the valve means closed, and the alternative driving step A driving step of simultaneously driving the suction pumps, and a valve opening step of opening the valve means disposed on the upstream side of the recording head when the suction pumps are simultaneously driven. It is done as follows.

As another preferred embodiment, a simultaneous driving step of simultaneously driving the respective suction pumps with the valve means opened, and a valve for closing the valve means with the respective suction pumps simultaneously driven. A valve closing step, a simultaneous driving step of simultaneously driving each suction pump in a state where the valve means is closed, and, following the simultaneous driving step, an alternative driving step of selectively driving each suction pump, In a state in which each of the suction pumps is selectively driven, a valve opening step of opening the valve means disposed upstream of the recording head may be sequentially performed to perform a cleaning control method. .

As still another preferred embodiment, a simultaneous driving step of simultaneously driving the suction pumps while the valve means is opened, and a valve other than the valve means corresponding to the nozzle row for ejecting the ink which is most likely to be thickened. A valve closing step for closing the valve, an alternative driving step for selectively driving each suction pump with the valve means closed, and following the alternative driving step, simultaneously operating each suction pump. A simultaneous driving step of driving and a valve opening step of opening the valve means in a closed state arranged on the upstream side of the recording head when the suction pumps are simultaneously driven are sequentially executed. In addition, a cleaning control method may be employed.

As still another preferred embodiment, a simultaneous driving step of simultaneously driving the respective suction pumps with the valve means opened, and a valve means other than the valve means corresponding to the nozzle row for ejecting the ink which is most likely to be thickened. A valve closing step of closing a valve, a simultaneous driving step of simultaneously driving each suction pump with the valve means closed, and selectively driving each suction pump following the simultaneous driving step And a valve opening step of opening the valve means in a closed state arranged on the upstream side of the recording head when the suction pumps are selectively driven. The cleaning control method performed as described above can also be adopted.

In any of the above-described cleaning control methods, it is preferable that the suction operation of the pump is controlled to continue for a predetermined time even after the valve opening step is performed. .

According to the ink jet recording apparatus employing the above-described cleaning control method, when the cleaning operation is performed, the carriage moves to the non-printing area (home position) and is moved by the capping means disposed at the home position. The nozzle forming surface of the recording head is sealed.

Then, the valve means disposed in the ink flow path between the ink storing section and the recording head is closed, and each suction pump connected to each suction port formed in the capping means is selectively used. Is driven. Alternatively, valve means disposed in a suction path from each suction port to each suction pump is controlled to open and close. As a result, the negative pressure acts on each of the suction ports spaced apart from the capping means.

Therefore, a negative pressure acts on the nozzle opening portion of the recording head, which is clogged at the nozzle opening portion, from a different direction. On the other hand, a so-called rocking operation is provided. Alternatively, the flow of the ink moving between the suction ports arranged in the capping means causes the ink to positively contact the clogged nozzle portion, thereby promoting the softening or dissolution of the solidified ink. be able to.

After such an operation is performed, the respective suction pumps are simultaneously driven to a pressure accumulation state. In this state, the valve means is opened, so that a rapid flow is instantaneously generated in the ink flow path. Can be. Therefore, by the rapid flow of the ink, the solidified material which has been subjected to the swinging operation or the solidified material in the softened state can be peeled off, and the bubbles existing in the ink flow path due to the rapid ink flow can be eliminated. It is possible to do. As a result, the function of the recording head is restored, and the printing quality of the recording apparatus can be maintained at a high level.

Further, with the valve means disposed in the ink flow path between the ink storage section and the recording head being closed, each suction pump is simultaneously driven, and then each suction pump is selectively operated. Even when the valve means is opened in the state of being driven in the same manner as in the above-described operation, a quick flow of ink can be generated by the accumulated negative pressure, and at the same time, the above-described shaking operation is given, Thereby, the recovery of the function of the recording head is promoted.

When, for example, a tube pump is used as the above-mentioned suction pump, a configuration in which the drive shafts of a plurality of tube pumps are arranged in a straight line and connected to each other can be adopted, and therefore the occupied volume of the plurality of pumps Can be relatively reduced, which can contribute to suppressing an increase in the size of the device.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus employing a cleaning control method according to the present invention will be described with reference to an embodiment shown in FIG. In the figure, reference numeral 1 denotes a carriage. The carriage 1 is configured to be reciprocated in the axial direction of a platen 5 while being guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2.

An ink jet recording head (not shown in FIG. 1) is mounted on the side of the carriage 1 facing the recording paper 6, and an ink reservoir for supplying ink to the recording head is provided above the ink jet recording head. Black ink cartridge 7 and color ink cartridge 8 are detachably mounted.

A capping means 9 is disposed at a home position (right side in the figure), which is a non-printing area of the recording apparatus. The capping means 9 moves a recording head, which will be described later, mounted on the carriage 1 to the home position. It is configured to seal the nozzle forming surface of the recording head when it moves. A pump unit 10 for applying a negative pressure to the internal space of the capping unit is disposed below the capping unit 9.

The capping means 9 functions as a lid for preventing the nozzle opening of the recording head from drying during the idle period of the recording apparatus, and also applies a driving signal unrelated to printing to the recording head to remove ink droplets. It functions as an ink receiver at the time of a flushing operation for performing idle discharge, and also has a function as a cleaning unit that suctions and discharges ink by applying a negative pressure from each of the suction pumps (described later) constituting the pump unit 10 to the recording head. ing.

In the vicinity of the printing area side of the capping means 9, a wiping means 11 having an elastic plate such as rubber is arranged so as to be able to advance and retreat in a horizontal direction with respect to the movement locus of the recording head, for example. Carriage 1
When reciprocating to the capping means 9 side, the nozzle forming surface of the recording head can be wiped as necessary.

Next, FIG. 2 shows the structure of a valve unit disposed between the ink cartridge and the recording head. 2 (a) and 2 (b) are cross-sectional views viewed from directions orthogonal to each other.
2A and 2B show a state in which the nozzle forming surface of the recording head 15 is sealed by the capping means 9 rising from below.

Reference numeral 7 in FIG. 2 denotes an ink cartridge. In the ink cartridge 7, a film member (not shown) is generally attached to the ink supply port 7a so that evaporation of the ink solvent during storage can be prevented. Has been made.

When a new cartridge is mounted, the ink supply port 7a of the cartridge 7 is opposed to the hollow ink supply needle 21 established upward from the back surface of the recording head 7. The cartridge 7 can be mounted by pushing the cartridge 7 as it is. By this operation, the ink supply needle 21 penetrates through the film attached to the ink supply port 7a, and the rubber sealing member 7 disposed inside the film is provided.
b, so that the ink is supplied from the cartridge 7 to the recording head 15.

As shown in FIG. 2, a valve unit 23 as valve means for opening and closing the ink supply path 22 is disposed in the ink supply path 22 from the ink supply needle 21 to the recording head 15. In this valve unit 23, a shaft 24 inserted and arranged so as to traverse the ink supply path 22 is configured to be rotatable in a range of substantially 90 degrees, and a confidential state is formed by a pair of O-rings 23a. Is configured to be held. A through hole 23b is formed in a portion of the shaft 24 crossing the ink supply path 22 in a direction perpendicular to the axial direction of the shaft.

Therefore, by rotating the shaft 24 reciprocally within a range of approximately 90 degrees by an actuator (not shown), the through hole 23b and the ink supply path 22 are aligned in a straight line. Ink supply path 2
A valve-closed state in which the valve 2 is in an orthogonal state is selected.

A filter member 15d is arranged in the ink supply path 22 between the valve unit 23 and the recording head 15. This filter member 1
5d is disposed immediately below the valve unit 23 as shown in the figure, removes foreign matter present in the ink supplied from the ink cartridge 7, and generates foreign matter due to the opening / closing valve action of the valve unit 23. In addition, they are configured so as to prevent them from entering the recording head 15 and to prevent the occurrence of printing trouble of the recording head 15.

The valve unit 23 shown in FIG.
Is configured to open and close an ink supply path 22 between, for example, the black ink cartridge 7 and a nozzle opening of the black ink in the recording head 15. This valve unit is supplied from the color ink cartridge 8. The ink supply paths for cyan, magenta, and yellow inks are similarly arranged. Also,
The valve unit 23 is not limited to the specific one as shown in FIG. 2, and it is a matter of course that a valve unit having another configuration can be used.

FIG. 3 is a schematic diagram showing a first embodiment of a suction and ink discharge path from the recording head and the capping means to the waste ink tank.
Reference numeral 9 shown in FIG. 3 schematically shows the capping means in a sectional state. The capping means 9 has a rectangular cap case 9a having an open upper surface.
And a cap member 9b housed in the cap case 9a and also made of a flexible material such as a square rubber material having an open upper surface, and the upper edge of the cap member 9b is larger than that of the cap case 9a. It is formed in a slightly protruding state.

An ink absorbing material 9c formed of a porous material is accommodated in the inner bottom of the cap member 9b, and the ink absorbing material 9c is held by a holding body 9d formed integrally with the cap member 9b. Have been. Further, two suction ports 9e and 9f and an air opening port 9g are formed in the lower bottom portion of the cap case 9a so as to penetrate the cap case 9a and the cap member 9b, respectively.

In the embodiment shown in FIG. 3, the two suction ports 9e and 9f are arranged apart from each other along the longitudinal direction of the cap member 9b.
g is formed at a position slightly approaching one suction port 9f.

On the other hand, reference numeral 15 in FIG. 3 shows a recording head in which the nozzle forming surface is sealed by the capping means 9 in a sectional state. As described above, this recording head 15 is located above the capping means 9. Is moved, the nozzle plate 15a as a nozzle forming surface is capped by the cap member 9b. The nozzle plate 15a has a nozzle opening 1
5b are formed, and each ink can be ejected from the nozzle opening 15b by the action of the piezoelectric vibrator 15c arranged corresponding to each nozzle opening 15b.

The two suction ports 9e and 9f formed in the cap case 9a are connected to tubes 10a and 10a, respectively.
0b is connected to these tubes 10a, 10b.
3, constitute a part of a first suction pump (tube pump) 10A and a second suction pump (tube pump) 10B that directly constitute the pump unit 10, as shown in FIG. The discharge side of one suction pump 10A is connected to a waste ink tank 30 containing a waste liquid absorbing material 30a.
The discharge side of the other suction pump 10B is connected to a waste ink tank 3 containing a waste liquid absorbing material 31a.
It is connected to 1.

On the other hand, a tube 32 is connected to an atmosphere opening port 9g formed in the cap case 9a, and communicates with an atmosphere opening valve 33. When the carriage 1 moves to the home position and the cleaning operation is performed, the air release valve 33 is moved with the movement of the carriage 1.
For example, the on-off valve is controlled by a mechanical interlocking action.

According to the configuration shown in FIG. 3, the internal space of the cap member 9b is alternately formed by the two suction pumps 10A and 10B connected to the two suction ports 9e and 9f formed in the cap case 9a. Alternatively, a negative pressure can be simultaneously drawn.

Next, FIG. 4 is a schematic view showing a second embodiment of a suction and ink discharge path from the recording head and the capping means to the waste ink tank. In FIG. 4, parts corresponding to the respective parts shown in FIG. 3 are denoted by the same reference numerals. The difference from the first embodiment shown in FIG. 3 is that the suction paths from the suction ports 9e, 9f formed in the capping means to the suction pumps 10A, 10B, that is, the tubes 10a, 10b Valve means 35A, which can open and close the suction path, will be described later. Instead of the valve means, a flow path resistance varying means 35B which can vary the flow path resistance of the suction path may be arranged.

According to the configuration shown in FIG. 4, the opening / closing operation of the valve means 35A or the flow path resistance varying means 35B
The flow path resistance is controlled by the
The internal space of b can be sucked to the negative pressure alternately or simultaneously.

FIGS. 5 and 6 show the valve means 3 described above.
5A and 5B schematically show the respective configurations of the flow path resistance varying means 35B. First, a valve means 35A shown in a sectional state in FIG. 5 is connected between tubes constituting a suction path, and a through hole 35 communicating with both tubes.
b, and a base member 35a
The shaft member 35c is provided so as to be rotatable in a shaft hole formed in the shaft member 35c. And the shaft member 35c
Also, a through hole 35d is formed.

Accordingly, by rotating the shaft member 35c by an actuator (not shown) in a range of approximately 90 degrees, the valve closing state shown in the figure or the valve opening state in which the through holes are formed in a straight line can be selected. Can be.

On the other hand, the flow path resistance varying means 35B shown in a sectional view in FIG. 6 has a through hole 35h formed in a semicircular cross section in a base member 35g.
An elastic member 35i which can be extended and contracted is provided in the opening of the through hole 35.
h so as to be airtight. An operating body 35j having a semi-cylindrical or semi-spherical tip is in contact with a substantially central portion of the elastic member 35i.

Accordingly, the flow path resistance varying means 35B having the above-described structure is provided with the operating member 35 with respect to the elastic member 35i.
j is brought into contact by the driving force of an unillustrated actuator, and the elastic member 35i is deformed toward the through hole 35h depending on the degree of contact, whereby the flow path resistance of the suction path can be varied.

The curvature of the through hole 35h formed in the base member 35g and the curvature of the distal end of the operating body 35j are substantially the same (strictly speaking, the curvature of the distal end of the operating body 35j is changed to the elastic member 35i that is deformed). ), The suction passage can be closed in a state where the operating body 35j enters the through hole 35h most.
Therefore, according to the above-described configuration, the same opening / closing valve action as the valve means 35A shown in FIG. 5 can be provided.

Next, FIG. 7 shows an example of a control circuit mounted on the recording apparatus having the above configuration. Note that the carriage 1, ink cartridge 7,
8, capping means 9, each suction pump 10A, 10B constituting the pump unit 10, the recording head 15, the atmosphere release valve 33, and two valve means 35A
Are denoted by the same reference numerals, and therefore, detailed description thereof is omitted.

In FIG. 7, reference numeral 40 denotes print control means. The print control means 40 generates bitmap data on the basis of print data supplied from a host computer. It functions to generate a drive signal to eject ink from the recording head 15. The head driving means 41 receives a flushing command signal from a flushing control means 42 in addition to a drive signal based on print data, and outputs a drive signal for a flushing operation to the recording head 1.
5 is also provided.

Reference numeral 43 denotes cleaning control means.
A command signal from the cleaning control means 43 is supplied to the cleaning sequence control means 44.
Pump driving means 4 by a command signal provided from
5 is operated so that the suction pumps 10A and 10B can be driven simultaneously or alternatively.

The cleaning control means 43 is configured to be supplied with a cleaning command signal from a host computer via the printing control means 40. The cleaning control means 43 further includes a cleaning command detecting means. A cleaning command signal provided by the controller 46 is also supplied. In addition,
A command switch 47 is connected to the cleaning command detecting means 46, and when the user presses the switch 47, for example, the detecting means 46 is operated to perform a manual cleaning operation. I have.

The cleaning sequence control means 44
Receives a command signal from the cleaning control unit 43 and receives first and second valve driving units 49 and 49 in the ink supply path and the suction path in the ink supply path.
The control signal can also be sent to 50. In addition, it is configured so that a control signal can be transmitted to the carriage driving means 51 as well.

The valve unit driving means 48 sends a command signal to an actuator (not shown) mounted on the carriage 1 to rotationally drive the shaft 24 constituting the valve unit 23 shown in FIG. , And act to open and close the valve unit 23. The carriage driving unit 51 drives the carriage motor 2 shown in FIG. 1 to move the carriage 1 to the home position, for example, and controls the capping unit 9 to cap the recording head 15.

The first and second valve driving means 4
9 and 50, when the embodiment shown in FIG. 4 is employed, send a command signal to an actuator (not shown) to change the valve means 35A or the flow path resistance variable means 3 instead of the valve means 35A.
5B operates to open and close simultaneously or alternatively (alternately).

FIG. 8 is a flow chart showing the structure of the recording apparatus described above, in particular, the cleaning operation of the recording head performed when the first embodiment having the suction and ink discharge paths shown in FIG. 3 is employed. The sequence of the cleaning operation will be described below with reference to FIG. For example, when a cleaning command is received on a utility in a printer driver stored in the host computer, a control signal is sent from the host computer to the cleaning control unit 43 via the print control unit 40, and the cleaning operation starts.

When the cleaning operation starts, the nozzle forming surface of the recording head 15 is wiped by the wiping member 11 as shown in step S11. This is because the cleaning control means 43 determines a cleaning sequence, a control signal is sent from the cleaning sequence control means 44 to the carriage driving means 51 based on the signal, and the carriage 1 is moved toward the home position. In the wiping member 11
Moves into the movement path of the recording head 15, and the recording head 15
This is achieved by wiping the nozzle forming surface. As a result, paper dust and the like adhering to the nozzle forming surface of the recording head 15 are removed, so that the adhesion of the cap is ensured.

Subsequently, as shown in step S12, the carriage 1 still moves to the home position side, and accordingly, as shown in step S13, the carriage 1 moves to the home position.
Is capped by capping means 9. At the same time, as shown in step S14, the atmosphere release valve 33 communicating with the atmosphere release port 9g formed in the capping means 9 is also closed.

Next, the suction pumps are simultaneously driven as shown in step S15. At this time, the valve unit 23 arranged in the ink supply path 22 is in the valve open state, and the simultaneous driving of the suction pump in step S15 sucks ink from the nozzle openings and fills the cap member 9b with ink.

In this state, as shown in step S16, the valve units 23 arranged in the black ink supply path and the cyan, magenta and yellow color ink supply paths are closed. This is achieved by sending a control signal from the cleaning sequence control means 44 to the valve unit driving means 48 shown in FIG.

Subsequently, as shown in step S17, alternative driving of the suction pump is executed. This is because a control signal is sent from the cleaning control means 43 to the cleaning sequence control means 44 and a control signal is sent from the cleaning sequence control means 44 to the pump driving means 45 shown in FIG.
Perform the suction operation alternately.

As a result, the cap case 9 shown in FIG.
Negative pressure is accumulated in the internal space of the cap member 9b while negative pressure is alternately applied to the two suction ports 9e and 9g formed separately at the lower bottom portion of the cap member 9b. By such a suction operation, negative pressure acts alternately from different directions on the nozzle openings that have clogged the nozzle openings of the recording head 15, and solidified ink present in the nozzle openings Is given a so-called swinging motion. Alternatively, the ink filling the cap member 9b generates a oscillating flow, and this flow causes the ink to positively contact the clogged nozzle portion, thereby preventing the solidified ink from softening or dissolving. Can be promoted.

Subsequently, as shown in step S18, the respective suction pumps are simultaneously driven. By the simultaneous driving of the suction pumps in step S18, the negative pressure in the internal space of the cap member 9b is further accumulated. In this state, the process proceeds to step S19, and each valve unit 23 is opened. This is achieved by sending a control signal from the sequence control means 44 to the valve unit driving means 48 in FIG.

By the valve opening operation of the valve unit 23 in step S19, a rapid flow of ink can be instantaneously generated in the ink flow path from the ink cartridge 7 to the recording head 15. Therefore, by the rapid flow of the ink, the solidified material that has already been subjected to the oscillating operation or the solidified material in the softened state can be easily peeled from the nozzle opening. Existing air bubbles can be eliminated. As a result, the function of the recording head is restored.

Subsequently, in step S20, it is determined whether or not the driving operation of the suction pump has been performed for a predetermined time. That is, the valve unit 2 in step S19
The ink is discharged into the capping means 9 by the valve opening operation of 3, but the ink discharged into the capping means 9 is immediately discharged to the waste ink tanks 30 and 31 by the subsequent driving operation of the suction pump.

By this operation, ink bubbles in the capping means 9, and the occurrence of printing defects or the occurrence of color mixing due to the penetration of ink bubbles into the nozzle openings by the action of negative pressure can be effectively prevented. .

If it is determined in step S20 that the predetermined time has elapsed, the operation of the suction pump is stopped in step S21. In the subsequent step S22, it is determined whether or not the number of times of ink suction has been performed a predetermined number of times. If the number of times has not been reached, the above-described steps S13 to S21 are repeatedly performed.

If it is determined in step S22 that the predetermined number of ink suctions has been performed, the capping state of the recording head is released in step S23, and then a wiping operation is performed as shown in step S24 to perform recording. The ink adhering to the nozzle forming surface of the head is wiped and cleaned by the wiping member 11. Then, in step S25, the recording head 1
5 is again capped by the capping means 9 and is brought into a state of waiting for the arrival of print data.

In the sequence shown in FIG. 8, it is determined in step S22 whether or not the number of times of ink suction has been performed a predetermined number of times. Need not be repeated multiple times.

In the sequence shown in FIG. 8, each suction pump is selectively driven in step S17, and each suction pump is simultaneously driven in step S18. However, steps S17 and S18 are performed. The same operation and effect can be obtained even if the order is reversed.

That is, by simultaneously driving the suction pumps 10A and 10B first with the valve unit 23 closed, the negative pressure in the internal space of the cap member 9b can be rapidly accumulated. continue,
By selectively driving each suction pump in this state, the solidified matter adhering to the nozzle opening is given a swinging operation under a large negative pressure, thereby accumulating in the nozzle opening. The peeling action of the solidified material can be promoted.

Next, FIG. 9 is a flowchart showing the cleaning operation of the recording head, which is performed when the second embodiment having the suction and ink discharge paths shown in FIG. 4 is employed. In the embodiment shown in FIG. 4, as described above, the valve means 35A or a flow path instead of the valve means 35A is provided in the suction path between each suction port 9e, 9f formed in the capping means and each suction pump 10A, 10B. The configuration is such that resistance varying means 35B is arranged. Therefore, each of the suction pumps 10A and 10B is set to a suction operation state, and in this state, the valve means 35A or the flow path resistance changing means 35B instead of the valve means 35A is alternately opened and closed.
As described above, the same operation as when the suction pumps 10A and 10B alternately execute the suction operation can be obtained.

FIG. 9 shows a cleaning sequence performed based on the above-described operation. In particular, steps S17 and S17 in the sequence shown in FIG.
The control mode at 18 is replaced with steps S31 to S33 shown in FIG.

That is, after the valve unit 23 is closed in step S16, in step S31, the driving of each suction pump is started simultaneously. Then, immediately in step S32, the respective valve means 35A disposed in the suction path or the flow path resistance changing means 35B in place of the valve means 35A are alternately opened and closed. This is achieved by sending control signals to the first and second valve driving means 49 and 50 from the cleaning sequence control means 44 shown in FIG.

By such an operation, each suction pump 10
A and 10B perform the same operation as when the suction operation is performed alternately, whereby the two suction ports 9e and 9g are provided.
Then, the negative pressure is accumulated in the internal space of the cap member 9b while the negative pressure acts alternately. Therefore, as described above, the negative pressure acts alternately on the nozzle openings that have clogged the nozzle openings of the recording head 15 from different directions, and the solidified ink existing in the nozzle openings is affected by the negative pressure. On the other hand, a so-called swing operation is provided.

Subsequently, the flow shifts to step S33, in which all the valve means 35A or the alternative flow path resistance varying means 35B are opened. This operation is also performed by the sequence control means 44 by the first and second valve driving means 4.
9, 50 by sending a control signal.

By this operation, each suction pump 10A, 1
0B performs the same operation as when the suction operation is performed at the same time, whereby the negative pressure in the internal space of the cap member 9b is further accumulated. Then, in this state, the process proceeds to step S19 and the valve unit 23 is opened, whereby a rapid flow of the ink is instantaneously generated in the ink flow path from the ink cartridge 7 to the recording head 15, and the above-described operation is performed. Similarly, the solidified material which has already been subjected to the rocking operation or the solidified material in the softened state can be easily peeled off from the nozzle opening. In addition, it is possible to remove bubbles existing in the ink flow path by carrying the ink quickly, so that the function of the recording head can be recovered.

The same operation and effect can be obtained even if step 32 and step S33 shown in FIG. 9 are interchanged. That is, the valve means 35A or the flow path resistance varying means 35B instead of
Are both opened, the negative pressure in the internal space of the cap member 9b is rapidly accumulated. Subsequently, in this state, by selectively opening each of the valve means 35A or the alternative flow path resistance varying means 35B, the solidified substance adhering to the nozzle opening under a large negative pressure is further received. Is given a swinging motion, whereby the effect of separating solidified matter accumulated in the nozzle opening can be promoted.

In the embodiment shown in FIG. 4, the valve means 35A or the passage resistance changing means 35B in place of the valve means 35A are arranged in the tubes 10a and 10b constituting the suction passage. Although this is not always sufficient even if it is arranged in at least one suction path, the solidified matter adhering to the nozzle opening can be given a swing operation.

The above description of the cleaning operation is as follows.
A description will be given based on the case where the valve units 23 arranged in the black ink supply path and the cyan, magenta, and yellow color ink supply paths are simultaneously opened and closed under the control of the valve unit opening and closing means 48. However, for example, the valve unit arranged in the supply path of the ink that is most likely to thicken, for example, the supply path of the black ink, is opened, and the valve units 23 arranged in the supply paths of the other color inks are opened. Control means for opening and closing the valve according to the above-described sequence may be employed.

That is, in the case where such a control means is employed, in step S16 shown in FIG. 8, the supply of each color ink other than the valve unit arranged in the supply path of the black ink, for example, which is most likely to thicken. Control is performed so as to close the valve unit 23 disposed on the road. In step S19, control is performed so as to open the valve units 23 arranged in the supply paths of the respective color inks in the valve closed state. Therefore, according to such a control sequence,
The valve unit arranged in the supply path of the black ink is in the valve open state, and can positively discharge the black ink which is easily thickened.

As described above, even when the control for maintaining only the valve unit arranged in the supply path of the black ink, which is most susceptible to thickening, is executed, the steps S17 and S17 in FIG. S18
Can obtain the same function and effect even if the front and rear are interchanged. Further, as described with reference to FIG. 9, the present invention can be similarly applied to the case where the valve means 35A disposed in the suction path or the flow path resistance changing means 35B which is an alternative thereto is controlled to open and close.

In the embodiment shown in FIGS. 3 and 4, the two suction ports 9e and 9f are formed apart from each other in the longitudinal direction of the cap case 9a.
In the state where the nozzle forming surface of the recording head is sealed by the capping means as shown in, suction ports are respectively provided at the bottoms of the capping means corresponding to both ends of the nozzle row which ejects the ink which is most easily thickened. Are preferably arranged in a state of being separated from each other.

That is, FIG. 10A shows the recording head 15 sealed by the capping means 9 in a see-through state from above, and black ink is ejected onto the nozzle forming surface 15a in order from the left. A pair of nozzle rows BL, a pair of nozzle rows CY for discharging cyan ink,
A pair of nozzle rows MA for discharging magenta ink and a pair of nozzle rows YE for discharging yellow ink are formed.

FIG. 10B is a plan view showing the structure of the capping means 9 for sealing the above-mentioned nozzle forming surface 15a from below. Two suction ports 9e and 9f are arranged at the bottom of capping means corresponding to both ends of the nozzle row in the row BL in a state where they are separated from each other.

In the configuration shown in FIG. 10, when the suction operation is alternately repeated in the two suction ports 9e and 9f as described above, both ends of the nozzle row BL which discharges the black ink which is most likely to thicken. The swinging motion can be effectively given in the direction of the section, and the clogging due to the black ink can be effectively eliminated.

As shown in FIG. 10 (b), the air opening 9g is preferably formed at the other end of the cap unit in which the suction ports 9e and 9f are formed, as much as possible in the longitudinal direction. By arranging each suction port and the atmosphere opening port in this way, when ink is discharged from the inside of the cap unit, the ink in the cap unit can be flowed in one direction in an orderly manner. Of the ink can be improved.

In the embodiment described above, two suction ports 9e and 9f are formed in the capping means 9. However, three or more suction ports 9e and 9f are formed, and each is suctioned by a suction pump. You may comprise. In this case, for example, by using a tube pump as the suction pump and connecting the drive shafts of the tube pumps in series, this can be realized without relatively increasing the occupied volume. That is, as compared with the case where the arc-shaped radius of the tube is increased in order to increase the capacity of the tube pump, the design of the pump arrangement is much easier, and the suction capacity of the pump is increased while contributing to downsizing of the entire apparatus. can do.

Further, in the above-described embodiment, an on-carriage type recording apparatus in which an ink cartridge as an ink storage section is mounted on a carriage is shown. In the present invention, the ink storage section is provided on the carriage as an ink storage section. Ink cartridge (main ink tank) with sub tanks arranged in part of the device
Therefore, it is needless to say that the present invention can be applied to a recording apparatus configured to supply each ink to the sub tank via a tube, for example.

[0097]

As is clear from the above description, according to the ink jet recording apparatus employing the cleaning control method according to the present invention, the valve means disposed upstream of the recording head is closed. Since the suction pumps connected to the respective suction ports formed in the capping means are controlled so as to selectively perform suction driving, the nozzle opening portions of the recording head which are clogged are generated. Negative pressure can be selectively applied to the solidified material from different directions. Therefore, the solidified material is easily released from the nozzle opening by receiving the rocking operation. Then, in a state in which the negative pressure from each pump is accumulated, the valve means disposed upstream of the recording head is opened, so that a quick flow can be instantaneously generated in the ink flow path, whereby the recording is performed. Sufficient function recovery of the head can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus employing a cleaning control method according to the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of an ink flow path from an ink cartridge mounted on the recording apparatus illustrated in FIG. 1 to a recording head.

FIG. 3 is a schematic diagram illustrating a first embodiment of a suction and ink discharge path from a recording head and a capping unit to a waste ink tank.

FIG. 4 is a schematic diagram illustrating a second embodiment of a suction and ink discharge path from a recording head and a capping unit to a waste ink tank.

FIG. 5 is a sectional view showing an example of a valve means employed in the embodiment shown in FIG.

FIG. 6 is a cross-sectional view showing an example of a flow path resistance varying means employed in the embodiment shown in FIG.

FIG. 7 is a block diagram illustrating an example of a control circuit mounted on the recording device illustrated in FIG. 1;

FIG. 8 is a flowchart showing a cleaning operation sequence performed by the control circuit shown in FIG. 7;

FIG. 9 is a flowchart illustrating another example of a cleaning operation sequence performed by the control circuit illustrated in FIG. 7;

FIGS. 10A and 10B are a perspective view and a plan view showing a preferred relationship between a nozzle array of a recording head and a suction port formed in a capping unit. FIGS.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Carriage 2 Carriage motor 3 Timing belt 4 Guide member 5 Platen 6 Recording paper 7, 8 Ink cartridge (ink storage part) 9 Capping means 9e, 9f Suction port 9g Atmospheric opening port 10 Pump unit 10A, 10B Suction pump 11 Wiping means 15 Recording head 15a Nozzle plate (nozzle forming surface) 22 Ink supply path 23 Valve unit 33 Atmospheric release valve 35A Valve means 35B Flow resistance variable means

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2C056 EA14 EA15 EA23 EB38 EC11 EC22 EC23 EC24 EC54 EC57 EC60 FA04 FA10 HA38 JA10 JA13 JA16 JA17 JB04 JC05 JC08 JC10 JC13 JC20 JC21 JC23 KB04 KB08 KB26 KB37 KC05 KC22

Claims (9)

[Claims] An ink storage unit for supplying ink to the print head; an ink jet print head for receiving ink from the ink storage unit and discharging ink droplets from nozzle openings based on print data; Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. And a valve means that opens when negative pressure is accumulated in the internal space of the capping means, wherein the capping means is provided with at least two suction ports separated from each other. And a suction pump is connected to each suction port to open and close the valve means arranged upstream of the recording head. Both an ink jet recording apparatus characterized by comprising a control means for selectively driving or simultaneously driving the respective suction pumps. 2. An ink reservoir for supplying ink to a recording head, an ink jet recording head for receiving ink from the ink reservoir and ejecting ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the recording head by receiving a negative pressure from the suction pump; and a plurality of ink reservoirs and a plurality of ink reservoirs between the ink reservoir and the recording head. An ink jet recording apparatus comprising: a plurality of valve means arranged in an ink flow path, wherein the capping means is provided with at least two suction ports separated from each other, and each of the suction ports has A suction pump is connected, and opens and closes the valve means disposed upstream of the recording head, and also selectively drives each suction pump. Ku is an ink jet recording apparatus characterized by comprising a control means for driving simultaneously. 3. An ink reservoir for supplying ink to a recording head, an ink jet recording head for receiving ink from the ink reservoir and ejecting ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. And a valve means that opens when negative pressure is accumulated in the internal space of the capping means, wherein the capping means is provided with at least two suction ports separated from each other. A suction pump is connected to each suction port, and the valve means disposed on the upstream side of the recording head is closed. An ink jet recording apparatus comprising: a controller for simultaneously driving the respective suction pumps and controlling opening and closing of valve means disposed in at least one of suction paths from the respective suction ports to the respective suction pumps. . 4. In a state in which the nozzle forming surface of the recording head is sealed by the capping means, a bottom of the capping means corresponding to both ends of the nozzle row in the nozzle row which ejects the ink which is most likely to thicken is provided. 4. The ink jet recording apparatus according to claim 1, wherein the suction ports are arranged apart from each other. 5. An ink reservoir for supplying ink to a recording head, an ink jet recording head for receiving ink from the ink reservoir and ejecting ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. A cleaning control method in an ink jet recording apparatus, comprising: a valve that opens with a negative pressure accumulated in the internal space of the capping unit, wherein the capping unit further includes:
A simultaneous driving step in which at least two suction ports are arranged apart from each other and a suction pump is connected to each suction port, and each suction pump is simultaneously driven with the valve means opened; A valve closing step of closing the valve means in a state where the suction pumps are simultaneously driven; and an alternative driving step of selectively driving each suction pump in a state in which the valve means is closed. Following the alternative driving step, a simultaneous driving step of simultaneously driving the respective suction pumps; and a valve for opening the valve means disposed on the upstream side of the recording head when the respective suction pumps are simultaneously driven. A cleaning control method for an ink jet recording apparatus configured to sequentially execute a valve opening step. 6. An ink reservoir for supplying ink to a recording head, an ink jet recording head for receiving ink from the ink reservoir and ejecting ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. A cleaning control method in an ink jet recording apparatus, comprising: a valve that opens with a negative pressure accumulated in the internal space of the capping unit, wherein the capping unit further includes:
A simultaneous driving step in which at least two suction ports are arranged apart from each other and a suction pump is connected to each suction port, and each suction pump is simultaneously driven with the valve means opened; A valve closing step for closing the valve means in a state where the suction pumps are simultaneously driven; a simultaneous driving step for simultaneously driving each suction pump in a state where the valve means is closed; Following the step, an alternative driving step of selectively driving each of the suction pumps; and a valve for opening the valve means disposed upstream of the recording head in a state where each of the suction pumps is selectively driven. A cleaning control method for an ink jet recording apparatus configured to sequentially execute a valve opening step. 7. An ink storage unit for supplying ink to a print head, an ink jet print head for receiving ink from the ink storage unit and discharging ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. A cleaning control method in an ink jet recording apparatus, comprising: a valve that opens with a negative pressure accumulated in the internal space of the capping unit, wherein the capping unit further includes:
A simultaneous driving step in which at least two suction ports are arranged apart from each other and a suction pump is connected to each suction port, and each suction pump is simultaneously driven with the valve means opened; And a valve closing step of closing a valve other than the valve means corresponding to the nozzle row that ejects the ink that is most likely to thicken, and selectively driving each suction pump with the valve means closed. An alternative driving step to be performed, following the alternative driving step, a simultaneous driving step of simultaneously driving the respective suction pumps, and a valve closing disposed upstream of the recording head in a state where the respective suction pumps are simultaneously driven. And a valve opening step of opening the valve means in a state. 8. An ink reservoir for supplying ink to a recording head, an ink jet recording head for receiving ink from the ink reservoir and discharging ink droplets from nozzle openings based on print data, and Capping means having a function of sealing the nozzle forming surface and sucking and discharging ink from the print head by receiving a negative pressure from the suction pump, and an ink flow path between the ink storage section and the print head. A cleaning control method in an ink jet recording apparatus, comprising: a valve that opens with a negative pressure accumulated in the internal space of the capping unit, wherein the capping unit further includes:
A simultaneous driving step in which at least two suction ports are arranged apart from each other and a suction pump is connected to each suction port, and each suction pump is simultaneously driven with the valve means opened; And a valve closing step of closing a valve other than the valve means corresponding to the nozzle row that ejects the ink that is most likely to thicken, and a simultaneous drive for simultaneously driving each suction pump with the valve means closed. Step, following the simultaneous driving step, an alternative driving step of selectively driving each of the suction pumps; and in a state in which each of the suction pumps is selectively driven, the suction pump is disposed on the upstream side of the recording head. And a valve opening step of opening the valve means in a closed state. 9. The cleaning method according to claim 5, wherein the suction operation of the pump is continued for a predetermined time even after the valve opening step is executed. Control method.