JP2005144737A - Inkjet printer and method for cleaning recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely avoid clogging with ink in a recording head. <P>SOLUTION: An inkjet printer 1 is equipped with recording heads 7-10 each discharging the ink from a discharging hole, a cleaning device 30 spraying a cleaning liquid for dissolving the ink onto discharging faces for the ink of respective recording heads 7-10, a blade 40 wiping the discharging faces for the ink of the respective recording heads 7-10, and a suction device 50 sucking the ink from the respective recording heads 7-10. In a cleaning processing for the respective recording heads 7-10 by the inkjet printer 1, the cleaning liquid is sprayed onto the discharging faces of the ink of the respective recording heads 7-10 by the cleaning device 30, and thereafter, the blade 40 wipes the discharging faces of the ink of the respective recording heads 7-10, and then, the suction device 50 sucks the ink from the respective recording heads 7-10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet printer and a recording head cleaning method, and more particularly to an ink jet printer and a recording head cleaning method in which various conditions of a cleaning process are optimized.

  Inkjet printers have the feature of being able to record high-resolution and high-quality images at a relatively low cost at a high speed, and are therefore intended to be displayed outdoors from recording on small and medium-sized paper for individual users. The application is widely expanded to recording on large format paper such as posters. In particular, when recording on large format paper for the purpose of outdoor display, it is common to use water-based pigment inks that are light-resistant. However, water-based pigment inks cause the ink to dry rapidly. In an environment, the ink is more likely to aggregate than the dye ink, and the ink is clogged when left for a long period of time without being discharged in the recording head.

Therefore, in Patent Document 1, a special cleaning liquid containing a surfactant, a basic compound, and water having a pH of 9.0 or more is circulated through an ink flow path (channel) in the recording head to improve the cleaning efficiency of the recording head. This prevents ink clogging in the recording head when pigment ink is used.
JP 2000-127419 A

However, as in Patent Document 1, it is difficult to obtain a sufficient recording head cleaning effect corresponding to all types of ink only by a cleaning operation using a cleaning liquid, and in particular, an ink excellent in image storability and color tone. In the case of using a colored fine particle ink composed of fine particles of a coloring material and a polymer, or an ink having a high polymer content by adding a latex or a water-soluble polymer, the cleaning effect of the recording head is not effective. Sufficiency appears remarkably. In other words, “colored fine particle ink” and “ink with a high polymer content” contain a polymer as a composition component thereof, and therefore, when the solvent volatilizes, the viscosity of the remaining component tends to increase, and in some cases, it may be completely solidified. Also, if such a solid content is present at the meniscus (the liquid level in the ink ejection holes) due to the volatilization of the solvent, it becomes difficult to suck ink, which is one of the cleaning operations, and avoid clogging of the ink in the recording head. I can't.
An object of the present invention is to provide an ink jet printer and a recording head cleaning method capable of reliably avoiding clogging of ink in the recording head.

In order to solve the above problem, an ink jet printer according to claim 1 is provided.
A recording head for discharging ink from the discharge holes;
A suction device for sucking ink from the ejection holes;
A removing device for removing clogging of ink in the ejection holes;
With
The removing device performs a removing operation for removing clogging of ink in the ejection holes, and then the suction device sucks ink from the ejection holes.

The invention described in claim 2
The inkjet printer according to claim 1, wherein
A blade for wiping the ink ejection surface of the recording head;
The cleaning device is a cleaning device that sprays a cleaning liquid that dissolves or redisperses ink onto the ejection surface,
The cleaning device sprays the cleaning liquid onto the discharge surface as the removing operation, and then the blade wipes the discharge surface, and then the suction device sucks ink from the discharge holes.

The invention according to claim 3
In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
The overlapping amount of the blade with respect to the discharge surface is variable before and after the suction operation by the suction device.

The invention according to claim 4
The inkjet printer according to claim 3.
The amount of overlap of the blade with the discharge surface is larger before the suction operation than after the suction operation by the suction device.

The invention described in claim 5
In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
The wiping speed of the blade with respect to the ejection surface is variable before and after the suction operation by the suction device.

The invention described in claim 6
The inkjet printer according to claim 5.
The wiping speed of the blade with respect to the discharge surface is faster before the suction operation than after the suction operation by the suction device.

The invention described in claim 7
In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
The number of times of wiping the blade with respect to the ejection surface is variable before and after the suction operation by the suction device.

The invention according to claim 8 provides:
The inkjet printer according to claim 7, wherein
The number of times of wiping the blade with respect to the ejection surface is greater before the suction operation than after the suction operation by the suction device.

The invention according to claim 9 is:
In the ink jet printer according to any one of claims 1 to 8,
The ink contains 2% by weight or more of a polymer as a composition component.

The invention according to claim 10 is:
In the ink jet printer according to any one of claims 1 to 8,
The ink contains colored fine particles composed of a color material and a polymer.

The invention according to claim 11
In the recording head cleaning method for discharging ink from the discharge holes,
A removal step for removing clogging of ink at the ejection holes;
A suction step of sucking ink from the ejection holes after the removing step;
It is characterized by having.

The invention according to claim 12
The method of cleaning a recording head according to claim 11.
The removing step is a step of spraying a cleaning liquid that dissolves or redisperses ink onto the ejection surface,
A wiping step of wiping the ink discharge surface of the recording head after the removing step and before the suction step is provided.

The invention according to claim 13
In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
The overlapping amount of the blade with respect to the ejection surface is variable between the first wiping step and the second wiping step.

The invention according to claim 14
The method for cleaning a recording head according to claim 13.
The overlap amount of the blade with respect to the discharge surface is larger in the first wiping step than in the second wiping step.

The invention according to claim 15 is:
In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
The wiping speed of the blade with respect to the discharge surface is variable between the first wiping step and the second wiping step.

The invention described in claim 16
In the recording head cleaning method according to claim 15,
The wiping speed of the blade with respect to the discharge surface is faster in the first wiping step than in the second wiping step.

The invention described in claim 17
In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
The number of times of wiping the blade with respect to the ejection surface is variable between the first wiping step and the second wiping step.

The invention described in claim 18
The recording head cleaning method according to claim 17,
The number of times of wiping the blade with respect to the discharge surface is larger in the first wiping step than in the second wiping step.

The invention according to claim 19 is
In the cleaning method of the recording head according to any one of claims 11 to 18,
The ink contains 2% by weight or more of a polymer as a composition component.

The invention according to claim 20 provides
In the cleaning method of the recording head according to any one of claims 11 to 18,
The ink contains colored fine particles composed of a color material and a polymer.

  According to the first aspect of the present invention, since the removing device performs the removing operation and the suction device then sucks the ink from the ejection holes of the recording head, it is possible to reliably avoid clogging of the ink at the ejection holes of the recording head. Can do.

  According to the second aspect of the present invention, since the cleaning device sprays the cleaning liquid onto the ejection surface of the recording head and the blade wipes the ejection surface, ink clogging at the ejection holes in the recording head can be avoided more reliably. Can do.

  According to the third aspect of the present invention, since the overlapping amount of the blade with respect to the ejection surface of the recording head is variable before and after the suction operation by the suction device, ink clogging at the ejection holes in the recording head can be reliably avoided. Can do.

  In the invention described in claim 5, since the wiping speed of the blade with respect to the ejection surface of the recording head is variable before and after the suction operation by the suction device, ink clogging at the ejection holes in the recording head can be reliably avoided. Can do.

  According to the seventh aspect of the invention, since the number of times of wiping the blade with respect to the ejection surface of the recording head is variable before and after the suction operation by the suction device, it is possible to reliably avoid clogging of ink at the ejection holes in the recording head. Can do.

  In the invention according to the eleventh aspect, since the suction step exists after the removing step, it is possible to reliably avoid clogging of the ink at the ejection holes in the recording head.

  In the twelfth aspect of the present invention, since the wiping step exists after the removing step, it is possible to more reliably avoid clogging of ink at the ejection holes in the recording head.

  In the invention according to the thirteenth aspect, since the overlapping amount of the blade with respect to the ejection surface of the recording head is variable between the first wiping step and the second wiping step, ink clogging at the ejection holes in the recording head is prevented. It can be avoided reliably.

  According to the fifteenth aspect of the invention, since the wiping speed of the blade with respect to the ejection surface of the recording head is variable between the first wiping step and the second wiping step, ink clogging at the ejection holes in the recording head is prevented. It can be avoided reliably.

  In the invention according to claim 17, since the number of times of wiping of the blade with respect to the ejection surface of the recording head is variable between the first wiping step and the second wiping step, clogging of ink at the ejection holes in the recording head is prevented. It can be avoided reliably.

The best mode for carrying out the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
FIG. 1 is a perspective view showing a schematic configuration of the ink jet printer 1.

  As shown in FIG. 1, the ink jet printer 1 has a flat platen 2 that supports a non-recording surface (a surface opposite to the recording surface) of a recording medium 99. 4 are arranged respectively. A conveyance motor 16 (see FIG. 3) serving as a driving source is connected to each of the conveyance rollers 3 and 4, and the conveyance rollers 3 and 4 rotate around the axis before and after the platen 2 as the conveyance motor 16 is driven. The recording medium 99 is transported along the transport direction A by rotating in predetermined directions.

  In FIG. 1, a guide member 5 extending in a direction B (hereinafter referred to as “scanning direction B”) orthogonal to the transport direction A is disposed above the platen 2, and the guide member 5 has a carriage 6. Is supported. The carriage 6 can be scanned (reciprocated) in the scanning direction B while being guided by the guide member 5.

  On the carriage 6, four recording heads 7 to 10 for discharging process color inks of yellow (Y), magenta (M), cyan (C), and black (K) toward the recording surface of the recording medium 99, respectively. The four recording heads 7 to 10 simultaneously follow the reciprocating movement of the carriage 6. A predetermined number of ink ejection holes (not shown) are formed in the lower surfaces 7a to 10a (surfaces facing the platen 2) of the recording heads 7 to 10, and the recording heads 7 to 10 receive ink from the ejection holes. Are discharged as droplets. That is, the lower surfaces 7a to 10a of the recording heads 7 to 10 are ink ejection surfaces.

  The “ink” discharged from each of the recording heads 7 to 10 may be a known dye ink or pigment ink, an ink containing 2% by weight or more of a polymer as a composition component, An ink containing colored fine particles composed of a polymer may be used, and any kind of ink can be applied as long as it is a known inkjet ink.

  In each of the recording heads 7 to 10, a flexible tube in which four ink tanks (not shown) for storing ink of each color of Y, M, C, and K for each color can follow the reciprocating movement of the carriage 6. (Not shown), and in accordance with the recording operation of the ink jet printer 1, ink is supplied from each ink tank to the four recording heads 7 to 10 via the flexible tube for each color. Yes.

  In FIG. 1, the left side of the platen 2 is a home position 11 serving as a standby position of the carriage 6, and the same four moisturizing caps 12 to 15 as the recording heads 7 to 10 are disposed at the home position 11. ing. Each of the moisturizing caps 12 to 15 is a member that covers the lower surfaces 7a to 10a of the recording heads 7 to 10, and prevents the ink from drying in the ejection holes of the recording heads 7 to 10. In the ink jet printer 1, the carriage 6 can be moved to the home position 11. When the ink jet printer 1 is not recording, the carriage 6 covers the bottom surfaces 7 a to 10 a of the recording heads 7 to 10 with the four moisture retaining caps 12 to 15. In this state, the robot is waiting at the home position 11.

  In FIG. 1, a cleaning mechanism 20 for cleaning the recording heads 7 to 10 is disposed on the right side of the platen 2. The cleaning mechanism 20 includes a box-shaped housing 21, a cleaning device 30 as a removing device that injects cleaning liquid onto the lower surfaces 7 a to 10 a of the recording heads 7 to 10, and the lower surfaces 7 a to 10 a of the recording heads 7 to 10. A blade 40 for wiping off adhering substances (ink, cleaning liquid, etc.) and a suction device 50 for sucking ink from the ejection holes of the lower surfaces 7a to 10a of the recording heads 7 to 10 are provided.

FIG. 2 is a diagram showing a schematic configuration of the cleaning device 30 in the cleaning mechanism 20.
As shown in FIG. 2, the cleaning device 30 has an injector 31 in which a large number of injection holes (not shown) for injecting the cleaning liquid are formed in the upper portion, and the upper portion of the injector 31 is outside the housing 21. Exposed. A tank 32 storing a cleaning liquid for dissolving or redispersing ink is disposed inside the casing 21, and the injector 31 and the tank 32 are connected by a tube 34 via a pump 33 inside the casing 21. It is. In the cleaning device 30, when the pump 33 is operated, the cleaning liquid stored in the tank 32 is supplied to the injector 31 through the tube 34, and the cleaning liquid is sprayed from each injection hole on the upper side of the injector 31 in a mist form. It is like that.

  In FIG. 1, a square plate-like blade 40 is disposed on the right side of the cleaning device 30. An elevating device 41 (see FIG. 3) that raises and lowers the blade 40 in the vertical direction in FIG. 1 is installed inside the housing 21, and the blade 40 is arranged at an arbitrary height position by the operation of the elevating device 41. Be able to. The blade 40 is made of an ink repellent (water repellent) material having elasticity. Examples of the “ink-repellent material” include silicon-based materials such as silicon rubber, silicon resin, room-temperature curable silicone resin, and room-temperature curable organic modified silicone resin, and highly water-repellent materials such as polytetrafluoroethylene.

  The blade 40 may be made of an ink-philic (hydrophilic) material having elasticity. Examples of the “ink-friendly material” include various known rubbers such as urethane rubber and butyl rubber. In the blade 40, the base material itself is made of an elastic material (for example, various known rubbers), and the base material is coated with a silane compound, or a hydrophilic polymer (nylon, polyurethane, polyvinyl alcohol, etc.) is coated. Alternatively, the surface of the base material may be subjected to a plasma treatment to perform a hydrophilic treatment.

  When the blade 40 is made of an ink-philic material, the ink adhering to the lower surfaces 7a to 10a of the recording heads 7 to 10 can be attracted and wiped off by the ink affinity. Since the ink may be drawn out from the ejection holes of the lower surfaces 7a to 10a, the blade 40 is preferably made of a material with low ink affinity, that is, an ink repellent material as described above.

  In FIG. 1, a suction device 50 is disposed on the right side of the blade 40. The suction device 50 has four suction caps 51 to 54. An elevating device 55 (see FIG. 3) for raising and lowering the suction caps 51 to 54 in the vertical direction in FIG. 1 is installed inside the housing 21, and the operation of the elevating device 55 causes the suction caps 51 to 54 to be moved up and down. The lower surface 7a to 10a of each recording head 7 to 10 can be covered by arbitrarily changing the height position. Each of the suction caps 51 to 54 is made of an elastic resin so that the airtightness with the lower surfaces 7a to 10a of the recording heads 7 to 10 can be improved.

  Inside the housing 21, a suction pump 56 (see FIG. 3) that generates a negative pressure (suction force) in each suction cap 51 to 54 and waste that stores ink sucked by each suction cap 51 to 54 as waste ink. Tanks (not shown) are respectively installed, and the suction caps 51 to 54 and the waste tank are connected by a suction tube (not shown) via a suction pump. In the suction device 50, when the suction pump 56 is operated in a state where the suction caps 51 to 54 cover the lower surfaces 7a to 10a of the recording heads 7 to 10, a negative pressure is generated in the suction caps 51 to 54, and each recording head. Ink is sucked from the ejection holes of the lower surfaces 7a to 10a of 7 to 10, and the ink flows through the suction tube and is stored in the waste ink tank.

Next, the circuit configuration of the inkjet printer 1 will be described.
FIG. 3 is a block diagram illustrating a circuit configuration of the control device 60 that controls the inkjet printer 1.
The control device 60 includes a control unit 61 composed of a general-purpose CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and the like. The control unit 61 expands the processing program recorded in the ROM to the RAM and executes the processing program by the CPU.

  Specifically, the control unit 61 includes a transport motor 16, a carriage 6, recording heads 7 to 10, a cleaning mechanism 20 (a pump 33 of the cleaning device 30, a lifting device 41 of the blade 40, a lifting device 55 of the suction device 50, and a suction pump. 56, etc.) are connected, and the control unit 61 controls the operation of each component based on the status such as the operation status of various members of the transport motor 16, the carriage 6, the recording heads 7 to 10, and the cleaning mechanism 20. It has become.

Next, the operation and action of the inkjet printer 1 will be described.
In a state before the image recording operation, the recording medium 99 is hung between the transport rollers 3 and 4 with the non-recording surface supported by the platen 2, and the carriage 6 is the lower surface 7a of the recording heads 7 to 10. -10a is on standby at the home position 11 in a state of being covered by the four moisturizing caps 12-15.

  When an image recording operation is started in this state, that is, when image data is input to the control unit 61 of the control device 60, the conveyance motor 16, carriage 6, recording heads 7 to 10, Control signals are transmitted to various members of the cleaning mechanism 20, and the operation of each component is controlled as follows. That is, the transport motor 16 is driven, and the transport rollers 3 and 4 are rotated by a predetermined amount and stopped. As a result, the recording medium 99 moves on the platen 2 along the conveyance direction A by a predetermined amount and stops.

  When the movement of the recording medium 99 is stopped, the carriage 6 is actuated to move the recording heads 7 to 10 from the left to the right in FIG. During the movement of the carriage 6, the recording heads 7 to 10 form ink as fine droplets from the ejection holes of the lower surfaces 7 a to 10 a toward the image recording area (area for recording an image) on the recording surface of the recording medium 99. Discharge each.

  When the carriage 6 deviates from the image recording area on the recording surface of the recording medium 99 to the right in FIG. 1, the conveying motor 16 is driven again, and the conveying rollers 3 and 4 are rotated by a predetermined amount and stopped. The recording medium 99 moves a predetermined amount on the platen 2 and stops.

  When the movement of the recording medium 99 stops, the carriage 11 is actuated again, and the recording heads 7 to 10 move from the right side to the left side in FIG. During the movement of the carriage 6, the recording heads 7 to 10 eject ink as fine droplets from the ejection holes of the lower surfaces 7 a to 10 a toward the image recording area of the recording surface of the recording medium 99.

  Thereafter, when the inkjet printer 1 repeats the above-described operation, images are sequentially recorded in the image recording area of the recording surface of the recording medium 99 that has passed over the platen 2. That is, in the inkjet printer 1, the recording medium 99 is intermittently transported along the transport direction A by repeating a predetermined amount of movement and stop, but when the recording medium 99 stops, the carriage 6 operates, The four recording heads 7 to 10 move along the scanning direction B immediately above the recording medium 99 supported by the platen 2. During the movement of the carriage 6, the recording heads 7 to 10 eject ink toward the recording medium 99, and an image is recorded on the recording medium 99.

  Here, in the ink jet printer 1, each time a predetermined number of images are recorded, each recording head by cooperation of the carriage 6 and the cleaning mechanism 20 in a state where the operation of each component is controlled by the control unit 61 of the control device 60. 7 to 10 “cleaning process” is performed. The cleaning process includes the following steps (1) to (4), and the following steps (1) to (4) are performed in numerical order.

(1) Removal Step This step is a step for removing clogging of ink at the ejection holes of the recording heads 7 to 10. Specifically, when the cleaning process is started, the carriage 6 moves from the left to the right in FIG. 1 so as to approach the cleaning mechanism 20, and each recording head 7 to 10 passes immediately above the cleaning device 30. To do. During the passing movement of the recording heads 7 to 10, the pump 33 of the cleaning device 30 is operated and the cleaning liquid is ejected from the ejector 31 toward the lower surfaces 7 a to 10 a of the recording heads 7 to 10. That is, in this removal step, a cleaning liquid for dissolving or redispersing the ink is sprayed onto the lower surfaces 7a to 10a of the recording heads 7 to 10 to dissolve or redisperse the ink in the discharge holes of the recording heads 7 to 10 in the cleaning liquid. The ink that causes clogging is removed from the ejection holes of the recording heads 7 to 10.

(2) First wiping process (wiping process)
This step is a step of wiping the lower surfaces 7a to 10a of the recording heads 7 to 10 with the blade 40. Specifically, when the recording heads 7 to 10 have finished passing immediately above the cleaning device 30, the movement of the carriage 6 is stopped, the lifting device 41 is operated, the height position of the blade 40 is adjusted, and each recording is performed. The overlapping amount of the blade 40 with respect to the lower surfaces 7a to 10a of the heads 7 to 10 is optimized. “The overlapping amount of the blade 40 with respect to the lower surfaces 7a to 10a of the recording heads 7 to 10” means that the upper part of the blade 40 overlaps with the lower part of the recording heads 7 to 10 as shown in FIG. Is an amount indicated by a distance d from the lower surface 7 a to 10 a of each recording head 7 to 10 to the upper surface of the blade 40.

  When the height position of the blade 40 is adjusted, the carriage 6 is actuated again, and the recording heads 7 to 10 pass over the blade 40. At this time, as shown in FIG. 4B, the recording heads 7 to 10 move from the left to the right in FIG. 4B, and the recording heads 7 to 10 are elastically deformed at the upper part of the blade 40. The lower surfaces 7a to 10a are wiped off. When each of the recording heads 7 to 10 finishes passing through the upper part of the blade 40, the lifting / lowering device 41 is actuated again to return the blade 40 to the original height position.

  In the first wiping step, the overlapping amount of the blade 40 with respect to the lower surfaces 7a to 10a of the recording heads 7 to 10, the wiping speed, and the number of wiping operations are variable. The “wiping speed of the blade 40 with respect to the lower surfaces 7 a to 10 a of the recording heads 7 to 10” is the moving speed of the recording heads 7 to 10 with respect to the blade 40. The “number of times the blade 40 is wiped with respect to the lower surfaces 7 a to 10 a of the recording heads 7 to 10” is the number of times each recording head 7 to 10 passes over the blade 40. An operation of moving the upper part of FIG. 1 from the left to the right or from the right to the left in FIG. 1 is counted as one time. When the blade 40 is wiped a plurality of times, the same operation as described above (the operation in which the recording heads 7 to 10 move from the left to the right in FIG. 1 while sliding on the blade 40) is repeatedly performed. Alternatively, an operation similar to the above and an operation opposite to the above (an operation in which each recording head 7 to 10 moves from the right to the left in FIG. 1 while sliding on the blade 40) are alternately performed. May be.

(3) Suction Step This step is a step of sucking ink from the ejection holes of the lower surfaces 7a to 10a of the recording heads 7 to 10. Specifically, each of the recording heads 7 to 10 that has passed through the upper part of the blade 40 moves to above the suction device 50 with the operation of the carriage 6 and stops at that position. When the movement of the recording heads 7 to 10 is stopped, the lifting device 55 of the suction device 50 is activated, and the suction caps 51 to 54 cover the lower surfaces 7 a to 10 a of the four recording heads 7 to 10. The suction pump 56 operates to suck ink from the ejection holes on the lower surfaces 7a to 10a of the recording heads 7 to 10. When a predetermined time has elapsed from the operation of the suction pump 56, the operation of the suction pump 56 is stopped and the lifting device 55 is operated again to return the suction caps 51 to 54 to their original positions.

(4) 2nd wiping process This process is a process after a suction process, Comprising: The process content is the same as that of the said 1st wiping process. Specifically, when the suction caps 51 to 54 of the suction device 50 are returned to their original positions, the elevation device 41 is operated to adjust the height position of the blade 40, and the lower surface 7 a of each recording head 7 to 10. The overlapping amount of the blade 40 with respect to -10a is optimized.

  When the height position of the blade 40 is adjusted, the carriage 6 operates and the recording heads 7 to 10 pass over the blade 40. At this time, the recording heads 7 to 10 move from right to left in FIG. 1, and the lower surfaces 7a to 10a of the recording heads 7 to 10 are wiped off while the upper portion of the blade 40 is elastically deformed. When each of the recording heads 7 to 10 finishes passing through the upper part of the blade 40, the lifting / lowering device 41 is actuated again to return the blade 40 to the original height position.

  In the second wiping step, as in the first wiping step, the overlapping amount of the blade 40 with respect to the lower surfaces 7a to 10a of the recording heads 7 to 10, the wiping speed, and the number of wiping operations are variable. In particular, the various conditions in the second wiping process (the overlapping amount of the blades 40, the wiping speed, and the number of wiping operations) are all controlled to exceed those in the first wiping process. That is, the overlapping amount of the blade 40 in the second wiping step is larger than that in the first wiping step, and the wiping speed of the blade 40 in the second wiping step is faster than that in the first wiping step. The number of times of wiping the blade 40 in the process is larger than that in the first wiping process.

  When the processes in the steps (1) to (4) are finished, the cleaning process for the recording heads 7 to 10 is finished, and the inkjet printer 1 is based on the image data input to the control unit 61 of the control device 60. The above-described image recording operation is resumed or the carriage 6 is moved to the home position 11 to prepare for the subsequent image recording operation.

  In the above embodiment, the cleaning device 30 injects the cleaning liquid onto the lower surfaces 7a to 10a of the recording heads 7 to 10 in the removing process, and the blade 40 of the recording heads 7 to 10 in the first or second wiping process. Since the lower surfaces 7a to 10a are wiped and the suction device 50 sucks ink from the ejection holes of the lower surfaces 7a to 10a of the recording heads 7 to 10, the ink clogging at the ejection holes in the recording heads 7 to 10 is ensured. Can be avoided.

  Furthermore, in this embodiment, each condition of the overlapping amount of the blade 40 with respect to the lower surfaces 7a to 10a of the recording heads 7 to 10, the wiping speed, and the number of wiping operations is variable in the first wiping process and the second wiping process. Therefore, it is possible to change the condition of the wiping operation by the blade 40 in accordance with the usage status (usage frequency, usage period, etc.) of each recording head 7-10. Ink clogging can be reliably avoided.

  The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the cleaning device 30 is installed in the cleaning mechanism 20, and the ink that causes clogging is removed from the ejection holes of the recording heads 7 to 10 by the cleaning device 30 in the removal process. Instead, a printable member having projections corresponding to and corresponding to the ejection holes of the printheads 7 to 10 is installed, and the printhead is moved up and down to remove ink that causes clogging in the printhead. You may make it remove from 7-10 discharge holes.

  In this example, when various conditions of the cleaning process by the cleaning mechanism are variously changed using a printer similar to the ink jet printer described in the above embodiment, the ink clogging recovery property in each recording head is tested and evaluated. did. Ink preparation, cleaning liquid preparation, ink clogging recovery test / evaluation, etc. are as shown in the following (1) to (3).

(1) Preparation of ink A dropping device, a thermometer, a nitrogen gas introduction tube, a stirring device, a reflux condenser, and the like were set in a three-liter four-necked flask, and 1000 g of ethyl acetate was heated to reflux. 500 g of styrene, 200 g of stearyl methacrylate, and 300 g of acetoacetoxy methacrylate are weighed, and a mixed solution obtained by adding 20 g of N, N′-azobisisovaleronitrile to the monomer is added dropwise over 2 hours, and the reaction is performed at the same temperature for 5 hours. Core polymer A having a solid content of 50% by weight was obtained.

  Once the core polymer A is obtained, 18 g of FS Blue 1504, 18 g of the above-mentioned core polymer A in terms of solid content and 140 g of ethyl acetate are placed in a pot of CLEARMIX CLM-0.8S (manufactured by MTechnic Co., Ltd.), stirred and dyed Was completely dissolved. 9 g of Aqualon KH-05 (Daiichi Kogyo Seiyaku Co., Ltd.) was added to 258 g of pure water, added to the dye solution, and emulsified for 5 minutes at a rotational speed of 20000 rpm. Thereafter, ethyl acetate was removed under reduced pressure to obtain a colored fine particle core dispersion B.

  When the colored fine particle core dispersion B was obtained, 260 g of the colored fine particle core dispersion B was transferred to a three-separable flask, the inside of the flask was purged with nitrogen, a heater was set, and the mixture was heated to 80 ° C. A mixed liquid of 4 g of methyl methacrylate and 0.5 g of N, N′-azobisisovaleronitrile was added dropwise over 1 hour and further reacted for 6 hours to obtain a core-shell colored fine particle dispersion C.

  When the core-shell colored fine particle dispersion C is obtained by the above method, the core-shell colored fine particle dispersion C 189 g, ethylene glycol 45 g, glycerin 45 g, Olfine E1010 (manufactured by Nissin Chemical) 1.5 g and antiseptic Proxel GXL (Avecia) (Product) 0.3g was mixed, respectively, and pure water was added to make 300g. Thereafter, the ink was filtered through a 0.8 μm membrane filter to remove impurities and coarse particles to prepare an ink.

(2) Preparation of cleaning solution 30 g of ethylene glycol, 30 g of triethylene glycol monobutyl ether, 1.0 g of Orphine E1010 (manufactured by Nissin Chemical Co., Ltd.) and 0.2 g of preservative Proxel GXL (manufactured by Avecia) were mixed. In addition, the weight was 200 g. Then, it filtered with a 0.8 micrometer membrane filter, the impurity and the coarse particle were removed, and the washing | cleaning liquid was prepared.

(3) Test / Evaluation of Ink Clogging Recoverability In order to test / evaluate the ink clogging recovery property, the above (1), ( The ink and cleaning liquid prepared in 2) are filled in a predetermined part of the ink jet printer, the ink jet printer is installed in an environment of 20 ° C. and 40% RH, and the filled ink is continuously ejected from each recording head for 10 minutes to perform each recording. The ink ejection surface of the head (the surface on which the ink ejection holes were formed) was left for 15 minutes without a moisturizing cap.

  Thereafter, each recording head was subjected to a cleaning process, and the amount of ink clogging in each recording head was recovered and tested in six steps (see Test Nos. 1 to 6 in Table 1). In each test, various conditions such as the presence or absence of the step of spraying the cleaning liquid to each recording head, the amount of blade overlap with each recording head, the wiping speed and the number of wiping operations are set as shown in Table 1 below. The evaluation results of clogging recovery properties are shown in Table 1 below.

In Table 1, the evaluation of “clogging recovery property” was indicated by “◯” or “×”, but the evaluation of “◯” or “×” was based on the following criteria.
“◯”: The ink clogging was restored in all the ejection holes of each recording head, and the ink was ejected normally.
“X”: In all of the ejection holes of each recording head, the clogging of ink did not return, and there was an ejection hole that did not eject ink normally.

  Test No. 1 and test no. From the results of 5 and 6, when the cleaning liquid is ejected onto the ink ejection surface of each recording head before the suction process as an operation for removing the ink from the ejection holes of each recording head, a good result can be obtained. I found out. Test No. 2 and test no. From the results of 5 and 6, good results can be obtained if the blade overlap amount in the wiping step before the suction step is larger than that in the wiping step after the suction step, and such a condition setting is useful. all right. Test No. 3 and test no. From the results of 5 and 6, good results can be obtained when the wiping speed of the blade in the wiping process before the suction process is faster than that in the wiping process after the suction process, and such a condition setting is useful. all right. Test No. 4 and test no. From the results of 5 and 6, when the number of times of wiping the blade in the wiping process before the suction process is larger than that in the wiping process after the suction process, good results can be obtained, and such condition setting is useful. all right.

1 is a perspective view illustrating a schematic configuration of an inkjet printer. It is drawing which shows schematic structure of the washing | cleaning apparatus of a cleaning mechanism. It is a block diagram which shows the circuit structure of a control apparatus. FIG. 4 is a side view schematically showing a relationship between a lower surface (ink ejection surface) of a recording head and a blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Platen 3, 4 Conveyance roller 5 Guide member 6 Carriage 7-10 Recording head 7a-10a Lower surface (discharge surface)
11 Home positions 12 to 15 Moisturizing cap 20 Cleaning mechanism 30 Cleaning device (removal device)
31 Pump 40 Blade 41 Lifting Device 50 Suction Device 51-54 Suction Cap 55 Lifting Device 56 Suction Pump 60 Control Device 61 Control Unit 99 Recording Medium

Claims (20)

A recording head for discharging ink from the discharge holes;
A suction device for sucking ink from the ejection holes;
A removing device for removing clogging of ink in the ejection holes;
With
An ink jet printer, wherein the removing device performs a removing operation for removing clogging of ink in the ejection holes, and then the suction device sucks ink from the ejection holes. The inkjet printer according to claim 1, wherein
A blade for wiping the ink ejection surface of the recording head;
The cleaning device is a cleaning device that sprays a cleaning liquid that dissolves or redisperses ink onto the ejection surface,
The inkjet printer, wherein the cleaning device sprays the cleaning liquid onto the ejection surface as the removing operation, the blade then wipes the ejection surface, and then the suction device sucks ink from the ejection holes. In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
The ink jet printer according to claim 1, wherein an amount of the blade overlapped with the discharge surface is variable before and after the suction operation by the suction device. The inkjet printer according to claim 3.
An ink jet printer, wherein the amount of overlap of the blade with respect to the ejection surface is greater before the suction operation than after the suction operation by the suction device. In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
An inkjet printer characterized in that the wiping speed of the blade with respect to the ejection surface is variable before and after the suction operation by the suction device. The inkjet printer according to claim 5.
An inkjet printer characterized in that the wiping speed of the blade with respect to the ejection surface is faster before the suction operation than after the suction operation by the suction device. In an inkjet printer comprising a recording head for ejecting ink from an ejection hole and a suction device for sucking ink from the ejection hole, wherein the suction device sucks ink from the ejection hole,
A blade for wiping the ink ejection surface of the recording head;
The blade wipes the ejection surface before and after the suction operation by the suction device;
An inkjet printer characterized in that the number of times of wiping the blade with respect to the ejection surface is variable before and after the suction operation by the suction device. The inkjet printer according to claim 7, wherein
The inkjet printer characterized in that the number of times of wiping the blade with respect to the ejection surface is greater before the suction operation than after the suction operation by the suction device. In the ink jet printer according to any one of claims 1 to 8,
An ink jet printer, wherein the ink contains 2% by weight or more of a polymer as a composition component. In the ink jet printer according to any one of claims 1 to 8,
An ink jet printer, wherein the ink contains colored fine particles composed of a color material and a polymer. In the recording head cleaning method for discharging ink from the discharge holes,
A removal step for removing clogging of ink at the ejection holes;
A suction step of sucking ink from the ejection holes after the removing step;
A method for cleaning a recording head, comprising: The method of cleaning a recording head according to claim 11.
The removing step is a step of spraying a cleaning liquid that dissolves or redisperses ink onto the ejection surface,
A recording head cleaning method comprising a wiping step of wiping the ink ejection surface of the recording head after the removing step and before the suction step. In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
A method of cleaning a recording head, wherein the amount of overlap of the blade with the ejection surface is variable between the first wiping step and the second wiping step. The method for cleaning a recording head according to claim 13.
A method for cleaning a recording head, wherein the amount of overlap of the blade with respect to the ejection surface is larger in the first wiping step than in the second wiping step. In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
A method for cleaning a recording head, wherein a wiping speed of the blade with respect to the ejection surface is variable between the first wiping step and the second wiping step. In the recording head cleaning method according to claim 15,
A method of cleaning a recording head, wherein the wiping speed of the blade with respect to the ejection surface is faster in the first wiping step than in the second wiping step. In the recording head cleaning method for discharging ink from the discharge holes,
A first wiping step of wiping the ink ejection surface of the recording head with a blade;
A suction step of sucking ink from the ejection holes after the first wiping step;
A second wiping step of wiping the discharge surface with the blade after the suction step;
With
The recording head cleaning method, wherein the number of times of wiping the blade with respect to the discharge surface is variable between the first wiping step and the second wiping step. The recording head cleaning method according to claim 17,
The recording head cleaning method, wherein the number of times of wiping the blade with respect to the ejection surface is larger in the first wiping step than in the second wiping step. In the cleaning method of the recording head according to any one of claims 11 to 18,
A method of cleaning a recording head, wherein the ink contains 2% by weight or more of a polymer as a composition component. In the cleaning method of the recording head according to any one of claims 11 to 18,
A recording head cleaning method, wherein the ink contains colored fine particles composed of a color material and a polymer.

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