JP2014061607A - Head cleaning mechanism in ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress adhesion of ink bubbles to a head in head cleaning.SOLUTION: Nozzles of recording heads 4, 6, 8, 10 are closed with a cap member 24 provided for a non-printing area of a printer body, and ink in the recording heads is sucked by vacuum force to clean insides of the recording heads. Inside the cap member, a liquid absorber 28 is placed. A vacuum force is generated inside the cap member, ink is sucked from the recording heads, and after the ink is sucked for a prescribed period of time, antifoaming liquid is supplied in the cap member.

Description

  The present invention relates to a head cleaning mechanism using an antifoaming liquid in an ink jet printer.

In a liquid ejecting apparatus, a configuration in which ink is sucked and discharged from a recording head into a cap member, and at the same time as the ink is sucked and discharged, an additive for preventing foaming of the ink is sucked and discharged into the cap member is conventionally known ( For example, see Patent Documents 1 and 2).
In addition, a configuration in which a defoamer is added to a waste ink tank in a liquid ejecting apparatus is conventionally known (see, for example, Patent Documents 3, 4, and 5).

JP 2002-36576 A JP 2002-36577 A JP 2006-21451 A JP 2006-116810 A JP 2007-30235 A

Bubbles may be generated during ink discharge and suction when cleaning the head nozzle using the negative pressure in the cap member. If bubbles are left in a state where bubbles are generated, the bubbles remain on the surface of the recording head. However, this affects the nozzles of the ink jet recording head and the like, causing a problem of ink ejection during printing.
In order to eliminate this bubble, an antifoaming liquid is added to the cap member during head cleaning. The ink is sucked from the head nozzle by the negative pressure of the cap member and the antifoaming liquid is injected into the cap member. If the discharge is performed simultaneously, the negative pressure in the cap member is affected by the discharge of the defoaming liquid, and there is a problem that the ink cannot be efficiently sucked and discharged from the head nozzle during head cleaning.
Further, there is a problem that the amount of the antifoaming liquid used is increased and the cost is increased.
The present invention aims to solve the above problems.

In order to achieve the above object, according to the present invention, the nozzle of the recording head is closed with a cap member provided in a non-printing area of the printer body, and the ink in the recording head is sucked into the cap member by a vacuum force to A head cleaning mechanism in an inkjet printer that performs cleaning, wherein a vacuum force is generated in the cap member to suck ink from the recording head, and the ink is sucked into the cap member after a predetermined time. A foam liquid is supplied.
Further, the present invention is characterized in that the supply of the antifoaming liquid into the cap member is performed in the latter half of the set driving time of the vacuum force into the cap member.
In the present invention, the defoaming liquid is supplied into the cap member by the ejection driving from the nozzle of the defoaming liquid ejection head provided on the recording head side, and the ejection driving is performed in the cap member. It is characterized in that it is performed simultaneously with the stop of the driving of the vacuum force to the.
Further, the invention is characterized in that a liquid absorber is disposed in the cap member.
Further, the invention is characterized in that the liquid absorber is a breathable sponge.

  The present invention can efficiently perform head cleaning, and can positively suppress ink bubbles from adhering to the recording head within the cap member. . Further, since the antifoaming liquid is effectively supplied in the latter half, there is an effect that the amount of the antifoaming liquid used can be reduced compared to the case where it is added from the beginning.

It is a time chart which shows operation | movement of this invention. It is a schematic explanatory drawing of a printer. It is explanatory drawing of the principal part of this invention. It is explanatory drawing of the principal part of this invention. It is explanatory drawing which shows other embodiment of the printer of this invention. It is explanatory drawing same as the above. FIG. 4 is an explanatory diagram of a bottom surface of a recording head.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 2 is an overall schematic view of the ink jet printer according to the present invention. In the figure, reference numeral 2 denotes a head carriage, which holds a plurality of ink jet recording heads 4, 6, 8, and 10. The head carriage 2 is linked to the Y-axis drive device of the printer body, so that the head carriage 2 is guided by the Y-axis rail 12 and reciprocated on the platen 14 in the horizontal direction (Y-axis direction) in the drawing. It is configured. A large number of ink discharge nozzles form one or more rows and open on the ink discharge surfaces of the recording heads 4, 6, 8, and 10.

The ink discharge surface on which the nozzles of the recording heads 4, 6, 8, 10 are opened is disposed on the nozzle opening bottom surface 2 a of the head carriage 2. Ink cartridges 16, 18, 20, and 22 are mounted on the main body side or Y-axis rail side of the printer, and each corresponding recording head 4 is connected from each ink cartridge 16, 18, 20, 22 via an ink supply tube. , 6, 8, and 10 are configured to be supplied with ink. A slit is formed in the platen 14 on which the paper is placed, and a paper driving roller (not shown) is disposed in the slit. The sheet placed on the platen 14 is configured to be sandwiched between the driving roller and a pressing roller installed on the Y-axis rail 12 side.

The driving roller and the pressing roller constitute a paper transport mechanism. At the time of printing, the paper on the platen 14 is sandwiched between the driving roller and the pressing roller, and is sent in the X-axis direction (sub-scanning direction) on the platen 14 by the rotation of the driving roller. On the other hand, the recording heads 4, 6, 8, and 10 are fed in the Y-axis direction (main scanning direction) along the Y-axis rail 12 while ejecting ink from the ink ejection nozzles, and print on the paper on the platen 14. Is called. The printer main body is provided with a home position in a non-printing area of the printer. A cap member 24 is disposed at the home position so as to be movable up and down. A known wiping member 26 is disposed near the front of the cap member 24. Yes.

The cap member 24 is pressed against the nozzle opening bottom surface 2a of the head carriage 2 when the recording heads 4, 6, 8, and 10 mounted on the head carriage 2 are moved to the home position, and the nozzle opening as shown in FIG. A sealed space is formed between the bottom surface 2a. The cap member 24 is filled with a liquid absorber 28 made of a porous material having air permeability such as sponge.

Below the cap member 24, a suction pump P for applying a negative pressure to the sealed space formed in the cap member 24 and the nozzle opening bottom surface 2a of the head carriage is disposed. A waste ink tank 30 is connected to the suction pump P. The cap member 24 functions as a lid for preventing the nozzle openings of the recording heads 4, 6, 8, and 10 from being dried during the pause period of the printer, and is not related to printing on the recording heads 4, 6, 8, and 10. Functions as an ink receiver during a flushing operation in which an ink droplet is ejected idly by applying a non-driving signal, and a negative pressure from the suction pump P is applied to the recording heads 4, 6, 8, and 10 to suck and discharge ink. It also functions as a cleaning mechanism. The waste liquid in the cap member 24 is forcibly discharged to the waste ink tank 30.

  The main body of the printer is provided with an antifoaming liquid tank 32 that is located above the cap member 24 and supplies an antifoaming liquid to the inside of the cap member 24. The inside of the tank 32 and the inside of the cap member 24 are provided. And communicates with each other through a liquid path such as a tube or a pipe. An electromagnetic valve 34 is provided in a liquid passage communicating the tank 32 and the cap member 24, and the valve 34 is configured to be opened and closed by a controller provided in the printer body. The antifoaming liquid is composed of a cleaning liquid and a cleaning liquid, and has a function of erasing bubbles because it contains a surfactant. In the embodiment, the antifoaming liquid supply port 38 and the liquid absorber 28 are set at substantially the same height in terms of structure, but the antifoaming liquid supply port 38 may be provided anywhere or a plurality of them may be provided. When the bottom of the cap member 24 is deep and the liquid absorber 28 is on the lower side, if the antifoaming liquid supply port 38 is provided on the upper side, smooth supply can be performed without any obstacles.

The drive unit of the suction pump P is connected to a controller provided in the printer main body, and is configured to be controlled by the controller. The liquid absorber 28 disposed in the cap member 24 is filled in the cap member 24 so that the upper surface of the liquid absorber 28 is slightly lower than the upper end of the side wall of the cap member 24 and opens to the side wall of the cap member 24. The supply port 38 is set at substantially the same height as the upper surface of the liquid absorber 28.

Next, the operation of the printer will be described in detail with reference to the time chart shown in FIG.
When the cleaning process is started, the printing operation of the printer is stopped, and the wiping member 26 ascends on the movement locus of the recording heads 4, 6, 8, 10 in the printing stopped state. Next, the controller moves the carriage head 2 to the non-printing area and wipes the nozzle opening bottom surface 2 a of the carriage head 2 with the wiping member 26. As a result, dust, paper dust and the like attached to the nozzles of the recording heads 4, 6, 8, and 10 are removed.

  Next, the controller moves the head carriage 2 to the capping position as shown in FIG. 3, and in this state, raises the cap member 24 as shown in FIG. 4 to seal the nozzle opening bottom surface 2a of the head carriage 2. Stop. Next, the controller drives the suction pump P. By driving the suction pump P, a negative pressure is generated in the cap member 24 as shown in FIG. 1F. Due to the negative pressure in the cap member 24 driven by the suction pump P, ink is sucked and discharged from the nozzles of the recording heads 4, 6, 8, and 10 into the cap member 24, and the ink in the recording heads 4, 6, 8, and 10 is discharged. The passage is cleaned.

As shown in FIG. 1B, the controller opens the valve 34 when a predetermined time has elapsed from the start of ink suction. When the valve 34 is opened, the defoaming liquid is sucked and discharged into the cap member 24 due to the difference between the suction force and the water head value inside the cap member 24, and the ink absorbed in the liquid absorber 28 inside the cap member 24. The cap member 24 is filled by mixing. The supply amount of the defoaming liquid is considerably larger than the ink discharge amount. The controller stops driving the suction pump P when a predetermined time has elapsed since the valve 34 was opened.

Simultaneously with the stop of the driving of the suction pump P, the valve 34 is closed as shown in FIG. 1B, and the supply of the antifoaming liquid into the cap member 24 is stopped. The solenoid valve can be opened and closed when it is at a high position. However, when the tank 32 is provided at a low position, a supply pump is provided instead of the solenoid valve 34, and this supply pump is controlled to turn on and off to eliminate the defoaming. The supply of liquid may be controlled on and off. Since the defoaming liquid has a defoaming effect on the liquid ink, bubbling of the ink generated on the upper surface of the liquid absorber 28 and the surface of the head is suppressed. Next, the controller lowers the cap member 24 after a predetermined time after the drive of the suction pump 30 is stopped, and drives the suction pump 30 to discharge ink from the cap member 24 to the outside. The discharged ink is discharged into the waste liquid tank 30.

  In the above embodiment, the antifoaming liquid is discharged from the upper part of the side wall of the cap member 24. However, the antifoaming liquid may be discharged into the cap member 24 from the nozzle on the head carriage 2 side. 5 to 7 show an embodiment in which the antifoaming liquid is discharged into the cap member 24 from the nozzle of the liquid discharge head provided on the head carriage. In the present embodiment, the carriage head 2 is mounted with a defoaming liquid discharging head 40 in addition to the recording heads 4, 6, 8, 10 for printing. The antifoaming liquid discharge head 40 is connected to the antifoaming liquid cartridge 40 provided on the main body side of the printer or the Y-axis rail 12 side via a liquid transport tube.

The defoaming liquid discharge head 40 has the same structure as the recording heads 4, 6, 8, and 10. The antifoaming liquid discharge head 40 is configured to discharge the antifoaming liquid from the nozzles 44 formed on the bottom surface of the head 40 under the control of the controller. FIG. 6 shows a state in which the cap member 24 seals the nozzle opening bottom surface 2 a of the head carriage 2, and in this state, the nozzle 44 of the defoaming liquid discharge head 40 faces the opening of the cap member 24. During the head cleaning operation of the printer, the controller controls the driving of the suction pump P at the timing shown in FIG. 1C, and at the same timing as the opening / closing operation of the valve 34 shown in FIG. 1B in the first embodiment, as shown in FIG. As shown, the antifoaming liquid discharge head 40 is driven for a predetermined time simultaneously with the stop of the driving of the suction pump P, and the antifoaming liquid is discharged from above the cap member 24 toward the inside thereof. Other configurations of the present embodiment are the same as those of the first embodiment.

2 Head carriage 2a Nozzle opening bottom surface 4 Recording head 6 Recording head 8 Recording head 10 Recording head 12 Y-axis rail 14 Platen 16 Ink cartridge 18 Ink cartridge 20 Ink cartridge 22 Ink cartridge 24 Cap member 26 Wiping member 28 Liquid absorber 30 Waste ink Tank 32 Defoaming liquid tank 34 Valve 38 Defoaming liquid supply port 40 Discharge head 42 Defoaming liquid cartridge 44 Nozzle P Suction pump

Claims (5)

  This is a head cleaning mechanism in an ink jet printer that closes the nozzles of the recording head with a cap member provided in a non-printing area of the printer main body and sucks the ink in the recording head into the cap member with a vacuum force to clean the inside of the recording head. A vacuum force is generated in the cap member to suck ink from the recording head, and after the ink is sucked for a predetermined time, an antifoaming liquid is supplied into the cap member. A head cleaning mechanism in an inkjet printer.   2. The head cleaning in an ink jet printer according to claim 1, wherein the supply of the defoaming liquid into the cap member is performed in the latter half of the set drive time of the vacuum force into the cap member. mechanism.   The defoaming liquid is supplied into the cap member by the ejection drive from the nozzle of the defoaming liquid ejection head provided on the recording head side, and the ejection drive is performed by the vacuum force into the cap member. 2. The head cleaning mechanism in an ink jet printer according to claim 1, wherein the head cleaning mechanism is performed simultaneously with the stop of driving. The head cleaning mechanism for an ink jet pudding according to claim 1, wherein a liquid absorber is disposed in the cap member.   The head cleaning mechanism for an ink jet pudding according to claim 4, wherein the liquid absorber is a breathable sponge.

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