JP2007244968A - Flushing device for ink ejection unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flushing device for an ink ejection unit which can eliminate conventional failure by performing a flushing in line without splashing mist produced in the flushing onto a recording medium. <P>SOLUTION: The drying of ink and the deposition of the ink on the inner wall of a flushing box 30 are eliminated by providing the flushing box 30 having an opening part 34 for sucking the flushed ink from the inkjet head 10, sucking the flushed ink and the mist produced in the flushing of the ink into the inside of the flushing box 30 from the opening part 34 by a suction mechanism 60 and passing the sucked ink through a cleaning liquid in the dipping member 33 to mix the ink with the cleaning liquid in the dipping part 33. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flushing device for an ink ejection unit that flushes (preliminary ejection) ink from an ink ejection unit such as an inkjet head.

  With the spread of personal computers, digital cameras, and the like, printers using an ink jet method in which ink is atomized into fine particles and ejected from ejection holes and printed on a target are widely spread as a method for quickly and easily printing. Further, as the recording capacity of an image recording apparatus such as a digital camera increases, it becomes possible to record a clear image, and accordingly, the printer is also required to reproduce the image clearly. Accompanying this, the miniaturization of injection holes and pigments in ink jet printers has progressed, and the control of the discharge amount and the like has dramatically improved, and recording in the pico order has become possible.

  In the ink jet system, the object that can be ejected from the discharge nozzle is not only liquid such as pigment ink, but also finely divided solids, and further, recording on a recording medium is possible without contact. Besides recording, it is widely used for pattern printing on large display parts and electronic board production.

  The ejection nozzle has a large number of ejection holes of several microns, inside which a piezoelectric element is arranged. By applying a pulse voltage to the piezoelectric element and deforming the piezoelectric element, ink is pushed out and ink is ejected from the ejection hole. The ink jet system emits light. However, in this ink jet system, the ink is dried around the ejection hole and inside the nozzle during the stop time when the ink is not ejected. For this reason, if the ink is ejected to the recording medium in this state, the dried ink is obstructed, the ink landing accuracy at the target point is extremely deteriorated, the ink is landed in the wrong place, and the worst case In such a case, the ejection holes are clogged with the ink, and the ink cannot be ejected. For this reason, conventionally, a flushing tray has been provided in the ink ejection device, and the ink ejection unit has been designed to eliminate these problems by preliminarily ejecting ink at the tray portion before ejecting ink onto the recording medium. A flushing device is known (see Patent Document 1).

Moreover, since ink accumulates by flushing the tray, it is necessary to remove it. As this removal method, an ink absorbing material is put in a tray, the ink is absorbed in this tray, the ink absorbing material is periodically replaced, the ink is dissolved by a dissolving solution, and the ink dissolving solution is discarded. There are methods.
JP 2002-264366 A

By the way, as described above, the ink jet system ejects ultrafine ink by deformation of the piezoelectric element, but fine mist is generated in addition to the ink ejected toward the target at that time. The number of mists generated increases depending on the state of the nozzle surface. In addition, the generated mist has a problem that it adheres to the recording medium because it is very light in mass and flies up even in a gentle wind. In view of this, there is a method in which the distance from the discharge nozzle to the recording medium is increased in consideration of mist scattering to prevent the mist from adhering.
However, in this method, the outer shape of the apparatus becomes larger and it is necessary to take extra space.Flushing while operating the nozzle also increases the distance that the mist rises with the operation, so that the raised mist is transferred to the recording medium. There is a risk of adhesion.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an ink discharge unit that can eliminate conventional problems by performing in-line flushing without causing mist generated at the time of flushing to be scattered on a recording medium. It is to provide a flushing apparatus.

  In order to achieve the above object, the invention of claim 1 is a flushing device for flushing ink from an ink ejection part, and includes a flushing box having an opening for sucking ink flushed from the ink ejection part, A suction mechanism that communicates with the flushing box and sucks the flushed ink and the liquid mist generated during the flushing of the ink into the flushing box through the opening; and And an immersion part for immersing the ink sucked into the ink.

  According to a second aspect of the present invention, in the flushing device for an ink discharge part according to the first aspect, a cleaning liquid is stored in the immersion part, and the ink is immersed in the cleaning liquid.

  According to a third aspect of the present invention, there is provided a flushing device for an ink discharge portion according to the first aspect, wherein the waste liquid tank is connected to the immersion portion and stores cleaning liquid that is periodically and partially discharged from the immersion portion, and the immersion portion. And a cleaning liquid supply tank for periodically supplying a new cleaning liquid corresponding to the amount partially discharged to the immersion part.

According to a fourth aspect of the present invention, in the flushing device for an ink discharge portion according to the first aspect, the flushing box includes a mist capturing member that captures a mist generated during the flushing of the ink.
According to a fifth aspect of the present invention, in the flushing device for an ink discharge portion according to the fourth aspect, the suction mechanism has a suction port opened in the flushing box, and the mist capturing member is formed at the suction port. It is characterized by comprising a plurality of baffle plates arranged so as to form a flow path in which a suction air flow in the flushing box accompanying suction meanders from the opening toward the suction port.

  According to a sixth aspect of the present invention, in the flushing device for an ink discharge portion according to the fourth aspect, a cleaning mechanism is provided for cleaning the ink adhering to the inner wall of the flushing box and the mist capturing member.

  According to a seventh aspect of the present invention, in the flushing device for an ink discharge portion according to the first aspect, a trap portion for trapping mist is provided in the suction passage of the suction mechanism.

  According to the first aspect of the invention, ink is ejected from the ink discharge portion toward the opening of the flushing box during flushing, and the liquid mist generated during the flushing is reliably sucked into the flushing box from the opening by the suction mechanism. And sent to the immersion part together with the flushed ink. As a result, the liquid mist generated by the flushing can be flushed in-line without scattering to the recording medium, and the productivity is improved without affecting the tact such as pattern formation by ink ejection onto the recording medium. it can.

  According to the invention of claim 2, since the cleaning liquid is stored in the immersion part, the ink sent to the immersion part falls into the cleaning liquid and mixes with the cleaning liquid, so that the ink is not dried, And it does not adhere in the immersion part. Further, even if the solvent evaporates, it is mixed with the cleaning liquid, so that ink is not deposited and dry foreign matter is not generated.

  According to the invention of claim 3, the cleaning liquid stored in the immersion part is periodically discharged to the waste liquid tank, and a new cleaning liquid corresponding to the discharge amount can be supplied from the cleaning liquid supply tank. The cleaning liquid in the section does not overflow, and the cleanliness in the flushing box can be maintained by replenishing with a new cleaning liquid, and the cleaning liquid in the immersion section increases in the degree of contamination according to the ink flushing. Nor.

  According to the fourth and fifth aspects of the present invention, since the mist capturing member made up of a plurality of baffle plates is provided in the flushing box, the mist sucked into the flushing box passes through the mist capturing member. It is possible to prevent mist from entering the suction mechanism.

According to the sixth aspect of the invention, the ink adhering to the inner wall of the flushing box and the mist capturing member can be washed by the washing mechanism.
According to the invention of claim 7, since the trap portion is provided in the suction passage of the suction mechanism, the mist that could not be trapped in the flushing box can be reliably captured by the trap portion, and the suction of the suction mechanism It is possible to prevent the mist from entering the suction mechanism without reducing the force.

  Embodiments of a flushing device according to the present invention will be described below with reference to the drawings. The flushing device according to the present invention is not limited to the embodiment described below.

(Embodiment 1)
FIG. 1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus provided with a flushing device according to the present invention, FIG. 2 is a schematic plan view of a stage of the ink jet recording apparatus in the present embodiment, and FIG. FIG. 4 is a block diagram showing the internal structure of the flushing device and its peripheral equipment in the present embodiment. FIG. 4 is a plan view for explaining the ink jet head constituting the ink discharge portion of the ink jet recording apparatus in the embodiment.

The ink jet recording apparatus shown in FIG. 1 includes an ink jet head 10 that ejects ink, a stage 20 on which a recording medium 40 is placed, and a flushing box 30 for performing ink flushing.
The ink jet head 10 can move in the X-axis direction in FIG. 1, and the stage 20 can move in the Y-axis direction in FIG. The flushing box 30 is provided adjacent to one side of the stage 20 and is moved together with the stage 20 in the Y-axis direction. This allows flushing inline. Further, as the recording medium 40 placed on the stage 20, for example, there is a color filter which is one of liquid crystal components, and the color filter 40 is moved in the Y axis direction together with the stage 20.

  When ink is ejected from the inkjet head 10 to the color filter 40 to form a filter pattern, the stage 20 is moved in the Y-axis direction. In this case, a plurality of suction holes 50 as shown in FIG. 2 are formed in the stage 20 so that the color filter 40 placed on the stage 20 does not shift in alignment. Thus, during the pattern forming operation on the color filter 40, the color filter 40 is sucked onto the stage 20 by evacuating the suction hole 50 through a suction means (not shown). For this reason, position shift does not occur in the color filter 40, and ink can be landed accurately on the color filter 40 that requires highly accurate pattern formation.

The ink jet head 10 for ejecting ink is composed of a number of arbitrarily arranged nozzles. Further, as shown in FIG. 3, red for ejecting each of R (red), G (green), and B (blue) inks. It is divided into a nozzle area 11, a green nozzle area 12 and a blue nozzle area 13. Thereby, it is possible to discharge three colors at a time. Moreover, the discharge waiting time of each nozzle is much shorter than the method of discharging one color at a time. However, a discharge waiting time occurs during the process time such as the movement of the stage 20, the replacement of the glass serving as the base material of the color filter 40, and the alignment. In addition, when the size of the color filter 40 is increased, the discharge waiting time is further increased.
The ink used for the color filter is an ink containing a solvent, and this solvent evaporates in the air as time passes. As a result, the ink is dried and fixed near the nozzle ejection hole. If the ink is ejected in this state, various problems such as landing violence, occurrence of mist, change in ejection amount, and generation of foreign matter occur in a place different from the place where the ink is aimed. For this reason, immediately after discharging to the color filter 40, it is possible to create a stable discharge state by removing the fixed ink by flushing to the flushing box 30 installed adjacent to the stage 20.

Next, the configuration of the flushing device will be described in detail with reference to FIGS.
As shown in FIGS. 1 and 4, the flushing device includes a flushing box 30 installed adjacent to one side of the stage 20, flushed ink communicated with the flushing box 30, and liquid generated at the time of flushing the ink. And a suction mechanism 60 for sucking mist into the flushing box.
The upper surface plate 31 of the flushing box 30 is formed with an elongated hole-like opening 34 extending along one side of the stage 20. The opening 34 is for sucking ink flushed during preliminary ejection of the inkjet head 10 that has been moved to a position opposite to the opening 34.

As shown in FIG. 4, a dipping part 33 for dipping the flushed ink is provided at the bottom of the flushing box 30, and the washing liquid is stored in the dipping part 33, and the flushed ink is contained in the washing liquid. The ink is prevented from drying by dipping.
Further, a waste liquid tank 71 for storing cleaning liquid periodically and partially discharged from the immersion part 33 is connected to the immersion part 33 via an air operation valve 72. Furthermore, a cleaning liquid supply tank 70 for periodically supplying a new cleaning liquid corresponding to the amount partially discharged into the immersion part 33 is connected to the immersion part 33 via an air operation valve 73.

As shown in FIG. 4, a mist capturing member 32 that captures mist generated during ink flushing is disposed in the flushing box 30.
As shown in FIG. 4, in the mist capturing member 32, the suction air flow in the flushing box 30 accompanying the suction at the suction port 60a of the suction mechanism 60 meanders from the opening 34 toward the suction port 60a. It is comprised from the several baffle plate 32a arranged so that a flow path may be formed. That is, the plurality of first baffle plates 32a vertically arranged at predetermined intervals downward from the upper surface plate 31 of the flushing box 30, and the bottom of the flushing box 30 so as to be positioned between the first baffle plates 32a. A meandering flow path is formed by a plurality of second baffle plates 32a arranged vertically at a predetermined interval toward the front.

  As shown in FIGS. 1 and 4, the suction mechanism 60 includes a suction source 63 composed of a vacuum pump, and a suction passage 64 connecting the suction source 63 and a suction port 60 a opened in the flushing box 30. And an electromagnetic on-off valve 61 provided in the suction passage 64 and a trap portion 62 with a filter provided in the suction passage 64 for trapping mist to be sucked into the suction source 63.

Next, the operation of the flushing device will be described.
In the state where the inkjet head 10 has been moved directly above the opening 34 of the flushing box 30 and the suction mechanism 60 has been activated, the ink that has been flushed during the preliminary ejection operation of the inkjet head 10 Is discharged into the flushing box 30 through the opening 34. Here, since the cleaning liquid that hardly evaporates is stored in the immersion part 33 of the flushing box 30, the flushed ink falls into the cleaning liquid and mixes with the cleaning liquid in the immersion part 33. For this reason, even if the solvent evaporates, the ink is not dried and is not fixed to the inner wall of the flushing box 30.

On the other hand, since the mist generated when the ink is flushed is scattered by the movement of the inkjet head 10 and the stage 20, if the mist adheres to the surface of the color filter 40, the color filter 40 becomes a defective product. In the embodiment, mist is sucked into the flushing box 30 through the opening 34 by the suction action of the suction mechanism 60 and dropped into the cleaning liquid in the same manner as the flushed ink. In this case, the mist is very fine and light and may not fall into the cleaning liquid. However, such mist contacts the baffle plate 32a while passing through the meandering flow path composed of the plurality of baffle plates 32a. Is trapped and adheres to the baffle plate 32a. The mist that has passed through the mist capturing member 32 and has been sucked into the suction mechanism 60 is collected by the trap 62. For this reason, even a very fine mist does not enter the suction source 63 of the suction mechanism 60 and the suction mechanism is not contaminated with ink.
Further, even if the mist tries to fly again from the flushing box 30 due to the influence of the air flow generated by the movement of the inkjet head 10 or the stage 20, the mist is collected by the suction action of the upper surface plate 31 and the suction mechanism 60, so that the mist is flushed. I will never leave 30.

  The cleaning liquid in the immersion part 33 is contaminated by the flushing described above, and the contamination degree gradually increases. In such a case, the air operation valve 72 is opened at a certain frequency to discharge a proper amount of the cleaning liquid in the immersion unit 33 to the waste liquid tank 71. Thereafter, the air operation valve 72 is closed and the air operation valve 73 is opened, and a new cleaning liquid having the same amount as the discharged cleaning liquid is supplied from the cleaning liquid supply tank 70 to the immersion unit 33. By doing so, the cleaning liquid in the immersion part 33 can maintain a certain degree of cleanliness. For this reason, the ink is not fixed to the immersion part 33.

In addition, if the flushing is performed many times, the ink adheres to and accumulates on the inner wall of the flushing box 30 and the mist capturing baffle plate 32a due to the influence of mist or the like. It may cause the occurrence.
Therefore, in this embodiment, the cleaning mechanism is operated. That is, the air operation valve 73 is opened at an appropriate frequency, and the flushing box 30 is filled with new cleaning liquid supplied from the cleaning liquid supply tank 70. Thereby, the ink adhering to the inner wall of the flushing box 30 and the baffle plate 32a for capturing mist is dissolved by the cleaning liquid. Thereafter, the air operation valve 72 is opened, and the dirty cleaning liquid is discharged from the flushing box 30 to the waste liquid tank 71. After the drainage is completed, the air operation valve 73 is opened again, a new cleaning liquid is supplied from the cleaning liquid supply tank 70, and a certain amount of cleaning liquid is accumulated in the immersion part 33 of the flushing box 30. During this operation, the electromagnetic on-off valve 61 is closed in order to prevent the cleaning liquid from flowing into the suction mechanism 60 and the trap unit 62.

1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus provided with a flushing apparatus according to the present invention. It is a schematic plan view of the stage of the ink jet recording apparatus in the present embodiment. 2 is a plan view for explaining an ink jet head constituting an ink discharge portion of the ink jet recording apparatus according to the present embodiment. FIG. It is a block diagram which shows the internal structure of the flushing apparatus in this Embodiment, and its peripheral equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inkjet head, 11 ... Red nozzle area, 12 ... Green nozzle area, 13 ... Blue nozzle area, 20 ... Stage, 30 ... Flushing box, 31 ... Top plate, 32 ... Mist capture member 32a ... baffle plate, 33 ... immersion part, 34 ... opening, 40 ... color filter, 50 ... suction hole, 60 ... suction mechanism, 60a ... suction port, 61 ... electromagnetic on-off valve, 62 ... Trap unit, 63 ... Suction source, 64 ... Suction passage, 70 ... Cleaning liquid supply tank, 71 ... Waste liquid tank, 72, 73 ... Air operation valve.

Claims (7)

A flushing device for flushing ink from an ink ejection unit,
A flushing box having an opening for sucking the flushed ink from the ink ejection part;
A suction mechanism that communicates with the flushing box and sucks the flushed ink and the liquid mist generated during the flushing of the ink into the flushing box through the opening;
An immersion part provided in the flushing box for immersing the ink sucked into the flushing box by the suction mechanism;
A flushing device for an ink discharge portion.   2. The flushing device for an ink discharge part according to claim 1, wherein a cleaning liquid is stored in the immersion part, and the ink is immersed in the cleaning liquid.   A waste liquid tank that communicates with the immersion unit and stores cleaning liquid that is periodically and partially discharged from the immersion unit, and a new amount corresponding to the amount of the partial discharge to the immersion unit that communicates with the immersion unit. The flushing device for an ink discharge unit according to claim 1, further comprising a cleaning liquid supply tank that periodically supplies the cleaning liquid.   2. The flushing device of an ink discharge unit according to claim 1, wherein the flushing box includes a mist capturing member that captures mist generated during the flushing of the ink. 3.   The suction mechanism has a suction port opened in the flushing box, and the mist capturing member causes a suction air flow in the flushing box accompanying suction at the suction port to flow from the opening to the suction port. 5. The flushing device for an ink discharge portion according to claim 4, wherein the flushing device is composed of a plurality of baffle plates arranged so as to form a flow path meandering in the direction.   5. The flushing device for an ink discharge portion according to claim 4, further comprising a cleaning mechanism for cleaning ink adhering to an inner wall of the flushing box and the mist capturing member. 2. The flushing device for an ink discharge portion according to claim 1, wherein a trap portion for trapping mist is provided in the suction passage of the suction mechanism.

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