JP2009018249A - Liquid material discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid material discharge device capable of cleaning the discharge face of the device with high reliability, and achieving stable discharge performance. <P>SOLUTION: The liquid material discharge device 40 is provided with a blade 1 wiping the discharge face of an ink jet head, and a cleaning liquid supply means 5 supplying cleaning liquid to the blade 1, and is constituted to flush ink from the head after wiping with the blade 1. The amount of the ink for flushing is set according to the contact time of the cleaning liquid attached to the blade 1 with the discharge face. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid material ejection device having a maintenance mechanism that removes liquid material adhering to the ejection surface of a head of the liquid material ejection device, and more specifically, after removing the liquid material adhering to the ejection surface, The present invention relates to a liquid material discharge device including a mechanism for discharging a fixed amount of liquid material by flushing.

  Liquid material discharge devices such as an ink jet type are configured to fly a liquid material (for example, ink) from a discharge surface of a nozzle plate to a discharge target material. Today, drop-on-demand type, which ejects ink only for printing, is attracting attention because of its good printing efficiency, low cost, and low running cost. The thermal jet type that can be manufactured at low cost because it can be used, and the piezoelectric type that does not degrade the ink and does not deteriorate the film and that can be used in many cases are mainly used. In recent years, there are many uses for ejecting a liquid material called functional ink by utilizing the feature that many inks can be used, and ink jets are used in manufacturing color filters and organic ELs for liquid crystal televisions. .

  Since the liquid material ejection device is configured to fly the liquid material as described above, ink mist accompanying ink droplet flight or ink mist bounced off the material to be ejected adheres to the ejection surface, impeding ink ejection. Or a problem such as deflection of the ejection direction may occur. In order to prevent such a situation, a maintenance (cleaning) mechanism for wiping (wiping) ink adhering to the ejection surface with a blade made of an elastic material or the like is known.

  However, when the functional ink described above is ejected from the inkjet head, there are the following problems. First, functional ink has a characteristic that it has a high viscosity and easily solidifies when dried. Furthermore, in order to increase the safety to humans for the solvent contained in the functional ink, or to prevent deterioration of the wiring of the device, the air in the device is exhausted in large quantities (solvent atmosphere exhaust) . Therefore, a maintenance device that performs maintenance (cleaning) of the ink jet head is placed under severe drying conditions, and the functional ink attached to the blade becomes highly viscous and solidifies. When wiping is performed with such a blade, high-viscosity ink adhering to the blade may enter the nozzle from the discharge port, causing the discharge direction to be shifted or undischarged. Such problems also exist in household printers as well as ink jet devices. For example, in Japanese Patent Application Laid-Open No. 2004-228688, the ink that has been solidified by re-watering the ink by ejecting the ink from the head and the high viscosity of the ink adhering to the blade. A technique for preventing the conversion is disclosed. Patent Document 2 discloses a technique for keeping a blade clean by immersing the blade in a cleaning liquid and scrubbing the blade with a brush.

  By the way, when functional ink is ejected from an inkjet head, the solvent of the functional ink is often used as the cleaning liquid. In this case, the cleaning liquid has a lower viscosity than the functional ink. However, if wiping is performed with a blade in which a cleaning liquid having a viscosity difference from that of functional ink is adhered, the cleaning liquid enters the nozzle from the discharge port and changes the viscosity and concentration of the functional ink in the head. The problem is that satellites are generated due to ejection failure, the coating amount is not stable, and the coating amount is different between the initial drawing cell and the later cell. Such a problem is fatal in an ink jet apparatus that produces color filters and the like. In Patent Document 1, since the ink used for printing is used as the cleaning liquid, the cleaning liquid and the printing ink have the same viscosity, and such a problem does not occur. Further, Patent Document 2 discloses a cleaning mechanism that wipes the cleaning liquid excessively attached to the blade with a brush. However, the cleaning liquid attached to the blade cannot be completely removed by such a mechanism, and as a result, the application is not stable. . Further, during wiping, the functional ink remaining on the head cover also has a high viscosity in the same manner as the ink remaining on the blade. It gradually grows and flakes by wiping. If the flakes themselves are larger than the gap between the substrate of the color filter and the head, the flakes may contaminate the substrate. Further, even when flakes are peeled off from the head cover by wiping and adhere to the head cover surface, if the flakes are larger than the inter-substrate gap, the substrate is soiled by the flakes as described above. Therefore, wiping while intentionally putting the cleaning liquid on the blade can prevent the ink remaining in the head cover from becoming highly viscous. In such a cleaning mechanism, the cleaning liquid adhering to the blade inevitably enters the nozzle, causing the problems described above.

Therefore, Patent Document 3 discloses a technique for performing flushing (also referred to as discard discharge) in order to reduce the ink viscosity in the head after wiping with a blade to which high viscosity ink is attached. Patent Documents 4 and 5 disclose a technique for performing flushing in order to prevent color mixing caused by wiping a nozzle plate having nozzles that discharge a plurality of colors to one head at a time. .
JP-A-4-232754 (published on August 21, 1992) JP 2002-273285 A (published September 24, 2002) JP 61-230950 A (released on October 15, 1986) Japanese Patent Laid-Open No. 3-73354 (published on March 28, 1991) Japanese Patent Laid-Open No. 7-195708 (published on August 1, 1995)

  However, none of the techniques described in Patent Documents 3 to 5 discusses how much ink is ejected in flushing to ensure drawing quality. In Patent Documents 4 and 5, it is disclosed that only high-lightness ink is ejected at the time of flushing. This is because deterioration in drawing caused by color mixture is easily visible in high-lightness ink. There is no description to examine the discharge amount at this time, and it is considered that an excessive amount is discharged.

  However, in an ink jet apparatus using functional ink, it is indispensable to stabilize the discharge amount regardless of the difference in lightness. If an excessive amount is discharged, a great increase in cost is caused.

  That is, conventionally, there is no idea that considers the relationship between the drawing quality and the amount of ejection (disposal ejection) during flushing.

  Further, the maintenance method of the ink jet head varies depending on the state of the head and the maintenance device even in the same device. For example, if there is variation in the landing of dots discharged from the nozzle, the wipe speed at the time of wiping is slowed down in order to wipe off carefully, or if the solid content of functional ink adheres to the vicinity of the nozzle, Since the meniscus in the vicinity of the ejection port cannot be maintained, wiping is performed by increasing the head differential of the head so that ink does not overflow from the nozzle, or by lowering the relative speed between the blade and the head. When the maintenance method is changed in this way, if the flushing amount after wiping is the same, problems such as inducing satellites at the time of coating or not being able to obtain a desired film thickness are caused.

  Furthermore, when cleaning the head by immersing the head in the cleaning liquid, the amount of the cleaning liquid flowing into the head varies depending on the immersion time, but there has been no examination of how much flushing should be performed so far. .

  Accordingly, the present invention has been made in view of the above-described problems, and the object thereof is a liquid material capable of minimizing the amount of liquid material used by flushing and maintaining a stable drawing quality. A discharge device is provided.

  The liquid material discharge device according to the present invention (hereinafter referred to as “first liquid material discharge device” in order to distinguish this liquid material discharge device from another liquid material discharge device described later) solves the above-described problems. In order to accomplish this, a liquid material discharge apparatus that includes a head having a plurality of nozzles that supply liquid material from a supply tank and discharges the liquid material from the discharge surface of the head, the cleaning liquid having a viscosity different from that of the liquid material A maintenance mechanism that removes the liquid material adhering to the ejection surface of the head from the ejection surface by bringing the liquid material into contact with the ejection surface of the head. After the discharge surface comes into contact, an amount of the liquid material based on the contact time between the cleaning liquid of the maintenance mechanism and the discharge surface is flushed from each nozzle. It is characterized in that to ring.

  According to said structure, the 1st liquid material discharge apparatus which concerns on this invention suppresses the usage-amount of the liquid material by flashing to the minimum, and can maintain the stable drawing quality. Can be provided.

  Specifically, the first liquid material discharge device according to the present invention first removes the liquid material adhering to the discharge surface using a cleaning liquid. However, as described above, when a cleaning liquid having a different viscosity from the liquid material to be discharged is used, as described above, the cleaning liquid enters the nozzle from the discharge port due to the difference in viscosity, and the liquid material in the nozzle Viscosity and density of the ink are changed, and satellites are generated due to defective discharge, and the coating amount is not stable, and the coating amount is different between the first cell and the last cell. The first liquid material discharge device according to the present invention is particularly suitable as a device for discharging a liquid material called functional ink by an ink jet method, but the above problems are fatal in the device. is there. Therefore, as described above, the first liquid material discharge device according to the present invention is configured to flush the liquid material from the head, so that the liquid material in the nozzle is caused by the flow of the cleaning liquid into the nozzle. The liquid material having a normal viscosity stored in the supply tank can be supplied into the nozzle by discarding the portion where the viscosity or concentration of the liquid has changed. Accordingly, it is possible to provide a liquid material discharge device that discharges a liquid material with a desired drawing quality without causing the above-described problems.

  It should be noted that the first liquid material ejection device according to the present invention sets the amount of the liquid material to be flushed based on the contact time between the cleaning liquid and the ejection surface. Although the liquid material to be flushed is important as maintenance of the liquid material discharge device, it is a liquid material that does not contribute to discharge to the discharge target material, and is discarded. Conventionally, as described above, there has been no idea to consider the discarded discharge amount, that is, the flushing amount for this discarded discharge. However, the present inventors diligently studied how the cost increase can be suppressed while realizing stable drawing quality when using functional ink, and paid attention to this discarded discharge. That is, the amount of liquid material to be flushed, which has not been considered at all until now, is examined, and it is found that the amount of liquid material to be flushed can be determined by the contact time between the cleaning liquid of the maintenance mechanism and the discharge surface. It was. That is, it has been found that by determining the amount of the liquid material to be flushed based on the present invention, it is possible to maintain a stable drawing quality without increasing unnecessary discharge.

  Specifically, the first liquid material discharge device according to the present invention can grasp the amount of the cleaning liquid flowing into the nozzle from the discharge port formed on the discharge surface by considering the contact time. By grasping the amount of the cleaning liquid flowing in, the amount of the liquid material (specifically, the liquid mixture of the liquid material and the flowing cleaning liquid) that may cause the above-described problems when discharged as it is in the nozzle is grasped. be able to. Thereby, the amount of liquid material to be flushed can be found.

  In addition, the first liquid material ejection device according to the present invention can grasp the amount of the liquid material to be flushed, and thus can cope with a change in the maintenance state of the liquid material ejection device. That is, in the maintenance, for example, when the solid content of the functional ink adheres to the vicinity of the nozzle, the meniscus in the vicinity of the ejection port cannot be maintained, so that the head head difference is increased so that the ink does not overflow from the nozzle. Even if the maintenance conditions change as described above, according to the configuration of the present invention, the amount of the liquid material to be flushed can be grasped based on the contact time, so that stable drawing quality can be maintained. Therefore, even when the maintenance method is changed, it is possible to provide good discharge performance without causing problems such as inducing satellites or failing to obtain a desired film thickness.

  The contact time is, for example, when the maintenance mechanism is a cleaning liquid tank and the head is immersed in the cleaning liquid, and after the cleaning liquid in the cleaning liquid tank starts to contact the head until it leaves. Say the time. Further, for example, when the maintenance mechanism is a wiping blade to which a cleaning liquid is attached as will be described later and the discharge surface is wiped by the blade, the cleaning liquid attached to the blade is in contact with the head. Say the time.

  In addition, another liquid material ejection device according to the present invention (hereinafter referred to as “second liquid material ejection device” in order to distinguish this liquid material ejection device from the above-described first liquid material ejection device) In order to solve the above-described problem, the liquid adhered to the ejection surface by wiping the ejection surface of the head with a head having a plurality of nozzles supplied with a liquid material from a supply tank and a wiping member to which the cleaning liquid is adhered. A liquid material discharge device including a mechanism for removing material, the liquid material discharging device including a cleaning liquid supply unit that supplies the cleaning liquid having a viscosity different from that of the liquid material, and using the wiping member to which the cleaning liquid is attached After wiping the discharge surface, an amount of the liquid material based on the contact time between the cleaning liquid adhering to the wiping member and the discharge surface is discharged from each nozzle. It is characterized in that it is configured to be sequenced.

  According to said structure, the 2nd liquid material discharge apparatus which concerns on this invention suppresses the usage-amount of the liquid material by flashing to the minimum, and can maintain the stable drawing quality. Can be provided.

  Specifically, in the second liquid material ejection device according to the present invention, first, the liquid material adhering to the ejection surface is removed using a blade to which a cleaning liquid is adhered. Therefore, the cleaning of the discharge surface can be performed based on high reliability as compared with the configuration in which the discharge surface is wiped only with the blade. Further, as will be described later, by using a cleaning liquid having a viscosity lower than that of the liquid material, the viscosity can be lowered even when the liquid material attached to the ejection surface has a high viscosity under dry conditions. As well as being able to maintain the wiping performance of the blade.

  Here, as described above, when the discharge surface is wiped by the blade to which the cleaning liquid is adhered using a cleaning liquid having a viscosity different from that of the liquid material to be discharged, as described above, due to the viscosity difference, The cleaning liquid enters the nozzle from the discharge port and changes the viscosity and concentration of the liquid material in the nozzle. Satellites are generated due to defective discharge, the coating amount is not stable, and the first and last cells are drawn. This causes the problem that the coating amount is different. The second liquid material discharge device according to the present invention is particularly suitable as a device for discharging a liquid material called functional ink by an ink jet method, but the above-described problems are fatal in the device. is there. Therefore, as described above, the second liquid material discharge device according to the present invention is configured to flush the liquid material from the head after wiping, so that the cleaning liquid flows into the nozzle to cause the nozzle to flow. The part in which the viscosity or concentration of the liquid material in the inside has changed is discarded, and the liquid material having a normal viscosity stored in the supply tank can be supplied into the nozzle. Accordingly, it is possible to provide a liquid material discharge device that discharges a liquid material with a desired drawing quality without causing the above-described problems.

  It should be noted that the second liquid material discharge device according to the present invention sets the amount of the liquid material to be flushed based on the contact time between the cleaning liquid adhering to the wiping member and the discharge surface. It is a point. Although the liquid material to be flushed is important as maintenance of the liquid material discharge device, it is a liquid material that does not contribute to discharge to the discharge target material, and is discarded. Conventionally, as described above, there has been no idea to consider the discarded discharge amount, that is, the flushing amount for this discarded discharge. However, the present inventors diligently studied how the cost increase can be suppressed while realizing stable drawing quality when using functional ink, and paid attention to this discarded discharge. In other words, the amount of liquid material to be flushed, which has not been considered at all until now, is examined, and the amount of liquid material to be flushed can be determined by the contact time between the cleaning liquid adhering to the wiping member and the ejection surface. I found it. That is, it has been found that by determining the amount of the liquid material to be flushed based on the present invention, it is possible to maintain a stable drawing quality without increasing unnecessary discharge.

  Specifically, the second liquid material discharge device according to the present invention is configured from a discharge port formed on the discharge surface by considering a contact time between the cleaning liquid adhering to the wiping member and the discharge surface. The amount of cleaning liquid flowing into the nozzle can be grasped. By grasping the amount of the cleaning liquid flowing in, the amount of the liquid material (specifically, the liquid mixture of the liquid material and the flowing cleaning liquid) that may cause the above-described problems when discharged as it is in the nozzle is grasped. be able to. Thereby, the amount of liquid material to be flushed can be found.

  Further, the second liquid material ejection device according to the present invention can grasp the amount of the liquid material to be flushed, and thus can cope with a change in the maintenance state of the liquid material ejection device. That is, for example, in the case where the dispersion of landing of dots discharged from the nozzle has deteriorated, the wiping speed at the time of wiping is reduced in order to wipe off well, or the solid content of the functional ink has adhered to the vicinity of the nozzle. In this case, the meniscus in the vicinity of the discharge port cannot be maintained, so that the head difference of the head is increased so that the ink does not overflow from the nozzle, or when the functional ink adhering to the wiping member is dried and solidified, Add a lot of cleaning liquid to the wiping member. Even if the maintenance conditions are changed in this way, according to the configuration of the present invention, the amount of liquid material to be flushed can be grasped based on the contact time between the cleaning liquid adhering to the wiping member and the ejection surface. , Stable drawing quality can be maintained. Therefore, even when the maintenance method is changed, it is possible to provide good discharge performance without causing problems such as inducing satellites or failing to obtain a desired film thickness.

  Specifically, it is preferable that the cleaning liquid supply means is configured to supply the cleaning liquid having a lower viscosity than the liquid material as described above.

  Further, the first and second liquid material discharge devices of the present invention have a negative pressure for generating a negative water head difference in the supply tank and the nozzle in addition to the above configuration. And a generation means, wherein the water head difference is P, the flow path resistance from the supply tank to the nozzle is R, and the contact time is t, the amount of the liquid material to be flushed is P · t / It is preferable to set so as to be in a range of R to 10 P · t / R.

  By setting the amount of the liquid material to be flushed within the above range, waste of the liquid material to be flushed can be eliminated and a stable drawing quality can be maintained.

  In addition to the above configuration, the liquid material ejection device of the present invention further includes a pattern holding unit in which a plurality of patterns of correlation data between the contact time and the amount of the liquid material to be flushed are set in advance. It is preferable.

  According to said structure, even if a maintenance condition changes, the pattern set to the pattern holding means can be applied and the quantity of the liquid material which should be flushed can be grasped | ascertained easily.

  Further, such a pattern holding means may be configured to acquire a plurality of patterns of correlation data between the contact time and the amount of the liquid material to be flushed using a dummy material to be discharged. A configuration may be adopted in which the created data is input from the outside.

  In addition to the above configuration, the second liquid material ejection device according to the present invention can remove the liquid material adhering to the wiping member from the wiping member by physically contacting the wiping member. preferable.

  According to said structure, since the 2nd liquid material discharge apparatus which concerns on this invention is equipped with the removal mechanism which contacts the said wiping member physically, liquid material accumulate | stores more than predetermined amount on a braid | blade. Therefore, even when the discharge surface blade is repeatedly used for a long time, the liquid material can be removed from the discharge surface based on high reliability.

  Specifically, the wiping member is a blade, and the removal mechanism can be a repelling plate configured to repel the blade. Alternatively, the wiping member may be a blade, and the removal mechanism may be a roller configured to abut the blade on the roller surface. And according to the structure of this invention, the said washing | cleaning liquid supply means may be comprised so that the said washing | cleaning liquid may be dripped at the said roller surface.

  Thus, by providing the removal mechanism, the liquid material transferred to the blade can be removed from the blade, and the liquid material transferred to the blade can be prevented from returning to the ejection surface.

  As described above, the liquid material discharge device according to the present invention is a liquid material discharge device that includes a head having a plurality of nozzles for supplying liquid material from a supply tank and discharges the liquid material from the discharge surface of the head. A maintenance mechanism that removes the liquid material adhering to the ejection surface of the head from the ejection surface by bringing a cleaning liquid having a viscosity different from that of the liquid material into contact with the ejection surface of the head. Flushing the amount of the liquid material from each nozzle based on the contact time between the cleaning liquid of the maintenance mechanism and the discharge surface after the cleaning liquid of the maintenance mechanism and the discharge surface of the head come into contact with each other. It is characterized by. In addition, as described above, another liquid material ejection device according to the present invention wipes the ejection surface of the head with a head having a plurality of nozzles to which liquid material is supplied from a supply tank and a wiping member to which a cleaning liquid is attached. And a mechanism for removing the liquid material adhering to the ejection surface, comprising a cleaning liquid supply means for supplying the cleaning liquid having a viscosity different from that of the liquid material, After wiping the discharge surface using a wiping member having a cleaning liquid attached thereto, the liquid material in an amount based on the contact time between the cleaning liquid attached to the wiping member and the discharge surface is flushed from each nozzle. It is characterized by the structure.

  As a result, the cleaning liquid that has flowed into the head can be discharged from the head, the ejection is stable, and the coating amount is stable. Even if the maintenance method changes, by changing the flushing amount accordingly, stable maintenance independent of the state of the maintenance device or the head can be performed. Therefore, the substrate can be prevented from being soiled by satellites, a desired film thickness can be obtained, and a highly reliable device can be obtained.

[Embodiment 1]
An embodiment of the present invention will be described with reference to FIGS. In the following description, various technically preferable limitations for carrying out the present invention are given, but the scope of the present invention is not limited to the following embodiments and drawings.

  FIG. 1 is a diagram illustrating a configuration of an ink jet type liquid material ejection device (hereinafter referred to as a liquid material ejection device) according to the present embodiment. The liquid material discharge device 40 of the present embodiment discharges, for example, three primary colors of ink (functional ink) of red (R), blue (B), and green (G) to one discharge target material, It can be used when manufacturing a color filter comprising three types of R, B and G filters. Therefore, in the present embodiment, a liquid material ejection device that ejects three types of inks R, B, and G will be described.

  As shown in FIG. 1, the liquid material ejection device 40 of the present embodiment includes supply tanks 55a, 55b, and 55c that supply R, B, and G inks, and tubing pumps 54a, 54b, and 54c (negative pressure generating means). ) And R, B, and G inkjet heads 50a, 50b, and 50c.

  The supply tanks 55a, 55b, and 55c are configured to store R, B, and G inks, and can be formed of a flexible film. The supply tanks 55 a, 55 b, and 55 c communicate with the insides of the corresponding ink jet heads 50 a, 50 b, and 50 c through tubes 56. The supply tanks 55a, 55b, and 55c are housed in negative pressure boxes 53a, 53b, and 53c having good airtightness.

  The tubing pumps 54a, 54b, and 54c can cause a negative water head difference with respect to the negative pressure boxes 53a, 53b, and 53c. As a result, the inside of the supply tanks 55a, 55b, and 55c, and the inkjet head A desired water head difference can be applied to the inside of 50a, 50b, and 50c (inside of the nozzle). If the negative pressure is too large, air is easily trapped during ejection and the ejection becomes unstable. On the other hand, if the negative pressure is too small, ink may overflow from the nozzle hole 52, so an appropriate water head difference is necessary. . As an example, it can be set to -0.5 kPa to -3 kPa.

  The configuration of the inkjet heads 50a, 50b, and 50c will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the state when the inkjet head 50a is cut along the cutting line AA ′ shown in FIG. Note that the configuration of the inkjet heads 50b and 50c is the same as that of the inkjet head 50a described below, and thus the description thereof is omitted.

  As shown in FIG. 2, the inkjet head 50 a includes a piezoelectric material (hereinafter referred to as PZT) 57, a cover plate 58, a nozzle plate 51, and a head cover 59. A plurality of grooves are formed in the PZT 57, and a plurality of ink chambers are formed in the direction perpendicular to the paper surface. These ink chambers are surrounded by the cover plate 58 and the PZT 57 because the PZT 57 and the cover plate 58 are in contact with each other on the front side of the paper surface of the inkjet head 50a. A constant gap is provided between the PZT 57 and the cover plate 58, and a common ink chamber 60 is formed in this gap portion. An electrode 61 is formed on the partition wall of each ink chamber and is electrically connected to the external electrode 63 via the conductive resin 62. A manifold 64 for smoothly supplying ink to each ink chamber is provided on the back side of the ink jet head 50a.

  The nozzle plate 51 is provided at a position facing a material to be ejected (not shown), can be configured using a conventionally known material, and can be configured using resin or metal. In the case of metal, durability and wear resistance are high, and in the case of resin, nozzle hole processing is easy. For example, polyimide having a thickness of 50 μm and 64 nozzle holes 52 having a taper of 11 ° and a diameter of 26 μm opened on the discharge side can be used. In the case of the present embodiment, the nozzle holes 52 formed on each ejection surface are arranged in a straight line having a predetermined angle with respect to the X axis and the Y axis shown in FIG. The arrangement, size, and number of nozzle holes 52 are not limited to those shown in FIG. When ink is ejected from the nozzle holes 52 as described above, when the driving voltage is 15 V, the ejection speed can be 6.7 m / s and the volume can be 6 pl.

  The ink jet heads 50a, 50b, and 50c can be further mounted with constituent members of a conventionally known ink jet head.

  By the way, the pixels of the color filter used in the liquid crystal panel are high definition with a width of about 200 μm. Therefore, the ejection accuracy of the ink jet apparatus for realizing this is required to be 10 μm or less. In order to maintain this discharge accuracy for a long time in a color filter manufacturing apparatus, it is necessary to always keep the discharge surface normal. However, since the inkjet head generally ejects liquid ink or stops ejection, ink adheres to the ejection surface of the nozzle plate or air (bubbles) enters the nozzle. . These phenomena may cause nozzle clogging and change the ejection angle of the ejected ink. Therefore, in the present embodiment, as shown in FIG. 1, in order to eliminate clogging in the nozzle, a suction device 7 configured to suck ink in the nozzle using a suction pump, and the inkjet head 50a. A blade 1 (wiping member, maintenance mechanism) for cleaning the nozzle surface (ejection surface) of the nozzle plate provided in 50b / 50c is disposed to perform maintenance of the inkjet heads 50a, 50b, 50c. Yes. The details of the suction device 7 and the blade 1 will be described below.

  The suction device 7 includes a cap 71 and a suction pump 72 as shown in FIG. When performing the suction operation, the cap 71 that is normally retracted so as not to hit the inkjet heads 50a, 50b, and 50c is raised, and the inkjet heads 50a, 50b, and 50c are capped. Then, the suction pump 72 is driven to keep the inside of the cap 71 at a negative pressure of about −40 kPa, and the ink is sucked and discharged from the nozzle (priming operation). Thereby, clogging in the nozzle can be eliminated.

  In the present embodiment, after the suction operation is finished and the cap 71 is lowered, the ink attached to the nozzle plate 51 is wiped (wiped) by the blade 1.

  The blade 1 is provided with wipe surfaces (vertical surfaces) parallel to the Z-axis in FIG. 1 on the front and back surfaces 11a and 11b in a state in which no external pressure is applied, and is detachably attached to the mounting base 12. . A total of three blades 1 are provided corresponding to the inkjet heads 50a to 50c arranged along the Y-axis direction. The blades 1 are arranged slightly apart from each other in the Y-axis direction, and are attached with their positions slightly shifted in the X-axis direction.

  The blade 1 is configured to be driven along the X axis of FIG. 1 by a driving means (not shown). The blade 1 can be made of an elastic material, and fluorine rubber is preferable. Among them, it is particularly preferable to use perfluoro rubber (Daikin Perflo (trade name)) having high chemical resistance. FIG. 3 is a cross-sectional view showing the state in which the ejection surface of the nozzle plate 51 of the inkjet head 50a shown in FIG. By this wiping operation, the ink adhering to the ejection surface of the nozzle plate 51 is transferred to the blade 1 and the ejection surface of the nozzle plate 51 can be cleaned.

  Furthermore, as shown in FIG. 1, the liquid material ejection device 40 of the present embodiment includes a repelling plate 2 (removal mechanism) for removing ink transferred from the ejection surface to the blade 1 from the blade 1. Yes.

  The repellent plate 2 can be made of a plate-like member whose elasticity is equal to or harder than that of the blade 1, and as shown in FIG. It is arranged on an extension line of one uniaxial (X axis) movement. As shown in FIG. 3, the blade 1 after wiping the discharge surface of the nozzle plate 51 is in contact with the repellent plate 2. The contact state is shown in FIG. As shown in FIG. 4, when the blade 1 comes into contact with the repellent plate 2, the ink adhering to one surface (11 a in FIG. 1) of the blade 1 is transferred to the repellent plate 2. After the blade 1 is repelled by the repelling plate 2, it further proceeds in the direction indicated by the arrow in FIG. Thereafter, the blade 1 moves again toward the repellent plate 2 (in the direction opposite to the direction indicated by the arrow in FIG. 4), and the surface opposite to the previous side (11b in FIG. 1) is repelled by the repellent plate 2. The ink adhering to the surface can be transferred to the repelling plate 2 by being brought into contact with.

  By the way, the R, G, and B inks used in the liquid material ejection device 40 of the present embodiment have high viscosity and tend to solidify when dried. Further, in order to increase safety for humans with respect to the solvent contained in the ink or to prevent deterioration of the wiring of the apparatus, it is preferable that a large amount of air in the liquid material discharge apparatus is exhausted. However, in such an environment, the ink adhering to the ejection surface of the nozzle plate 51 and the ink adhering to the blade 1 as shown in FIG. Will cause problems. Accordingly, the liquid material discharge device 40 of the present embodiment is configured to prevent the viscosity of the ink adhering to the discharge surface and the ink adhering to the blade 1 as shown in FIG. ing. Specifically, the liquid material discharge device 40 is provided with a cleaning liquid supply means 5 as shown in FIG.

  The cleaning liquid supply means 5 includes a cleaning liquid tank 5a that stores the cleaning liquid and a pump 5b that is controlled to drop the cleaning liquid onto the upper surface (XY plane) of the blade 1 by a pipe as shown in FIG. Have. By driving the pump 5b, the cleaning liquid in the cleaning liquid tank 5a is dropped onto the blade 1. As the cleaning liquid, the solvent of the ink in each of the supply tanks 55a, 55b, and 55c can be used. Specific examples include ethanol, acetone, and isopropyl alcohol. The amount of dripping can be controlled by the driving time of the pump 5b. For example, when the pump 5b is driven for 1.5 seconds, two droplets are dropped from the pipe onto the blade 1, and the amount can be 0.02 cc. Further, in order to uniformly supply the cleaning liquid to the blade 1, a plurality of dropping portions may be provided for one blade 1. Also, if the ink adhering to the blade is considered to have increased viscosity without performing the wiping operation for a long time, the amount is increased (for example, 0.06 cc). Reduction (for example, 0.01 cc) is controlled.

  As shown in FIG. 1, the viscosity of the ink attached to the blade 1 can be reduced by dropping the cleaning liquid onto the blade 1. Further, by wiping the discharge surface of the nozzle plate 51 with the blade 1 with the cleaning liquid attached, the cleaning liquid can also reduce the viscosity of the ink attached to the discharge surface of the nozzle plate 51. The wiping efficiency by can be increased. By the way, in this embodiment, since a liquid having a lower viscosity than the ink is used as the cleaning liquid, if the discharge surface is left wiped by the blade to which the cleaning liquid is attached, the difference in viscosity between the cleaning liquid and the ink is caused. Thus, the cleaning liquid may enter the nozzle from the nozzle hole 52 (FIG. 2). Therefore, the liquid material discharge device 40 of the present embodiment has a mechanism for performing flushing and discharging the cleaning liquid that has entered the nozzle, like the conventionally known liquid material discharge device. The characteristic configuration of the liquid material discharge device 40 is that flushing is performed by an amount corresponding to the amount of the cleaning liquid flowing into the nozzle after wiping the discharge surface with a blade to which the cleaning liquid is attached. This point will be described in detail below.

  The inventors of the present application pay attention to the fact that the conventional technology is not suitable for the cost increase due to excessive flushing and the change in the maintenance method, and as a result of intensive studies, the amount of the cleaning liquid flowing into the nozzle is It has been found that it can be estimated from the contact time between the cleaning liquid adhering to the blade 1 and the ejection surface.

Specifically, it has been found that the amount V of the cleaning liquid flowing into the nozzle is expressed by the following formula (1), where T is the contact time between the cleaning liquid adhering to the blade 1 and the discharge surface.
V = PT / R (1)
Here, P in the formula (1) indicates a water head difference with respect to the inside of the supply tanks 55a, 55b, and 55c and the inside of the nozzles of the inkjet heads 50a, 50b, and 50c, and R is the supply tank 55a. The flow path resistance from 55b / 55c to the nozzle hole 52 is shown.

The time T during which the nozzle hole 52 is in contact with the cleaning liquid during wiping can be expressed as shown in Equation (2).
T = t / w (2)
Here, t in the formula (2) indicates the thickness of the blade 1, and w indicates the wiping speed of the blade 1.

From the equation (2), the above equation (1) is
V = PT / R = t · P / (R · w) (3)
It can be expressed as.

  In addition, as for R in the above formula (1), the flow resistance of the nozzle 51 ′ shown in the nozzle plate 51 (FIG. 2) is large, so that the flow resistance of the nozzle can be substituted. FIG. 5 shows an enlarged view of the nozzle plate 51. The diameter of the nozzle outlet is Dout, the diameter of the nozzle inlet is Din, the thickness of the nozzle plate 51 is L, the number of channels is N, and the viscosity of the cleaning liquid is ν. Then, the channel resistance R is given by the following equation (4)

It can be shown as follows.

Based on the above formula (1), the amount V of the cleaning liquid flowing into the nozzle is calculated by way of an example as follows. Ethanol is used as the cleaning liquid. Since the viscosity ν of ethanol is 1.07 mPa · s (27 ° C.), the flow path resistance R can be obtained as 1.55 × 10 ¹⁰ kg / (s · m ⁴ ). Further, the head head difference P at the time of wiping is set to -0.5 kPa, the thickness t of the blade 1 is set to 0.5 mm, and the wiping speed (relative speed between the head and the blade) w is set to 2 mm / s. Substituting these conditions into equation (1),
V = 0.5e-3 * 0.5e3 / [1.55e10 * 2e-3]
= 0.0081
In this example, the amount V flowing into the head can be calculated as 0.0081 cc. Here, a power of 10 is expressed using “e”. That is, for example, 0.5 × 10 ⁻³ is represented as 0.5e−3.

  Table 1 below shows the amount of cleaning liquid flowing into the nozzle using the wiping speed as a parameter.

  Table 1 shows the amount of flushing when 5,000 to 1,000,000 drops are flushed (64-channel all-channel discharge, 6 pl per drop) and the amount of cleaning liquid flowing into the nozzle. The ratio of the flushing amount is also shown. The inventors of the present application examined the appropriate flushing amount with respect to the amount of the cleaning liquid flowing into the nozzle by using Table 1. The inventors of the present application have studied the appropriate flushing amount by utilizing the fact that the discharge speed greatly changes when the density of the ink in the nozzle hole and its vicinity is different from the original density of the ink. The change in the discharge speed means that when the ink is thinner than the original density (the cleaning liquid is darker than the ink), the viscosity of the ink in the nozzle hole and its vicinity is lowered, and the discharge speed is increased while the discharge speed is increased. If the speed is high, the flight time until landing on the discharge plate is shortened. Details are as follows.

  That is, first, as a blade, polyimide having a thickness of 50 μm and 64 nozzle holes 52 having a taper of 11 ° having a diameter of 26 μm opened on the discharge side is used. The cleaning liquid is ethanol and is dropped about 0.02 cc on one blade. Then, the nozzle plate is wiped with a blade at each wiping speed shown in Table 1. After wiping, flushing is performed with each flushing amount shown in Table 1. Then, while moving the inkjet head (gap 0.5 mm) at 100 mm / s, about 10 droplets are ejected onto the material to be ejected (dummy material to be ejected) at a driving frequency of 500 Hz (ejection at intervals of 200 μm). Here, if the interval between the ink dots is shorter than 200 μm, the viscosity of the ink in the nozzle hole and the vicinity thereof is lowered, indicating that the ejection speed is increased. This also varies depending on the channel. By counting the number of normal channels in which the ink dot interval is 200 μm, it is possible to easily determine whether sufficient flushing has been performed. In addition, if the viscosity of the ink in the nozzle hole and its vicinity is small, it becomes a satellite. Table 2 shows the results.

  From the results of Tables 1 and 2, it was found that the flushing amount necessary for obtaining stable print quality was not the absolute amount of flushing. That is, it has been found that there are conditions where the discharge is stable and conditions that are not stabilized depending on the wipe speed even with the same flushing amount. However, when the wiping speed is changed (that is, when the contact time between the head and the cleaning liquid is changed), if the amount of the cleaning liquid flowing into the nozzle is focused, the flushing amount with a ratio of 1 or more, that is, the inside of the nozzle It can be seen that a stable drawing quality can be obtained by performing flushing in the same amount as the amount of the cleaning liquid flowing into the. In addition, even when the amount of the cleaning liquid is large, it is understood that the ratio should be 10. That is, the flushing amount may be increased by 10 times the inflow amount of the cleaning liquid flowing into the nozzle.

  From the above, based on this embodiment, the flushing amount is preferably in the range of PT / R to 10 PT / R from the formula (1), so that there is no satellite and the ink density is constant. It has been shown that it is possible to provide a liquid material discharge device capable of performing drawing.

  Further, when the ink jet head is used for a long time, the ink is solidified around the nozzle hole, and the ink overflows from the nozzle even if a normal water head difference (for example, -1.0 kPa) is given to the head. At that time, the water head difference is set to, for example, −1.5 kPa so that ink does not overflow from the nozzles. Then, if the water head difference applied to the ink jet head is large from the equation (3), the ink must be discharged excessively. That is, when the water head difference is changed, the flushing amount is increased in direct proportion according to the equation (3). By doing in this way, even if the water head difference changes depending on the state of the ink jet head or the like, stable ejection can be performed and a highly reliable apparatus can be obtained. Thus, by changing the maintenance depending on the state of the head and flushing a predetermined flushing amount accordingly, a highly reliable apparatus can be obtained. On the other hand, if the water head difference is reduced only during wiping (for example, -0.5 kPa), the amount of the cleaning liquid flowing in is small and the flushing amount is small. Therefore, a device that does not waste ink can be realized by reducing the water head difference during wiping.

  For the adjustment (control) of the flushing amount as described above, for example, the wipe speed and flushing amount parameters obtained as described above are stored in a memory, and when the wipe speed changes, the corresponding flushing amount is read and flashed. Can be done.

  As described above, the liquid material discharge device according to the present embodiment uses the cleaning liquid adhered to the wiping member after wiping the ejection surface using the blade to which the cleaning liquid is adhered. In addition, it was found that a stable drawing quality can be maintained without increasing the number of discarded discharges more than necessary, because it is set based on the contact time with the discharge surface. That is, in this embodiment, the amount of cleaning liquid flowing into the nozzle formed on the nozzle plate can be grasped by considering the contact time between the cleaning liquid attached to the blade and the ejection surface. By grasping the amount of cleaning liquid flowing in, it is possible to grasp the amount of ink (specifically, a mixed liquid of ink and flowing cleaning liquid) that may cause the above-described problems if it is discharged as it is in the nozzle. it can. Thereby, the amount of ink to be flushed can be found.

  In addition, since the amount of ink to be flushed can be grasped, it is possible to cope with a change in the maintenance state of the liquid material ejection device. That is, for example, in the case where the dispersion of landing of dots discharged from the nozzle has deteriorated, the wiping speed at the time of wiping is reduced in order to wipe off well, or the solid content of the functional ink has adhered to the vicinity of the nozzle. In this case, the meniscus in the vicinity of the discharge port can no longer be maintained, so that the head head difference is increased so that the ink does not overflow from the nozzle, or the functional ink adhering to the blade is dried and solidified. Add more cleaning solution. Even if the maintenance conditions change in this way, according to the above configuration, the amount of ink to be flushed can be grasped based on the contact time between the cleaning liquid adhering to the blade and the ejection surface, so that stable drawing quality can be obtained. Can be maintained. Therefore, even when the maintenance method is changed, it is possible to provide good discharge performance without causing problems such as inducing satellites or failing to obtain a desired film thickness.

In addition, although the example when using ethanol as a washing | cleaning liquid was shown above, for example, when using acetone as a washing | cleaning liquid, since a viscosity is 3.05 mPa * s (27 degreeC),
t · P / (R · w) -10 · t · P / (R · w)
0.5e-3 * 0.5e3 / [4.4e10 * 2e-3]
~ 10 * 0.5e-3 * 0.5e3 / [4.4e10 * 2e-3]
Thus, it is understood that the flushing of 0.003 cc to 0.029 cc may be performed.

  In addition, as shown in Table 1, when the wiping speed is 0.5 mm / s, a very large amount of flushing is required. However, since continuous discharge induces instability factors such as cavitation, the first time After the flushing, the flushing may be performed separately, such as waiting for about 1 second and then performing the second flushing.

  In the present embodiment, the maintenance using the blade is shown. However, the same applies to the case where the maintenance is performed by immersing the inkjet head (nozzle plate) in the cleaning liquid for a certain period of time. The immersion time is equivalent to the contact time between the inkjet head and the cleaning liquid.

[Embodiment 2]
Another embodiment according to the present invention will be described below with reference to FIG. In addition, in this embodiment, in order to explain a difference from the first embodiment, for the sake of convenience of explanation, members having the same functions as the members described in the first embodiment are denoted by the same member numbers, and the description thereof. Is omitted.

  FIG. 7 is a diagram showing a configuration of an ink jet type liquid material ejection device (hereinafter referred to as a liquid material ejection device). For convenience of explanation, illustration of the suction device 7 in the liquid material ejection device 40 ′ of the present embodiment is omitted.

  In the first embodiment described above, the ink adhering to the blade 1 is removed from the blade 1 using the repelling plate 2 (FIGS. 1 and 4). On the other hand, as shown in FIG. 7, the liquid material discharge device 40 ′ of this embodiment includes a roller 8 (removal mechanism) configured to contact the blade 1 and a cleaning for cleaning the roller 8. And a blade 9 (removal mechanism). Further, in the first embodiment described above, as shown in FIG. 1, the cleaning liquid is directly dropped onto the blade 1. On the other hand, as shown in FIG. 7, the liquid material discharge device 40 ′ of the present embodiment is provided with a cleaning liquid supply unit 5 ′ that supplies the cleaning liquid to the surface of the roller 8.

  The roller 8 is arranged in the movement path of the blade 1 so that the blade 1 can come into contact therewith. Specifically, as shown in FIG. 7, the roller 8 has the roller shaft 82 of the roller 8 positioned substantially at the same height as the discharge surface of the nozzle plate 51, and extends from the nozzle plate 51 in the X-axis direction. A predetermined distance is arranged along. As a result, when the blade 1 from which the ink has been transferred by wiping the ejection surface moves along the X axis, as shown in FIG. 8, the center line is below the roller axis and passes through the roller axis 32. The ink of the blade 1 can be transferred to the surface of the roller 8 by contacting the roller surface closer to the head 50 than C. That is, the ink can be removed from the blade 1. Further, the roller 8 has a cylindrical shape as shown in FIG. 7, and is configured to be able to rotate about the roller shaft 82 as a rotation axis by a driving means (not shown).

  As shown in FIG. 8, when one surface of the blade 1 uniformly contacts the surface of the roller 8, the ink attached to the one surface is transferred to the surface of the roller 8. Move in the direction indicated by the arrow. This state is shown in FIG. In FIG. 9, the blade 1 can move to the side opposite to the head 50 side (the cleaning blade 9 side) across the center line C while contacting the roller surface. Next, the blade 1 moves in the direction opposite to the movement direction so far. This state is shown in FIG. The blade 1 moves in the direction of the arrow shown in FIG. 10 to bring the other surface of the blade 1 into contact with the surface of the roller 8. By this contact, the ink attached to the other surface of the blade 1 is transferred to the surface of the roller 8.

  The surface of the roller 8 is higher in lyophilicity than the surface of the blade 1, and the roller 8 has a structure with no irregularities in the region where the blade 1 abuts. The structure having no irregularities means that the roller 8 is in contact with the blade 1 evenly when the roller 8 rotates with the roller axis as the rotation axis while the blade 1 is in contact. Is a structure that is not porous and has no ridges or grooves. The roller 8 in the present embodiment is configured so that the length from the roller shaft to the surface of the roller 8 (that is, the radius of the roller 8) is equal or substantially equal at any location in at least the region where the blade 1 abuts. ing.

  Specifically, the surface of the roller 8 preferably has a surface roughness Ra of 0.1 or more and 2.0 or less. When Ra is smaller than 0.1, the lyophilicity of the surface of the roller 8 becomes lower than that of the surface of the blade 1, and ink cannot be transferred from the blade 1. On the other hand, when Ra becomes larger than 2.0, the blade 1 brought into contact is damaged. As described above, if the blade 1 is damaged, the discharge surface of the nozzle plate 51 is eventually damaged, causing a change in shape (deterioration) of the discharge surface, and stable discharge performance cannot be obtained. Therefore, the surface of the roller 8 preferably has a Ra in the range of 0.1 to 2.0. Further, when the blade 1 is a fluorine rubber such as perfluoro rubber, Ra is more preferably 0.4 or more, and more preferably 1.2 or less. Of these, Ra is most preferably about 0.8.

  As the material of the surface of the roller 8, a resin such as PTFE can be used. By using resin, a roller having a small surface roughness can be obtained by cutting at a low cost. There are also resins with strong chemical resistance, and it is possible to realize rollers with higher cost and performance than rubber rollers that require mold molding. In the case of using a resin, it is necessary to perform a lyophilic treatment (plasma treatment, ashing, etc.) in order to obtain a desired lyophilic property.

  Further, the material of the surface of the roller 8 is not limited to resin, but may be configured using a metal such as stainless steel (for example, SUS304), aluminum, or brass. By using a metal, a roller having a small surface roughness such as a mirror finish can be obtained by cutting at a low cost, and a wide range of materials can be selected from the viewpoint of chemical resistance. There are a wide variety of liquid materials discharged by the liquid material discharge device, and any metal roller can handle various liquid materials, and since it is not consumed, the replacement frequency can be suppressed.

  In the above description, when Ra is less than 0.1, lyophilic problems occur. However, if the surface of the roller 8 is lyophilic, Ra may be less than 0.1. It may be mirror-finished. If Ra is smaller than 0.1 or mirror-finished, the blade 1 can be further prevented from being damaged as compared to the case where Ra is in the above range. it can.

  The length of the roller 8 (the length in the roller axis direction) has a length that allows all three blades 1 on the mounting base 22 to come into contact with each other. As a result, the three blades 1 arranged so as to be shifted from each other in the X-axis direction sequentially come into contact with the roller 8.

  As shown in FIG. 7, a convex color mixing prevention unit 81 is provided at a position corresponding to a gap provided in the Y-axis direction between the blades 1 arranged in the Y-axis direction on the surface of the roller 8. Is provided. Since this embodiment is also configured to eject three types of inks, R, B, and G, as in the first embodiment, the radius of the roller 8 is uniform over the entire axial length of the roller 8. In this case, there is a possibility that three types of inks of R, B, and G may be mixed on the surface of the roller 8, and if the mixed ink is attached to the blade 1 for some reason, as a result, the discharge surface of each inkjet head The mixed color ink adheres to the ink dots, and the color accuracy of the ink dots is significantly reduced. Therefore, by providing the color mixing prevention unit 81, it is possible to prevent the color inks adhering to the surface of the roller 8 from being mixed and mixed. The height (protrusion length) of the color mixing prevention unit 81 from the surface of the roller 8 (the region where the blade 1 abuts) is not particularly limited as long as each ink does not mix.

  The cleaning blade 9 is provided to remove the ink adhering to the surface of the roller 8 from the surface of the roller 8, and always contacts the roller 8 at a position where the cleaning operation of the blade 1 by the roller 8 is not hindered. ing. Specifically, as shown in FIG. 7, the cleaning blade 9 is preferably in contact with the surface of the roller 8 above the roller shaft. Like the blade 1, the cleaning blade 9 is made of an elastic material and is configured to abut on a region other than the color mixing prevention portion 81 on the surface of the roller 8. Thereby, the ink adhering to the surface of the roller 8 can be removed without scratching the surface of the roller 8.

  The length (width) of the cleaning blade 9 along the roller shaft 82 is longer (wider) than that of the blade 1. This is shown in FIG. As shown in FIG. 9, the width 9H of the cleaning blade 9 is configured to be larger than the width 1H of the blade 1. With this configuration, even if the ink transferred from the blade 1 to the roller 8 spreads on the surface of the roller 8, the ink can be efficiently removed from the roller 8 by the wide cleaning blade 9. it can.

  The rotation of the roller 8 can be performed using a driving unit for moving the blade 1 in one axis (X axis). Specifically, as a mechanism for rotating the roller 8, a rack gear integrally formed with the blade 1 and a rotation gear mechanism can be provided. As a result, the rack gear moves on the X axis along with the movement of one axis (X axis) of the blade 1. A rotation gear mechanism whose rotation axis is positioned coaxially with the roller shaft 82 of the roller 8 is disposed in the rack gear. Accordingly, the roller 8 can be rotated by the rack gear that moves as the blade 1 moves along one axis (X axis) of the blade 1 by the driving means, and the rotation gear mechanism rotates around the rotation axis.

  When the roller 8 is rotated using the rack gear and the rotation gear as described above, the rotation gear mechanism may be configured to rotate in one direction only when the rack gear moves in a certain direction. By comprising in this way, the rotation direction of the roller 8 can be limited to one direction. Thereby, rotation control of the roller 3 can be simplified. Further, when the cleaning blade 9 brought into contact with the roller 3 removes ink adhering to the surface of the roller 8, it is not necessary to consider the entrainment of the cleaning blade 9 due to the reverse rotation of the roller 8. Therefore, the attachment mechanism of the cleaning blade 9 can be simplified. Furthermore, there is no possibility that the ink spreads on the surface of the roller 3 wiped by the cleaning blade 9 due to the reverse rotation of the roller 8.

  As shown in FIG. 7, the cleaning liquid supply means 5 ′ is configured so that the cleaning liquid can be dropped onto the surface of the roller 8 from above the roller shaft of the roller 8. The cleaning liquid dropped on the surface of the roller 8 spreads on the surface of the roller 8 and has an effect of reducing the adhesive force of the ink attached to the surface of the roller 8 and increasing the removal efficiency by the cleaning blade 9. The same cleaning liquid as that in the first embodiment can be used.

  The cleaning liquid supply means 5 ′ will be described in detail with reference to FIG. FIG. 12 is a perspective view illustrating the dropping position of the cleaning liquid supply unit 5 ′. As shown in FIG. 12, the cleaning liquid supply means 5 ′ is arranged so that the cleaning liquid can be dripped in the area other than the color mixing prevention portion 81 on the surface of the roller 8 and the area where the cleaning blade 9 does not contact. ing. The cleaning liquid dropped in this area spreads in the area shown in gray in FIG. This area is a portion where ink that could not be removed by the cleaning blade 9 is likely to remain. Due to the contact of the cleaning blade 9, there is a possibility that the ink on the surface of the roller 8 spreads outside the cleaning blade contact area. If the ink spreading outside the cleaning blade contact area is accumulated over a long period of time, the accumulated ink may enter the cleaning blade contact area. Thus, the ink accumulated over a long period of time has dried and solidified on the surface of the roller 8 to the extent that it cannot be removed by the cleaning blade 9. For this reason, as the roller 8 rotates, the cleaning blade 9 rides on the solidified ink lump, resulting in a state where it cannot contact the surface of the roller 8 accurately. Accordingly, by dripping the cleaning liquid into the area shown in gray in FIG. 8 by the cleaning liquid supply means 5, the solidified ink as described above can be removed, and the cleaning blade 9 is brought into precise contact with the surface of the roller 8. Thus, the cleaning operation of the cleaning blade 9 can be normally realized.

  Also in the configuration of the present embodiment, the cleaning liquid supplied to the surface of the roller 8 adheres to the blade 1 and finally also adheres to the discharge surface of the nozzle plate 51. Therefore, the liquid material discharge device 40 ′ of the present embodiment also estimates the amount of cleaning liquid flowing into the nozzle from the contact time between the blade 1 and the discharge surface of the nozzle plate 51, as in the first embodiment. A corresponding amount can be discharged by flushing.

  The liquid material discharge apparatus of the present invention can discharge the cleaning liquid that has flowed into the nozzle of the head without wasting ink, so that the discharge is stable and the coating amount is stable. Even if the head maintenance method changes, the amount of flushing can be changed accordingly, so that stable maintenance independent of the state of the maintenance device and the head can be performed.

  Therefore, the present invention can be applied to a liquid material discharging apparatus such as a color filter manufacturing apparatus, and can be applied to all apparatuses for discharging a liquid material.

It is the figure which showed the structure of one Embodiment of the liquid material discharge apparatus which concerns on this invention. 1 shows one configuration of a main part of the liquid material discharge device shown in FIG. 1, and is a cross-sectional view taken along the line AA ′ shown in FIG. 1 showing a state in which the main part is cut. is there. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. FIG. 2 is an enlarged cross-sectional view illustrating one configuration of a main part of the liquid material discharge device illustrated in FIG. 1. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is the figure which showed the structure of other embodiment of the liquid material discharge apparatus which concerns on this invention. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG. It is sectional drawing which showed one structure of the principal part of the liquid material discharge apparatus shown in FIG.

Explanation of symbols

1 Blade (wiping member, maintenance mechanism)
2 Flip board (removal mechanism)
5.5 'Cleaning fluid supply means 5a Cleaning fluid tank 5b Pump 7 Suction device 8 Roller 9 Cleaning blades 11a and 11b (Blade) surfaces 40 and 40' Liquid material ejection devices 50a, 50b and 50c Inkjet head 51 Nozzle plate (ejection surface)
51 'Nozzle 52 Nozzle hole 53a / 53b / 53c Negative pressure box 54a / 54b / 54c Tubing pump (negative pressure generating means)
55a, 55b, 55c Supply tank 56 Tube 57 Piezoelectric material (PZT)
58 Cover plate 59 Head cover 60 Common ink chamber 61 Electrode 62 Conductive resin 63 External electrode 64 Manifold 71 Cap 72 Suction pump 81 Color mixing prevention unit 82 Roller shaft

Claims (9)

A liquid material discharge device comprising a head having a plurality of nozzles to which liquid material is supplied from a supply tank, and discharging the liquid material from the discharge surface of the head,
A maintenance mechanism for removing the liquid material adhering to the ejection surface of the head from the ejection surface by bringing a cleaning liquid having a viscosity different from that of the liquid material into contact with the ejection surface of the head;
After the cleaning liquid of the maintenance mechanism comes into contact with the discharge surface of the head, the head flushes the liquid material in an amount based on the contact time between the cleaning liquid of the maintenance mechanism and the discharge surface from each nozzle. A liquid material discharge device characterized in that the liquid material discharge device is provided. A head having a plurality of nozzles to which a liquid material is supplied from a supply tank, and a mechanism for removing the liquid material adhering to the discharge surface by wiping the discharge surface of the head with a wiping member to which the cleaning liquid is attached A liquid material discharge device,
Cleaning liquid supply means for supplying the cleaning liquid having a viscosity different from that of the liquid material,
After wiping the discharge surface using the wiping member to which the cleaning liquid is attached, an amount of the liquid material based on the contact time between the cleaning liquid attached to the wiping member and the discharge surface is flushed from each nozzle. A liquid material discharge device, characterized in that it is configured to be   3. The liquid material discharge device according to claim 2, wherein the cleaning liquid supply unit is configured to supply the cleaning liquid having a lower viscosity than the liquid material. A negative pressure generating means for generating a negative water head difference with respect to the inside of the supply tank and the inside of the nozzle;
When the water head difference is P, the flow path resistance from the supply tank to the nozzle is R, and the contact time is T,
4. The liquid material ejection device according to claim 1, wherein an amount of the liquid material to be flushed is set to be in a range of P · T / R to 10P · T / R. 5. .   5. The apparatus according to claim 1, further comprising a pattern holding unit in which a plurality of patterns of correlation data between the contact time and the amount of the liquid material to be flushed are set in advance. Liquid material discharge device.   6. The pattern holding unit is configured to acquire a plurality of patterns of correlation data between the contact time and the amount of the liquid material to be flushed using a dummy material to be discharged. The liquid material discharge device according to 1.   3. The liquid material ejection device according to claim 2, further comprising a removing mechanism for removing the liquid material adhering to the wiping member from the wiping member by physically contacting the wiping member. . The wiping member is a blade,
The liquid material discharging apparatus according to claim 7, wherein the removing mechanism is a repelling plate configured to repel the blade. The wiping member is a blade,
The removal mechanism is a roller configured such that the blade contacts the roller surface,
The liquid material discharge apparatus according to claim 7, wherein the maintenance mechanism is configured to drop the cleaning liquid onto the roller surface.