JP2008073997A - Ink jet printing device and color filter printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and space-saving inkjet printing device having an ink supply tank, an inkjet head and an ink supply tube connecting them and capable of keeping a stable meniscus of the nozzle without fluctuation in pressure in the head due to vibration of the inkjet head and free from troubles such as failure of discharge and a miss of a landing position, and to manufacture printed matter with high quality using a color filter printing device making the stable meniscus. <P>SOLUTION: The ink supply tube is constituted by connecting tubes of at least two kinds of materials, is constituted of tubes with at least two kinds of different wall thickness, or a highly extendable tube is arranged in one kind of ink supply tubes, and the highly extendable tube or the tube with the different wall thickness is directly connected with the inkjet head in the inkjet printing device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet printing apparatus, and more specifically to an ink jet printing apparatus used for forming a colored layer of a color filter, an organic electroluminescence element, and the like, and a color filter printing apparatus using the same.

  In recent years, when obtaining patterns such as organic electroluminescence elements and color filters, ink jet printing apparatuses excellent in fine pattern printing have been used. In such an industrial ink jet printing apparatus, an ink jet head having a piezoelectric element is provided inside one or a plurality of ink passages connected to an ink supply tank, and ink is ejected from the nozzles of the ink jet head for printing. There is a printing device to do.

  In this type of ink jet head, it is necessary to keep the meniscus of the nozzle in a stable state in order to obtain a stable ink discharge property. In the ink jet head, the ink is deformed so as to increase the volume in the nozzle, and then the volume in the nozzle is contracted again to rapidly pressurize the ink in the nozzle and eject the ink from the nozzle. In this case, it is necessary that the ink liquid level in each nozzle is stable at the same position, that is, the ink liquid level (meniscus) is in a stable state.

  It is important to keep the meniscus of the nozzle of the inkjet head in a stable state, and various methods are employed. As a typical method, as described in Patent Document 1, a fluorine-containing polyimide film is formed on the surface and irradiated with laser light. Although a method of forming a stable meniscus by processing the shape to prevent entrainment of air etc. is considered, there is a problem that air can not be stably ejected due to vibration of the device etc., and stable meniscus is maintained Not enough to do.

  FIG. 3 is a side sectional view for explaining an example of an ink supply device of a conventional ink jet printing apparatus. This will be described below.

  The ink 2 used in the ink jet printing apparatus is stored in the ink supply tank 1, and is sent to the sub tank 3 of the atmosphere release unit 4 through the tube 5 that leads from the ink supply tank to the sub tank. Thereafter, the ink 2 is sent to the inkjet head 8 through the tube 6 that leads from the sub tank to the inkjet head. Ink is supplied in a state where the liquid level height in the sub tank and the water head difference 7 between the ink jet heads are ensured and the ink surface of each ink discharge port becomes a meniscus surface.

  The tubes 5 and 6 in the ink supply path are generally made of fluororesin tubes such as PFA tubes and PTFE tubes that have excellent heat resistance, chemical resistance, non-adhesiveness, low friction and the like, and are less likely to generate foreign matter. is there. However, the fluororesin tube has an elongation of 180 to 250% in the test method according to ASTM D412 and is not stretchable, or the tube material is hard. As the pressure in the head fluctuates and the meniscus of the nozzle fluidizes, it is impossible to maintain a stable meniscus, and there are problems such as non-ejection for each nozzle and deviation of the landing position. There are problems that arise.

Thus, an ink jet printing apparatus using a pump has been proposed. FIG. 4 is a side sectional view for explaining an example of an ink supply device of an ink jet printing apparatus using a conventional diaphragm pump. This will be described with reference to FIG.

  The ink 11 used in the ink jet printing apparatus is stored in the ink supply tank 10 and passes through the suction side tube 12 to the diaphragm pump 13. The diaphragm pump 13 is a suction side tube 12 for forcibly sucking ink, and the ink jet head 16 side is a sending side tube 15 for forcibly sending ink. In addition, a servo motor 14 for driving the diaphragm pump is connected to the ink delivery means, and the diaphragm pump for accurately ejecting ink is driven and controlled by the operation of the servo motor. After passing through the tube 15, it is sent directly to the inkjet head 16.

  The pressure sensor 18 is provided between the inkjet head 16 and the delivery side of the diaphragm pump 13 and constantly detects the ink pressure. Then, via the data path 19 from the pressure gauge to the servo motor in the figure, the ink pressure detected by the sensor of this pressure gauge is used as data to be sent to the servo motor.

  Even when such a pump is used, the tube paths 12 and 15 connecting the ink supply tank 10 and the inkjet head 16 are excellent in heat resistance, chemical resistance, non-adhesiveness, low friction, and the like, and foreign matter is generated. Generally, a fluororesin tube such as a small PFA tube or PTFE tube is used. However, even when such a pump is used, a stable meniscus can be maintained because the pressure in the ink jet head fluctuates due to vibration of the ink jet head on the apparatus and the meniscus of the nozzle flows. However, there may be a problem that non-ejection occurs or the landing position shifts.

  The ink supply device in the conventional ink jet printing apparatus uses a hard tube for the sending side tubes 6 and 15 for sending out the inks 1 and 11 to the ink jet heads 8 and 16, and therefore the vibration of the ink jet head affects the ink jet head. The internal pressure fluctuates and the meniscus of the nozzle flows, so it is not possible to maintain a stable meniscus, causing problems such as non-ejection or shifting of the landing position for each nozzle. (See FIGS. 3 and 4).

The known literature is described below.
JP 2002-1963 A JP 2002-160371 A

  The present invention has been created in view of the above circumstances, and the object is to provide a stable meniscus of a nozzle that is simple and space-saving, and in which the pressure in the head does not fluctuate due to vibration of the inkjet head or the like. High quality printed matter using a color filter printing apparatus that can maintain an ink jet printing apparatus that does not have problems such as non-ejection or landing position shift and that stabilizes the meniscus of the ink jet head Is to manufacture.

The invention according to claim 1 of the present invention is an ink jet printing apparatus having an ink supply tank, an ink jet head, and an ink supply tube connecting the two, wherein the ink supply tube includes at least two types. The inkjet printing apparatus is characterized by being connected to a tube made of a material.

  The invention according to claim 2 of the present invention is the ink jet printing apparatus according to claim 1, wherein a tube having high stretchability is provided in one kind of the tube for supplying ink.

  The invention according to claim 3 of the present invention is the ink jet printing apparatus according to claim 1 or 2, wherein the highly stretchable tube is provided directly connected to the ink jet head.

  The invention according to claim 4 of the present invention is an ink jet printing apparatus having an ink supply tank, an ink jet head, and an ink supply tube connecting the two, wherein the ink supply tube includes at least two types. An ink jet printing apparatus comprising tubes having different wall thicknesses.

  The invention according to claim 5 of the present invention is the ink jet printing according to claim 4, wherein the tube having the smaller wall thickness among the tubes having different wall thicknesses is directly connected to the ink jet head. Device.

  The invention according to claim 6 of the present invention is a color filter printing apparatus having a structure in which a stage and a plurality of inkjet printing apparatuses are arranged, and printing each of a plurality of colors at the same time. The inkjet head printing apparatus according to any one of Items 1 to 5 is arranged side by side, and each color ink is ejected while moving to a predetermined position on the substrate placed on the stage, and each color pattern is changed. The color filter printing apparatus is characterized by printing simultaneously.

  According to the present invention, the ink supply tube connecting the ink supply tank and the inkjet head is provided by connecting two or more types of tubes including at least a stretchable tube or a tube having a different wall thickness, The effect of the vibration of the inkjet head can be prevented, the pressure inside the inkjet head can be stabilized, the meniscus of the inkjet head can be stabilized, non-ejection occurs for each nozzle, and the landing position is shifted. Is prevented, and high-quality printed matter can be obtained.

  An ink jet printing apparatus and a color filter printing apparatus of the present invention will be described below based on an embodiment.

  FIG. 1 is a side sectional view for explaining an embodiment of an ink supply device of an ink jet printing apparatus of the present invention. This will be described below.

  The ink 2 used in the ink jet printing apparatus is stored in the ink supply tank 1, and is sent to the sub tank 3 of the atmosphere release unit 4 through the tube 5 that leads from the ink supply tank to the sub tank. After that, the ink 2 passes through the tube 6 leading from the sub tank to the ink jet head, and the tube 9 connected to the tube 6 from the sub tank to the ink jet head and having a different wall thickness, or the tube 17 having high stretchability. Then, it is sent to the inkjet head 8. By ensuring the liquid level height in the sub tank 3 and the water head difference 7 between the ink jet head 8 and supplying the ink in a state where the ink surface of each ink discharge port becomes a meniscus surface, The ink surface at the ink discharge port can be in a meniscus stable state, and the ink can be a droplet having an appropriate flow rate.

  As the tubes 5, 6, 9, and 17 of the ink supply path, fluororesin tubes such as PFA tubes and PTFE tubes that have excellent heat resistance, chemical resistance, non-adhesiveness, low friction, and the like, and are less likely to generate foreign matters are used. Is common. In response to the fluctuation of the pressure in the ink jet head due to the vibration of the ink jet head on the apparatus and the prevention of the meniscus flow of the nozzle, only the elasticity between the ink jet head 8 and the sub tank 3 as in the present invention is slightly The high-strength tube 17 or the tube 9 having a different thickness can absorb the pressure fluctuation even if the pressure in the head fluctuates. The meniscus of the nozzle becomes difficult to flow, a stable meniscus can be maintained, and high-quality printing can be performed.

  The highly stretchable tube 17 or the tube 9 having a different thickness can be connected from the sub tank 3 to any location in the ink supply path of the inkjet head 8, but the closer to the inkjet head 8 absorbs pressure fluctuations of the inkjet head. Because it can, it is more effective.

  Examples of the highly stretchable tube 17 include a rubber tube and a silicone tube, and it is sufficient if the degree of elongation is 300 to 700%. However, considering the effects of handling and foreign matter or tube breakage, the tube is stretched with a silicone tube. A degree of 300 to 450% is desirable. Further, the highly stretchable tube 17 includes tubes 9 having different thicknesses.

  The tube 9 having a different thickness can be substituted by changing the thickness of the tube without changing the material of the highly stretchable tube 17. The tube 9 having a different wall thickness may be thinned so that a part of the tube 6 in the supply path from the sub tank 3 to the inkjet head 8 has an elongation of 300 to 700%. In view of handling, a content of 300 to 450% is desirable.

  In this discharge method using the water head difference, the liquid surface that is in contact with the air dries and adheres as a solid matter to the inner peripheral surface of the tank and accumulates easily. There are problems such as causing ejection defects such as clogging.

  Therefore, an ink jet apparatus using a pump has been proposed. FIG. 2 is a side sectional view for explaining an ink supply apparatus using the diaphragm pump of the present invention. An embodiment will be described with reference to FIG.

  The ink 11 used in the ink jet printing apparatus is stored in the ink supply tank 10 and passes through the suction side tube 12 to the supply source side of the diaphragm pump 13. In the diaphragm pump 13, the ink supply source side is a suction side tube 12 that forcibly sucks ink, and the ink jet head 16 side is a sending side tube 15 that forcibly sends ink. Further, a servo motor 14 for driving the diaphragm pump is connected to the ink delivery means, and the diaphragm pump for accurately ejecting ink is driven and controlled by the operation of the servo motor. After passing through the tube 15, it is sent to the inkjet head 16 via a different type of elastic tube 17.

  The sensor of the pressure gauge 18 is provided between the inkjet head 16 and the delivery side of the diaphragm pump 13 and constantly detects the ink pressure. Then, via a data path 19 from the pressure gauge to the servo motor in the figure, the ink pressure detected by the pressure sensor is connected as data to be sent to the servo motor.

  Even when such a pump is used, the paths 11, 15, and 17 connecting the ink supply tank 10 and the inkjet head 16 are excellent in heat resistance, chemical resistance, non-adhesiveness, low friction, and the like, and foreign matter is generated. Generally, a fluororesin tube such as a small PFA tube or PTFE tube is used. However, even when such a pump is used, in order to prevent the flow of the meniscus of the nozzle due to fluctuations in the pressure of the head due to the vibration of the ink jet head on the apparatus or the like, the highly elastic tube 17 is therefore provided. Is interposed between the pump 13 and the ink jet head 16 so that even if the pressure in the ink jet head fluctuates, the tube 17 having high elasticity can absorb the pressure fluctuation, and the meniscus of the nozzle becomes difficult to flow. A stable meniscus can be maintained, and high-quality printing can be performed.

  The color filter printing apparatus of the present invention has a structure in which the inkjet head printing apparatus of the present invention is arranged for each color ink. For example, an ink supply apparatus for R color ink, G color ink, and B color ink is disposed. This is the structure. The ink supply device of the color filter printing device is characterized in that each color ink is ejected from each nozzle while moving to a predetermined position on the substrate placed on the stage, and each color pattern is printed at the same time. In the color filter printing apparatus of the present invention, the pressure in the head fluctuates by interposing a tube having a slightly high elasticity or a tube having a different thickness only between the ink jet head of the ink supply device and the sub tank. The pressure fluctuation can be absorbed by the highly elastic tube 17 or the tube 9 of different wall thickness, the meniscus of the nozzle becomes difficult to flow, a stable meniscus can be maintained, and high quality multicolor Printing can be performed simultaneously.

  Here, an embodiment of the present invention in a method for producing a color filter using a diaphragm pump will be described below.

  In Example 1, a partition pattern (hereinafter referred to as a black matrix in a color filter) was first formed on a substrate. The black matrix was produced using a photolithography method. Non-alkali glass was used as the substrate. On the substrate, a photosensitive resin composition containing a fluororesin was applied over the entire surface in a thin film having a thickness of 2 μm. Then, it exposed using the photomask which has a grid | lattice-like pattern, developed after that with an alkali, and the black matrix was produced on the single side | surface of the glass substrate by putting this board | substrate into oven and performing a thermosetting process.

  Next, as a discharge ink for a color filter, the pigment is prepared for each color so that the proportion of the total solid content of the ink is 50% by mass and the required spectral characteristics are obtained, and the solvent is the total solid content of the ink. The concentration was adjusted to 30% by mass.

  Next, in the ink jet printing apparatus, the ink to be used is stored in a supply tank, and the supply tank passes through a tube and is connected to the supply source side of the diaphragm pump. As the tube, a PFA tube manufactured by NICHIAS Corporation was used. In the diaphragm pump, the ink supply source side is a suction side for forcibly sucking ink, and the ink jet head side is a delivery side for forcibly sending ink. Further, a servo motor for driving the diaphragm pump is connected to the ink delivery means, and the diaphragm pump for accurately ejecting ink is controlled by the operation of the servo motor, and the ink is a PFA manufactured by NICHIAS. After passing through the tube, it is sent to the inkjet head via a highly elastic Saint-Gobain Co., Ltd. Tygon R-3603 tube (see FIG. 2).

The pressure sensor of the ink jet printing apparatus is provided between the ink jet head and the delivery side of the diaphragm pump, and always detects the ink pressure. The pressure sensor is connected so that the detected ink pressure is sent as data to a servo motor in the ink delivery means.

  Next, a color filter was manufactured using the inkjet printing apparatus. When a print start signal is output, the inkjet head moves onto the black matrix provided with glass. Next, the diaphragm pump was driven based on the ejection data, and the ink was sent from the inkjet head, whereby a high-quality color filter could be obtained.

  The comparative example of this invention was implemented. Example 2 of the comparative example will be described below.

  In Example 2, since the ink jet printing apparatus composed of only the conventional low-stretch PFA tube was used from the ink supply tank to the ink jet head, the ink jet head moved onto the black matrix attached to the glass. Since the meniscus surface of the ink jet head flows due to the vibration of the PFA tube and non-ejection occurs, a color filter in which the non-ejection portion is missing is formed (see FIG. 4).

It is a sectional side view explaining the inkjet head printing apparatus using the water head difference of this invention. It is a sectional side view explaining the inkjet head printing apparatus using the pump of this invention. It is a sectional side view explaining the inkjet head printing apparatus using the conventional water head difference. It is a sectional side view explaining the inkjet head printing apparatus using the conventional pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ink supply tank 2 ... Ink 3 ... Sub tank 4 ... The atmosphere release part 5 of a sub tank ... The tube 6 leading from an ink supply tank to a sub tank ... The tube 7 leading from a sub tank to an inkjet head ... The water head difference 8 of an inkjet head and a sub tank ... Inkjet head 9... Tube having a different thickness from the tube leading from the sub tank to the inkjet head... Ink supply tank 11... Ink 12. 17 ... Highly elastic tube 18 ... Pressure gauge 19 ... Data path from pressure gauge to servo motor

Claims (6)

In an inkjet printing apparatus having an ink supply tank, an inkjet head, and an ink supply tube connecting the two,
An ink jet printing apparatus, wherein the ink supply tube is provided by connecting tubes of at least two kinds of materials.   2. The ink jet printing apparatus according to claim 1, wherein a tube having high stretchability is provided in one kind of the tube for supplying ink.   The inkjet printing apparatus according to claim 1, wherein the highly stretchable tube is provided directly connected to an inkjet head. In an inkjet printing apparatus having an ink supply tank, an inkjet head, and an ink supply tube connecting the two,
An ink jet printing apparatus, wherein the ink supply tube is composed of at least two types of tubes having different wall thicknesses.   5. The inkjet printing apparatus according to claim 4, wherein, among the tubes having different thicknesses, the tube having the smaller thickness is directly connected to the inkjet head. A color filter printing apparatus that prints a plurality of colors at the same time in a structure in which a stage and a plurality of inkjet printing apparatuses are arranged,
A structure in which the inkjet head printing device according to any one of claims 1 to 5 is arranged for each color ink, and each color ink is moved to a predetermined position on a substrate placed on a stage. A color filter printing apparatus characterized by discharging and printing each color pattern simultaneously.

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