JP2006248083A - Liquid filling method, liquid filling device, and inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inject a liquid without the mixture of air bubbles into the liquid by preventing the generation of excessive pressure stress, when a head with a tank or a cartridge is filled with the liquid. <P>SOLUTION: The head with the tank is placed in a chamber in such a manner that a nozzle surface is directed downward (S1). The inside of the chamber is brought under vacuum (S2), and after the checking of the degree of vacuum, a cap part is brought into close contact with the nozzle surface (S3). An ink storage part under vacuum is brought under atmospheric pressure (S4), and after the checking of it, a three-way valve is switched to the state of communication between the ink storage part and the cap part (S5). The ink is infilled by making an entry via the cap part and the nozzle surface by differential pressure between the chamber and the ink storage part (S6). The predetermined quantity of the infilled ink is detected (S7: Yes), and the three-way valve is brought into a pressure-equilibrium state by establishing communication via an air bypass between the chamber and the cap part, so that ink filling can be stopped (S8). The cap part abutting on the nozzle surface descends (S9), and a stop valve is opened so that the ink flowing into the air bypass can be discharged into an ink pan (S10). The head with the tank is taken out (S11). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filling method and apparatus for filling a work with liquid, and is not limited to high-viscosity ink filled in a tank head or cartridge of a consumer inkjet printer, but also an industrial discharge device such as an organic EL ( Liquid filling method and liquid filling apparatus for filling a liquid material discharge head used for forming a light emitting layer and a hole injection layer in an electro-luminescence device, a metal wiring of various devices of a color filter in a liquid crystal device, and a microlens And the inkjet head.

  In general, when ink is filled in the head of an ink jet printer, if bubbles are mixed, the pressure of the bubbles due to heat generated as ink discharge energy or the pressure of the driving body for pushing out the ink is not transmitted to the nozzles well. The problem that ink is not ejected from the nozzles easily occurs. In particular, in the initial filling of a new head, the wettability with respect to the ink inside the head is low and the filling is difficult. Therefore, various methods have been taken for the purpose of filling the ink into every corner of the head without mixing bubbles.

  For example, a method of filling ink into the head by injecting ink into the head and sucking ink from the nozzle side is generally used. This most common method of sucking and discharging the ink filled in the head from the nozzle side to the outside of the head greatly increases the cost due to the waste of discharged ink. In particular, from the viewpoint of printing durability, the mainstream of ink is changing from dye-based to pigment-based, and in the case of pigment-based high-viscosity ink, bubbles in the ink are difficult to flow and the ink itself is also difficult to move. Therefore, it is necessary to discharge a large amount of ink by suction, which also increases the cost due to waste of ink.

  As another ink filling method, for example, in Patent Document 1, a liquid ejection apparatus and a liquid filling method thereof, and a device manufacturing apparatus and a device manufacturing method and a device using a drawing liquid having a high viscosity, In order to maintain predetermined liquid discharge characteristics, it is described that filling without bubbles is completed by switching and filling the liquid discharge head with the first liquid and the second liquid having different viscosities.

  Further, in Patent Document 2, as an ink filling method and an ink injection device, the air mixed in the head and the cartridge causes problems such as print blurring and non-ejection, but the ink cartridge is evacuated and then the ink is discharged. The problem is solved by filling. As the filling method, the drawing tank connected to the ink cartridge has a step of making the vacuum state, and the step of sucking the ink of the ink cartridge into the tank in the vacuum state is quantitatively sucked to ensure the ink filling. It is described to do.

Japanese Patent Application Laid-Open No. 2004-228688 discloses a method for filling an ink jet head with ink stored in an ink cartridge or a head tank as a liquid filling method for an ink jet recording apparatus and an ink jet head, and a liquid filling method for a microarray manufacturing apparatus and its discharge head. It is described that the suction cap is brought into close contact with the nozzle opening surface of the inkjet head through a gas permeable filter, and the air is filled to the nozzle tip by sucking only the air in the suction cap. Yes.
JP 2003-344463 A JP 2002-166565 A JP 2004-66506 A

  However, in Patent Document 1 of the prior art, in order to improve the filling efficiency, an attempt is made to secure liquid discharge characteristics by using an ink having a low viscosity at the beginning and an ink having a high viscosity after being in contact with the inside. Two types of ink must be prepared, and since it is assumed to be discharged, it leads to an increase in cost, and the initial filling ink has a difference in viscosity, and therefore it is necessary to discharge all.

  In addition, filling the head or cartridge in a vacuum as described in Patent Document 2 generally maintains the internal space at atmospheric pressure when the head tank is provided integrally with the head. In order to smoothly supply ink from the ink containing portion to the print head through the ink supply hole, an air communication hole is provided separately from the ink supply hole. However, such a head tank increases the capacity. It is preferable and the head tank must be reduced in weight because it scans on the printing paper together with the head. However, if ink filling is performed using the vacuum in an atmospheric atmosphere, it is crushed to atmospheric pressure and deformed. For this reason, it is unavoidable to use a structure with high strength. This increases the weight of the carriage itself that moves the head, necessitates a large motor for driving the carriage, and there is a problem in that the printer itself is increased in size and cost, such as vibration suppression.

  The present invention is directed to solving the above-described problems of the prior art, and is not limited to consumer inkjet printers, but may include ink or the like for a tank-equipped head or cartridge used for a liquid material discharge head of an industrial discharge device. Liquid filling that fills all corners of the interior without introducing air bubbles into the interior of the tank, even when initially filling a new tank head or cartridge, without causing excessive pressure stress It is an object to provide a method, a filling device and an inkjet head.

  In order to achieve the above object, a liquid filling method according to claim 1 according to the present invention is a liquid filling method for filling a liquid into a work without immersing the whole work, and a liquid inlet A first step of placing the workpiece in an airtight structure chamber with the lower side being a lower side, a second step of reducing the pressure in the chamber close to a vacuum, a third step of closely attaching the cap portion to the inlet, and a cap A fourth step of filling the work with a fixed amount of liquid from the supply tank via a pipe connected to the section, a fifth step of stopping the filling of the liquid with the pressure inside and outside the work in an equilibrium state, and the inside of the chamber By the method consisting of the sixth step of discharging the liquid remaining inside the pipe by pressurization, the pressure equilibrium state is not used regardless of the structure of the workpiece, and without excessively applying a pressure load to the workpiece itself. Promptly The free liquid bubbles throughout the interior can be accurately filled.

  Further, in the liquid filling method described in claims 2 to 5, in the fourth step of the liquid filling method of claim 1, the flow rate is controlled by means for adjusting the flow rate of the liquid filled in the workpiece, The means for adjusting the flow rate controls the flow rate of the liquid filled in the work by adjusting the inflow conductance of the pipe, and the means for adjusting the flow rate adjusts the pressure of the liquid supply tank into the work. Controlling the flow rate of the liquid to be filled and the means for adjusting the flow rate prevent the overfilling of the filling amount by controlling the flow rate of the liquid to be filled in the work by the valve opening / closing time of the pipe connected to the cap part Can be filled with high accuracy, and the filling process can be shortened.

  Further, in the fifth step of the liquid filling method according to the first aspect, the liquid filling method described in claims 6 to 8 is based on the result of the means for detecting the inflow amount of the liquid filling the workpiece. Further, the means for detecting the amount of inflow of liquid detects the amount of filling in the work by energizing with the liquid filled in the electrode provided in the work, and also detects the amount of inflow of liquid. The means can accurately fill the liquid by detecting the filling amount in the workpiece using a reflection-type or transmission-type optical sensor.

  Further, in the liquid filling method according to claims 9 and 10, in the fifth step of the liquid filling method of claim 1, an air pipe provided between the cap portion and the chamber is connected to balance the pressure inside and outside the workpiece. In addition, the air piping provided between the cap part and the chamber can be stopped suddenly by adjusting the inflow conductance of the piping to control the pressure inside and outside the workpiece to be in an equilibrium state. Equilibrium can be achieved without causing fluctuations.

  In addition, in the liquid filling method according to claims 11 and 12, the work in the liquid filling method according to claims 1 to 10 is at least one of an injection hole and an air communication hole as an opening communicating with the liquid discharge hole and the inside and outside. And using the liquid discharge hole as the injection port, and further, the work is a tank-equipped head or cartridge used in an inkjet printer for discharging and printing ink or an apparatus for discharging an industrial liquid material. Even if it is a flexible workpiece or a highly viscous liquid such as ink or liquid material, it does not contain air bubbles in every corner of the workpiece without excessively applying a pressure load to the workpiece itself. It can be filled with liquid.

  The liquid filling apparatus according to any one of claims 13 to 15, which is a liquid filling apparatus for filling a work with a liquid, a chamber for maintaining confidentiality during pressurization and decompression with respect to atmospheric pressure, and a work in the chamber. The holder part that is placed with the liquid inlet side down, the cap part that moves up and down in order to fill the work with liquid while contacting the inlet and maintaining confidentiality, and the inflow amount of liquid that fills the work A detection means for detecting, an air pipe that balances the pressure inside and outside the work, and a liquid supply tank in an airtight structure, and an injection hole serving as an opening through which the work communicates with the liquid discharge hole and the inside and outside , Having at least one air communication hole and using the liquid discharge hole as an injection port, and also for an ink jet printer that discharges and prints ink or an apparatus that discharges industrial liquid material. The tank-equipped head or cartridge is configured to quickly contain air bubbles in every corner of the workpiece without using pressure balance on the workpiece itself or excessively applying pressure load to the workpiece itself. It is possible to accurately fill with no liquid.

  In addition, an ink jet head described in claims 16 and 17 includes a tank-equipped head or a cartridge filled with ink without air bubbles mixed by the liquid filling method according to any one of claims 1 to 12, Also, the head with tank is a side shooter type head that supplies ink from the side surface, and can stably discharge ink and obtain an ink jet head in which ink is in contact with every corner of a fine ink flow path. Can do.

  According to the present invention, the tank-equipped head or cartridge is a flexible work, and even if it is a highly viscous liquid such as ink or liquid material, the pressure equilibrium state is used regardless of the structure of the work. Without excessive pressure load on the workpiece itself, even in the initial filling into a new workpiece immediately after manufacturing, it is possible to quickly fill liquids without bubbles to every corner of the workpiece without waste. Ink-jet heads that are filled with ink that is free of air bubbles and that can discharge ink stably and have ink in contact with every corner of the fine ink flow path can be obtained. There is an effect that the processing speed can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a liquid filling apparatus that fills ink in a tank-equipped head or cartridge of an ink jet printer according to an embodiment of the present invention.

  As shown in FIG. 1, the inside of the chamber 9 having an airtight structure includes a holder portion 9a that is detachably mounted with the nozzle surface 7a of the tank-equipped head 7 serving as a work on the lower side. The cap portion 8 is sealed by a bellows or an O-ring so as to be able to come into contact with the nozzle surface 7a of the tank-equipped head 7, so that the cap portion 8 can be moved up and down while maintaining a vacuum in the chamber 9. It has become.

  Further, there is an air communication hole 7b in the upper part of the tank head 7 so that the inside and outside of the tank head 7 communicate with each other, and in addition, there is an injection hole for replenishing ink later. It does not have to be in the form of a bag having only one opening.

  The vacuum valve 1 connected to the vacuum pump 6 is opened when the chamber 9 is evacuated. Furthermore, the vacuum pump 6 is connected via the vacuum valve 3 so that the inside of the ink storage unit 12 having an airtight structure can also be evacuated.

  Further, the three-way valve 2 is configured to switch between the supply bypass 17 that communicates between the ink storage section 12 and the cap section 8 to flow and transport the ink, and the air bypass 10 that communicates between the chamber 9 and the cap section 8. Yes. An ink pan 13 is arranged in the middle of the air bypass 10 that communicates between the chamber 9 and the cap portion 8, and the communication can be cut off by the stop valve 4.

  An open valve 5 used for vacuum break is connected to the chamber 9, and at the time of vacuum break, dry or clean nitrogen or air is introduced into the chamber 9 through the regulator 11 by the open valve 5, or the vacuum break or internal Pressurization can be performed.

  Similarly, the ink storage unit 12 is provided with an opening valve 14, and dry and clean nitrogen or air can be introduced into the ink storage unit 12 through the regulator 16, and vacuum breakage or internal pressurization can be performed. It can be done.

  Next, the operation of filling the ink with the ink in the ink storage section into the tank-equipped head will be described with reference to FIG. 1 based on the flowchart shown in FIG.

  The ink stored in the ink storage unit 12 is maintained at a predetermined weak vacuum level by feedback from a pressure gauge (not shown) while being agitated by, for example, a stirrer, and the air bubbles of the ink stored inside are always degassed. Waiting in a state where In this case, the degree of vacuum is preferably slightly higher than the saturated vapor pressure of water at room temperature in order to avoid excessive water evaporation.

  In this state, the liquid filling device is closed with the vacuum valve 1, the stop valve 4, and the open valves 5 and 14, and the three-way valve 2 is in communication with the air bypass 10 between the chamber 9 and the cap portion 8. 3 is open, the ink storage unit 12 is in a vacuum state, and the cap unit 8 is lowered and is not in a contact position with the nozzle surface 7a of the head 7 with tank.

  First, the tank-equipped head 7 is placed in the chamber 9 with the nozzle surface 7a facing downward (S1). After the tank-attached head 7 is placed, the chamber 9 is sealed in an airtight state by, for example, a door sealed with an O-ring or the like, and the vacuum valve 1 is opened and the inside of the chamber 9 is evacuated by the vacuum pump 6 ( S2).

  After confirming that the inside of the chamber 9 has reached a predetermined degree of vacuum with a vacuum gauge or the like, the vacuum valve 1 is closed, and then the cap portion 8 is raised to move the nozzle surface 7a below the head 7 with tank. (S3).

  At this time, the material of the contact portion of the cap portion 8 is preferably made of rubber or the like as a material having a high degree of adhesion in order to increase the degree of sealing. The confirmation of the degree of vacuum and the raising of the cap unit 8 may be automated by a program sequencer or the like using a motor or an air cylinder using a contact of a vacuum gauge.

  Next, after the vacuum valve 3 is closed, the release valve 14 is opened, clean and dry nitrogen or air is introduced, and the inside of the ink storage unit 12 which is in a vacuum state for deaeration is set to a substantially atmospheric pressure. (S4). After the atmospheric pressure is confirmed by a pressure gauge (not shown) provided in the ink storage unit 12, the three-way valve 2 is switched to the supply bypass 17 that communicates between the ink storage unit 12 and the cap unit 8 (S5).

  Then, due to the pressure difference between the vacuum pressure in the chamber 9 and the atmospheric pressure in the ink storage unit 12, the ink in the ink storage unit 12 enters through the cap unit 8 from the nozzle surface 7 a of the ink injection port of the tank-equipped head 7. The ink is filled into the attached head 7 (S6).

  At this time, since the pressure difference between the vacuum pressure in the chamber 9 and the atmospheric pressure in the ink storage unit 12 suddenly pushes up the ink, the ink may be rapidly filled. In order to prevent this, for example, the flow rate of the ink is adjusted by providing a flow rate adjusting valve 15a in the supply bypass 17 so that the inflow conductance of the ink can be adjusted, or by providing an orifice. Alternatively, it is desirable to prevent the ink from suddenly entering the tank-equipped head 7 against the impact of the differential pressure by adjusting the pressure in the ink storage unit 12 to be low by opening the vacuum valve 3 or the like. .

  Further, it is better that these methods are provided with a programmable mechanism that can be gradually changed along with the ink entry or the elapsed time. Specifically, it is desirable that the inflow conductance or the differential pressure in the chamber 9 and the ink storage unit 12 can be changed as the ink enters.

  Eventually, a predetermined amount of ink will be filled into the tank-equipped head 7. In order to make the amount constant, a method for detecting the amount of ink to be filled or a switching time for switching the three-way valve 2 is set constant. The amount of ink to be filled is adjusted (S7).

  In the case of detecting the amount of ink, as the detection method, the ink filling amount is detected by energization of an electrode provided in the tank head 7 in advance, or when the tank head is made of a transparent material, the reflection type is used. Or you may detect non-contact using a transmission type optical sensor.

  When it is confirmed that the predetermined amount of ink filling has been detected by the above method (Yes in S7), the three-way valve 2 is switched to the communication of the air bypass 10 between the chamber 9 and the cap portion 8. As a result, there is no difference between the pressure in the cap portion 8 and the pressure in the chamber 9, and the ink filling is stopped (S8).

  At that time, since a flow is generated from the cap portion 8 side, which was atmospheric pressure, to the chamber 9 side, the ink flows into the air bypass 10. In order to reduce the degree of inflow of ink due to this sudden pressure change, it is desirable to provide a flow rate adjusting valve 15b in the path of the air bypass 10.

  Further, in the ink storage unit 12, the release valve 14 is closed again to return to the state where the bubbles of the stored ink are deaerated, and waiting until the next head with tank 7 is placed in the chamber 9. To do.

  Then, after waiting for about 5 seconds, the ink state has settled, and the cap portion 8 that has been in contact with the nozzle surface 7a of the tank-equipped head 7 is lowered (S9). It would be better if these were also automated.

  Next, the open valve 5 is opened, dry and clean nitrogen or air is introduced into the chamber 9, and after confirming that the pressure has become substantially atmospheric by a vacuum gauge or the like, the stop valve 4 is opened and the air bypass 10 is turned on earlier. The ink that has flowed in and stored is discharged into the ink pan 13 (S10).

  The remaining ink in the air bypass 10 is sufficiently discharged. For example, after discharging for a certain period of time, the release valve 5 is closed, the introduction of the purge air from the regulator 11 is stopped, and the stop valve 4 is also closed after a while. .

  Since the inside of the chamber 9 has already returned to atmospheric pressure, the tank-equipped head 7 is taken out of the chamber 9 and the filling is completed (S11). By repeating this, ink can be filled without bubbles one after another.

  From the above, by placing in a chamber and making it in a vacuum state, ink can be filled without causing a pressure difference between the inside and outside of the tank-equipped head. An ink jet head using a head with a tank is obtained.

  The liquid filling method, the liquid filling apparatus, and the ink jet head according to the present invention use a pressure equilibrium state even if the head with a tank or the cartridge is a flexible work, and even a highly viscous liquid such as an ink or a liquid material. As a result, it is possible to quickly fill liquids that do not contain bubbles to every corner of the workpiece without waste, regardless of the structure of the workpiece and without excessively applying pressure to the workpiece itself. Inkjet heads filled with unfilled ink and capable of stable ink discharge, and ink in contact with every corner of the fine ink flow path, are obtained, and the liquid material discharge heads of consumer inkjet printers and industrial discharge devices are obtained. Useful for filling liquid in tanked heads or cartridges.

The figure which shows schematic structure of the liquid filling apparatus which fills the ink in the head with a tank in embodiment of this invention. Flowchart showing the operation of filling the tank-equipped head in the present embodiment with ink.

Explanation of symbols

1, 3 Vacuum valve 2 Three-way valve 4 Stop valve 5, 14 Open valve 6 Vacuum pump 7 Head 7 a with tank Nozzle surface 7 b Air communication hole 8 Cap portion 9 Chamber 9 a Holder portion 10 Air bypass 11, 16 Regulator 12 Ink storage portion 13 Ink pan 15a, 15b Flow rate adjusting valve 17 Supply bypass

Claims (17)

A liquid filling method for filling a liquid in the work without immersing the whole work,
A first step of placing the workpiece in a chamber having an airtight structure with a liquid injection port on the lower side; a second step of reducing the pressure in the chamber to be close to a vacuum; and a cap portion in close contact with the injection port A third step, a fourth step of filling the work with a certain amount of liquid from a supply tank via a pipe connected to the cap, and filling the liquid with the pressure inside and outside the work in an equilibrium state. A liquid filling method comprising a fifth step of stopping and a sixth step of pressurizing the chamber and discharging the liquid remaining in the pipe.   2. The liquid filling method according to claim 1, wherein in the fourth step, the flow rate is controlled by means for adjusting the flow rate of the liquid filled in the workpiece.   3. The liquid filling method according to claim 2, wherein the means for adjusting the flow rate controls the flow rate of the liquid filled in the work by adjusting the inflow conductance of the pipe.   3. The liquid filling method according to claim 2, wherein the means for adjusting the flow rate controls the flow rate of the liquid filled in the work by adjusting the pressure of the liquid supply tank.   3. The liquid filling method according to claim 2, wherein the means for adjusting the flow rate controls the flow rate of the liquid filled in the work according to a valve opening / closing time of a pipe connected to the cap portion.   The liquid filling method according to claim 1, wherein in the fifth step, the filling of the liquid is stopped based on a result of the means for detecting an inflow amount of the liquid filled in the workpiece.   7. The liquid filling method according to claim 6, wherein the means for detecting the inflow amount of the liquid detects the filling amount in the work by energizing with the liquid filled in the electrode provided in the work.   7. The liquid filling method according to claim 6, wherein the means for detecting the inflow amount of the liquid detects a filling amount in the work using a reflection type or transmission type optical sensor.   The liquid filling method according to claim 1, wherein in the fifth step, an air pipe provided between the cap portion and the chamber is connected to bring the pressure inside and outside the workpiece into an equilibrium state.   The liquid filling method according to claim 9, wherein the air pipe provided between the cap part and the chamber adjusts the inflow conductance of the pipe to control the pressure inside and outside the workpiece to be in an equilibrium state.   11. The work according to claim 1, wherein the work has at least one of an injection hole and an air communication hole as an opening communicating with the liquid discharge hole and the inside and outside, and the liquid discharge hole is used as the injection hole. 2. The liquid filling method according to item 1.   12. The head according to claim 1, wherein the work is a head with a tank or a cartridge used in an ink jet printer for discharging ink to print or an apparatus for discharging an industrial liquid material. Liquid filling method.   A liquid filling apparatus for filling a work with a liquid, and a chamber for maintaining confidentiality at the time of pressurization and depressurization with respect to atmospheric pressure, and a liquid injection port of the work in the chamber. A holder portion, a cap portion that is driven up and down to fill the workpiece with liquid while keeping contact with the inlet, and detecting means for detecting an inflow amount of the liquid filled in the workpiece; A liquid filling apparatus comprising: an air pipe for bringing the pressure of the liquid into an equilibrium state; and a liquid supply tank having an airtight structure.   14. The liquid filling apparatus according to claim 13, wherein the work has at least one of an injection hole and an atmosphere communication hole as an opening communicating with the liquid discharge hole and the inside and outside, and the liquid discharge hole is used as the injection port. .   15. The liquid filling apparatus according to claim 13, wherein the workpiece is a head with a tank or a cartridge used in an ink jet printer for discharging ink to print or an apparatus for discharging an industrial liquid material.   An ink-jet head comprising a tank-equipped head or a cartridge filled with ink free from air bubbles mixed by the liquid filling method according to claim 1.   The inkjet head according to claim 16, wherein the tank-attached head is a side shooter type head that supplies ink from a side surface.

Images