JP4455277B2 - Printing method, head module, and printing apparatus - Google Patents

Description

  The present invention relates to a printing method, and more particularly to a method and apparatus for printing a spacer for maintaining a uniform cell gap between a color filter substrate and an array substrate of a liquid crystal display on a substrate.

  Conventionally, as a method of arranging spacer particles at a predetermined position on a substrate, a spacer dispersion liquid in which spacer particles are dispersed in a solvent is filled in a printing apparatus, and discharged from the head of the printing apparatus toward a predetermined position on the substrate. An inkjet method is used.

  When printing with the ink jet method, if the spacers are not evenly dispersed in the discharge liquid, the discharge becomes unstable, causing defective discharge, abnormal discharge speed and discharge direction, and discharge spacers in the droplets It is easy to cause the problem that the number of the is not stable.

  Japanese Patent Laid-Open No. 11-7028 “Spacer Discharging Device and Liquid Crystal Display Element Manufacturing Method” includes a cooling tank and an ultrasonic generator using a piezoelectric element in a stirring tank that contains a solution containing a spacer. It is characterized in that the solution containing the spacer is stirred and dispersed by ultrasonic waves without increasing the temperature, and the spacer is discharged, but when ink is not discharged, the spacer settles in the piping between the stirring tank and the head, inside the head ink chamber, etc. Is a problem.

  In the spacer spraying method and apparatus disclosed in Japanese Patent Laid-Open No. 2002-72218, ink in the ink chamber of the head can be circulated. However, there is a problem due to clogging of the head nozzle plate due to foreign matters mixed in the ink.

As the apparatus becomes larger, the length of the ink supply line from the ink bottle to the head module becomes longer, and the sedimentation and aggregation of the spacers inside the ink supply line cause various problems.
Japanese Patent Laid-Open No. 11-7028 JP 2002-72218 A JP 2002-277622 A JP 2003-275659 A

  The present invention has been created to solve the above-mentioned disadvantages of the prior art, and an object of the present invention is to provide an apparatus capable of printing in a state where the dispersed state of the spacer particles is always kept uniform.

In order to solve the above problem, the invention according to claim 1 is characterized in that the spacer dispersion liquid supplied to the supply chamber of the head body divided into the supply chamber and the discharge chamber by the internal filter is passed through the internal filter, A printing method of supplying to the discharge chamber and discharging toward a print object from an ejection hole provided in the discharge chamber, wherein the supply chamber is in a print state in which the spacer dispersion liquid is discharged to the print object. In the standby state in which at least a part of the spacer dispersion liquid supplied to is discharged from the supply chamber and the spacer dispersion liquid is not discharged to the printing object, the spacer dispersion liquid is supplied to at least the discharge chamber, and In the printing method, the spacer dispersion liquid supplied to the discharge chamber is discharged from the discharge chamber.
A second aspect of the present invention is the printing method according to the first aspect, wherein in the standby state, the spacer dispersion liquid is also supplied to the supply chamber, and the spacer dispersion liquid supplied to the supply chamber is discharged. Is a printing method.
A third aspect of the present invention is the printing method according to the first or second aspect, wherein the spacer dispersion liquid discharged from the supply chamber is supplied to either the discharge chamber or the supply chamber. This is a printing method for returning to one or both.
A fourth aspect of the present invention is the printing method according to any one of the first to third aspects, wherein the spacer dispersion liquid discharged from the discharge chamber is supplied to either the discharge chamber or the supply chamber. This is a printing method for returning to one or both.
According to a fifth aspect of the present invention, in the printing method according to any one of the second to fourth aspects, the standby state includes the spacer dispersion liquid discharged from the discharge chamber and the supply chamber. In this printing method, the discharged spacer dispersion liquid is mixed and then returned to both the discharge chamber and the supply chamber.
The invention according to claim 6 is an internal hollow head main body, a nozzle plate constituting one wall surface of the head main body, one or more ejection holes provided in the nozzle plate, and a spacer in the head main body. A supply unit configured to supply a dispersion liquid; and a discharge unit configured to discharge the spacer dispersion liquid from the inside of the head body, so that the spacer dispersion liquid supplied from the supply unit is discharged from the ejection holes. The internal space of the head body is divided into a discharge chamber on the nozzle plate side and a supply chamber on the opposite side of the nozzle plate by an internal filter through which the spacer dispersion liquid can pass. And the supply section has a discharge side inlet provided in the discharge chamber and a supply side inlet provided in the supply chamber, and the spacer dispersion liquid is It is configured to be supplied from the outlet side inlet to the discharge chamber and to be supplied from the supply side inlet to the supply chamber, and the discharge portion includes a discharge side discharge port provided in the discharge chamber, and the supply A supply-side discharge port provided in the chamber, and the spacer dispersion liquid is discharged from the discharge chamber and the supply chamber through the discharge-side discharge port and the supply-side discharge port, respectively. The head module.
A seventh aspect of the present invention is the head module according to the sixth aspect, wherein the head module has a circulation system, and the circulation system is configured to return the spacer dispersion discharged to the discharge unit to the supply unit. The head module.
The invention according to claim 8 is the head module according to claim 7, wherein the circulation system includes the spacer dispersion liquid discharged from the discharge side discharge port and the spacer discharged from the supply side discharge port. It is a head module configured to mix the dispersion and return to the supply unit.
The invention according to claim 9 is the head module according to claim 7 or 8, wherein the circulation system has a buffer chamber in which a spacer dispersion liquid is stored, and the buffer chamber The spacer dispersion liquid stored in the head module is supplied to the supply section, and the spacer dispersion liquid discharged from the discharge section is a head module configured to return to the buffer chamber.
The invention according to claim 10 is a printing apparatus having a storage system in which a spacer dispersion liquid is stored, and one or more head modules to which the spacer dispersion liquid is supplied from the storage system. The head module is a printing apparatus configured with the head module according to any one of claims 6 to 9, wherein the spacer dispersion liquid is supplied from the storage system to the circulation system.

  It is possible to stably supply the spacer dispersion liquid to the head body without agglomeration and sedimentation of the spacer particles in the spacer dispersion liquid in which the spacer particles are dispersed, and a spacer for a large substrate using a plurality of heads. The discharge device can be put to practical use.

  Reference numeral 2 in FIG. 2 shows an example of the head module of the present invention. The head module 2 includes a head body 20, a nozzle plate 31, a supply unit 25, a discharge unit 26, and a circulation system 10. is doing.

  The inside of the head main body 20 is hollow, and the nozzle plate 31 is configured by one wall surface of the head main body 20. Inside the head body 20, an internal filter 30 is disposed away from both the nozzle plate 31 and the wall surface of the head body 20 opposite to the nozzle plate 31, and the inside of the head body 20 is an internal filter. The space is divided into a space between 30 and the wall surface, and a space between the internal filter 30 and the nozzle plate 31.

  2 indicates a discharge chamber surrounded by the nozzle plate 31, the internal filter 30, and the side wall of the head main body 20. Reference numeral 22 in FIG. 2 indicates a wall surface of the head main body 20 on the side opposite to the nozzle plate 31. And a supply chamber surrounded by the inner filter 30 and the side wall of the head main body 20.

  The circulation system 10 includes a circulation path 11 and a buffer chamber 17 provided in the middle of the circulation path 11. One end of a supply path 56 is connected to the buffer chamber 17, and when the supply source valve 41 provided in the supply path 56 is opened, the buffer chamber 17 is connected to a large circulation path 50 described later, and a spacer that flows through the large circulation path 50. The dispersion liquid flows into the buffer chamber 17.

  When the amount of the spacer dispersion liquid flowing into the buffer chamber 17 exceeds the set amount, the spacer dispersion liquid flows out to the one end portion side of the circulation path 11. The buffer chamber 17 is connected to a meniscus control mechanism 8 which will be described later. The meniscus control mechanism 8 exchanges the spacer dispersion liquid or solvent with the buffer chamber 17 for fine adjustment of the meniscus. When supplied to the buffer chamber 17, the spacer dispersion liquid supplied from the large circulation path 11 is mixed with the buffer chamber 17, and flows out to the one end side of the circulation path 11 together.

  The supply unit 25 is provided at a connection position between the first and second supply pipes 13 and 14, one end of which is connected to one end of the circulation path 11, and the first and second supply pipes 13 and 14 and the circulation path 11. The supply side switching valve 43 provided on the wall surface of the supply chamber 22, provided on the supply chamber side inlet 23 connected to the other end of the first supply pipe 13, and on the wall surface of the discharge chamber 21, The other end of the supply pipe 14 is connected to the discharge chamber side inlet 24. By switching the supply side switching valve 43, the buffer chamber 17 is connected to the discharge chamber 21 and the supply chamber 22 via the circulation path 11. The spacer dispersion liquid flowing through the circulation path 11 flows into either one or both of the discharge chamber 21 and the supply chamber 22.

  In the middle of the first and second supply pipes 13 and 14, first and second external filters 37 and 38 are provided. When the spacer dispersion liquid passes through the external filters 37 and 38, the spacer particles Since the aggregated particles and dust are removed, the spacer dispersion liquid in which the spacer particles are dispersed is supplied to the discharge chamber 21 and the supply chamber 22.

  With reference to FIG. 3, the nozzle plate 31 is provided with one or more ejection holes 32. Piezo elements 36 are provided between the nozzle plate 31 and the piezo support plate 35 on the nozzle plate 31 and in the vicinity of the ejection holes 32. When printing is stopped, the piezo elements 36 Since the pressure 36 is higher than the pressure inside the discharge chamber 22, the spacer dispersion liquid 67 is not discharged from the ejection holes 32.

  The discharge portion 26 is provided at a position separated from the supply chamber side discharge port 27 provided at a position separated from the supply chamber side inlet 23 on the wall surface of the supply chamber 22 and the discharge chamber side supply port 24 provided at the wall surface of the discharge chamber 21. The discharge chamber side discharge port 28, the first discharge pipe 18 having one end connected to the supply chamber side discharge port 27, and the second discharge pipe 19 having one end connected to the discharge chamber side discharge port 28. The spacer dispersion liquid that has flowed in the supply chamber 22 from the supply chamber side inlet 23 toward the supply chamber side outlet 27 is discharged to the first discharge pipe 18, and the discharge chamber 21 flows in the discharge chamber side flow. The spacer dispersion that has flowed from the inlet 24 toward the discharge chamber side discharge port 28 is discharged to the second discharge pipe 19.

  The other end of the first discharge pipe 18 is connected to the end of the circulation path 11 opposite to the side to which the first and second supply pipes 13 and 14 are connected. The end is connected to the other end of the discharge path 57 whose one end is connected to a general circulation path described later.

  The connection position of the first discharge pipe 18 and the circulation path 11 and the connection position of the second discharge pipe 19 and the discharge path 57 are connected by a connecting pipe 49, and the first discharge pipe 18 and the circulation path 11 are connected. The discharge chamber 21 and the supply chamber 22 are switched by switching the switching valve 42 provided at the connection position of the pipe 49 and the switching valve 44 provided at the connection position of the second discharge pipe 19, the discharge path 57 and the connecting pipe 49. The spacer dispersion liquid connected to either the circulation path 11 or the discharge path 57 and discharged from the supply chamber 22 to the first discharge pipe 18 is discharged to either the circulation path 11 or the discharge path 57 and from the discharge chamber 21. The spacer dispersion discharged to the second discharge pipe 19 is discharged to either the circulation path 11 or the discharge path 57.

  Here, the circulation pump 15 is provided at a position between the discharge portion 26 and the buffer chamber 17 in the circulation path 11, and the spacer dispersion discharged from the discharge portion 26 is moved by the operation of the circulation pump 15. To the supply unit 25 again.

  Accordingly, when the spacer dispersion liquid is not discharged from the discharge unit 26 to the discharge path 57, the spacer dispersion liquid circulates among the buffer chamber 17, the supply unit 25, and the discharge unit 26.

  The buffer chamber 17 is provided with stirring means (not shown). When the stirring means is operated, the spacer dispersion liquid in the buffer chamber 17 is irradiated with ultrasonic waves intermittently or continuously. The spacer dispersion is agitated and the spacer particles are uniformly dispersed.

  Accordingly, both the spacer dispersion liquid newly supplied from the general circulation system 50 and the spacer dispersion liquid returned from the discharge unit 26 are uniformly dispersed in the buffer chamber 17 and circulate in the head module 2.

  The buffer chamber 17 is provided with a temperature control means (not shown). When the temperature of the spacer dispersion liquid in the buffer chamber 17 exceeds a set temperature, the buffer chamber 17 is cooled by the temperature control means, and the inside thereof is transferred by heat conduction. Since the spacer dispersion liquid is cooled, even if the spacer dispersion liquid in the buffer chamber 17 is heated by ultrasonic vibration, the temperature is always maintained at a constant temperature.

  Next, an example of a printing apparatus using the head module 2 will be described.

Reference numeral 1 in FIG. 1 shows an example of a printing apparatus according to the present invention. This printing apparatus 1 has a storage system 5, a large circulation path 50, and one or more of the head modules 2 described above. Here, the printing apparatus 1 has four head modules 2, and each head module 2 and its members are distinguished from each other by adding suffixes a to d.

  The storage system 5 has a storage tank 58 and a buffer tank 59. A spacer dispersion liquid is stored inside the storage tank 58, and the spacer dispersion liquid is supplied from the storage tank 58 to the buffer tank 59 by the supply pump 79, and once stored in the buffer tank 59, What is excessively stored in the tank 59 returns to the storage tank 58.

  The storage tank 58 and the buffer tank 59 each have a stirring means (not shown), and the spacer dispersion liquid stored in the storage tank 58 and the buffer tank 59 is stirred by the stirring means, so that the spacer particles are made uniform. The dispersed state is maintained.

  Both ends of the general circulation path 50 are connected to the buffer tank 59. When the general circulation pump 55 provided in the large circulation path 50 is operated, the spacer dispersion liquid stored in the buffer tank 59 is converted into the large circulation path 50. And then flows through the large circulation path 50 from one end to the other end, and then returns to the buffer tank 59 again. That is, the spacer dispersion liquid is circulated between the buffer tank 59 and the large circulation path 50 by the operation of the large circulation pump 55.

  Assuming that the side where the spacer dispersion liquid is supplied from the buffer tank 59 of the large circulation path 50 is the upstream side, and the other end side where the spacer dispersion liquid returns to the buffer tank 59 is the downstream side, the supply paths 56a to 56d of the head modules 2a to 2d. 56 d is connected to the large circulation path 50 in order from the upstream side to the downstream side, and the supply valve 41 provided in the supply paths 56 a to 56 d is opened to connect the large circulation path 50 and the buffer chamber 17. Then, the spacer dispersion liquid flows into the buffer chamber 17.

  Since the large circulation path 50 is configured to flow a larger amount of the spacer dispersion liquid than the total amount of the spacer dispersion liquid flowing through the supply paths 56a to 56d, when each supply source valve 41 is opened at the same time, The spacer dispersion liquid reaches not only the supply path 56a but also the downstream supply path 56d, and eventually the spacer dispersion liquid is supplied to all the head modules 2a to 2d.

  The buffer chamber 17 is provided with a liquid volume control means (not shown). When the liquid volume inside the buffer chamber 17 detected by the liquid volume control means becomes less than the set volume, the liquid volume control means circulates through the buffer chamber 17 in a large circulation. When the spacer dispersion liquid is supplied to the buffer chamber 17 and supplied to the buffer chamber 17 and the amount of liquid in the buffer chamber 17 exceeds the set amount, the liquid amount control means shuts off the buffer chamber 17 from the large circulation path and moves the spacer. Stop supplying the dispersion.

  Further, a buffer liquid such as a spacer dispersion liquid or a solvent is stored in the tank 80 of the meniscus control mechanism 8, and the liquid level height of the buffer liquid in the tank 80 is determined by the spacer dispersion liquid in the ejection hole 32. The meniscus control mechanism 80 supplies an amount of buffer liquid corresponding to the fluctuation amount from the tank 80 to the buffer chamber 17 by the decompression mechanism so that the meniscus is always constant. Maintain the state.

  That is, in the head module 2, the supply of the spacer dispersion liquid from the large circulation path 50 to the head module 2 is controlled, and the liquid amount in the head module 2 is finely adjusted by the meniscus control mechanism 8, so that the head module is always maintained. The liquid amount in 2 is kept constant, and as a result, the spacer dispersion liquid is stably discharged.

  The discharge paths 57a to 57d of the head modules 2a to 2d are connected to the large circulation path 50 at positions further downstream than the supply path 56d located on the most downstream side, and the discharge sections of the head modules 2a to 2d When the spacer dispersion liquid discharged from 26 is discharged to the large circulation path 50, it returns to the buffer tank 59 again.

  The printing apparatus 1 includes a cleaning mechanism 70 that cleans the head modules 2a to 2d. The cleaning mechanism 70 includes a cleaning tank 71 filled with a cleaning liquid such as an organic solvent, one end connected to the cleaning tank 71, and the other end connected to a connection position of the supply paths 56a to 56d and a connection position of the discharge paths 57a to 57d. And a cleaning system 72 connected to the general circulation path 50.

  The cleaning liquid in the cleaning tank 71 passes through the cleaning system 72 and the large circulation path 50 and is discharged from the large circulation path 50 to the drain tank 3 before being sent to the buffer tank 59.

  One end of the cleaning path of each head module 2 is connected to the cleaning system 72. When one head module 2 is described with reference to FIG. 2, the switching valve 76 provided in the middle of the cleaning path 75 is opened. The cleaning liquid of the cleaning system 72 is supplied to the cleaning path 75.

  Here, the other end of the cleaning path 75 is connected in the middle of the second supply pipe 14, and the cleaning path 75 is changed to the first by switching the switching valve 77 provided at the connection position and the supply side switching valve 43. The one connected to one or both of the discharge chamber 21 and the supply chamber 22 via the second supply pipes 13 and 14 is supplied with the cleaning liquid, and at the same time, the one connected to the cleaning path 75 is supplied from the buffer chamber 17. The supply of the spacer dispersion liquid is stopped.

  When the cleaning liquid is supplied to the discharge chamber 21 or the supply chamber 22, the spacer dispersion liquid remaining inside is washed away by the cleaning liquid and discharged to the first and second discharge pipes 18 and 19 together with other impurities.

  If the cleaning liquid discharged to the first and second discharge pipes 18 and 19 is discharged to the discharge path 57 by switching the switching valves 42 and 44 of the discharge unit 26, the cleaning liquid is discharged from the discharge path 57 to the large circulation path 50. To the drain tank 3 without returning to the buffer tank 59 from the general circulation path 50.

  Next, a method for discharging the spacer dispersion liquid to the substrate that is the printing object using the printing apparatus 1 will be described.

  By operating the general circulation pump 55 and circulating the spacer dispersion liquid between the general circulation path 50 and the buffer tank 59, the liquid amount inside the buffer chamber 17 of each of the head modules 2a to 2d is controlled by the liquid amount control means described above. Keep constant.

  In this state, the circulation pump 15 of each of the head modules 2 a to 2 d is operated so that the first and second supply pipes 13 and 14 and the first and second discharge pipes 18 and 19 are connected to the buffer chamber 17. In addition, when the supply side switching valve 43 and the switching valves 42 and 44 of the discharge unit 26 are switched, the spacer dispersion liquid flows in both the discharge chamber 21 and the supply chamber 22, and the spacer dispersion liquid that flows in the discharge chamber 21 The spacer dispersion liquid flowing in the supply chamber 22 is mixed in the same circulation path 11, passes through the buffer chamber 17, and is sent again to the supply unit 25 side.

  At this time, the spacer dispersion liquid does not stagnate in both the discharge chamber 21 and the supply chamber 22, and the flowing state is maintained. Therefore, the spacer particles do not settle in the liquid, and the dispersed state is maintained.

  While maintaining this state, the nozzle plates 31 of the head modules 2a to 2d are opposed to the substrate that is the printing object, and alignment is performed so that the ejection holes 32 are opposed to the printing position of the substrate.

  When the piezo element 36 corresponding to the ejection hole 32 directly above the printing position is vibrated, the spacer dispersion liquid 67 is discharged from the ejection hole 32 toward the printing position.

  Immediately before the spacer dispersion liquid 67 is discharged from the ejection holes 32, the discharge chamber 21 is connected to the discharge path 57 and the buffer chamber 11 while maintaining the state in which the spacer dispersion liquid circulates between the buffer chamber 17 and the supply chamber 22. When the supply side switching valve 43 and the switching valves 42 and 44 of the discharge unit 26 are switched so as to be blocked from both, the spacer dispersion liquid flows inside the supply chamber 22, but the spacer dispersion liquid does not flow inside the discharge chamber 21. .

  If the state is maintained while the spacer dispersion liquid 67 is discharged from the ejection holes 32 (printed state), the ejection holes 32 are not affected by the pressure change due to the flow of the spacer dispersion liquid 67, and thus are ejected from the ejection holes 32. The discharge amount of the spacer dispersion liquid 67 is constant.

  When the spacer dispersion 67 is discharged from the ejection holes 32, the amount of the liquid decreases. However, a passage (not shown) through which the spacer particles 69 in the spacer dispersion and the solvent 68 can pass is formed in the internal filter 30. The spacer dispersion 67 is replenished to the discharge chamber 21 through the passage of the internal filter 30.

  In the printing state, the spacer dispersion liquid 68 from the buffer tank 17 is always supplied to the supply chamber 22, and the spacer dispersion liquid in the buffer tank 17 is supplied by the liquid amount control means and the meniscus control mechanism 8 as described above. Since the liquid amount is always kept constant, a constant amount of the spacer dispersion liquid 67 is always arranged in the discharge chamber 21, and the meniscus in the ejection hole 32 is always kept constant, and as a result, the spacer dispersion liquid Discharge is performed stably.

  When the discharge of the set amount of the spacer dispersion liquid is finished at the printing position, the discharge from the ejection holes 32 is stopped to finish the printing state, and both the supply chamber 22 and the discharge chamber 21 are connected to the buffer chamber 17. If the supply side switching valve 43 and the switching valves 42 and 44 of the discharge unit 26 are switched so that the spacer dispersion liquid is supplied to both the supply chamber 22 and the discharge chamber 21 and then circulates back to the same buffer tank 17. The spacer dispersion liquid flows in both the supply chamber 22 and the discharge chamber 21.

  For example, the spacer dispersion liquid is supplied to the supply chamber in a standby state in which printing is stopped for a relatively short period of time, such as when the substrate after printing is replaced with a new substrate, or when the above-described substrate alignment is performed. 22 and the discharge chamber 21, the spacer particles do not settle inside the discharge chamber 21 and the supply chamber 22, and the internal filter 30 and the ejection hole 32 do not clog.

  When printing is stopped for several hours or more, if the spacer dispersion liquid in the discharge chamber 21 and the supply chamber 22 is discharged by the cleaning mechanism 70 described above, the large circulation pump 50 and the circulation pump 15 can be stopped. The internal filter 30 and the ejection holes 32 are not clogged with spacer particles.

  When the printing apparatus 1 has a plurality of head modules 2a to 2d, the spacer dispersion liquid can be printed at a wide printing position on a large substrate by simultaneously printing using all the head modules 2a to 2d. Further, when printing is performed by selecting one or more head modules 2a to 2d from among the plurality of head modules 2a to 2d, if the head modules 2a to 2d that do not perform printing are in the above-described standby state, The head modules 2a to 2d are not clogged with spacer particles.

  In the above, the case where the temperature control means is provided only in the buffer chamber 17 has been described. However, the present invention is not limited to this. For example, one or both of the first and second external filters 37 and 38 are provided. By providing temperature control means and heating or cooling one or both of the first and second external filters 37 and 38 based on the measured temperature of the spacer dispersion liquid, the first and second external filters The spacer dispersion liquid after passing through 37 and 38 can be set to a set temperature. The temperature control of the spacer dispersion liquid may be performed by either one of the buffer chamber 17 and the first and second external filters 37 and 38, or by both.

  The type of spacer particles used in the present invention is not particularly limited. For example, those having a diameter of 4 μm or more and 6 μm or less can be used.

  The type of the internal filter 30 is not particularly limited, and various types such as a nonwoven fabric and a metal filter can be used. However, the diameter of the passage through which the spacer particles pass is preferably at least twice the diameter of the spacer particles.

  The shape and size of the ejection holes 32 are not particularly limited, but those having a diameter that is at least twice the diameter of the passage of the internal filter 30 are preferable in consideration of stable discharge performance. Further, the size of the ejection hole 32 of the nozzle plate 26 can be selected according to the target ejection droplet size, but the diameter is desirably 20 μm or more and 40 μm or less.

  The ultrasonic irradiation in the buffer chamber 17 may be performed only when printing is performed by the head module 2, or may be continued even when printing is not performed by the head module 2. When performing ultrasonic irradiation, ultrasonic irradiation may be performed continuously or intermittently.

  The above is a description of the case where the ejection at the ejection holes 32 is controlled by a piezo element system in which a piezo element is provided in the vicinity of the ejection holes 32. However, the ejection control method is not limited to this, and the bubble jet (registered trademark) ) Method, thermal jet method and the like.

[Number of spacer particles discharged]
The printing apparatus 1 shown in FIGS. 1 and 2 printed a commercially available spacer dispersion solution, and evaluated the number of spacers in the discharged droplets.

  The spacer dispersion solution is prepared by dispersing spacer particles produced for spraying commercially available spacers in an alcohol-based mixed solvent and removing aggregates with a filter in advance. What adjusted 4.1 micrometer and the density | concentration of spacer particle | grains to 0.1 wt% was used.

  When the nozzle (ejection hole 32) diameter was 28 μm, the discharge droplet size was 20 pl, and the number of spacers in one droplet was 3.2 ± 0.2.

  Furthermore, when the nozzle diameter was 23 μm, the ejection droplet size was 8 pl, and the number of spacers in one droplet was 2.0 ± 0.9.

  From these results, it can be seen that the ejection droplet size and the number of spacers in the droplet can be easily controlled by changing the nozzle diameter.

[Discharge stability evaluation test]
When the spacer dispersion liquid is made to flow inside the supply chamber 22 while circulating the spacer dispersion liquid in the large circulation path 50 using the printing apparatus 1 shown in FIGS. When the spacer dispersion liquid is circulated and the spacer dispersion liquid is not flown inside the supply chamber 22 (Comparative Example 1), the spacer dispersion liquid is circulated through the large circulation path 50 and the spacer dispersion liquid is caused to flow inside the supply chamber 22. At the same time, the spacer dispersion liquid stored in the buffer chamber 17 is irradiated with ultrasonic waves under the three conditions (Example 2), and the spacer dispersion liquid is continuously discharged from the ejection holes 32 for 60 minutes. The number of spacers in the droplet at the time was evaluated.

  The results are shown in Table 1 below.

  As apparent from Table 1 above, Comparative Example 1 in which the spacer dispersion liquid is not allowed to flow in the supply chamber 22 in the printing state is from the initial 2.0 ± 0.9 to 1.5 ± 1.0 after 60 minutes. A decrease in the number of spacers was observed. On the other hand, in Example 1 in which the spacer dispersion liquid was flowed in the supply chamber 22, 1.9 ± 0.9 pieces were obtained in 60 minutes, which was an improvement with respect to the reduction in the number of spacers. Further, in Example 2 in which ultrasonic irradiation was performed while flowing the spacer dispersion liquid inside the supply chamber 22, there was no change even after 60 minutes, and the effect of ejection stability was confirmed.

  After continuous ejection for 60 minutes, ultrasonic irradiation in the head module 2, circulation of the spacer dispersion liquid, and evaluation of the number of spacers after the flushing operation of the head module 2 were performed, and maintenance was performed even when there was no circulation in the head module 2. It returned to the initial 2.0 ± 0.9 by the operation.

  In this way, it can be seen that by supplying the spacer dispersion liquid to the supply chamber 22 and more preferably irradiating the spacer dispersion liquid in the head module 2 with ultrasonic waves, the ejection stability in the printed state is improved.

FIG. 2 is a diagram illustrating an example of a printing apparatus according to the present invention. The figure explaining the head module of this invention An enlarged sectional view for explaining an example of a head body used in the present invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 2 ... Head module 5 ... Storage system 10 ... Circulation system 17 ... Buffer chamber 20 ... Head main body 21 ... Discharge chamber 22 ... Supply chamber 25 ... Supply part 26 ... Discharge part 30 …… Internal filter 31 …… Nozzle plate 32 …… Blowout hole

Claims (10)

The head body divided into a supply chamber and a discharge chamber by an internal filter passes through the internal filter the spacer dispersion liquid supplied to the supply chamber and supplies it to the discharge chamber, and a jet provided in the discharge chamber A printing method for discharging from a hole toward a printing object,
In a printing state in which the spacer dispersion liquid is discharged onto the printing object, at least a part of the spacer dispersion liquid supplied to the supply chamber is discharged from the supply chamber,
In a standby state in which the spacer dispersion liquid is not discharged onto the printing object, the printing method is to supply at least the spacer dispersion liquid to the discharge chamber and to discharge the spacer dispersion liquid supplied to the discharge chamber from the discharge chamber.   The printing method according to claim 1, wherein in the standby state, the spacer dispersion liquid is also supplied to the supply chamber, and the spacer dispersion liquid supplied to the supply chamber is discharged.   The printing method according to claim 1, wherein the spacer dispersion liquid discharged from the supply chamber is returned to one or both of the discharge chamber and the supply chamber.   The printing method according to any one of claims 1 to 3, wherein the spacer dispersion liquid discharged from the discharge chamber is returned to one or both of the discharge chamber and the supply chamber.   3. The standby state includes mixing the spacer dispersion liquid discharged from the discharge chamber and the spacer dispersion liquid discharged from the supply chamber, and then returning the mixture to both the discharge chamber and the supply chamber. Item 5. The printing method according to any one of Items4. An internal hollow head body;
A nozzle plate constituting one wall surface of the head body;
One or more ejection holes provided in the nozzle plate;
A supply unit for supplying a spacer dispersion into the head body;
A discharge part for discharging the spacer dispersion from the inside of the head body,
The spacer dispersion liquid supplied from the supply unit is a head module configured to be discharged from the ejection holes,
The internal space of the head body is divided into a discharge chamber on the nozzle plate side and a supply chamber on the opposite side of the nozzle plate by an internal filter through which the spacer dispersion liquid can pass.
The supply unit has a discharge side inlet provided in the discharge chamber and a supply side inlet provided in the supply chamber, and the spacer dispersion liquid is supplied from the discharge side inlet to the discharge chamber. And is configured to be supplied from the supply side inlet to the supply chamber,
The discharge section includes a discharge side discharge port provided in the discharge chamber and a supply side discharge port provided in the supply chamber, and the spacer dispersion liquid includes the discharge side discharge port and the supply side discharge port. A head module configured to be discharged from the discharge chamber and the supply chamber through an outlet.   The head module according to claim 6, further comprising a circulation system, wherein the circulation system is configured to return the spacer dispersion liquid discharged to the discharge unit to the supply unit.   8. The circulation system is configured to mix the spacer dispersion discharged from the discharge side discharge port and the spacer dispersion discharged from the supply side discharge port, and return the mixture to the supply unit. The head module described. The circulation system has a buffer chamber in which a spacer dispersion is stored,
The spacer dispersion liquid stored in the buffer chamber is supplied to the supply unit,
9. The head module according to claim 7, wherein the spacer dispersion liquid discharged from the discharge portion is configured to return to the buffer chamber. A storage system in which the spacer dispersion is stored;
A printing apparatus having one or more head modules to which the spacer dispersion is supplied from the storage system,
Each said head module is comprised with the head module of any one of Claim 6 thru | or 9,
The printing apparatus configured to supply the spacer dispersion liquid from the storage system to the circulation system.

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