Liquid discharge device

Abstract

To provide a liquid discharge device capable of recovering a filter function.SOLUTION: The liquid discharge device includes: a head tank for storing liquid; a liquid discharge head for discharging the liquid supplied from the head tank; liquid feeding means for feeding the liquid from the head tank to the liquid discharge head through a liquid supply path between the head tank and the liquid discharge head; a filter provided in the liquid supply path; pressure measurement means respectively provided on an upstream side and a downstream side of the filter; and control means for controlling a liquid discharge operation in which the liquid feeding means discharges the liquid in the head tank based on a result calculated from a measurement value of the pressure measurement means.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device. [Background technology]

[0002] 2. Description of the Related Art A conventional liquid ejection device (for example, an inkjet device) has been disclosed that includes a filter for filtering ink in a supply path that supplies ink to an inkjet head, and pressure sensors and the like upstream and downstream of the filter.

[0003] As a specific example, a liquid supply device has been proposed that has a discrimination means for discriminating the degree of clogging of a filtering means based on the pressure difference between the flow pressure of the liquid flowing through a first region located upstream of the filtering means in the liquid supply flow path and the flow pressure of the liquid flowing through a second region located downstream of the filtering means in the liquid supply flow path (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection device that can restore the filter function. [Means for solving the problem]

[0005] The liquid ejection device of the present invention as a means for solving the above problems comprises: a head tank for storing liquid; a liquid ejection head that ejects the liquid supplied from the head tank; a liquid delivery unit that delivers the liquid from the head tank to the liquid ejection head via a liquid supply path between the head tank and the liquid ejection head; a filter provided in the liquid supply path; pressure measuring means provided on the upstream side and downstream side of the filter; and a control means for controlling the liquid discharge operation of the liquid delivery means to discharge the liquid in the head tank based on the result calculated from the measurement value of the pressure measurement means. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a liquid ejection device that can recover the filter function. [Brief explanation of the drawings]

[0007] [Figure 1A] FIG. 1A is a schematic plan view showing an example of a liquid ejection device of the present invention. [Figure 1B] FIG. 1B is a schematic plan view showing another example of the liquid ejection device of the present invention. [Figure 2] FIG. 2 is a schematic plan view showing still another example of the liquid ejection device of the present invention. [Figure 3] FIG. 3 is a flowchart for explaining an embodiment of the control means of the present invention. [Figure 4] FIG. 4 is a flowchart for explaining another embodiment of the control means of the present invention. [Figure 5A] FIG. 5A is a schematic plan view showing an example of a mechanism of an image forming apparatus according to the present invention. [Figure 5B] FIG. BA is a schematic side view showing an example of a mechanism of an image forming apparatus according to the present invention. [Figure 5C] FIG. 5C is a schematic plan view showing an example of an inkjet head of an image forming apparatus according to the present invention. [Figure 6] FIG. 6 is a diagram showing an example of the hardware configuration of an image forming apparatus according to the present invention. [Figure 7A] FIG. 7A is an example of a functional block diagram relating to image formation in the image forming apparatus according to the present invention. [Figure 7B] FIG. 7B is an example of a functional block diagram relating to maintenance in the image forming apparatus according to the present invention. [Figure 8]FIG. 8 is a schematic plan view of one embodiment of a three-dimensional modeling apparatus according to the present invention. [Figure 9] FIG. 9 is a schematic cross-sectional view showing an example of the three-dimensional modeling apparatus of FIG. 8 as viewed from the right side in FIG. [Figure 10] FIG. 10 is a schematic cross-sectional view showing an example of the powder holding unit of FIG. [Figure 11] FIG. 11 is a perspective explanatory view showing an example of a main part of a three-dimensional modeling apparatus according to the present invention. [Figure 12] FIG. 12 is a block diagram showing an outline of a control unit in the three-dimensional modeling apparatus. [Figure 13] FIG. 13 is an explanatory diagram for explaining an example of the powder layer forming operation according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Pigment inks used in conventional liquid ejection devices (e.g., inkjet printers) sometimes contain solvents and inorganic pigments. Due to the large density difference between the solvent and the inorganic pigment, it is difficult to maintain a stable dispersion state over a long period of time. Therefore, in areas where ink stagnates, such as head tanks and filter units, the pigment components contained in the ink can settle or aggregate, increasing fluid resistance and causing problems such as clogged filters and missing nozzles. Similar problems can occur with inks with high solid content or high viscosity used in 3D printers, etc., due to the settling or aggregation of solids.

[0009] Conventional printing devices, including those described in Patent Document 1, resolve the problem by determining and notifying the user of filter deterioration (clogging) based on the pressure difference measured by pressure sensors installed upstream and downstream of the filter, and prompting the user to replace the filter. However, these printing devices do not have a means to restore the function of the filter after determining that the filter has deteriorated, making filter replacement essential.

[0010] The liquid ejection device of the present invention can fully resolve various concerns in the prior art. More specifically, it is as follows. The liquid ejection device of the present invention controls the liquid discharge operation in the head tank based on the results calculated by pressure measurement means provided upstream and downstream of the filter. By configuring in this way, foreign matter that causes clogging of the filter is removed and the liquid in the head tank is replaced, restoring the function of the filter.

[0011] The present invention will be described in detail below.

[0012] (Liquid discharge device) The liquid ejection device of the present invention comprises a head tank for storing liquid, a liquid ejection head for ejecting the liquid supplied from the head tank, a liquid delivery means for delivering the liquid from the head tank to the liquid ejection head via a liquid supply path between the head tank and the liquid ejection head, a filter provided in the liquid supply path, pressure measurement means provided respectively upstream and downstream of the filter, and a control means for controlling the liquid ejection operation of the liquid delivery means to eject the liquid from the head tank based on the result calculated from the measurement value of the pressure measurement means, and may also comprise a cleaning means for cleaning the liquid ejection head and other parts as necessary.

[0013] Here, an embodiment of a printing apparatus according to the present invention will be described with reference to the drawings, although the present invention is not limited to this embodiment. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to this embodiment, and may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0014] [Figures 1A and 1B] FIG. 1A is a schematic plan view showing an example of a liquid ejection device of the present invention. FIG. 1B is a schematic plan view showing another example of the liquid ejection device of the present invention. The liquid ejection device 1000 has a head tank 5 as the head tank, a recording head 4 as the liquid ejection head, a liquid delivery pump 54 as the liquid delivery means, a filter 40 as the filter, a pressure sensor (upstream) 41 and a pressure sensor (downstream) 42 as the pressure measurement means, and a control unit 500 as the control means, and other parts include a suction cap 21, a suction pump 27, a waste liquid tank 28, and a main tank 50.

[0015] In the liquid ejection device 1000, the liquid is supplied from the main tank 50 to the head tank 5 via a supply tube 56 by a liquid supply pump 54, and is temporarily stored therein. Similarly, the liquid is supplied from the head tank 5 to the recording head 4 via a liquid supply path 57 by the liquid supply pump 54. The drive control of this liquid supply pump 54 is performed by a control unit 500.

[0016] A filter 40 for filtering the liquid is provided in a liquid supply path 57 from the head tank 5 to the recording head 4, and a pressure sensor (upstream) 41 is provided upstream of the filter 40, and a pressure sensor (downstream) 42 is provided downstream of the filter 40. The control of the driving of these pressure sensors is performed by a control unit 500.

[0017] The recording head 4 has a suction cap 21 that caps the nozzle surface, and a suction pump 27 connected to the suction cap 21 . When the suction pump 27 is driven while the nozzle surface is capped with the suction cap 21, the liquid inside the head tank 5 and the recording head 4 is sucked through the nozzles and the suction tube 26. The sucked liquid is discharged into the waste liquid tank 28. The driving control of the suction pump 27 is performed by the control unit 500.

[0018] [Figure 2] FIG. 2 is a schematic plan view showing still another example of the liquid ejection device of the present invention. In addition to the structure of the liquid ejection device 1000 shown in Figure 1, the liquid ejection device 2000 has the following other components: a displacement member 205, an atmosphere release mechanism 207, a feeler sensor 301, an atmosphere release solenoid 302, an operating member 303, and a temperature sensor 572.

[0019] The displacement member 205 is a member that is displaced according to the amount of liquid remaining inside the head tank 5. The displacement member 205 is detected and positioned by a feeler sensor 301. Based on the detection result of the feeler sensor 301, it is possible to control a recovery operation (for example, control the delivery of liquid while the head tank 5 is open to the atmosphere) which will be described later. It should be noted that if the pressure inside the head tank 5 is controlled to be negative by the pressure sensor (upstream) 41 and the pressure sensor (downstream) 42, the feeler sensor 301 does not need to be provided.

[0020] The head tank 5 is provided inside with an openable atmosphere release mechanism 207 that opens the inside of the head tank 5 to the atmosphere. On the other hand, provided outside the head tank 5 are an operating member 303 that operates to open the atmosphere release mechanism 207, and an atmosphere release solenoid 302 that moves the operating member 303. By operating this atmosphere release solenoid 302, the inside of the head tank 5 can be opened to the atmosphere via the atmosphere release mechanism 207. The drive control of this atmosphere release solenoid 302 is performed by a control unit 500.

[0021] The print head 4 has a temperature sensor 572 as a temperature detection means for detecting the temperature of the print head 4 (head temperature).

[0022] <Liquid Delivery Means> The liquid delivery means is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a reversible pump (reversible liquid delivery means) configured with a tube pump, etc. Here, the reversible pump is a pump that can perform both a liquid delivery operation of delivering liquid from the main tank 50 to the head tank 5 and a reverse delivery operation of delivering liquid from the head tank 5 to the main tank 50.

[0023] <filter> The filter is preferably provided in a filter chamber. The structure of the filter chamber is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably a structure that allows air bubbles to be easily discharged. Examples of such a structure that allows air bubbles to be easily discharged include the structure described in JP 2008-030333 A.

[0024] The shape of the filter is not particularly limited and can be appropriately selected from known filters. However, from the viewpoint of excellent long-term discharge stability, a filter in which a large number of uniform holes are made in a stainless steel or polyimide plate by a punch or a laser, a sintered filter in which stainless steel fibers are laminated into a felt-like state and sintered, or a twill weave filter formed by weaving stainless steel fibers in a twill weave is preferred.

[0025] The material of the filter is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of corrosion resistance, it is preferably made of stainless steel or polyimide. Among these, austenitic stainless steel is preferable as the material for the filter because of its excellent corrosion resistance, and SUS304, SUS316, and SUS316L are more preferable. These may be used alone or in combination of two or more.

[0026] The average pore size of the filter is not particularly limited and can be appropriately selected depending on the physical properties of the liquid to be used, but is preferably 5 μm or more and 20 μm or less from the viewpoint of achieving good discharge stability and liquid permeability.

[0027] The average thickness of the filter is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 mm or more and 0.5 mm or less in order to improve the ejection stability and liquid permeability.

[0028] <Pressure measurement means> The pressure measuring means is a means for measuring the pressure in the liquid supply passage, and is provided on the upstream side and downstream side of the filter. The pressure measuring means is not particularly limited as long as it can ultimately measure / calculate pressure and can be appropriately selected depending on the purpose, and examples thereof include a pressure sensor and a flow rate sensor.

[0029] The pressure sensor may be provided within the liquid supply path, or may be provided at a different location by creating a branch from the liquid supply path, or may be provided upstream of the head tank 5 and downstream of the liquid feed pump 54.

[0030] In the liquid ejection device of the present invention, the pressure may be calculated from the flow rate of the liquid. When the flow rate of the liquid is calculated, a flow rate sensor is provided in the liquid supply path. Here, the method for calculating the pressure in the liquid supply channel is not particularly limited and can be selected appropriately depending on the purpose, and for example, since the diameters of the liquid supply channels on the upstream and downstream sides are constant, it can be calculated from the relationship between pressure and flow rate (pressure is proportional to the square of the flow rate). Note that the flow rate sensor may be provided separately from the pressure measuring means.

[0031] <Control means> The control means is means for controlling the liquid discharge operation of the liquid delivery means to discharge the liquid in the head tank based on the result calculated from the measurement value of the pressure measurement means.

[0032] It is preferable that the control means controls the liquid discharge operation of the liquid delivery means to discharge the liquid from the head tank based on the fluid resistance value or pressure loss value calculated from the measurement value of the pressure measurement means. Here, the fluid resistance value and the pressure loss value indicate the deterioration (clogging) state of the filter.

[0033] As a method for calculating the pressure loss value, for example, there is a method of finding it from the difference between the pressure measured / calculated by the pressure measuring means provided upstream of the filter and the pressure measured / calculated by the pressure measuring means provided downstream of the filter.

[0034] Examples of methods for calculating the fluid resistance include a method of finding the fluid resistance from the equation [fluid resistance = pressure value / flow rate] based on the relational expression [voltage = current x resistance]. More specifically, examples include a method of finding the fluid resistance by dividing the difference between the pressure value measured by the pressure measuring means provided upstream of the filter and the pressure value measured by the pressure measuring means provided downstream of the filter by the flow rate measured by the pressure measuring means. In the case where the flow rate sensor is provided separately from the pressure measuring means, one method is to divide the difference between the pressure value measured by the pressure measuring means provided upstream of the filter and the pressure value measured by the pressure measuring means provided downstream of the filter by the flow rate value measured by the flow rate sensor.

[0035] It is preferable that the calculation of the fluid resistance value and the pressure loss value is performed at the same time as regular maintenance of the liquid ejection device. Here, "regular maintenance" refers to a cleaning operation performed by the cleaning device at regular, preset times (for example, once every few hours). There are no particular restrictions on the cleaning operation, and it can be selected appropriately depending on the purpose, as long as it is a cleaning operation performed on the head tank and the liquid ejection head, but it is preferable that the cleaning operation is a series of operations that drains the liquid in the head tank by suction, wipes the nozzle surface of the liquid ejection head, and then performs a blank ejection operation. The periodic maintenance may be performed manually.

[0036] The timing for calculating the fluid resistance value and the pressure loss value is not particularly limited and can be appropriately selected depending on the purpose, but is preferably any one of the following (1) to (4), and more preferably any one of the following (1) to (2). (1) When the suction pump is suctioning liquid during regular maintenance. (2) During dry discharge operation, which is performed during regular maintenance (3) When the suction pump is suctioning liquid, which is performed at a time other than the regular maintenance. (4) When the supply pump supplies liquid, which is performed at a time other than the regular maintenance. In the liquid suction operation (3) and the liquid supply operation (4), the amount of liquid used is preferably about 0.2 mL. In addition, the liquid supply operation (4) is an operation in which the liquid is continuously supplied into the head tank by the supply pump, thereby pressurizing and discharging the liquid.

[0037] <<Liquid discharge operation>> The liquid discharging operation is controlled by the control means based on the fluid resistance value or pressure loss value calculated from the measurement value of the pressure measurement means.

[0038] [One embodiment of the control means] An embodiment of the control means of the present invention will be described with reference to the flowchart of FIG. If the calculated fluid resistance value and pressure loss value meet any of the following conditions (S1 conditions), the liquid discharging operation is performed (see S1 in FIG. 3, Yes direction). -S1 conditions- When the fluid resistance exceeds the threshold value r - When the fluid resistance or pressure loss exceeds 110% of the initial value By setting such conditions, the total amount of liquid discharged during the periodic maintenance can be reduced, which is preferable. If the calculated fluid resistance value and the pressure loss value do not satisfy any of the S1 conditions, it is preferable to perform the cleaning operation without performing the liquid discharging operation (see S1 in FIG. 3, No direction).

[0039] The "threshold value r" for the fluid resistance is a specific value that differs depending on the liquid used. The threshold value r for the liquid can be set to the maximum fluid resistance value at which the fluid resistance of the liquid can be restored to its initial value by a recovery operation using an actual device and actual liquid. In the present invention, by using the liquid in combination with a liquid ejection device in which a threshold value r corresponding to the liquid is registered in advance, the total amount of liquid discharged during the periodic maintenance can be reduced, which is advantageous. Furthermore, the "initial values" of the fluid resistance value and the pressure loss value are values measured / calculated during the suction operation at the time of initial filling of the liquid.

[0040] If the calculated fluid resistance value and pressure loss value do not satisfy any of the above-mentioned conditions S1, it is preferable to continue the cleaning operation. This cleaning operation is the same as the cleaning operation during the periodic maintenance, so a description thereof will be omitted.

[0041] The liquid discharge operation is not particularly limited and can be selected appropriately depending on the purpose as long as it is an operation in which the liquid in the head tank is discharged outside the head tank, but it is preferable that it is any of the following (5) to (8). (5) Liquid suction operation by a suction pump (6) Liquid supply operation by supply pump (7) Liquid suction operation by the suction pump and liquid supply operation by the supply pump (8) The operation of ejecting liquid from the liquid ejection head. Here, the liquid supply operation (6) is an operation in which the liquid is continuously supplied into the head tank by the supply pump, thereby pressurizing and discharging the liquid. The liquid discharge operation is preferably an operation in which the liquid suction operation (7) and the liquid supply operation are performed simultaneously, from the viewpoint that the pressure difference is increased, which is expected to further improve the filter function, and that only one wiping is required after the liquid discharge operation. The liquid suction operation (5) is preferable because only one wiping operation is required after the liquid discharging operation, and the liquid discharge operation (8) is preferable because no wiping operation is required after the liquid discharging operation.

[0042] The liquid discharge operation is preferably an operation of discharging ink in the vicinity of the filter in the head tank. There are no particular limitations on the method of discharging the liquid in the vicinity of the filter and it can be appropriately selected depending on the purpose. For example, the method can be implemented by providing the suction pump in the vicinity of the filter or by positioning the filter in the head tank in the vicinity of the liquid ejection head.

[0043] The amount of liquid discharged in one liquid discharge operation is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of achieving good liquid permeability, it is preferably at least 5 times the amount of liquid used in the cleaning operation and not more than 2.5 times the capacity of the head tank. Note that "5 times the amount of liquid used in the cleaning operation" is, for example, 1 mL, and "2.5 times the capacity of the head tank" is, for example, 10 mL. In other words, the amount of liquid discharged in one liquid discharging operation is preferably 1 mL or more and 10 mL or less.

[0044] If the liquid discharging operation is only a liquid suction operation by the suction pump, it is preferable to stop the liquid suction operation when half the capacity of the head tank is sucked, and resume the liquid suction operation after the liquid supply operation has been completed, in order to prevent damage to the head tank due to negative pressure and backflow of air.

[0045] During the liquid discharging operation, it is preferable to continue calculating the fluid resistance value or pressure loss value at specific intervals (for example, every cleaning operation).

[0046] During the liquid discharging operation, it is preferable to terminate the liquid discharging operation when the calculated fluid resistance value and the pressure loss value meet any of the following conditions (S2 conditions) (see S2 in FIG. 3). -S2 conditions- When the fluid resistance falls below the threshold value r When the fluid resistance or pressure loss value becomes less than 110% of the initial value When the amount of liquid discharged reaches 2.5 times the head tank capacity

[0047] If the liquid discharge operation is terminated when the fluid resistance value falls below the threshold value r, or when the fluid resistance value or pressure loss value becomes less than 110% of the initial value, it is preferable to continue the cleaning operation (see S2 in Figure 3, Yes direction). When the liquid discharging operation is completed when the amount of liquid discharged reaches 2.5 times the head tank capacity (for example, 10 mL), it is preferable to display a message such as "Filter clogged abnormality" to the user and urge them to replace the filter (see S2 in Figure 3, No direction). If the fluid resistance value and the pressure loss value calculated during the liquid discharging operation tend to decrease as the liquid is discharged and are close to 110% of the threshold value r or the initial value, strong cleaning such as refreshing may be performed. By performing strong cleaning such as refreshing, the fluid resistance value and the pressure loss value may each fall within an allowable range.

[0048] [Another embodiment of the control means] Another embodiment of the control means of the present invention will be described using the flowchart of Fig. 4. Fig. 4 is a flowchart for explaining another embodiment of the control means of the present invention. Fig. 4 is also a flowchart derived from the case where the result of S2 in Fig. 3 is "No."

[0049] It is preferable that the control means has a recovery control means that operates the liquid delivery means based on the fluid resistance value or the pressure loss value calculated from the measurement value of the pressure measurement means, and controls the recovery operation to recover from clogging of the filter. In other words, if the fluid resistance value and the pressure loss value calculated after the liquid discharging operation do not satisfy the condition S2, it is preferable to operate the liquid delivery means to perform a recovery operation to recover the clogged filter. The recovery operation is preferably the same as the liquid supply operation by the supply pump described above in (6). The recovery operation is preferably performed repeatedly from the viewpoint of further improving the fluid resistance value and the pressure loss value.

[0050] During the recovery operation, it is preferable to continue calculating the fluid resistance value and / or the pressure loss value at specific intervals (for example, after each cleaning operation).

[0051] During the recovery operation, it is preferable to terminate the recovery operation when the calculated fluid resistance value and the pressure loss value meet any of the following conditions (S3 conditions) (see S3 in FIG. 4). -S3 Condition- When the fluid resistance falls below the threshold value r When the fluid resistance or pressure loss value becomes less than 110% of the initial value When the amount of liquid discharged reaches 2.5 times the head tank capacity When the recovery operation is terminated when the fluid resistance value falls below the threshold value r, or when the fluid resistance value or pressure loss value becomes less than 110% of the initial value, it is preferable to terminate the recovery operation and continue the cleaning operation (see S3 in Figure 4, Yes direction). If the liquid discharging operation is completed when the amount of discharged liquid reaches 2.5 times the head tank capacity (for example, 10 mL), it is preferable to repeat the recovery operation (see S3 in FIG. 4, No direction).

[0052] Here, when the number of times the recovery operation is repeated is n, it is preferable that the control means determines whether to perform the (n+1)th recovery operation based on the fluid resistance value or the pressure loss value calculated after the nth recovery operation (see S4 to S6 in FIG. 4). Similarly, the control means may determine whether to perform the (n+2)th recovery operation. The number of repetitions n is not particularly limited and can be appropriately selected depending on the purpose.

[0053] Furthermore, it is preferable that the control means performs the (n+1)th recovery operation when the fluid resistance value or the pressure loss value calculated after the nth recovery operation shows a recovery (see S5 in FIG. 4, Yes direction). In other words, it is preferable that the control means does not perform the (n+1)th recovery operation when the fluid resistance value or the pressure loss value calculated after the nth recovery operation does not show a recovery (see S5 in FIG. 4, No direction). In that case, it is preferable to display a message such as "Filter clogging abnormality" to the user to urge them to replace the filter. By setting such a condition, it is possible to prevent the recovery operation from discharging more liquid than necessary, which is preferable.

[0054] It is also preferable that the control means terminates the recovery operation when the number of times the recovery operation has been repeated reaches a predetermined number. Here, the "predetermined number of times" is not particularly limited and can be set appropriately depending on the number of repetitions n. For example, this is effective when the fluid resistance value or the pressure loss value calculated after the recovery operation shows recovery but the degree of recovery is small, and is preferable because it can prevent more liquid than necessary from being discharged by the recovery operation.

[0055] <Liquid> The liquid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include ink. The ink is not particularly limited and can be appropriately selected depending on the purpose. For example, the ink may contain an organic solvent, a coloring material, a resin, and water, and may contain other components as needed. In order to easily obtain the effect of the recovery operation, it is preferable that the ink used in the liquid ejection device of the present invention has a total content (solid content) of the colorant and the resin of 15% by mass or more relative to the total amount of the ink.

[0056] -Organic solvents- The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, and for example, a water-soluble organic solvent can be used, such as polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohols, ethers such as aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds.

[0057] Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, and 1,6-pentanediol. Polyhydric alcohols such as hexanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, and petriol; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethyl ... Examples of suitable amines include polyhydric alcohol alkyl ethers such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate, and ethylene carbonate. Among these, it is preferable to use an organic solvent having a boiling point of 250° C. or less, since it not only functions as a wetting agent but also provides good drying properties.

[0058] As the organic solvent, polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Specific examples of the glycol ether compound include polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; and polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether. The polyol compound having 8 or more carbon atoms and the glycol ether compound can improve the permeability of ink when paper is used as a recording medium.

[0059] The content of the organic solvent is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, the content of the organic solvent is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 60% by mass or less, of the total amount of the ink.

[0060] -water- The content of the water is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, the content of the water is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 60% by mass or less, of the total amount of the ink.

[0061] -Coloring materials- The coloring material is not particularly limited and can be appropriately selected depending on the purpose, and pigments and dyes can be used. The pigment may be an inorganic pigment or an organic pigment. These may be used alone or in combination of two or more. Mixed crystals may also be used.

[0062] Examples of the pigment that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver pigments, and metallic pigments.

[0063] Examples of the inorganic pigment that can be used include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon black produced by known methods such as a contact method, a furnace method, and a thermal method.

[0064] Examples of the organic pigment that can be used include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, and aniline black. Of these pigments, those with good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.

[0065] Specific examples of black pigments include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black; metals such as copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1). Specific examples of pigments for color include CI Pigment Yellow 1, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 17, CI Pigment Yellow 24, CI Pigment Yellow 34, CI Pigment Yellow 35, CI Pigment Yellow 37, CI Pigment Yellow 42 (yellow iron oxide), CI Pigment Yellow 53, CI Pigment Yellow 55, CI Pigment Yellow 74, C CI Pigment Yellow 81, CI Pigment Yellow 83, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Yellow 100, CI Pigment Yellow 101, CI Pigment Yellow 104, CI Pigment Yellow 108, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 117, CI Pigment Yellow 120, CI Pigment Yellow 138, CI Pigment Yellow 150, CI Pigment Yellow 153, CI Pigment Yellow 155, CI Pigment Yellow 180, CI Pigment Yellow 185, CI Pigment Yellow 213, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 36, CI Pigment Orange 43, CI Pigment Orange 51, CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 5 , CI Pigment Red 17, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 31, CI Pigment Red 38, CI Pigment Red 48:2, CI Pigment Red 48:2 (Permanent Red 2B (Ca)), CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 49:1, CI Pigment Red 52:2, CI Pigment Red 53:1, CI Pigment Red 57:1 (Brilliant Carmine 6B), CIPigment Red 60:1, CI Pigment Red 63:1, CI Pigment Red 63:2, CI Pigment Red 64:1, CI Pigment Red 81, CI Pigment Red 83, CI Pigment Red 88, CI Pigment Red 101 (Red Foot), CI Pigment Red 104, CI Pigment Red 105, CI Pigment Red 106, CI Pigment Red 108 (Cadmium Red), CI Pigment Red 112, CI Pigment Red 114, CI Pigment Red Pigment Red 122 (Quinacridone Magenta), CI Pigment Red 123, CI Pigment Red 146, CI Pigment Red 149, CI Pigment Red 166, CI Pigment Red 168, CI Pigment Red 170, CI Pigment Red 172, CI Pigment Red 177, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 190, CI Pigment Red 193, CI Pigment Red Red 202, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 213, CI Pigment Red 219, CI Pigment Red 224, CI Pigment Red 254, CI Pigment Red 264, CI Pigment Violet 1 (Rhodamine Lake), CI Pigment Violet 3, CI Pigment Violet 5:1, CI Pigment Violet 16, CI Pigment Violet 19, CI Pigment Violet 2 3, CI Pigment Violet 38, CI Pigment Blue 1, CI Pigment Blue 2, CI Pigment Blue 15 (Phthalocyanine Blue), CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4 (Phthalocyanine Blue), CI Pigment Blue 16, CI Pigment Blue 17:1, CI Pigment Blue 56, CI Pigment Blue 60, CI Pigment Blue 63, CI Pigment Green 1, CIPigment Green 4, CI Pigment Green 7, CI Pigment Green 8, CI Pigment Green 10, CI Pigment Green 17, CI Pigment Green 18, and CI Pigment Green 36.

[0066] The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. These dyes can be used alone or in combination of two or more. Specific examples of the dyes include CI Acid Yellow 17, CI Acid Yellow 23, CI Acid Yellow 42, CI Acid Yellow 44, CI Acid Yellow 79, CI Acid Yellow 142, CI Acid Red 52, CI Acid Red 80, CI Acid Red 82, CI Acid Red 249, CI Acid Red 254, CI Acid Red 289, CI Acid Blue 9, CI Acid Blue 45, CI Acid Blue 249, CI Acid Black 1, CI Acid Black 2, CI Acid Black 24, CI Acid Black 94, CI Food Black 1, CI Food Black 2, CI Direct Yellow 1, CI Direct Yellow 12, CI Direct Yellow 24, CI Direct Yellow 33, CI Direct Yellow 50, CI Direct Yellow 55, CI Direct Yellow 58, CI Direct Yellow 86, CI Direct Yellow 132, CI Direct Yellow 142, CI Direct Yellow 144, CI Dye Direct Yellow 173, CI Direct Red 1, CI Direct Red 4, CI Direct Red 9, CI Direct Red 80, CI Direct Red 81, CI Direct Red 225, CI Direct Red 227, CI Direct Blue 1, CI Direct Blue 2, CI Direct Blue 15, CI Direct Blue 71, CI Direct Blue 86, CI Direct Blue 87, CI Direct Blue 98, CI Direct Blue 165, CI Direct Blue 199, CI Direct Blue 202, CI Direct Black 19, CI Direct Black 38, CI Direct Black 51, CI Direct Black 71, CI Direct Black 154, CI Direct Black 168, CI Direct Black 171, CI Direct Black 195, CI Reactive Red 14, CI Reactive Red 32, CI Reactive Red 55, CI Reactive Red 79, CI Reactive Red 249, CI Reactive Black 3Examples include Reactive Black 4 and CI Reactive Black 35.

[0067] The content of the coloring material is preferably 0.1% by mass or more and 15% by mass or less, and more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the ink, from the viewpoints of improving image density, good fixability, and ejection stability.

[0068] Methods for dispersing a pigment to obtain an ink include a method of introducing a hydrophilic functional group into the pigment to make it a self-dispersing pigment, a method of dispersing the pigment by coating the surface of the pigment with a resin, and a method of dispersing the pigment using a dispersant. As a method for introducing a hydrophilic functional group into a pigment to make it a self-dispersible pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (e.g., carbon) to make it dispersible in water can be mentioned. One method for dispersing a pigment by coating its surface with a resin is to encapsulate the pigment in microcapsules to make it dispersible in water. This can be rephrased as a resin-coated pigment. In this case, it is not necessary for all of the pigments blended into the ink to be coated with resin; uncoated or partially coated pigments may be dispersed in the ink, provided that the effects of the present invention are not impaired. Examples of the method for dispersing using a dispersant include a method for dispersing using a known low molecular weight dispersant or a high molecular weight dispersant, such as a surfactant. As the dispersant, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used depending on the pigment. RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used as dispersants. The dispersant may be used alone or in combination of two or more kinds.

[0069] --Pigment dispersions-- Ink can be obtained by mixing a pigment with water, an organic solvent, or other materials. Alternatively, ink can be produced by mixing a pigment with other materials such as water and a dispersant to form a pigment dispersion, and then mixing the resulting mixture with water, an organic solvent, or other materials. The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and optionally other components, and adjusting the particle size. Dispersion is preferably performed using a disperser. The particle size of the pigment in the pigment dispersion is not particularly limited, but in terms of improving the dispersion stability of the pigment and improving the image quality such as ejection stability and image density, the maximum frequency in terms of maximum number is preferably 20 nm to 500 nm, and more preferably 20 nm to 150 nm. The particle size of the pigment can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.). It is preferable that the pigment dispersion is degassed, if necessary, by filtering coarse particles using a filter, a centrifugal separator, or the like.

[0070] The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of obtaining good ejection stability and increasing image density, the content is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 0.1% by mass or more and 30% by mass or less.

[0071] -resin- The resin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, acrylic silicone resin, etc. Resin particles made of these resins may also be used. Ink can be obtained by mixing resin particles dispersed in water as a dispersion medium in the form of a resin emulsion with materials such as coloring materials and organic solvents. The resin particles may be appropriately synthesized or commercially available. These may be used alone or in combination of two or more types of resin particles.

[0072] The volume average particle size of the resin particles is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of obtaining good fixing properties and high image hardness, the volume average particle size is preferably 10 nm or more and 1,000 nm or less, more preferably 10 nm or more and 200 nm or less, and particularly preferably 10 nm or more and 100 nm or less. The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0073] The content of the resin is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of fixability and storage stability of the ink, the content of the resin is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, of the total amount of the ink.

[0074] The physical properties of the ink are not particularly limited and can be appropriately selected depending on the purpose. For example, it is preferable that the viscosity, surface tension, pH, etc. are within the following ranges. The viscosity of the ink at 25°C is preferably 5 mPa·s or more and 30 mPa·s or less, and more preferably 5 mPa·s or more and 25 mPa·s or less, in order to improve print density and character quality and obtain good ejection properties. Here, the viscosity can be measured using, for example, a rotational viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.). Measurement conditions are 25°C, a standard cone rotor (1°34' x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes. The surface tension of the ink is preferably 35 mN / m or less, and more preferably 32 mN / m or less at 25° C., in order to ensure that the ink is properly leveled on the recording medium and the drying time of the ink is shortened. The pH of the ink is preferably 7 to 12, and more preferably 8 to 11, from the viewpoint of preventing corrosion of metal members that come into contact with the ink.

[0075] -Recording Media- The recording medium used for recording is not particularly limited, but examples include plain paper, glossy paper, special paper, cloth, film, OHP sheets, and general-purpose printing paper. The recording medium is not limited to those generally used as recording media, and can be wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather, etc. Ceramics, glass, metal, etc. can also be used by adjusting the configuration of the path along which the recording medium is conveyed.

[0076] The use of the ink according to the present invention is not particularly limited and can be appropriately selected depending on the purpose, and can be applied to, for example, printed matter, paint, coating material, base, etc. Furthermore, in addition to being used as an ink to form two-dimensional characters and images, it can also be used as a material for three-dimensional modeling to form three-dimensional solid images (three-dimensional models). The three-dimensional modeling apparatus for forming a three-dimensional object can be a known one and is not particularly limited. For example, an apparatus equipped with ink storage means, supply means, discharge means, drying means, etc. can be used. Three-dimensional models include three-dimensional models obtained by applying ink multiple times. They also include molded products obtained by processing a structure to which ink has been applied onto a substrate such as a recording medium. The molded products are, for example, records or structures formed in a sheet or film form that have been subjected to molding processes such as heat stretching or punching, and are suitable for applications in which the surface is decorated and then molded, such as meters and operation panel panels for automobiles, office automation equipment, electrical and electronic devices, cameras, etc.

[0077] In addition, in the present invention, the terms image formation, recording, printing, printing, etc. are all synonymous.

[0078] Recording medium, media, and printed material are all synonymous terms.

[0079] [Image forming method and image forming apparatus] The liquid ejection apparatus of the present invention can be applied to an image forming apparatus and an image forming method. The image forming apparatus has the liquid ejection device, and also has a white ink application means for applying white ink to the fabric, and a color ink application means for applying color ink to the area to which the white ink has been applied, and may also have a white ink storage means for storing the white ink, a color ink storage means for storing the color ink, and other means as necessary. The image forming method includes a white ink application step of applying white ink to a fabric, and a color ink application step of applying color ink to the area to which the white ink has been applied, and may include other steps as necessary. The white ink applying step can be suitably carried out by the white ink applying means, the color ink applying step can be suitably carried out by the color ink applying means, and the other steps can be suitably carried out by the other means.

[0080] The image forming apparatus and image forming method in this specification refer to an apparatus capable of ejecting the white ink, the color ink, and, if necessary, various other processing liquids onto a recording medium, and a method of recording using the apparatus. The recording medium means a material to which the white ink, the color ink, and, if necessary, other various treatment liquids can be attached even temporarily, and is preferably a fabric.

[0081] <Fabric> The fabric is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include cotton broadcloth and polyester tropical fabric.

[0082] <White Ink Applying Step, White Ink Applying Unit, Color Ink Applying Step, and Color Ink Applying Unit> The white ink applying step is a step of applying white ink to the fabric. The white ink applying means is a means for applying white ink to the fabric. The color ink application step is a step of applying color ink to the area to which the white ink has been applied. The color ink applying means is a means for applying color ink to the area to which the white ink has been applied. These application steps (means) are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include inkjet method, blade coating method, gravure coating method, bar coating method, roll coating method, dip coating method, curtain coating method, slide coating method, die coating method, spray coating method, etc. Among these, the inkjet method is preferred.

[0083] <Other steps and other means> The other steps are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a pre-treatment liquid application step, a drying step, and a post-treatment liquid application step. The other means are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a pre-treatment liquid applying means, a drying means, and a post-treatment liquid applying means.

[0084] <<Pretreatment Liquid Application Step and Pretreatment Liquid Application Unit>> The pretreatment liquid application step is a step of applying a pretreatment liquid to a fabric. The pretreatment liquid applying means is a means for applying a pretreatment liquid to a fabric. The pretreatment liquid applying means is not particularly limited and can be appropriately selected depending on the purpose. For example, the same applying means as those described above can be used.

[0085] <<Drying process and drying means>> The drying step is a step of drying the fabric to which the white ink or the color ink has been applied. The drying means includes a means for drying the fabric to which the white ink or the color ink has been applied. The drying step can be suitably carried out by the drying means. The drying step (means) can also be called a heating step (means). The drying (heating) step and the drying (heating) means are not particularly limited, but for example, a hot air heater, an infrared heater, etc. Heating and drying can be carried out before, during, or after printing.

[0086] <<Post-treatment liquid application step and post-treatment liquid application unit>> The post-treatment liquid application step is a step of applying a post-treatment liquid to the fabric to which the color ink has been applied. The post-treatment liquid applying unit applies a post-treatment liquid to the fabric to which the color ink has been applied. The post-treatment liquid application step can be suitably carried out by the post-treatment liquid application unit. The post-treatment liquid applying means is not particularly limited and can be appropriately selected depending on the purpose. For example, the same applying means as those described above can be used.

[0087] As one aspect of the post-treatment liquid application means, a liquid storage section having the post-treatment liquid and a liquid ejection head are added, and the post-treatment liquid is ejected by an inkjet recording method, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y).

[0088] The image forming apparatus can be applied to various recording apparatuses using an inkjet recording method, such as printers, facsimile machines, copying machines, printer / fax / copier combination machines, and three-dimensional modeling apparatuses.

[0089] The image forming method and image forming device are not limited to those that visualize meaningful images such as letters and figures using ink, but also include those that form patterns such as geometric designs and those that create three-dimensional images. Unless otherwise specified, the image forming apparatus includes both serial type apparatuses in which the ejection head moves and line type apparatuses in which the ejection head does not move.Furthermore, it also includes not only desktop types but also wide recording apparatuses that can print on A0 size fabrics and continuous feed printers that can use, for example, rolled fabrics as a recording medium.

[0090] Here, an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments.

[0091] Fig. 5A is a schematic plan view showing an example of a mechanical section of an image forming apparatus according to the present invention. Fig. 5B is a schematic side view showing an example of a mechanical section of an image forming apparatus according to the present invention. Fig. 5C is a schematic plan view showing an example of an inkjet head of an image forming apparatus according to the present invention. Note that Fig. 5C shows the head in a see-through state from above.

[0092] The image forming apparatus in Fig. 5A is a serial inkjet recording apparatus, and a carriage 3 is held movably in the main scanning direction by a main guide member 1 and a secondary guide member (not shown) that are hung between left and right side plates (not shown). A main scanning motor 5 causes the carriage 3 to move back and forth in the main scanning direction (carriage movement direction) via a timing belt 8 that is hung between a drive pulley 6 and a driven pulley 7.

[0093] The carriage 3 is equipped with, as image forming means, two recording heads 4a and 4b each consisting of a liquid ejection head, and head tanks 5a and 5b for supplying liquid to the recording heads 4a and 4b, respectively.

[0094] As shown in Fig. 5C, the print head 4a and print head 4b (sometimes collectively referred to as "print head 4") each have two nozzle rows Na and Nb, each of which has a plurality of nozzles 4n arranged therein. The nozzle rows Na and Nb are arranged in a staggered pattern, with the nozzles offset in the nozzle arrangement direction.

[0095] One nozzle row Na in recording head 4a ejects black (K) droplets, and the other nozzle row Nb ejects cyan (C) droplets. Also, one nozzle row Na in recording head 4b ejects magenta (M) droplets, and the other nozzle row Nb ejects yellow (Y) droplets. The recording head 4 may be a single recording head (liquid ejection head) having a plurality of nozzle rows on the nozzle surface 41, each nozzle row ejecting droplets of each color.

[0096] The carriage 3 has four recording heads, two of which can eject white (Wh). Two carriages 3 (carriage 3, carriage 3') can also be provided, one dedicated to color inks and the other for white ink.

[0097] Furthermore, the liquid ejection head constituting the recording head 4 may be, for example, a piezoelectric actuator such as a piezoelectric element, or a thermal actuator that utilizes a phase change caused by film boiling of the liquid using an electrothermal conversion element such as a heating resistor.

[0098] The head tank 5a and the head tank 5b are configured to have a plurality of tank sections, each of which is a pair of two tank sections corresponding to the two nozzle rows Na and Nb of each of the recording heads 4a and 4b. The main body of the device is provided with a cartridge holder 51 to which main tanks (liquid cartridges) 50 (50y, 50m, 50c, 50k) containing liquids of the respective colors are replaceably attached. A liquid feed pump unit 52 is provided in this cartridge holder 51, and the liquid feed pump unit 52 supplies the liquids of the respective colors from the main tank 50 to the head tanks 5a and 5b via supply tubes (also referred to as "liquid supply paths") 56 of the respective colors.

[0099] On the other hand, a conveyor belt 12 is provided as a conveying means for adsorbing the paper P and conveying it to a position facing the recording head 4. The conveyor belt 12 is an endless belt, and is stretched between a conveyor roller 13 and a tension roller 14. The conveyor belt 12 moves in a circular motion in the sub-scanning direction as the conveyor roller 13 is rotationally driven by a sub-scanning motor 16 via a timing belt 17 and a timing pulley 18. While moving in a circular motion, the conveyor belt 12 is charged (charged) by a charging roller (not shown) or the paper P is sucked by a suction means (not shown). When the recording medium is not paper (such as fabric), the recording medium is placed on a flat platen instead of a conveyor belt, and the platen is moved by a sub-scanning motor.

[0100] On one side of the carriage 3 in the main scanning direction, a maintenance recovery mechanism 20, which is one of recovery operation means that performs recovery operation of the recording head 4, is arranged on the side of the conveyor belt 12. On the other side of the carriage 3 in the main scanning direction, a blank discharge receiver 81 that performs blank discharge from the recording head 4 is arranged on the side of the conveyor belt 12.

[0101] The maintenance and recovery mechanism 20 is composed of, for example, a suction cap 21 that caps the nozzle surface 41 of the recording head 4, a moisture retention cap 22, a wiper member 23 that wipes the nozzle surface 41, and a blank discharge receiver 24 that discharges droplets that do not contribute to image formation. Blank discharge can also be performed on the suction cap 21.

[0102] Further, outside the recording area between the conveyor belt 12 and the maintenance and recovery mechanism 20, in an area that can face the recording head 4, a discharge detection unit 100 that detects the presence or absence of droplet discharge (discharge state) is disposed. The discharge detection unit 100 includes an electrode plate when configuring a discharge detection device that detects the presence or absence of droplet discharge by detecting an electrical change caused by droplets landing on the electrode plate. Also, the discharge detection unit 100 includes a light emitting section and a light receiving section when configuring a discharge detection device that detects the presence or absence of droplet discharge by laser light.

[0103] An encoder scale 123 with a predetermined pattern formed on it is stretched between both side plates along the main scanning direction of the carriage 3, and the carriage 3 is provided with an encoder sensor 124 consisting of a transmission type photosensor that reads the pattern on the encoder scale 123. The encoder scale 123 and encoder sensor 124 together form a linear encoder (main scanning encoder) that detects the movement of the carriage 3.

[0104] A code wheel 125 is attached to the shaft of the conveying roller 13, and an encoder sensor 126 consisting of a transmission type photosensor is provided to detect a pattern formed on this code wheel 125. The code wheel 125 and encoder sensor 126 together form a rotary encoder (sub-scanning encoder) that detects the amount of movement and movement position of the conveying belt 12.

[0105] In the image forming apparatus configured in this manner, the paper P is fed onto the charged conveyor belt 12, where it is attracted to the conveyor belt 12, and is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 12. Therefore, while moving the carriage 3 in the main scanning direction, the recording head 4 is driven in accordance with an image signal to eject ink droplets onto the stationary paper P, thereby recording one line. Then, after the paper P is transported a predetermined distance, the next line is recorded. Upon receiving a recording end signal or a signal indicating that the rear end of the paper P has reached the recording area, the recording operation is terminated and the paper P is discharged to a paper discharge tray (not shown).

[0106] FIG. 6 is a diagram showing an example of the hardware configuration of an image forming apparatus according to the present invention. The control unit 500 includes a CPU 301 , a ROM 302 , a RAM 303 , a non-volatile memory (NVRAM) 304 , an external device connection I / F 305 , and a network I / F 306 . The CPU 301 controls the image forming apparatus 3000 . The ROM 302 stores programs including a program for causing the CPU 301 to execute control according to the present invention, and other fixed data. The RAM 303 temporarily stores image data and the like. Non-volatile memory (NVRAM) 304 retains data even when the device is powered off. The external device connection I / F 305 and the network I / F 306 transmit and receive data and signals used when receiving data from the outside.

[0107] The control unit 500 controls the driving of the liquid ejection head driver 307 of the carriage 3 , and drives the liquid ejection head 4 via the liquid ejection head driver 307 . The control unit 500 controls the driving of the main scanning driver 308 , and drives the carriage 3 via the main scanning driver 308 . The control unit 500 controls the driving of the sub-scanning driver 309 , and drives the paper transport unit or the platen operating unit 12 via the sub-scanning driver 309 . The control unit 500 drives and controls the pressure sensors 41 and 42 of the carriage 3, the maintenance and recovery mechanism 20, and the operation panel 310 for inputting and displaying information required for the apparatus.

[0108] FIG. 7A is an example of a functional block diagram relating to image formation in the image forming apparatus according to the present invention. The storage unit 300 is a hard disk drive or the like, and stores data such as images to be printed. The main control unit 500 is a CPU or the like, and issues instructions to the storage unit and each control unit. The ink applying unit 3 is an inkjet head or the like, and applies ink to an object. The ink application control unit controls the ink application unit, the main scanning motor, and the sub scanning motor in response to instructions from the main control unit.

[0109] FIG. 7B is an example of a functional block diagram relating to maintenance in the image forming apparatus according to the present invention. The ink application control unit controls the ink application unit 3, the ink delivery unit 52, and the ink suction unit 20. The ink suction unit 20 sucks ink from the ink application unit 3 (maintenance module). The ink delivery unit 52 supplies ink to the ink application unit 3 (supply module). The resistance value detection units 41 and 42 are pressure sensors that detect the fluid resistance value when the ink flows. The sensor control unit compares the fluid resistance values detected by the resistance value detection units 41 and 42 with threshold values or the like, and controls the ink application control unit.

[0110] The liquid ejection device of the present invention can also be applied to a three-dimensional modeling device (3D printer). An embodiment of a three-dimensional modeling device according to the present invention will be described below.

[0111] Fig. 8 is a schematic plan view of one embodiment of a three-dimensional modeling apparatus according to the present invention. Fig. 9 is a schematic cross-sectional view showing an example of the three-dimensional modeling apparatus of Fig. 8 when viewed from the right in Fig. 8. Fig. 10 is a schematic cross-sectional view showing an example of a powder holding unit of Fig. 9. Fig. 11 is a perspective explanatory view showing an example of a main part of a three-dimensional modeling apparatus according to the present invention. Fig. 10 is a schematic cross-sectional view of the AA cross section in Fig. 11.

[0112] The three-dimensional modeling apparatus 700 is a powder modeling apparatus (also referred to as a "powder modeling apparatus"). The three-dimensional modeling apparatus 700 includes a powder holding unit 701 in which a layered modeled object 730 formed by bonding powder 720 (powder) is formed, and a modeling unit 705 that ejects a modeling liquid 710 onto the powder layer of the powder 720 spread in layers on the powder holding unit 701. The liquid in the liquid ejection device of the present invention can be used as this modeling liquid 710.

[0113] The powder holding unit 701 and the modeling unit 705 are configured to be relatively movable in the Y direction, and the liquid discharge unit 750 of the modeling unit 705 is configured to be relatively movable in the X direction with respect to the powder holding unit 701.

[0114] The powder holding unit 701 includes a powder container 711 and a flattening roller 712, which is a rotating member serving as a flattening member constituting a flattening means (recoater). The flattening member may be, for example, a plate-like member (blade) instead of a rotating member.

[0115] The powder storage tank 711 includes a modeling tank 722 in which a layered model 730 is stacked to form a three-dimensional object, a supply tank 721 that stores powder 720 to be supplied to the modeling tank 722, and an excess powder collection tank 729 that collects excess powder 720 supplied to the modeling tank 722. The modeling tank 722 and the supply tank 721 are arranged side by side in the Y direction.

[0116] A supply stage 723, which constitutes the bottom of the supply tank 721, is movable up and down in the vertical direction (height direction). Powder 720, which will be the modeling material, is placed on the supply stage 723. A modeling stage 724, which constitutes the bottom of the modeling tank 722, is also movable up and down in the vertical direction (height direction). A three-dimensional modeled object is formed on the modeling stage 724 by stacking layered models 730.

[0117] 12 is a block diagram showing an overview of the control unit in the three-dimensional printing apparatus. The control unit 5000 controls the drive of the supply stage lift motor 2700, thereby raising and lowering the supply stage 723 in the Z direction (height direction). The control unit 5000 also controls the drive of the modeling stage lift motor 2800, thereby raising and lowering the modeling stage 724 in the Z direction (height direction).

[0118] The side of the supply stage 723 is disposed so as to contact the inner surface of the supply tank 721. The side of the modeling stage 724 is also disposed so as to contact the inner surface of the modeling tank 722. The upper surfaces of the supply stage 723 and the modeling stage 724 are kept horizontal.

[0119] A powder supply device 5540 is disposed in the supply tank 721. During the initial operation of modeling or when the amount of powder in the supply tank 721 decreases, the control unit 5000 controls the driving of the powder supply drive unit 5170 to supply powder 720 in a tank constituting the powder supply device 5540 to the supply tank 721. Examples of powder transport methods for supplying powder include a screw conveyor system using a screw and a pneumatic transport system using air.

[0120] The flattening roller 712 has an axial length (length in the X direction) longer than the inner widths of the modeling tank 722 and the supply tank 721. The flattening roller 712 is disposed so as to be able to reciprocate in the Y direction relative to the stage surface (the surface on which the powder 720 is loaded) of the modeling stage 724. The controller 5000 controls the drive of the flattening roller reciprocating motor 2500, so that the flattening roller 712 moves horizontally along the upper surfaces of the supply stage 723 and the modeling stage 724. When supplying the powder 720 to the modeling tank 722, the flattening roller 712 moves horizontally, so that the flattening roller 712 pushes a portion of the powder 720 stored on the supply stage 723 of the supply tank 721 horizontally, transferring the powder 720 to the modeling tank 722, and supplying it. At this time, the flattening roller 712 flattens the surface (upper surface) of the powder 720 supplied to the modeling tank 722, forming a powder layer 731 of a predetermined thickness.

[0121] The flattening roller 712 is rotated by a flattening roller rotation motor 2600. The flattening roller 712 moves back and forth horizontally while being rotated by the flattening roller rotation motor 2600, passing above the supply tank 721 and the model-forming tank 722. As a result, the powder 720 above the supply tank 721 is pushed by the flattening roller 712 and transferred to the model-forming tank 722, and the flattening roller 712 passes over the model-forming tank 722, transferring and flattening the powder 720, thereby forming a powder layer 731 of a desired thickness.

[0122] The modeling unit 705 is equipped with a liquid ejection unit 750 that ejects (applies) modeling liquid 710 that bonds powder 720 to a powder layer 731 of a predetermined thickness on the modeling stage 724, thereby forming a layered modeled object 730 as a layered structure in which the powder 720 is bonded.

[0123] The liquid ejection unit 750 comprises a carriage 751 and two (or one or three or more) liquid ejection heads mounted on the carriage 751, namely a first head 752a and a second head 752b (when not distinguishing, referred to as "heads 752").

[0124] The carriage 751 is held by a first guide member 754 and a second guide member 755 so as to be movable in the arrow X direction, which is the main scanning direction (hereinafter simply referred to as the "X direction"; the same applies to the other directions Y and Z). Both ends of the first guide member 754 and the second guide member 755 in the X direction are supported by support members 775 (first support member 775a and second support member 775b), and are held so as to be able to move up and down relative to side plates 770 (first side plate 770a and second side plate 770b). The carriage 751 is moved back and forth in the X direction, which is the main scanning direction, via pulleys and a belt by an X-direction scanning motor that constitutes a main scanning direction movement mechanism 5500.

[0125] Each head 752 has two nozzle rows, each of which has an array of nozzles that eject the modeling liquid 710. The two nozzle rows of the first head 752a eject the cyan modeling liquid and the magenta modeling liquid, respectively. The two nozzle rows of the second head 752b eject the yellow modeling liquid and the black modeling liquid, respectively. The configuration of the head 752 and the colors of the modeling liquids that are ejected are not limited to this.

[0126] As shown in FIG. 8, multiple tanks 760 containing the cyan, magenta, yellow, and black modeling liquids are mounted on the tank mounting portion 756, and the modeling liquids of each color are supplied to the head 752 via supply tubes or the like.

[0127] A maintenance mechanism 761 that maintains and recovers the head 752 of the liquid ejection unit 750 is disposed on one side (the right side in FIG. 8 ) of the movement range of the carriage 751 in the X direction. The maintenance mechanism 761 is mainly composed of a cap 762 and a wiper 763. The maintenance mechanism 761 brings the cap 762 into close contact with the nozzle surface (the surface on which the nozzles are formed) of the head 752 and sucks the modeling liquid from the nozzles. This is to discharge the powder 720 that has clogged the nozzles and the modeling liquid that has become highly viscous. After that, the maintenance mechanism 761 wipes (wipes) the nozzle surface with the wiper 763 to form a meniscus in the nozzle. In addition, the maintenance mechanism 761 covers the nozzle surface of the head 752 with the cap 762 during periods when the modeling liquid is not being ejected, preventing the powder 720 from entering the nozzles and the modeling liquid 710 from drying out.

[0128] The modeling unit 705 has a slider portion 772 movably held by a guide member 771 disposed on a base member 707, and the entire modeling unit 705 is reciprocable in the Y direction (sub-scanning direction) perpendicular to the X direction. The entire modeling unit 705 is reciprocated in the Y direction by a sub-scanning direction movement mechanism 5520.

[0129] The liquid discharge unit 750 is arranged so as to be able to move up and down in the Z direction together with the first guide member 754 and the second guide member 755, and is raised and lowered in the Z direction by a discharge unit lifting mechanism 5510.

[0130] Next, an overview of the control unit 5000 of the three-dimensional modeling apparatus 700 will be described with reference to FIG. The control unit 5000 includes a main control unit 5000A including a CPU 5010, a ROM 5020, and a RAM 5030. The CPU 5010 is responsible for overall control of the 3D printing apparatus 700. The ROM 5020 stores programs including a program for causing the CPU 5010 to execute control of the 3D printing operation, and other fixed data, and the RAM 5030 temporarily stores printing data, etc.

[0131] The control unit 5000 includes a nonvolatile memory (NVRAM 5040) for storing data even when the power to the device is cut off. The control unit 5000 also includes an ASIC 5050 for image processing, which performs various signal processing on image data, and for processing input / output signals for controlling the entire device.

[0132] The control unit 5000 includes an external interface 5060 (external I / F) for transmitting and receiving data and signals used when receiving modeling data from an external modeling data creation device 800. The modeling data creation device 800 is a device that creates modeling data by slicing a final three-dimensional model into individual layered models, and is implemented by an information processing device such as a personal computer. The control unit 5000 also includes an input / output unit 5070 (I / O) for receiving detection signals from various sensors. Detection signals from a temperature and humidity sensor 5600 that detects temperature and humidity as environmental conditions of the device, and other sensors, are input to the input / output unit 5070.

[0133] The control unit 5000 includes a head drive control unit 5080 that controls the driving of the head 5200 of the liquid ejection unit 750 . The control unit 5000 also includes a main scanning direction drive unit 5100 and a sub-scanning direction drive unit 5120. The main scanning direction drive unit 5100 drives a motor constituting a main scanning direction movement mechanism 5500 that moves the carriage 751 of the liquid discharge unit 750 in the X direction (main scanning direction). The sub-scanning direction drive unit 5120 drives a motor constituting a sub-scanning direction movement mechanism 5520 that moves the modeling unit 705 in the Y direction (sub-scanning direction).

[0134] Furthermore, the control unit 5000 includes a discharge unit lifting drive unit 5110 that drives a motor constituting a discharge unit lifting mechanism 5510 that moves (lifts and lowers) the carriage 751 of the liquid discharge unit 750 in the Z direction. The lifting in the Z direction can also be configured to lift and lower the entire modeling unit 5.

[0135] The control unit 5000 includes a supply stage driver 5130 that drives a supply stage lift motor 2700 that raises and lowers the supply stage 723, and a modeling stage driver 5140 that drives a modeling stage lift motor 2800 that raises and lowers the modeling stage 724. The control unit 5000 also includes a flattening reciprocating driver 5150 that drives a flattening roller reciprocating motor 725 that moves the flattening roller 712, and a flattening rotation driver 5160 that drives a flattening roller rotation motor 2600 that rotates the flattening roller 712.

[0136] The control unit 5000 includes a powder supply driving unit 5170 that drives a powder supplying device 5540 that supplies powder 720 to the supply tank 721 , and a maintenance driving unit 5180 that drives a maintenance mechanism 6100 of the liquid discharge unit 750 .

[0137] The control unit 5000 is connected to an operation panel 5220 for the user to input necessary information and for the information to be displayed to the user.

[0138] In one example of a process for supplying powder 720 to the modeling tank 722, the supply stage 723 is raised by 200 μm, the modeling stage 724 is lowered by 100 μm, and the flattening roller 712 is moved to the right in FIG. 10. As a result, the flattening roller 712 pushes the powder 720 equivalent to the amount of powder 720 that was raised by the supply stage 723, moving it to the right in FIG. 10, and a new powder layer of 100 μm can be deposited on the modeling tank 722. Of the powder 720 pushed and transferred by the flattening roller 712, the excess powder 720 that does not fit into the modeling tank 722 is collected in the excess powder collection tank 729.

[0139] The powder 720 may be, for example, a powder of stainless steel powder coated with a resin material. The stainless steel powder may be gas atomized powder PSS316L-20 μm grade (manufactured by Sanyo Special Steel Co., Ltd.). The resin material used for coating is not limited to those mentioned above. Examples include polyvinyl alcohol (PVA-205C, PVA-220C, manufactured by Kuraray Co., Ltd.), polyacrylic acid (Jurymer AC-10, manufactured by Toagosei Co., Ltd.), sodium polyacrylate (Jurymer AC-103P, manufactured by Toagosei Co., Ltd.), acetoacetyl-modified polyvinyl alcohol (Gosenex Z-300, Gosenex Z-100, Gosenex Z-200, Gosenex Z-205, Gosenex Z-210, Gosenex Z-220, manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.), and carbomer. Examples of suitable polymers include carboxyl-modified polyvinyl alcohol (Gohsenx T-330, Gohsenx T-350, and Gohsenx T-330T, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), butanediol-vinyl alcohol copolymer (Nichigo G-Polymer OKS-8041, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), carboxymethyl cellulose (Cellogen 5A, manufactured by Daiichi Kogyo Co., Ltd.), starch (Histard PSS-5, manufactured by Sanwa Starch Industry Co., Ltd.), and gelatin (B-Matrix Gelatin, manufactured by Nitta Gelatin Co., Ltd.).

[0140] Next, an example of the operation of forming a powder layer in the three-dimensional modeling apparatus will be described with reference to FIG. FIG. 13 is an explanatory diagram for explaining an example of the powder layer forming operation according to this embodiment. First, as shown in FIG. 13( a ), it is assumed that one or more layered objects 730 are formed on the modeling stage 724 of the modeling tank 722 .

[0141] When forming a powder layer 731 of a predetermined thickness on the topmost layer-like object 730 to form the next layer-like object 730, as shown in FIG. 13(b), the supply stage 723 of the supply tank 721 is raised in the "Z1" direction (upward) by a movement amount "z1". At the same time, the modeling stage 724 of the modeling tank 722 is lowered in the "Z2" direction (downward) by a movement amount "z2". The movement amounts "z1" and "z2" are set to values greater than the target thickness "Δt" of the powder layer 731 of the predetermined thickness (the thickness when the modeling liquid 710 is supplied and the layer-like object 730 is formed). The target thickness "Δt" is preferably, for example, approximately several tens to several hundred μm.

[0142] By raising the supply stage 723 by "z1", the height of the top surface of the powder 720 on the supply stage 723 becomes higher by "Δt1 (≒z1)" than the upper end of the side wall that forms the supply tank 721. In addition, by lowering the modeling stage 724 by "z2", the height of the top surface of the powder 720 on the modeling stage 724 becomes higher by "Δt2 (≒z2)" than the upper end of the side wall that forms the modeling tank 722.

[0143] The relationship between the movement amount "z1" of the supply stage 723 and the movement amount "z2" of the modeling stage 724 is "z1 ≧ z2." The upper surface of the supply stage 723 and the upper surface of the modeling stage 724 have the same area. This allows a sufficient amount of powder 720 to be supplied from the supply tank 721 to the modeling tank 722 to cover the entire gap above the top surface of the powder 720 in the modeling tank 722, which is created by the lowering of the modeling stage 724. Of the powder 720 transferred from the supply tank 721 to the modeling tank 722, the excess powder 720 that does not enter the modeling tank 722 and is not supplied into the modeling tank 722 falls into the excess powder collection tank 729 as excess powder 720a and is collected.

[0144] By generating such excess powder 720a, while the flattening roller 712 transfers the powder 720 from the supply tank 721 to the downstream end of the modeling tank 722 in the "Y2" direction from the supply tank 721 toward the modeling tank 722, the excess powder 720 is always present downstream in the movement direction of the flattening roller 712. The presence of the excess powder 720 downstream in the movement direction of the flattening roller 712 in this way causes the weight of the excess powder 720 to press against the powder 720 that forms the powder layer 731 of the predetermined thickness up to the downstream end of the flattening roller 712 in the movement direction of the modeling tank 722. This is advantageous for forming the powder layer 731 of the predetermined thickness with a more uniform and high powder density.

[0145] Next, as shown in FIGS. 13(b) and 13(c), the flattening roller 712 is moved in the “Y2” direction (flattening direction on the way thereto) from the supply tank 721 toward the modeling tank 722. At this time, the flattening roller 712 is rotated in the direction of the arrow in FIGS. 13(b) and 13(c) (counterclockwise in FIG. 13). This rotation causes the surface of the flattening roller 712 to move in the “Y2” direction, with the lowermost part of the circumferential surface of the flattening roller 712 moving in the same direction as the “Y2” direction. As the flattening roller 712 moves in the “Y2” direction while rotating counterclockwise in FIG. 13, the powder 720 present above the upper surface level of the supply tank 721 can be smoothly transferred in the “Y2” direction and supplied to the modeling tank 722. Then, as the flattening roller 712 continues to rotate and moves further in the “Y2” direction, it passes above the modeling tank 722, smoothing and flattening the surface of the powder 720 supplied to the modeling tank 722. As a result, a pre-powder layer 731a having a thickness greater than the target thickness "Δt" of the powder layer 731 of predetermined thickness that will ultimately be formed is formed on the uppermost layer of the layered shaped object 730.

[0146] 13(d), the supply stage 723 of the supply tank 721 is lowered in the "Z2" direction (downward) by a movement amount "z3," and the modeling stage 724 of the modeling tank 722 is raised in the "Z1" direction by a movement amount "z4." As a result, the powder 720 in the upper layer portion of the pre-powder layer 731a formed on the modeling stage 724 of the modeling tank 722 by the flattening process on the outward path described above rises above the level of the upper surface of the modeling tank 722. The movement amount "z4" of the modeling stage 724 at this time is set so that the distance between the upper surface of the previously formed lower predetermined thickness powder layer 731 and the bottom of the flattening roller 712 becomes the target thickness "Δt1" of the predetermined thickness powder layer 731.

[0147] Then, as shown in FIG. 13(e), the flattening roller 712 is moved in the Y1 direction (flattening direction on the return path) from the modeling tank 722 toward the supply tank 721. At this time, the flattening roller 712 is rotated in the direction of the arrow in FIG. 13(d) (clockwise direction in FIG. 13). This rotation causes the surface of the lowermost side of the circumferential surface of the flattening roller 712 to move in the same direction as the Y1 direction. As the flattening roller 712 moves in the Y1 direction while rotating clockwise in FIG. 13, the powder 20 present above the upper surface level of the modeling tank 722 is transported in the Y1 direction, and the surface of the powder 720 in the modeling tank 722 is smoothed and flattened. As a result, a powder layer 731 of a predetermined thickness having a target thickness “Δt” is formed in the modeling tank 722.

[0148] Then, as the flattening roller 712 continues to rotate and moves further in the "Y1" direction, when it passes above the forming tank 722, it forms a pre-powder layer 731a, and the unused powder 720 that was not used to form the powder layer 731 of the specified thickness is returned to the supply tank 721. After forming the powder layer 731 of the predetermined thickness, the flattening roller 712 passes above the supply tank 721 and returns (returns) to its initial position (origin position), as shown in Fig. 13(f). Thereafter, the operation returns to that shown in Fig. 13(a), and droplets of the modeling liquid 710 are ejected from the head 752 to form a layered model 730 of a desired shape on the formed powder layer 731 of the predetermined thickness.

[0149] Thereafter, a powder layer formation process is performed in which a powder layer 731 of a predetermined thickness is formed by supplying and flattening the above-mentioned powder 720, and a modeling liquid ejection process is performed in which the modeling liquid 710 is ejected by the head 752, thereby forming a new layered object 730 above the already formed layered object 730. The layered object 730 is formed, for example, when the modeling liquid 710 discharged from the head 752 is mixed with the powder 720, dissolving the adhesive contained in the powder 720, and the dissolved adhesive bonds to bond the powder 720. The new layered object 730 and the layered object 730 below it are integrated to form part of the three-dimensional object. By repeating the above-described powder layer forming step and modeling liquid discharging step a required number of times, a three-dimensionally shaped object (a three-dimensional object) in which layered objects 730 are stacked is completed.

[0150] The present invention includes, for example, the following aspects. <1> a head tank for storing liquid; a liquid ejection head that ejects the liquid supplied from the head tank; a liquid delivery unit that delivers the liquid from the head tank to the liquid ejection head via a liquid supply path between the head tank and the liquid ejection head; a filter provided in the liquid supply path; pressure measuring means provided on the upstream side and downstream side of the filter; This liquid ejection device is characterized by having a control means that controls the liquid discharge operation of the liquid delivery means to discharge the liquid in the head tank based on the results calculated from the measurements of the pressure measurement means. <2> The liquid discharging operation is an operation of discharging liquid near the filter. <1> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <3> the amount of liquid discharged in one liquid discharging operation is 10 mL or less; <1> or the above <2> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <4> the control means controls the liquid discharge operation of the liquid delivery means to discharge the liquid from the head tank based on the fluid resistance value or the pressure loss value calculated from the measurement value of the pressure measurement means; <1> From the above <3> 1. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <5> The liquid discharging operation is performed when the pressure loss value exceeds 110% of the initial value. <4> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <6> the liquid ejection device has a suction pump that sucks the liquid from the head tank, and / or a supply pump that supplies new liquid to the head tank, The liquid discharging operation includes: A liquid suction operation by the suction pump. a liquid suction operation by the suction pump and a liquid supply operation by the supply pump; or the operation of ejecting the liquid from the liquid ejection head; <1> From the above <5> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <7> The control means has a recovery control means that operates the liquid delivery means based on the fluid resistance value or the pressure loss value calculated after the liquid discharging operation, and controls a recovery operation to recover the clogging of the filter. <4> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <8> the recovery control means repeatedly calculates the fluid resistance value and / or the pressure loss value during the recovery operation; <7> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <9> the control means determines whether to perform the (n+1)th recovery operation based on the fluid resistance value or the pressure loss value calculated after the nth recovery operation; <7> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <10> The control means When recovery is observed in the fluid resistance value or the pressure loss value calculated after the n-th recovery operation, the (n+1)-th recovery operation is performed; When recovery is not observed in the fluid resistance value or the pressure loss value calculated after the n-th recovery operation, the (n+1)-th recovery operation is not performed. <9> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <11> the control means terminates the recovery operation when the number of repetitions of the recovery operation reaches a predetermined number; <9> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <12> the liquid ejection device has a cleaning means for cleaning the liquid ejection head, The calculation of the fluid resistance value or the pressure loss value is performed at the same time as the periodic maintenance by the cleaning means. <4> From the above <11> 1. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <13> The filter is replaceable. <1> From the above <12> 1. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <14> the liquid includes a colorant, an organic solvent, and a resin; The total content (solid content) of the coloring material and the resin is 15% by mass or more with respect to the total amount of the liquid. <1> From the above <13> 1. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus.

[0151] The aforementioned <1> from <14> The liquid ejection device according to any one of the above can solve the above-mentioned problems in the prior art and achieve the object of the present invention. [Explanation of symbols]

[0152] 1000 liquid dispensing device 4 recording head 5 Head Tank 21 Suction cap 27 Suction Pump 28 Waste liquid tank 40 filters 41 Pressure sensor (upstream) 42 Pressure sensor (downstream) 54 Liquid transfer pump 50 Main Tank 500 control section [Prior art documents] [Patent documents]

[0153] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-228147

Claims

1. a head tank for storing liquid; a liquid ejection head that ejects the liquid supplied from the head tank; a liquid delivery unit that delivers the liquid from the head tank to the liquid ejection head via a liquid supply path between the head tank and the liquid ejection head; a filter provided in the liquid supply path; pressure measuring means provided on the upstream side and downstream side of the filter; a control means for controlling the liquid discharge operation of the liquid delivery means to discharge the liquid in the head tank based on the result calculated from the measurement value of the pressure measurement means.

2. The liquid ejection device according to claim 1 , wherein the liquid discharging operation is an operation for discharging liquid near the filter.

3. The liquid ejection device according to claim 1 , wherein the amount of liquid ejected in one liquid ejection operation is 10 mL or less.

4. 4. A liquid ejection device according to claim 1, wherein the control means controls the liquid discharge operation of the liquid delivery means to discharge the liquid from the head tank based on a fluid resistance value or a pressure loss value calculated from the measurement value of the pressure measurement means.

5. The liquid ejection device according to claim 4 , wherein the liquid ejection operation is performed when the pressure loss value exceeds 110% of the initial value.

6. the liquid ejection device has a suction pump that sucks the liquid from the head tank, and / or a supply pump that supplies new liquid to the head tank, The liquid discharging operation includes: A liquid suction operation by the suction pump. a liquid suction operation by the suction pump and a liquid supply operation by the supply pump; or The liquid ejection apparatus according to claim 1 , wherein the liquid is ejected from the liquid ejection head.

7. 5. The liquid ejection device according to claim 4, wherein the control means has a recovery control means that operates the liquid delivery means based on the fluid resistance value or the pressure loss value calculated after the liquid ejection operation, and controls a recovery operation to recover from clogging of the filter.

8. The liquid ejection apparatus according to claim 7 , wherein the recovery control unit repeatedly calculates the fluid resistance value and / or the pressure loss value during the recovery operation.

9. The liquid ejection device according to claim 7 , wherein the control means determines whether to perform the (n+1)th recovery operation based on the fluid resistance value or the pressure loss value calculated after the nth recovery operation.

10. The control means When recovery is observed in the fluid resistance value or the pressure loss value calculated after the n-th recovery operation, the (n+1)-th recovery operation is performed; The liquid ejection apparatus according to claim 9 , wherein if recovery is not observed in the fluid resistance value or the pressure loss value calculated after the nth recovery operation, the (n+1)th recovery operation is not performed.

11. The liquid ejection apparatus according to claim 9 , wherein the control unit terminates the recovery operation when the number of times the recovery operation has been repeated reaches a predetermined number.

12. the liquid ejection device has a cleaning means for cleaning the liquid ejection head, The liquid ejection apparatus according to claim 4 , wherein the calculation of the fluid resistance value or the pressure loss value is performed at the same time as the periodic maintenance by the cleaning device.

13. The liquid ejection device according to claim 1 , wherein the filter is replaceable.

14. the liquid includes a colorant, an organic solvent, and a resin; The liquid ejection device according to claim 1 , wherein a total content (solid content) of the color material and the resin is 15% by mass or more with respect to a total amount of the liquid.

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