Discharge device and detection method

Abstract

This ejection device comprises: a tank for storing a fluid; a supply path for supplying the fluid downward from a recess formed in a part of a bottom surface of the tank; an ejection port, connected to the supply path, for ejecting the fluid; and a detection sensor for detecting the amount of fluid inside the recess.

Description

Technical Field

[0006] , , , , hardening resin ,

[0004] , hardening resin , , , , , , ,

[0005] , , , , , , , , [Figure 1] , , ,

[0007] , hardening resin , , hardening resin

[0001] The present invention relates to a discharge device that discharges a fluid stored in a tank from a discharge port and the like.

Background Art

[0002] The following patent documents describe a discharge device that discharges a fluid stored in a tank from a discharge port.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] This specification aims to reduce the amount of fluid remaining in the tank.

Means for Solving the Problems

[0005] To solve the above problems, this specification discloses a discharge device including: hardening resin a tank for storing hardening resin a supply path for supplying hardening resin downward from a recess formed in a part of the bottom surface of the tank, a discharge port connected to the supply path for discharging <000003​​​​​​​​​​​​​​​This is a diagram showing a circuit forming apparatus. [Figure 2] Control device branch. [Figure 3] This is a cross-sectional view showing a circuit in which a resin laminate has been formed. [Figure 4] This is a cross-sectional view showing a circuit with wiring formed on a resin laminate. [Figure 5] This is a cross-sectional view showing a circuit with conductive resin paste applied to the wiring. [Figure 6] This is a cross-sectional view showing a circuit with electronic components installed. [Figure 7] This is a cross-sectional view showing a circuit in which electronic components are fixed in place by resin. [Figure 8] This is a cross-sectional view showing a conventional inkjet head. [Figure 9] This is a cross-sectional view showing the inkjet head of the present invention. [Figure 10] This is a cross-sectional view along line AA in Figure 9. [Figure 11] This is a cross-sectional view showing a modified inkjet head. [Modes for carrying out the invention]

[0008] Figure 1 shows a circuit forming apparatus 10. The circuit forming apparatus 10 comprises a transport device 20, a first molding unit 22, a second molding unit 24, a third molding unit 25, a fourth molding unit 26, a mounting unit 27, and a control device (see Figure 2) 28. The transport device 20, the first molding unit 22, the second molding unit 24, the third molding unit 25, the fourth molding unit 26, and the mounting unit 27 are arranged on a base 29 of the circuit forming apparatus 10. The base 29 is generally rectangular in shape, and in the following description, the longitudinal direction of the base 29 will be referred to as the X-axis direction, the short direction of the base 29 as the Y-axis direction, and the direction perpendicular to both the X-axis direction and the Y-axis direction as the Z-axis direction.

[0009] The transport device 20 comprises an X-axis slide mechanism 30 and a Y-axis slide mechanism 32. The X-axis slide mechanism 30 includes an X-axis slide rail 34 and an X-axis slider 36. The X-axis slide rail 34 is mounted on a base 29 so as to extend in the X-axis direction. The X-axis slider 36 is held by the X-axis slide rail 34 so as to be slidable in the X-axis direction. Furthermore, the X-axis slide mechanism 30 has an electromagnetic motor (see Figure 2) 38, and the X-axis slider 36 moves to any position in the X-axis direction by the drive of the electromagnetic motor 38. The Y-axis slide mechanism 32 includes a Y-axis slide rail 50 and a stage 52. The Y-axis slide rail 50 is mounted on a base 29 so as to extend in the Y-axis direction and is movable in the X-axis direction. One end of the Y-axis slide rail 50 is connected to the X-axis slider 36. The stage 52 is held on the Y-axis slide rail 50 so as to be slidable in the Y-axis direction. Furthermore, the Y-axis sliding mechanism 32 has an electromagnetic motor (see Figure 2) 56, and the stage 52 moves to any position in the Y-axis direction when driven by the electromagnetic motor 56. As a result, the stage 52 moves to any position on the base 29 when driven by the X-axis sliding mechanism 30 and the Y-axis sliding mechanism 32.

[0010] The stage 52 comprises a base 60, a holding device 62, and a lifting device 64. The base 60 is formed in a flat plate shape, and a substrate is placed on its upper surface. The holding devices 62 are provided on both sides of the base 60 in the X-axis direction. The substrate is held fixedly in place by the holding devices 62, which clamp both edges of the substrate in the X-axis direction. The lifting device 64 is located below the base 60 and raises and lowers the base 60.

[0011] The first molding unit 22 is a unit that molds wiring on a substrate placed on the base 60 of the stage 52, and has a first printing unit 72 and a firing unit 74. The first printing unit 72 has an inkjet head (see Figure 2) 76, which ejects metallic ink in a linear fashion. The metallic ink consists of nanometer-sized metal particles, such as silver, dispersed in a solvent. The surface of the metal particles is coated with a dispersant to prevent aggregation in the solvent. The inkjet head 76 ejects the metallic ink from multiple nozzles, for example, using a piezoelectric system with a piezoelectric element.

[0012] The firing section 74 has an infrared irradiation device (see Figure 2) 78. The infrared irradiation device 78 is a device that irradiates the ejected metal ink with infrared rays, and the metal ink irradiated with infrared rays is fired, forming wiring. The firing of metal ink is a phenomenon in which, by applying energy, the solvent vaporizes, the protective film of the metal nanoparticles, i.e., the dispersant decomposes, and the metal nanoparticles come into contact or fuse together, resulting in increased conductivity. As the metal ink is fired, metal wiring is formed.

[0013] Furthermore, the second molding unit 24 is a unit that molds a resin layer on a substrate placed on the base 60 of the stage 52, and has a second printing unit 84 and a curing unit 86. The second printing unit 84 has an inkjet head (see Figure 2) 88, which ejects ultraviolet-curable resin. The ultraviolet-curable resin is a resin that hardens when exposed to ultraviolet light. The inkjet head 88 may be, for example, a piezo type using a piezoelectric element, or a thermal type that heats the resin to generate bubbles and ejects it from multiple nozzles.

[0014] The curing unit 86 includes a flattening device (see FIG. 2) 90 and an irradiation device (see FIG. 2) 92. The flattening device 90 flattens the upper surface of the ultraviolet-curable resin discharged by the inkjet head 88. For example, while leveling the surface of the ultraviolet-curable resin, the excess resin is scraped off by a roller or a blade to make the thickness of the ultraviolet-curable resin uniform. The irradiation device 92 includes a mercury lamp or an LED as a light source and irradiates the discharged ultraviolet-curable resin with ultraviolet rays. As a result, the discharged ultraviolet-curable resin cures and a resin layer is formed.

[0015] The third shaping unit 25 is a unit that shapes the connection portions between the electrodes and wirings of electronic components on a substrate placed on the base 60 of the stage 52, and includes a third printing unit 100 and a first heating unit 102. The third printing unit 100 has a dispenser (see FIG. 2) 106, and the dispenser 106 discharges a conductive resin paste. The conductive resin paste is a resin that cures by heating at a relatively low temperature and in which metal particles of micrometer size are dispersed. Incidentally, the metal particles are in the form of flakes, and the viscosity of the conductive resin paste is relatively high compared to metal ink.

[0016] The first heating unit 102 has a heater (see FIG. 2) 108. The heater 108 is a device that heats the conductive resin paste applied by the dispenser 106, and in the heated conductive resin paste, the resin cures. At this time, in the conductive resin paste, the resin cures and shrinks, and the flaky metal particles dispersed in the resin come into contact. As a result, the conductive resin paste exhibits conductivity. Also, the resin of the conductive resin paste is an organic adhesive and exhibits adhesive force by curing by heating.

[0017] The fourth molding unit 26 is a unit for molding resin to fix the electronic components described later, and has a fourth printing unit 110 and a second heating unit 112. The fourth printing unit 110 has an inkjet head (see Figure 2) 116, which extrudes thermosetting resin. Thermosetting resin is a resin that hardens when heated. The inkjet head 116 is, for example, a piezo type using a piezoelectric element. The second heating unit 112 has a heater (see Figure 2) 118. The heater 118 is a device that heats the extruded thermosetting resin, and the heated thermosetting resin hardens.

[0018] Furthermore, the mounting unit 27 is a unit that mounts electronic components onto a substrate placed on the base 60 of the stage 52, and has a supply unit 120 and a mounting unit 122. The supply unit 120 has multiple tape feeders (see Figure 2) 124 that feed out taped electronic components one by one, and supplies electronic components at the supply position. Note that the supply unit 120 is not limited to tape feeders 124, but may also be a tray-type supply device that picks up and supplies electronic components from a tray. In addition, the supply unit 120 may be configured to have both tape-type and tray-type supply devices, or other types of supply devices.

[0019] The mounting unit 122 includes a mounting head (see Figure 2) 126 and a moving device (see Figure 2) 128. The mounting head 126 has a suction nozzle (not shown) for adsorbing and holding electronic components. The suction nozzle adsorbs and holds electronic components by air suction when negative pressure is supplied from a positive / negative pressure supply device (not shown). Then, when a small amount of positive pressure is supplied from the positive / negative pressure supply device, the electronic components are released. The moving device 128 moves the mounting head 126 between the supply position of electronic components by the tape feeder 124 and the substrate placed on the base 60. As a result, in the mounting unit 122, electronic components supplied from the tape feeder 124 are held by the suction nozzle, and the electronic components held by the suction nozzle are mounted on the substrate.

[0020] Furthermore, as shown in Figure 2, the control device 28 includes a controller 130 and a plurality of drive circuits 132. The plurality of drive circuits 132 are connected to the electromagnetic motors 38, 56, holding device 62, lifting device 64, inkjet head 76, infrared irradiation device 78, inkjet head 88, planarization device 90, irradiation device 92, dispenser 106, heater 108, inkjet head 116, heater 118, tape feeder 124, mounting head 126, and moving device 128. The controller 130 is a computer-based device equipped with a CPU, ROM, RAM, etc., and is connected to the plurality of drive circuits 132. As a result, the operation of the transport device 20, the first molding unit 22, the second molding unit 24, the third molding unit 25, the fourth molding unit 26, and the mounting unit 27 is controlled by the controller 130.

[0021] In the circuit forming apparatus 10, a resin laminate is formed on the substrate (see Figure 3) 70 using the configuration described above, and wiring is formed on the upper surface of the resin laminate. Then, the electrodes of the electronic components are electrically connected to the wiring via a conductive resin paste, and the electronic components are fixed by the resin.

[0022] Specifically, the substrate 70 is set on the base 60 of the stage 52, and the stage 52 is moved below the second molding unit 24. Then, in the second molding unit 24, as shown in Figure 3, a resin laminate 150 is formed on the substrate 70. The resin laminate 150 is formed by repeatedly ejecting ultraviolet-curable resin from the inkjet head 88 and irradiating the ejected ultraviolet-curable resin with ultraviolet light from the irradiation device 92.

[0023] More specifically, in the second printing section 84 of the second molding unit 24, the inkjet head 88 extrudes a thin film of ultraviolet-curable resin onto the upper surface of the substrate 70. Subsequently, once the ultraviolet-curable resin is extruded as a thin film, the ultraviolet-curable resin is flattened by the planarization device 90 in the curing section 86 so that the film thickness of the ultraviolet-curable resin becomes uniform. Then, the irradiation device 92 irradiates the thin film of ultraviolet-curable resin with ultraviolet light. As a result, a thin film of resin 152 is formed on the substrate 70.

[0024] Next, the inkjet head 88 ejects a thin film of UV-curable resin onto the thin film resin layer 152. Then, the planarization device 90 flattens the thin film of UV-curable resin, and the irradiation device 92 irradiates the ejected thin film of UV-curable resin with ultraviolet light, thereby laminating another thin film of resin layer 152 on top of the previous one. In this way, the ejection of UV-curable resin onto the thin film resin layer 152 and the irradiation with ultraviolet light are repeated, and multiple resin layers 152 are laminated to form a resin laminate 150.

[0025] Once the resin laminate 150 is formed by the procedure described above, the stage 52 is moved below the first molding unit 22. Then, in the first printing section 72 of the first molding unit 22, the inkjet head 76 ejects metallic ink 154 in a linear pattern onto the upper surface of the resin laminate 150, as shown in Figure 4. Subsequently, the infrared irradiation device 78 in the firing section 74 of the first molding unit 22 irradiates the ejected metallic ink 154 with infrared light. As a result, the metallic ink 154 is fired, and wiring 156 is formed on the resin laminate 150.

[0026] Next, once the wiring 156 is formed on the resin laminate 150, the stage 52 is moved below the third molding unit 25. Then, in the third printing section 100 of the third molding unit 25, the dispenser 106 dispenses conductive resin paste 157 onto the ends of the wiring 156, as shown in Figure 5. Once the conductive resin paste 157 is dispensed onto the ends of the wiring 156, the stage 52 is moved below the mounting unit 27. In the mounting unit 27, an electronic component (see Figure 6) 160 is supplied by the tape feeder 124, and the electronic component 160 is held by the suction nozzle of the mounting head 126. The electronic component 160 consists of a component body 162 and two electrodes 164 arranged on the lower surface of the component body 162. The mounting head 126 is then moved by the moving device 128, and the electronic component 160 held by the suction nozzle is mounted on the upper surface of the resin laminate 150, as shown in Figure 6. In this case, the electronic component 160 is mounted on the upper surface of the resin laminate 150 such that the electrode 164 of the electronic component 160 contacts the conductive resin paste 157 extruded onto the wiring 156. Since the lower surface of the electrode 164 protrudes below the lower surface of the component body 162, the electrode 164 makes suitable contact with the conductive resin paste 157.

[0027] As the electronic component 160 is mounted on the resin laminate 150, the stage 52 is moved below the third molding unit 25. Then, in the first heating section 102 of the third molding unit 25, the conductive resin paste 157 is heated by the heater 108. As a result, the conductive resin paste 157 becomes conductive, and the electrode 164 is electrically connected to the wiring 156 via the conductive resin paste 157. In addition, the adhesive force of the conductive resin paste 157 fixes the electronic component 160 to the wiring 156, thereby fixing it to the resin laminate 150.

[0028] As described above, when the electronic component 160 is connected to the wiring, the stage 52 is moved below the fourth molding unit 26. Then, in the fourth printing section 110 of the fourth molding unit 26, the inkjet head 116 ejects thermosetting resin 170 between the lower surface of the component body 162 of the electronic component 160 and the upper surface of the resin laminate 150, as shown in Figure 7. This seals the thermosetting resin 170 between the upper surface of the resin laminate 150 and the lower surface of the component body 162 of the electronic component 160. In other words, the thermosetting resin 170 is sealed between the upper surface of the resin laminate 150 and the lower surface of the component body 162. Furthermore, the inkjet head 116 also ejects thermosetting resin 170 around the electronic component 160 so as to cover the sides of the component body 162 of the electronic component 160. Then, in the second heating section 112, the thermosetting resin 170 is heated by the heater 118, causing the thermosetting resin 170 to be sealed between the upper surface of the resin laminate 150 and the lower surface of the component body 162, and to harden while covering the sides of the component body 162. As a result, the electronic component 160 mounted on the upper surface of the resin laminate 150 is fixed in place by the hardened resin.

[0029] In this way, in the circuit forming apparatus 10, a resin laminate 150 is formed on the substrate 70, and wiring 156 is formed on the upper surface of the resin laminate. Then, the electrodes 164 of the electronic component 160 are electrically connected to the wiring via a conductive resin paste 157, and the electronic component is fixed with thermosetting resin, thereby forming a circuit. The inkjet head that ejects fluids such as metal ink and UV-curing resin consists of a head that ejects the fluid and a tank that stores the fluid, and when the amount of fluid remaining in the tank becomes low due to fluid ejection, the tank is replenished with fluid. Furthermore, among the fluids used in the circuit forming apparatus 10, for example, metal ink has a short lifespan and is used in small quantities, so it is desirable to reduce the amount of metal ink supplied to the tank. Moreover, if metal ink remains in the tank, the remaining metal ink in the tank is discarded, so it is desirable to use the metal ink in the tank until it is almost gone. For this reason, the tank is equipped with a detection sensor to detect the remaining amount of fluid stored therein. Then, when the detection sensor detects that the amount of fluid remaining in the tank is almost zero, the tank is replenished with metallic ink. However, the detection sensor naturally has a detection error, and since the remaining amount of fluid is detected taking this error into account, there is a risk that the amount of metallic ink remaining in the tank will be too large with conventional inkjet heads.

[0030] More specifically, as shown in Figure 8, a conventional inkjet head 200 consists of a head 202 that ejects metallic ink and a tank 204 that stores the metallic ink. Multiple ejection ports 210 are formed on the lower surface of the head 202, and these multiple ejection ports 210 communicate with a retention space 212 formed inside the head 202. The tank 204 is generally box-shaped, and the bottom surface 216 inside the tank 204 is a flat surface. Three through holes 220, 222, and 224 are formed on the upper surface of the tank 204.

[0031] The through-hole 220 is for refilling ink, which may be done automatically by a refilling device or manually by an operator. The through-hole 222 is for adjusting the internal pressure of the tank 204 and is connected to a pump or the like. The through-hole 224 is for installing the detection sensor 228. The detection sensor 228 is a laser displacement meter and irradiates laser light through the through-hole 224 towards the metal ink stored in the tank 204. The detection sensor 228 receives the laser light reflected from the liquid surface of the metal ink stored in the tank 204 and detects the distance to the liquid surface of the metal ink based on the received laser light. This allows the amount of metal ink stored in the tank 204, specifically the depth dimension of the metal ink, that is, the distance from the bottom surface 216 of the tank to the liquid surface of the metal ink, to be detected. The detection sensor 228 irradiates laser light using a laser element.

[0032] Furthermore, the lower end surface of the tank 204 and the upper end surface of the head 202 are connected by two pipes 230 and 232. The inside of the tank 204 and the inside of the retention space 212 of the head 202 are connected by two supply passages 236 and 238 formed in the pipes 230 and 232 and the head 202. With this structure, in the inkjet head 200, the metallic ink stored in the tank 204 is supplied to the retention space 212 of the head 202 via the two supply passages 236 and 238 and ejected from multiple ejection ports 210. As the metallic ink is ejected, the amount of metallic ink stored in the tank 204 decreases, and at this time, the depth dimension of the metallic ink stored in the tank 204 is detected by the detection sensor 228. For example, if the depth dimension of the metallic ink becomes, for example, 1 mm, it can be considered that there is almost no metallic ink remaining in the tank. Therefore, it is preferable to eject the metallic ink from the inkjet head 200 until the depth dimension of the metallic ink reaches 1 mm. However, if the detection error of the detection sensor 228 is 3 mm, for safety reasons, the metallic ink is supplied to the tank 204 when the depth dimension of the metallic ink detected by the detection sensor reaches 4 mm. Therefore, with conventional inkjet heads 200, it is rarely possible to use the metallic ink until the actual depth dimension of the metallic ink reaches 1 mm. As a result, with conventional inkjet heads 200, the amount of metallic ink remaining in the tank 204 increases, which may lead to a large amount of metallic ink being wasted. The detection error of the detection sensor 228 can be calculated based on the detection accuracy of the detection sensor.

[0033] In light of these considerations, the inkjet head 76 of the circuit forming apparatus 10 employs the tank 300 shown in Figures 9 and 10. The inkjet head 76 is identical to the conventional inkjet head 200, except for the tank 300. Therefore, the components other than the tank 300 are given the same reference numerals as the components of the inkjet head 200, and their descriptions are omitted. Furthermore, the tank 300 of the inkjet head 76 has almost the same configuration as the tank 204 of the conventional inkjet head 200, except for the recess 310. Therefore, only the recess 310 will be described. The components of the tank 300 other than the recess 310 are given the same reference numerals as the components of the tank 204, and their descriptions are omitted.

[0034] The recess 310 is formed in a part of the bottom surface 312 inside the tank 300 and is located below the detection sensor 228. Therefore, the detection sensor 228 detects the amount of metallic ink inside the recess 310. In addition, a supply passage 238 that supplies fluid to the discharge port 210 of the head 202 opens to the bottom surface of the recess 310. In other words, the recess 310 is formed at the opening of the supply passage 238 to the tank 300. Therefore, metallic ink flows downward from the recess 310 in the tank 300 into the supply passage 238, and the metallic ink is supplied to the discharge port 210 via the supply passage 238. However, there is no recess formed at the opening of the supply passage 236, which is different from the supply passage 238, to the tank 300, and the supply passage 236 opens to the flat bottom surface 312 of the tank 300. The recess 310 is a recessed shape that is partitioned below the bottom surface of the tank 300. In other words, the recess 310 is a cylindrical recessed shape defined by a wall perpendicular to the bottom surface of the tank. Furthermore, the depth dimension of the recess 310 is greater than or equal to the detection error range of the detection sensor 228, and is set to the depth dimension of the metal ink to be detected plus the detection error of the detection sensor 228. For example, if the detection error of the detection sensor 228 is 3 mm and the depth dimension of the metal ink to be detected is 1 mm, the depth dimension of the recess is set to 4 (= 3 + 1) mm.

[0035] By adopting a tank 300 of this shape, the inkjet head 76 can reduce the amount of metal ink remaining in the tank 300 and decrease the amount of metal ink waste. Specifically, when the depth dimension of the metal ink to be detected is 1 mm, the detection error of the detection sensor 228 is 3 mm. For safety reasons, the metal ink is supplied to the tank 300 when the depth dimension of the metal ink detected by the detection sensor reaches 4 mm. At this time, since the detection sensor 228 detects the depth dimension of the metal ink inside the recess 310, even if the depth dimension of the metal ink is 4 mm, the metal ink does not overflow from the recess 310 and remains only in the recess 310. Therefore, even if metal ink with a depth dimension of 4 mm remains in the tank 300, the metal ink remains only in the recess 310, thus reducing the amount of remaining metal ink. In other words, with the conventional inkjet head 200, an amount of metal ink remains equal to the area of ​​the bottom surface 216 of the tank 204 multiplied by the depth dimension of the metal ink. On the other hand, in the inkjet head 76 of the circuit forming apparatus 10, an amount of metal ink remains equal to the area of ​​the bottom surface of the recess 310 multiplied by the depth dimension of the metal ink. The area of ​​the bottom surface 216 of the tank 204 and the area of ​​the bottom surface 312 of the tank 300 are the same, and as shown in Figure 10, the area of ​​the bottom surface of the recess 310 is about 10% of the area of ​​the bottom surface 312 of the tank 300. For this reason, the inkjet head 76 can reduce the amount of remaining metal ink by about 1 / 10 compared to the conventional inkjet head 200.

[0036] Furthermore, in the inkjet head 76, the recess 310 is formed only at the opening to the tank 300 of one of the two supply paths 236, 238, so the amount of residual metallic ink can be further reduced. In other words, if recesses are formed at the openings to the tank 300 of both supply paths 236, 238, metallic ink will remain in two recesses. On the other hand, in the inkjet head 76, the recess 310 is formed only at the opening to the tank 300 of one of the two supply paths 238, so metallic ink will remain in only one recess. Thus, by forming the recess 310 only at the opening to the tank 300 of one of the two supply paths 238, the amount of residual metallic ink can be further reduced.

[0037] In the above embodiment, the inkjet head 76 is an example of an ejection device. The ejection port 210 is an example of an ejection port. The detection sensor 228 is an example of a detection sensor. The supply path 238 is an example of a supply path. The tank 300 is an example of a tank. The recess 310 is an example of a recess.

[0038] In the embodiment described above, the following effects are achieved.

[0039] In an inkjet head 76 comprising a tank 300 for storing metallic ink and a supply path 238 for supplying metallic ink from a recess 310 formed in the tank 300 to an ejection port 210, a detection sensor 228 detects the amount of metallic ink inside the recess 310. Based on the detection value of the detection sensor, the remaining amount of metallic ink in the tank 300 is then detected. This makes it possible to detect the remaining amount of metallic ink in the recess 310, which has a bottom surface area smaller than the bottom surface area of ​​the tank 300, thereby reducing the amount of metallic ink remaining in the tank.

[0040] Furthermore, the fluid used to create the circuit through curing, specifically the metallic ink, is stored in the tank 300. Since metallic ink is a relatively expensive material with a short lifespan, adopting the tank 300 in the inkjet head 76 makes it possible to reduce the amount of metallic ink waste, resulting in a cost advantage.

[0041] Furthermore, the depth dimension of the recess 310 is greater than or equal to the detection error range of the detection sensor 228. This makes it possible to leave the metallic ink only inside the recess 310, thereby reducing the amount of metallic ink remaining in the tank.

[0042] Furthermore, the recess 310 is a compartmentalized shape located below the bottom surface of the tank 300, and is counterbore-shaped. This makes it possible to reduce the internal volume of the recess 310, thereby reducing the amount of residual metallic ink.

[0043] It should be noted that the present invention is not limited to the above embodiments, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. For example, in the above embodiments, the recess 310 is cylindrical, but it may be grooved. Also, in the above embodiments, it is partitioned by a wall perpendicular to the bottom surface of the tank, but it may be partitioned by an inclined wall. In other words, as shown in Figure 11, a recess 330 partitioned by a tapered surface may be formed on the bottom surface 312 of the tank 300. That is, a recess 330 with a shape in which the cross-sectional area in the left-right direction decreases as it goes downwards may be formed on the bottom surface 312 of the tank 300.

[0044] Furthermore, for example, in the above embodiment, the present invention is applied to an inkjet head 76 that ejects metallic ink, but the present invention may also be applied to inkjet heads 88 and 116 that eject ultraviolet curing resin and thermosetting resin, or to a dispenser 106 that ejects conductive resin paste. Also, in the above embodiment, the present invention is applied to an inkjet head that ejects fluid for creating a circuit as a three-dimensional object, but the present invention may also be applied to an ejection device that ejects fluid for creating three-dimensional objects such as figurines.

[0045] In the above embodiment, the depth of the metal ink is detected by detecting the distance to the liquid surface of the metal ink stored in the tank 300 using laser light emitted from a laser element. Alternatively, the depth of the metal ink may be detected by detecting the distance to the liquid surface of the metal ink using LED light emitted from an LED, ultrasonic waves, etc. The amount of metal ink stored in the tank 300 may also be detected using a differential pressure gauge or the like. Specifically, the pressure near the bottom of the tank in which the metal ink is stored is measured, as well as the pressure above the metal ink in the tank. The amount of metal ink may then be calculated based on the differential pressure between the pressure near the bottom of the tank and the pressure above the metal ink in the tank.

[0046] Furthermore, in the above embodiment, the detection error of the detection sensor is 3 mm and the depth dimension of the metal ink to be detected is 1 mm, so the depth dimension of the recess is set to 4 mm. However, the depth dimension of the recess can be arbitrarily set according to the detection error of the detection sensor 228 and the depth dimension of the metal ink to be detected. That is, for example, if the detection error of the detection sensor is 2 mm and the depth dimension of the metal ink to be detected is 0.1 mm, the depth dimension of the recess can be set to 2.1 mm. Alternatively, the depth dimension of the recess can be set regardless of the detection error of the detection sensor. That is, even if the detection error of the detection sensor is 3 mm, the depth dimension of the recess can be set to 2 mm, which is smaller than the detection error. In such cases, although metal ink overflows from the recess at the timing of ink replenishment detected by the detection sensor, the amount of metal ink remaining in the tank can be reduced by accumulating the metal ink in the recess.

[0047] Furthermore, in the above embodiment, an inkjet head 76 is used in which the tank 300 is located outside the head 202, but an inkjet head with the tank built inside the head may also be used. [Explanation of symbols]

[0048] 76: Inkjet head (discharge device) 210: Discharge port 228: Detection sensor 238: Supply path 300: Tank 310: Recess

Claims

1. A tank for storing a curable resin, A supply passage for supplying curable resin downward from a recess formed in a part of the bottom surface of the tank, A discharge port connected to the aforementioned supply path for discharging a curable resin, A detection sensor for detecting the amount of curable resin inside the recess, A dispensing device equipped with the following features.

2. The discharge device according to claim 1, wherein the recess is shaped to be partitioned below the bottom surface of the tank.

3. The discharge device according to claim 1 or claim 2, wherein the recess has a counterbore shape.

4. A discharge device for discharging a curable resin supplied from a recess formed in a part of the bottom surface of a tank for storing a curable resin, wherein the remaining amount of curable resin in the tank is detected based on the amount of curable resin inside the recess.

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