Waste liquid recovery device and liquid ejection device

Abstract

To provide a waste liquid recovery device which can continue recovery of a waste liquid regardless of a position of a waste liquid surface in a waste liquid tank.SOLUTION: A waste liquid recovery device includes: a tank housing which stores a liquid; a pipe-like member which allows the liquid to flow into the tank housing; an interval holding part which is provided at an end of the pipe-like member hanging in an internal space of the tank housing; and a buoyancy providing part which has buoyancy against the liquid and causes the interval holding part to float on a liquid surface of the liquid. The interval holding part holds a predetermined interval between the end of the pipe-like member and the liquid surface by the buoyancy of the buoyancy providing part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In a liquid ejection device that includes a liquid ejection unit that ejects liquid and forms an image or the like by ejecting the liquid onto a medium, in addition to the ejection operation for image formation, a maintenance ejection operation may be performed to prevent the liquid from solidifying or thickening due to drying, thereby reducing the deterioration of ejection characteristics. The liquid ejected during the maintenance ejection operation is recovered as waste liquid, and some liquid ejection devices are therefore equipped with a waste liquid recovery device. The waste liquid recovery device includes a waste liquid tank that stores the waste liquid and is equipped with a sensor that detects the amount of waste liquid stored in the waste liquid tank. The sensor provides a full-liquid detection function that detects when the waste liquid tank is full.

[0003] Conventional waste liquid recovery devices have a full-capacity detection function that uses a float switch to detect the amount of waste liquid by the position of a float suspended in the waste liquid. However, float switches can sometimes fail to function normally when handling waste liquid that is prone to sticking or solidifying.

[0004] To solve this problem, a liquid level detection device is known that can determine whether an abnormality has occurred in the float based on the detected content, regardless of the type of liquid, and detect the normal operation of the full detection function (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] As in the device disclosed in Patent Document 1, waste liquid is generally transported to a waste liquid tank via a tube, where it naturally falls from the opening of the tube that hangs down into the waste liquid tank and accumulates inside the tank. In this case, as the amount of waste liquid increases in the waste liquid tank and the liquid level rises, the tip of the tube becomes submerged in the waste liquid. The waste liquid recovery device is configured to use a pressurizing means such as a pump to push the waste liquid into the waste liquid tank, but if the liquid pressure at the tip of the tube becomes higher than the pressure generated by the pump, this can hinder the recovery of the waste liquid when a maintenance operation is subsequently performed.

[0006] That is, with the conventional technology, there are problems such as difficulty in recovering the waste liquid, and the waste liquid remaining in the tube after the pump is stopped flowing back into the liquid discharge unit.

[0007] An object of the present invention is to provide a waste liquid recovery device that can continue to recover waste liquid regardless of the position of the waste liquid level in the waste liquid tank. [Means for solving the problem]

[0008] The present invention, which aims to solve the above-mentioned problems, relates to a waste liquid recovery device, comprising: a tank casing for storing a liquid; a tubular member for causing the liquid to flow into the tank casing; a spacing retaining portion provided at an end of the tubular member that hangs down into an internal space of the tank casing; and a buoyancy imparting portion that has buoyancy with respect to the liquid and causes the spacing retaining portion to float on the surface of the liquid, an opening is provided at an end of the tubular member on a side surface opposite to the surface facing the spacing portion, The spacing portion maintains a predetermined distance between the end of the tubular member and the liquid surface by the buoyancy of the buoyancy imparting portion. [Effects of the Invention]

[0009] According to the present invention, the waste liquid can be continuously collected regardless of the position of the waste liquid surface in the waste liquid tank. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are a perspective view and an XZ cross-sectional view, respectively, of a UV inkjet device according to one embodiment of the present invention; [Figure 2] 10A and 10B are diagrams for explaining problems in a comparative example of a waste liquid recovery device according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing the configuration of a waste liquid recovery device according to an embodiment of the present invention. [Figure 4] 5A to 5C are schematic diagrams showing an example of operation of the waste liquid recovery device according to the embodiment. [Figure 5] FIG. 3 is an enlarged view showing an example of a characteristic part of the waste liquid recovery device according to the embodiment. [Figure 6] 4A to 4C are explanatory diagrams illustrating the effects of the above-mentioned characteristic parts. [Figure 7] FIG. 10 is an enlarged view showing another example of a characteristic portion of the waste liquid recovery device according to the embodiment. [Figure 8] FIG. 10 is an enlarged view showing another example of a characteristic portion of the waste liquid recovery device according to the embodiment. [Figure 9] FIG. 10 is a front view illustrating another example of a liquid ejection unit according to the present invention. [Figure 10] FIG. 10 is an explanatory side view of a main part showing another example of a liquid ejection device according to the present invention. [Figure 11] FIG. 2 is an explanatory plan view of a main part showing an example of a liquid ejection unit according to the present invention. [Figure 12] FIG. 10 is a front view illustrating another example of a liquid ejection unit according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment of Liquid Discharge Apparatus] Hereinafter, embodiments of a waste liquid recovery device and a liquid ejection device according to the present invention will be described with reference to the drawings. First, a UV inkjet device 200 as an embodiment of a liquid ejection device according to the present invention will be described with reference to Fig. 1. Fig. 1(a) is a perspective external view of the UV inkjet device 200 as seen from an oblique direction. Fig. 1(b) is a cross-sectional view of the UV inkjet device 200 taken along an XZ plane near the center in the Y direction.

[0012] In the UV inkjet device 200, functional components for ejecting ultraviolet curable ink (UV ink 211) are arranged on a device base 230. By the operation of these functional components, the UV ink 211 is ejected toward a recording medium 1 placed on a linear stage 203, and an image or the like is formed on the recording medium 1.

[0013] In the following description, the three-dimensional Cartesian coordinate system shown in Fig. 1 may be used to explain the arrangement and operation of each functional component. As shown in Fig. 1, the UV inkjet device 200 has each component arranged on the top surface of a device base 230 having a bottom surface parallel to the XY plane. The device base 230 has a predetermined height in the height direction, which is the Z direction. It is assumed that the waste liquid recovery device according to the present invention is mounted inside the device base 230, which has a thickness in the Z direction.

[0014] It should be noted that the positional relationship between the waste liquid recovery device and the device base 230 is not limited to this. The effect obtained by this embodiment is the same even if a configuration similar to the waste liquid recovery device described below is provided at a position separated from the device base 230.

[0015] The UV inkjet device 200 includes a linear actuator 201 that moves a carriage 202 along the X direction. The linear actuator 201 is made up of an elongated member whose longitudinal direction is the X direction.

[0016] A carriage 202 that can be moved in the X direction by a linear actuator 201 is equipped with multiple inkjet heads 210. Each of the inkjet heads 210 is formed with nozzles that are ejection ports for UV ink 211. The nozzles are formed as a nozzle surface that is two-dimensionally arranged on the surface of the inkjet head 210 that faces the linear stage 203. The inkjet head 210 is configured to be able to reciprocate in the X direction by the carriage 202. The carriage 202 is also equipped with an actuator that enables movement in the Z direction, so that the carriage 202 can be moved in the Z direction.

[0017] The linear stage 203 is configured to be able to move the recording medium 1 in the Y direction with the recording medium 1 placed on it. By combining the movement of the linear stage 203 in the Y direction with the movement of the carriage 202 in the X direction, the inkjet head 210 is configured to be able to scan the recording medium 1 two-dimensionally along the XY plane. By controlling the scanning timing of the inkjet head 210 and the ejection timing of UV ink 211 (ultraviolet curable ink) onto the recording medium 1, an image or the like can be formed on the recording medium 1 using the UV ink 211.

[0018] The linear stage 203 is equipped with a rotation mechanism that not only moves in a plane in the Y direction but also rotates around the Z direction as a rotation axis, and also rotates around the Y and X directions as rotation axes. The UV inkjet device 200 is configured to be able to accommodate recording media 1 of various shapes by moving the linear actuator 201 in the X direction, moving the linear stage 203 in the Y direction, and rotating the linear stage 203. The linear stage 203 corresponds to a conveying unit.

[0019] The surface of the linear stage 203 has small holes at regular intervals, and a vacuum pressure generating source such as a vacuum pump mounted inside the device base 230 is connected to these holes. This allows a thin recording medium 1, such as a film, placed on the linear stage 203 to be adsorbed and fixed to the linear stage 203. Note that the recording medium 1 may be a thick material such as a plate material (wood, metal, resin) other than a sheet-like film. When using recording media 1 of different thicknesses, an appropriate distance can be maintained between the recording medium 1 and the inkjet head 210 and UV lamp 204 by moving the carriage 202 in the Z direction.

[0020] The ejection operation of the UV ink 211 is controlled by a controller provided in the UV inkjet device 200. On the left and right sides of the carriage 202, UV lamps 204 are mounted to irradiate ultraviolet light to cure the UV ink 211 that has landed on the recording medium 1. The UV lamps 204 correspond to ultraviolet irradiation devices and irradiate ultraviolet light (UV light) 209 toward the recording medium 1. FIG. 1(b) shows an image of UV light 209 being irradiated from the right UV lamp 204R. Note that in addition to the diffused light type UV lamp 204 shown in FIG. 1(b), a concentrated light type UV lamp 204 or the like can also be used. The UV lamp 204 may be selected from a variety of types depending on the purpose.

[0021] The sub-tank provided in the inkjet head 210 is replenished with UV ink 211 from a main tank mounted inside the device base 230. When the amount of UV ink 211 in the sub-tank becomes low, the controller operates a supply pump provided inside the device base 230 to replenish the UV ink 211 from the main tank to the sub-tank via a supply tube. The sub-tank is controlled by the controller using an air pipe, a solenoid valve, and an air negative pressure generating pump to create a slight negative pressure appropriate for ejecting the UV ink 211.

[0022] The air pipe provided in the subtank is also connected to an air pressure source via an electromagnetic valve. The air pressure source is used when, for example, the presence of dust or air bubbles in the nozzles of the inkjet head 210 prevents normal ejection. In this case, the inkjet head 210 is moved above the waste liquid receiver 205 and the air pressure source is operated, switching the subtank from negative pressure to pressurized pressure and forcibly ejecting the UV ink 211 from the inkjet head 210 (nozzles). This forced ejection pushes out dust and air bubbles present in the nozzles of the inkjet head 210.

[0023] If ink is left being pushed out of the nozzles of the inkjet head 210, the UV ink 211 will adhere to the nozzle surface, which may cause problems with subsequent ejection operations. Therefore, after the forced ejection operation, an operation to wipe the nozzle surface (wiping) is performed on the inkjet head 210. Wiping is an operation to wipe the nozzle surface using a wiper 208 that is provided so as to be movable in the Y direction, and is an example of a maintenance operation for the inkjet head 210. Note that the wiper 208 generally uses a material with rubber elasticity, such as rubber or elastomer.

[0024] The UV ink 211 extruded from the nozzles and the UV ink 211 wiped away by wiping are collected in a waste liquid tank 110 provided inside the device base 230 via a waste liquid receiver 205. The waste liquid tank 110 will be described later together with an explanation of a recovery device 100 as an embodiment of the waste liquid recovery device according to the present invention.

[0025] A cap 206 is disposed on the top surface of the device base 230 near one end of the linear actuator 201 in the longitudinal direction. The cap 206 is fixed at a predetermined height from the top surface of the device base 230. The cap 206 is provided to cover the inkjet head 210 to protect the nozzle surface and the ink near the nozzle surface when the UV inkjet device 200 is not to be used for an extended period of time, such as when the device is finished using it.

[0026] Additionally, a blank discharge receiver 207 is disposed on the top surface of the device base 230, near the longitudinal end of the linear actuator 201 and near the cap 206. The blank discharge receiver 207 is a component that receives discarded UV ink 211 when UV ink 211 that has deteriorated due to exposure to air or the like is discarded by so-called "blank discharge." By using the blank discharge receiver 207, the inkjet head 210 can perform a discharge operation (blank discharge) that does not involve image formation, thereby supplying fresh UV ink 211 to the nozzles of the inkjet head 210. This blank discharge maintains the quality of image formation. Therefore, blank discharge is also performed when the UV inkjet device 200 is first used and between image formation operations after a certain period of continuous use. The UV ink 211 discharged by blank discharge is also collected in the waste liquid tank 110, which will be described later.

[0027] 1(a) and 1(b) illustrate an example of how the carriage 202 forms an image by ejecting UV ink 211 onto the recording medium 1 while moving from the positive direction to the negative direction of the X axis. When the carriage 202 moves in the negative X direction (-X direction) while ejecting UV ink 211, the right UV lamp 204R, which is mounted further in the positive X direction (+X direction) than the inkjet head 210, irradiates ultraviolet light after the UV ink 211 lands on the recording medium 1. This starts the effect of the UV ink 211 attached to the recording medium 1.

[0028] When the carriage 202 is moving in the +X direction, UV light 209 is emitted from the left UV lamp 204L, which is mounted in the -X direction from the inkjet head 210, to cure the UV ink 211 that has landed on the recording medium 1. If the UV ink 211 does not cure well with only one UV lamp 204 and an integrated amount of ultraviolet light is required, it is sufficient to irradiate the UV light 209 from both the left and right UV lamps 204.

[0029] Next, a recovery device 100 will be described as an embodiment of the waste liquid recovery device according to the present invention. The recovery device 100 according to this embodiment can be mounted in a housing separate from the UV inkjet device 200. In this case, it is only necessary that the waste liquid 111 can be moved from the waste liquid receiver 205 or the blank discharge receiver 207 to the waste liquid tank 110 via the waste liquid tube 120, which will be described later.

[0030] Here, in order to clarify the features of the present invention, an example of a recovery device 100z having a configuration that serves as a comparative example will be described with reference to FIG. 2. FIG. 2 is a configuration diagram showing an example of the internal structure of a recovery device 100z as an embodiment that does not have the characteristic configuration of the present invention compared to the recovery device 100. Note that the recovery device 100z as a comparative example for the embodiment of the present invention and the recovery device 100 according to this embodiment share some common parts. Therefore, in the following description, components of the recovery device 100z that are common to the recovery device 100 are assigned the same reference numerals as those used for the recovery device 100. Components assigned the same reference numerals are considered to have the same structure, operation, and effect as those of the recovery device 100z.

[0031] The recovery device 100z recovers the UV ink 211 and the like discharged by the inkjet head 210 in a liquid discharge operation that does not involve the formation of an image or the like.

[0032] The recovery device 100z has at least a waste liquid tank 110 mounted inside a device base 230, a waste liquid tube 120, and a float switch .

[0033] The waste liquid tank 110 is a container placed on the bottom surface 230B inside the device base 230, and has a capacity capable of storing a certain amount of waste liquid 111. An opening into which the waste liquid tube 120 is inserted and an opening into which the float switch shaft 131 constituting the float switch 130 is inserted are formed in the upper part of the waste liquid tank 110. The waste liquid tank 110 corresponds to a tank housing.

[0034] The waste liquid tube 120 is a tubular member that guides unused UV ink 211 (waste liquid 111) collected in the empty discharge receiver 207 or the waste liquid receiver 205 to the waste liquid tank 110. One end of the waste liquid tube 120 is connected to the empty discharge receiver 207 or the waste liquid receiver 205, and the other end is held in a hanging state in the internal space of the waste liquid tank 110. A pressure means such as a suction pump is connected to the waste liquid tube 120, and the waste liquid 111 collected in the empty discharge receiver 207 or the waste liquid receiver 205 is sucked out and sent to the waste liquid tank 110.

[0035] The float switch 130 includes a float switch shaft 131, a float 132, a lower stopper 133, and an upper stopper 134.

[0036] The float switch shaft 131 is a rod-shaped member having one end fixed to the top surface 230T of the device base 230 and the other end fixed in a hanging state toward the inside of the waste liquid tank 110. A reed switch, for example, is provided at a predetermined position inside the float switch shaft 131. The operating state of this reed switch is detected by a control unit provided in the recovery device 100z. The amount of waste liquid 111 stored inside the waste liquid tank 110 can be detected based on the operating state of the reed switch. A lower stopper 133 is attached to the outer periphery near the lower end of the float switch shaft 131. In addition, an upper stopper 134 is attached to the outer periphery at a predetermined height position from the lower stopper 133. The reed switch provided inside the float switch shaft 131 is mounted between the lower stopper 133 and the upper stopper 134.

[0037] A float 132 is attached to the float switch shaft 131 so as to be movable up and down. The float 132 is made of a material that floats in the waste liquid 111. The lower limit of the float 132's movable range is restricted by a lower stopper 133, and the upper limit is similarly restricted by an upper stopper 134. That is, the float 132 is movable up and down between the lower stopper 133 and the upper stopper 134. When the float 132 floats from the lower stopper 133 side to the upper stopper 134 side depending on the amount of waste liquid 111, the magnet embedded inside moves upward along the float switch shaft 131. This movement causes the magnet inside the float 132 to operate a reed switch inside the float switch shaft 131, thereby detecting the amount of waste liquid 111. That is, when the reed switch operates, it can be determined that the waste liquid 111 is full.

[0038] That is, as the amount of waste liquid stored inside the waste liquid tank 110 increases, the float 132 rises and the state of the reed switch of the float switch 130 transitions to ON (or OFF). This transition of the switch state is detected by a control unit provided in the recovery device 100z, and it is determined that the amount of waste liquid stored in the waste liquid tank 110 is full.

[0039] In the recovery device 100z, the control unit constantly or periodically monitors the state of the float switch 130. The control unit has a function of executing processing based on a predetermined sequence, such as notifying the user when the reed switch turns ON. When the waste liquid 111 becomes full, the contents of the waste liquid tank 110 are discarded and the waste liquid tank 110 is either reused or replaced with a new waste liquid tank 110. When the waste liquid 111 is completely removed from the waste liquid tank 110, the float switch 130 turns OFF.

[0040] 2(a) illustrates an example in which the waste liquid is not full (a state in which the float switch 130 has not detected fullness). When the amount of waste liquid 111 is low and the liquid level does not reach a position where the float 132 can float, the float 132 is in a position where it comes into contact with the lower stopper 133. This lower stopper 133 prevents the float 132 from falling off the float switch shaft 131. When the amount of waste liquid 111 increases from the state in FIG. 2(a), the position of the float 132 floating on the surface of the waste liquid 111 rises.

[0041] FIG. 2(d) illustrates a state in which the waste liquid 111 is full (a state in which the float switch 130 detects that the waste liquid tank 110 is full). As shown in FIG. 2(d), when the liquid level of the waste liquid 111 rises above the waste liquid tank 110, the float 132 rises accordingly. The float 132 is restricted from moving upward by the upper stopper 134. When the float 132 rises to a position where it contacts the upper stopper 134, a magnet provided inside the float 132 activates a reed switch inside the float switch shaft 131. This allows the control unit of the recovery device 100z to determine whether the waste liquid 111 is full.

[0042] Then, as shown in FIG. 2(d), if the tip of the waste liquid tube 120 (the opening portion that descends into the inside of the waste liquid tank 110) is positioned below the liquid surface of the waste liquid 111 before the waste liquid 111 becomes full, the tip will sink into the waste liquid 111.

[0043] The waste liquid 111 is pushed into the waste liquid tank 110 by the suction pressure of the suction pump, but depending on the solidification state and viscosity of the waste liquid 111 already accumulated in the waste liquid tank 110, the pressure of the suction pump may not be enough to push new waste liquid 111 out from the tip of the waste liquid tube 120 submerged in the waste liquid 111.

[0044] [Features of the recovery device 100] As described above, in order to prevent any problems that may occur in the recovery of new waste liquid 111, the recovery device 100 according to this embodiment is provided with a tube float 160 at the tip of the waste liquid tube 120. As shown in Fig. 3, in the recovery device 100, the tube float 160 is provided at the tip of the waste liquid tube 120 and has a structure that allows the waste liquid 111 recovered via the waste liquid tube 120 to flow into the waste liquid tank 110.

[0045] 4 is a schematic diagram showing the state inside the recovery device 100 when the liquid level of the waste liquid 111 rises and becomes higher than the tip of the hanging waste liquid tube 120. As shown in FIG. 4, the effect of the tube float 160 prevents the tip of the waste liquid tube 120 from sinking in the waste liquid 111.

[0046] The tube float 160 is also a buoyancy imparting member made of a material that exerts buoyancy on the waste liquid 111. Therefore, when the liquid level of the waste liquid 111 rises, the tip of the waste liquid tube 120 also rises due to the tube float 160. Because the waste liquid tube 120 is made of an elastic material, the rise of the tip portion allows the entire waste liquid tube 120 to move upward.

[0047] The tube float 160 also functions as a spacing maintaining part for keeping the opening at the tip of the waste liquid tube 120 at a position that maintains a certain distance from the liquid surface of the waste liquid 111. This spacing maintaining part maintains a state in which the waste liquid 111 can continue to hang down from the waste liquid tube 120 toward the waste liquid tank 110.

[0048] [First embodiment] Next, a first embodiment of the waste liquid tube 120 and the tube float 160 provided in the recovery device 100 will be described with reference to Fig. 5. Fig. 5 is a side view showing the state in which the waste liquid tube 120 and the tube float 160 are separated.

[0049] 5, the waste liquid tube 120 is a tubular member having a hollow portion 121 through which the waste liquid 111 passes. The waste liquid tube 120 is made of an elastic material such as silicon or rubber, and is made of a material that does not undergo a chemical reaction with the waste liquid 111 and deteriorates slowly over time. An opening 123 is formed in an outer peripheral portion 122 that forms the outer wall of the waste liquid tube 120.

[0050] The opening 123 is a waste liquid outlet formed by cutting out a portion of the side surface of the end of the opening side that comes into contact with the tube float 160. The opening 123 is formed on the surface facing the tube float 160. The opening 123 is configured so that when the waste liquid tube 120 is fitted or joined to it, the waste liquid 111 sent through the hollow portion 121 flows out of the waste liquid tube 120 to the outside through the opening 123.

[0051] 5, the tube float 160 has a spacing member 161 as a spacing portion for maintaining the tip of the waste liquid tube 120 at a certain distance without directly contacting the liquid surface of the waste liquid 111 stored in the waste liquid tank 110. The tube float 160 also has a buoyancy imparting member 162 as a buoyancy imparting portion for imparting buoyancy to the spacing member 161 so that it floats on the liquid surface of the waste liquid 111.

[0052] The spacing member 161 has a tube positioning portion 163 on the surface facing the waste liquid tube 120. The tube positioning portion 163 is a protrusion having an outer diameter substantially equal to the diameter of the hollow portion 121 of the waste liquid tube 120. When the hollow portion 121 is fitted or joined to the tube positioning portion 163, the waste liquid tube 120 and the tube float 160 become one unit.

[0053] 5, the buoyancy imparting member 162 is conical in shape and tapers toward the side that is immersed in the waste liquid 111. The shape of the buoyancy imparting member 162 is not limited to this, and it may be flat. Whatever shape it is, it is sufficient as long as it can float the spacing member 161 on the surface of the waste liquid 111 so that the waste liquid tube 120 and the waste liquid 111 can be maintained at a constant distance.

[0054] Fig. 6 is a diagram illustrating the flow of waste liquid 111 in an integrated unit of waste liquid tube 120 and tube float 160. In Fig. 6, the flow of waste liquid 111 is indicated by dashed arrows. Note that in Fig. 6, some symbols are omitted.

[0055] As shown in FIG. 6, when waste liquid 111 flows in the direction of gravity through hollow portion 121, it flows out onto the upper surface of spacing member 161 from opening 123 formed at the downstream end.

[0056] The waste liquid 111 that has flowed out onto the upper surface of the spacing member 161 flows over the upper surface of the spacing member 161 due to its fluidity, reaches the outer diameter, and then drips down from the spacing member 161 in the direction of gravity.

[0057] In this way, when the waste liquid 111 is pushed out from the opening 123 by the suction pump, the fluidity of the waste liquid 111 causes it to flow from the tube float 160 to the waste liquid tank 110. At this time, the opening 123 as an outlet for the waste liquid 111 in the waste liquid tube 120 is located at a distance without coming into contact with the liquid surface of the waste liquid 111, thereby eliminating the conventional problem of backflow due to solidification or increased viscosity of the waste liquid stored in the waste liquid tank 110.

[0058] [Second embodiment] Next, a second embodiment of the waste liquid tube 120 provided in the recovery device 100 will be described with reference to Fig. 7. As shown in Fig. 7(a), the waste liquid tube 120a according to this embodiment does not have an opening 123. However, the waste liquid tube 120a may have an opening 123.

[0059] 7(b) is a view of the tip of the waste liquid tube 120a seen from the downstream side, showing the cross-sectional shape of the waste liquid tube 120a. As shown in FIG. 7(b), the hollow portion 121a of the waste liquid tube 120a is not cylindrical, but has a generally gear-like shape with protruding portions arranged circumferentially.

[0060] When the hollow portion 121a is fitted into the tube positioning portion 163 of the spacing member 161, the waste liquid 111 that has flowed down the waste liquid tube 120b can be made to flow out from the gap between the hollow portion 121a and the tube positioning portion 163. That is, instead of the opening 123 shown in the first embodiment, the hollow portion 121a functions as an outlet for the waste liquid 111, thereby holding the tip portion of the waste liquid tube 120b in a position floating above the upper surface of the spacing member 161, and allowing the waste liquid 111 to be discharged.

[0061] [Third embodiment] Next, a third embodiment of the waste liquid tube 120 provided in the recovery device 100 will be described with reference to Fig. 8. As shown in Fig. 8(a), the waste liquid tube 120b according to this embodiment also does not have an opening 123. However, the opening 123 may be included.

[0062] 8(b) is a view of the waste liquid tube 120b as seen from the upstream side, showing the cross-sectional shape of the waste liquid tube 120b. As shown in FIG. 8(b), the waste liquid tube 120b has a hollow portion 121b that is not cylindrical, but has a structure in which the waste liquid 111 flows through a space formed by two slits that intersect in the center.

[0063] 8(c) is an enlarged view of the area surrounded by the dashed-dotted circle R in FIG. 8(a), illustrating an enlarged example of the shape of the tip of the waste liquid tube 120b. As shown in FIG. 8(c), the tip of the hollow portion 121b, which faces the spacing member 161, has a tapered cross section with a diameter that widens toward the outlet.

[0064] When hollow portion 121b is fitted into tube positioning portion 163 of spacing member 161, waste liquid 111 that has flowed down waste liquid tube 120b flows down the flared inclined surface (inclined portion) at the tip of hollow portion 121b and flows out from the gap between hollow portion 121b and tube positioning portion 163. The tip of hollow portion 121b is maintained in a state where it is held at a predetermined position away from the liquid surface of waste liquid 111 by spacing member 161.

[0065] That is, instead of the opening 123 shown in the first embodiment, the hollow portion 121b functions as an outlet for the waste liquid 111, thereby holding the tip portion of the waste liquid tube 120b in a position above the upper surface of the spacing member 161, and allowing the waste liquid 111 to be discharged. Note that the opening 123 may also be provided.

[0066] The recovery device 100 according to this embodiment is used in a UV inkjet device 200. The UV inkjet device 200 includes an inkjet head 210. The inkjet head 210 is a so-called "liquid ejection head."

[0067] In this specification, a "liquid ejection head" refers to a functional component that ejects and sprays liquid from nozzles. The ejected liquid may be any liquid with a viscosity and surface tension that allows it to be ejected from the head. It is not limited to UV-curable inks. However, as explained above, it is intended to be any liquid that may interfere with the operation of a sensor that detects whether a tank for collecting waste liquid is full. Therefore, it is preferable that the viscosity of the liquid be 30 mPa·ss or less at room temperature and pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural dye. These liquids can be used, for example, in inkjet inks, surface treatment solutions, liquids for forming components of electronic devices and light-emitting elements, resist patterns for electronic circuits, and liquid materials for 3D modeling.

[0068] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0069] Next, a liquid ejection unit including a liquid ejection head according to the present invention and an embodiment of a liquid ejection device will be described again. First, an embodiment of a liquid ejection device according to the present invention will be described with reference to Figs. 9 and 10. Fig. 9 is a plan view illustrating a main part of a liquid ejection device 400 according to this embodiment. Fig. 10 is a side view illustrating a main part of the liquid ejection device 400.

[0070] A serial type device is exemplified as the liquid ejection device 400. In this device, a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B and movably holds the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0071] The carriage 403 is equipped with a liquid ejection unit 440 that integrates a nozzle 1 and a head tank 441 .

[0072] Liquid ejection unit 1 of 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). Furthermore, liquid ejection unit 1 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

[0073] The head tank 441 is supplied with the liquid stored in the liquid cartridge 450 by a supply mechanism 494 for supplying the liquid stored outside the head tank 441 to the head tank 441 .

[0074] The supply mechanism 494 is composed of a cartridge holder 451 which is a filling section to which the liquid cartridge 450 is attached, a tube 456, a liquid delivery unit 452 including a liquid delivery pump, etc. The liquid cartridge 450 is detachably attached to the cartridge holder 451. The liquid is delivered from the liquid cartridge 450 to the head tank 441 by the liquid delivery unit 452 via the tube 456.

[0075] The liquid ejection device 400 includes a transport mechanism 495 for transporting the paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0076] The conveyor belt 412 attracts the paper 410 and conveys it at a position facing 1. The conveyor belt 412 is an endless belt that is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction. The conveyor belt 412 moves in a circular motion in the sub-scanning direction when the conveyor roller 413 is rotated by a sub-scanning motor 416 via a timing belt 417 and a timing pulley 418. Furthermore, a maintenance and recovery mechanism 420 that maintains and recovers 1 is disposed on one side of the conveyor belt 412 in the main scanning direction.

[0077] The maintenance and recovery mechanism 420 is made up of, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzles are formed), a wiper member 422 that wipes the nozzle surface, and the like.

[0078] The main scanning movement mechanism 493, the supply mechanism 494, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0079] In the liquid ejection device 400 having the above configuration, a sheet of paper 410 is fed onto and adsorbed to the conveyor belt 412, and the sheet of paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412. Then, by driving the carriage 403 in accordance with an image signal while moving the carriage 403 in the main scanning direction, UV ink 211 is ejected onto the stationary sheet of paper 410 to form an image.

[0080] Next, an example of a liquid discharge unit according to the present invention will be described with reference to Fig. 11. Fig. 11 is an explanatory plan view of the main part of the liquid discharge unit.

[0081] Of the components that make up liquid ejection device 400, liquid ejection device 400 according to this embodiment is made up of a housing portion made up of side plates 491A, 491B and back plate 491C, a main scanning movement mechanism 493, and a carriage 403. It is also possible to configure a liquid ejection unit in which at least one of the maintenance and recovery mechanism 420 and the supply mechanism 494 described above is further attached to, for example, side plate 491B of the liquid ejection unit.

[0082] Next, another example of a liquid ejection unit that can be mounted on a liquid ejection device according to the present invention will be described with reference to Fig. 12. Fig. 11 is an explanatory front view of the liquid ejection unit according to this embodiment.

[0083] The liquid discharge unit is composed of 1 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444. The flow path part 444 is disposed inside a cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting with 1 is provided on the upper part of the flow path part 444.

[0084] In the present invention described above, a "liquid ejection device" is a device that includes a liquid ejection head or a liquid ejection unit and ejects liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0085] Furthermore, the term "liquid ejection device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0086] For example, examples of "liquid ejection devices" include image forming devices, which are devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices), which eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0087] Furthermore, the term "liquid ejection device" is not limited to devices that visualize meaningful images such as letters and figures using ejected liquid. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0088] The term "liquid-adherable object" means an object to which a liquid can be attached, even if only temporarily. The material of the "liquid-adherable object" may be any material to which a liquid can be attached, even if only temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0089] Furthermore, unless otherwise specified, the "liquid ejection device" includes both a serial type device in which the liquid ejection head is moved and a line type device in which the liquid ejection head is not moved.

[0090] Other examples of the "liquid ejection device" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that sprays a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0091] The "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and is a collection of parts related to ejecting liquid. For example, the "liquid ejection unit" includes a liquid ejection head combined with at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism.

[0092] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism fixed to each other by fastening, bonding, engaging, etc., or one held movably relative to the other. The liquid ejection head, functional part, or mechanism may also be configured to be detachable from each other.

[0093] For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, such as the liquid ejection unit shown in Figure 10. Other liquid ejection units have a liquid ejection head and a head tank integrated together by being connected to each other by a tube or the like. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0094] Furthermore, some liquid ejection units have a liquid ejection head and a carriage integrated together.

[0095] In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, as shown in Figure 11, the liquid ejection head, carriage, and main scanning movement mechanism are integrated together.

[0096] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which a liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0097] As shown in FIG. 12, the liquid discharge unit may be such that a tube is connected to a liquid discharge head to which a head tank or flow path components are attached, and the liquid discharge head and supply mechanism are integrated.

[0098] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0099] Furthermore, the pressure generating means used in the "liquid ejection head" is not limited. For example, in addition to the piezoelectric actuator (which may use a laminated piezoelectric element) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a vibration plate and an opposing electrode may be used.

[0100] In this specification, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

[0101] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist thereof. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0102] 1: Recording medium 100: Recovery device 110: Waste liquid tank 111: Waste liquid 120: Waste liquid tube 121:Hollow part 122: Outer periphery 123: Opening 160: Tube float 161: Spacing member 162: Buoyancy imparting member 163: Tube positioning part 200: UV inkjet device 230: Equipment base [Prior art documents] [Patent documents]

[0103] [Patent Document 1] Japanese Patent Application Publication No. 2019-151082

Claims

1. a tank housing for storing liquid; a tubular member for allowing the liquid to flow into the tank housing; a spacing retaining portion provided at an end of the tubular member that hangs down into the internal space of the tank housing; a buoyancy imparting portion that has buoyancy with respect to the liquid and floats the spacing portion on the surface of the liquid, an opening is provided at an end of the tubular member on a side surface opposite to the surface facing the spacing portion, the spacing maintaining portion maintains a predetermined distance between the end portion of the tubular member and the liquid surface by the buoyancy of the buoyancy imparting portion. A waste liquid recovery device characterized by:

2. A tank housing for storing liquid; a tubular member for allowing the liquid to flow into the tank housing; a spacing retaining portion provided at an end of the tubular member that hangs down into the internal space of the tank housing; a buoyancy imparting portion that has buoyancy with respect to the liquid and floats the spacing portion on the surface of the liquid, an end of the tubular member has a flared inclined portion on a surface facing the spacing retaining portion, the spacing maintaining portion maintains a predetermined distance between the end portion of the tubular member and the liquid surface by the buoyancy of the buoyancy imparting portion. A waste liquid recovery device characterized by:

3. a conveying unit that conveys the recording medium; a liquid ejection unit that ejects liquid onto a recording medium, a waste liquid recovery device having a tank housing for recovering liquid that is discarded when the liquid discharge unit performs a liquid discharge operation not onto the recording medium, 3. The liquid ejection apparatus according to claim 1, wherein the waste liquid recovery device is the waste liquid recovery device according to claim 1.

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