JP2010221589A - Droplet discharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet discharging device which discharges air bubbles generated in liquid and reducing a size and weight of a droplet discharging head, which discharges droplets while moving. <P>SOLUTION: In an image formation part 12, an ink droplet discharging part 72 and a switching valve 75 are provided. The ink droplet discharging part 72 is filled with the ink liquid, which is supplied from an ink liquid filling part 70A filled with the ink liquid supplied from an ink tank 44, and discharges ink droplets. The switching valve 75 switches the flow of the liquid so that either one of the ink liquid filling part 70A and the ink droplet discharging part 72 is communicated with a returning path 48 for returning the ink liquid to the ink tank 44. When the image formation part 12 is moved to a home position, electric power is supplied thereto via a connector provided at the home position of the body of the apparatus; as a result, the ink liquid filling part 70A and the returning path 48 are communicated with each other. When the image formation part 12 is positioned at a position other than the home position, the switching valve 75 is switched so that the ink droplet discharging part 72 and the returning path 48 are communicated with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a droplet discharge device that discharges droplets.

  In recent years, a droplet discharge device that forms dots on an image recording medium by discharging droplets from a droplet discharge head has become widespread.

  Further, in order to suppress the increase in the viscosity of the liquid supplied to the liquid droplet discharge head, in the liquid droplet discharge device that circulates the liquid, when bubbles are generated in the liquid, a liquid discharge failure may occur due to the bubbles. There was a problem of having sex.

  In order to solve this problem, Patent Document 1 discloses a first liquid chamber into which liquid flows, a second liquid chamber that communicates with the first liquid chamber via a filter, and causes the liquid to flow out to the droplet discharge head. Any one of a liquid chamber, a circulation outlet provided in the first liquid chamber and the second liquid chamber, for discharging the liquid to the circulation channel, a circulation outlet of the first liquid chamber, and a circulation outlet of the second liquid chamber And switching means for connecting one of them to the circulation flow path, and when removing bubbles accumulated in the first liquid chamber, the switching means connects the circulation outlet of the first liquid chamber and the circulation flow path. Technology is disclosed.

JP 2006-263996 A

  However, in the technique described in Patent Document 1, since the control unit for controlling the switching unit and the power supply source are provided in the droplet discharge head, the size and weight of the droplet discharge head increase. However, in the liquid droplet ejection apparatus provided with the liquid droplet ejection head that ejects the liquid droplets while moving, there is a problem in that the size and weight of the liquid droplet ejection head are hindered.

  The present invention has been made to solve the above-described problems, and is a liquid that can discharge bubbles generated in a liquid and can reduce the size and weight of a droplet discharge head that discharges droplets while moving. An object is to provide a droplet discharge device.

  In order to achieve the above object, the droplet discharge device according to claim 1 is a liquid filling unit filled with a liquid supplied from a storage unit for storing a liquid, and filled with a liquid supplied from the liquid filling unit. In addition, a droplet discharge unit that discharges a droplet according to an applied pressure, and any one of the liquid filling unit and the droplet discharge unit and a return path that returns the liquid to the storage unit are provided. A droplet discharge head provided with a switching valve for switching to communicate, a moving means for moving the droplet discharge head in a predetermined direction with respect to the apparatus main body, and the movement provided at a predetermined position of the apparatus main body; When the droplet discharge head is moved to the predetermined position by the means, the switching valve is switched so that the liquid filling unit and the return path are communicated, and the droplet discharge head is positioned at a position other than the predetermined position. Located in If that, the liquid and the droplet ejecting section and the feedback path is provided with a switching means for switching the switching valve so as to communicate.

  The droplet discharge head of the droplet discharge apparatus according to claim 1 is filled with a liquid filling unit filled with a liquid supplied from a storage unit for storing a liquid, and filled with a liquid supplied from the liquid filling unit. At the same time, switching is performed so that the droplet discharge unit that discharges the droplet according to the applied pressure, and either the liquid filling unit or the droplet discharge unit and the return path that returns the liquid to the storage unit communicate with each other. A switching valve is provided. Then, when the droplet discharge head is moved in a predetermined direction with respect to the apparatus main body by the moving means and the liquid droplet discharge head is moved to the predetermined position, the liquid filling is performed by the switching means provided at the predetermined position of the apparatus main body. When the switching valve is switched so that the head and the return path are in communication, and the droplet discharge head is located at a position other than the predetermined position, the switching valve is set so that the droplet discharge section and the return path are in communication. Can be switched.

  Thus, according to the droplet discharge apparatus of the first aspect, when the droplet discharge head is moved to the predetermined position by the switching means provided at the predetermined position of the apparatus main body, the liquid filling unit and the return path are arranged. Since the switching valve is switched so as to communicate with each other, bubbles generated in the liquid can be discharged, and a droplet discharge head that discharges droplets while moving can be reduced in size and weight.

  In addition, the liquid droplet ejection apparatus according to claim 1 includes a detection unit that detects a height of a liquid level filled in the liquid filling unit, as in the invention according to claim 2, and includes the detection unit. When the liquid level detected by the above is below a predetermined height, the switching means may switch the switching valve. Thereby, the return to the unnecessary storage part with respect to the liquid with which the liquid filling part was filled can be prevented.

  Further, in the liquid droplet ejection device according to claim 1 or 2, as in the invention according to claim 3, the liquid filling unit is provided with a filter for removing foreign matters mixed in the supplied liquid. Also good. As a result, it is possible to prevent a liquid droplet ejection failure caused by contamination of foreign matter.

  In addition, in the liquid droplet ejection device according to any one of claims 1 to 3, as in the invention according to claim 4, when the electric power is supplied to the switching valve, the liquid filling device When the power is not supplied, the electromagnetic discharge valve and the feedback path are connected to each other, and the switching means supplies power to the switching valve. By doing so, you may comprise by the supply means which switches the said switching valve. Thereby, with a simple configuration, it is possible to reduce the size and weight of a droplet discharge head that discharges bubbles while discharging bubbles generated in a liquid.

  Moreover, the droplet discharge device according to any one of claims 1 to 3 communicates the switching valve with the liquid filling portion and the return path as in the invention according to claim 5. And a valve body located at a second position where the droplet discharge unit and the return path communicate with each other, and the switching means moves the valve body from the second position to the first position. You may comprise with the moving member which moves and switches the said valve body. Thereby, with a simple configuration, it is possible to reduce the size and weight of a droplet discharge head that discharges bubbles while discharging bubbles generated in a liquid.

  As described above, according to the present invention, it is possible to discharge bubbles generated in a liquid, and it is possible to reduce the size and weight of a droplet discharge head that discharges droplets while moving.

1 is a cutaway side view showing a configuration of an ink jet recording apparatus according to an embodiment. FIG. 3 is a top view of the image forming unit and its periphery according to the embodiment. FIG. 3 is a schematic diagram illustrating a flow path of an ink liquid in an image forming unit according to an embodiment. It is a schematic diagram which shows the relationship between the height of the liquid level detected by the liquid level sensor which concerns on embodiment, and the ON state and OFF state of a switch. 1 is a block diagram illustrating a configuration of a main part of an electric system of an ink jet recording apparatus according to an embodiment. It is a flowchart which shows the flow of a process of the valve switching program which concerns on embodiment. It is a schematic diagram which shows the structure of the switching valve which concerns on another form.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to an ink jet recording apparatus will be described.

  FIG. 1 shows an overall configuration of an inkjet recording apparatus 10 according to the present embodiment.

  As shown in FIG. 1, the inkjet recording apparatus 10 includes an image forming unit 12 including a recording head including a plurality of nozzles that form dots on a recording paper 14 by ejecting ink droplets. A paper supply unit 16 that supplies the recording paper 14, a decurling unit 18 that removes curling of the recording paper 14, and a surface on which ink droplets are ejected from the recording head provided in the image forming unit 12 (hereinafter referred to as “ A belt conveying unit 20 that conveys the recording paper 14 while maintaining the flatness of the recording paper 14, and a paper discharge that discharges the recording paper 14 on which an image is formed. Part 22.

  In the inkjet recording apparatus 10 according to the present embodiment, the paper feed unit 16 is loaded with a magazine for rolled paper (continuous paper). However, the present invention is not limited to this, and a plurality of magazines differing in paper width, paper quality, and the like. May be loaded. Further, instead of or in combination with the roll paper magazine, a cassette loaded with stacked cut sheets may be loaded.

  In the case where a plurality of types of recording paper 14 can be used, an information recording body such as a barcode or a wireless tag that records the type information of the recording paper 14 is attached to the magazine, and the information on the information recording body is stored in a predetermined manner. It is preferable that the type of the recording paper 14 to be used is automatically determined by reading with the reading device, and ink ejection control is performed so as to realize appropriate ink ejection according to the type.

  The recording paper 14 delivered from the paper supply unit 16 retains curl due to having been loaded in the magazine. In order to remove this curl, heat is applied to the recording paper 14 by the heating drum 24 in the direction opposite to the curl direction of the magazine in the decurling unit 18. At this time, it is more preferable to control the heating temperature so that the surface on which the image is formed on the recording paper 14 (hereinafter referred to as “image forming surface”) is weakly curled outward.

  In the case of an apparatus configuration using roll paper, a cutter 26 is provided as shown in FIG. 1, and the roll paper is cut into a desired size by the cutter 26. Note that the cutter 26 is not necessary when cut paper is used.

  After the decurling process, the recording paper 14 cut by the cutter 26 is sent to the belt conveyance unit 20.

  The belt conveyance unit 20 is configured to have a structure in which an endless belt 32 is wound between rollers 28 and 30. When the power of a motor (not shown) is transmitted to at least one of the rollers 28 and 30 around which the belt 32 is wound, the belt 32 is driven in the clockwise direction in FIG. 14 is conveyed from left to right in FIG.

  The belt 32 has a width that is wider than the width of the recording paper 14, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in the figure, an adsorption chamber 34 is provided inside the belt 32 spanned between the rollers 28 and 30 at a position facing the ink discharge surface, and the air in the adsorption chamber 34 is provided. Is sucked by the fan 36 to obtain a negative pressure, whereby the recording paper 14 is adsorbed and held on the belt 32. In the inkjet recording apparatus 10 according to the present embodiment, the suction suction method using the suction chamber 34 is applied as a method for holding the recording paper 14 on the belt 32. However, the invention is not limited thereto, and the recording paper 14 is not limited thereto. An electrostatic attraction method in which the belt 32 is electrostatically attracted to the belt 32 may be applied. Further, the recording paper 14 may be transported by installing a nip roll on the roller 28 without using an endless belt.

  A heating fan 38 is provided upstream of the image forming unit 12 in the conveyance direction of the recording paper 14 by the belt conveyance unit 20. The heating fan 38 blows heated air on the recording paper 14 before image formation to heat the recording paper 14. By heating the recording paper 14 immediately before image formation, it becomes easy to dry after ink droplets have landed on the recording paper 14.

  A post-drying unit 40 including a heating fan that blows hot air is provided at the subsequent stage of the image forming unit 12, and the post-drying unit 40 dries the image forming surface of the recording paper 14 on which the image is formed. The recording paper 14 on which the image is formed is discharged from the paper discharge unit 22.

  In addition, since ink droplets ejected from the image forming unit 12 may adhere to the belt 32, the belt cleaning unit 42 is provided outside the region of the belt 32 that transports the recording paper 14. Note that the ink jet recording apparatus 10 according to the present embodiment uses a brush / roll as the belt cleaning unit 42, but is not limited thereto, a water absorbing roll, an air blow for blowing clean air, or a combination thereof. May be applied.

  Further, the ink jet recording apparatus 10 according to the present embodiment includes an ink tank 44 that stores ink liquid. The ink liquid stored in the ink tank 44 is supplied to the image forming unit 12 through the supply path 46, and part of the ink liquid supplied to the image forming unit 12 returns the ink liquid to the ink tank 44. The ink is returned to the ink tank 44 via the return path 48.

  FIG. 2 shows a top view of the image forming unit 12 provided in the ink jet recording apparatus 10 according to the present embodiment and the periphery thereof.

  As shown in the figure, the image forming unit 12 uses a yellow (Y) ink liquid to form an image on the recording paper 14 and a magenta (M) ink liquid to form an image on the recording paper 14. , A recording head 50C that forms an image on the recording paper 14 using cyan (C) ink liquid, and a recording head that forms an image on the recording paper 14 using black (K) ink liquid It has 50K. The recording heads 50Y, 50M, 50C, and 50K are mounted on the carriage 52. In the following description, when distinguishing corresponding colors, description is given with any one of Y, M, C, K corresponding to the end of the code, and when not distinguishing corresponding colors, Y, M, C, and K are omitted.

  The carriage 52 moves the image forming unit 12 in a predetermined direction with respect to the ink jet recording apparatus 10. In the inkjet recording apparatus 10 according to the present embodiment, the predetermined direction is a direction orthogonal to the direction in which the recording paper 14 is conveyed by the belt conveyance unit 20 (hereinafter referred to as “main scanning direction”). .

  The carriage 52 according to the present embodiment includes an insertion hole in a direction corresponding to the main scanning direction, and a guide rail 54 arranged in parallel to the main scanning direction is inserted through the insertion hole. . As a result, the carriage 52 is slidable along the guide rail 54.

  Furthermore, the carriage 52 includes a belt connecting portion 56 that is connected to a carriage belt 58 that is arranged in parallel to the main scanning direction.

  The carriage belt 58 is wound around the main pulley 60A and the driven pulley 60B. The main driving pulley 60A is mechanically connected to the rotation shaft of the carriage motor 62, and forward rotation (in the direction of arrow A shown in FIG. 2) and reverse rotation (arrow shown in FIG. 2) of the rotation shaft of the carriage motor 62. Rotate forward and backward according to (B direction). For this reason, the carriage belt 58 rotates in accordance with the forward rotation and the reverse rotation of the rotation shaft of the carriage motor 62, whereby the carriage 52 reciprocates in the main scanning direction along the guide rail 54.

  On the side surface of the carriage 52, a connector 64A for supplying electric power to a switching valve 75 (see FIG. 3, details will be described later) as an electromagnetic valve is provided.

  Further, in the inkjet recording apparatus 10 according to the present embodiment, when the image forming process for forming the image indicated by the image data on the recording paper 14 is completed, the image forming unit 12 moves the predetermined position (home position (reference position) of the apparatus main body. The carriage motor 62 is controlled to move to)). In the ink jet recording apparatus 10 according to the present embodiment, the predetermined position is the right end of FIG.

  Furthermore, in the inkjet recording apparatus 10 according to the present embodiment, a connector 64B that can be electrically connected to the connector 64A is provided at the home position. The connector 64B is connected to the output terminal of the switching valve power supply unit 66 that supplies power for switching the switching valve 75. When the image forming unit 12 is moved to the home position, power is supplied to the switching valve 75. To switch the switching valve.

  The connector 64B may be provided with a spring (damper) for absorbing vibrations and shocks generated when the image forming unit 12 is moved to the home position and connected to the connector 64A.

  FIG. 3 shows the structure of the recording heads 50Y, 50M, 50C, and 50K according to the present embodiment.

  The recording head 50 according to the present embodiment is provided with an ink liquid filling unit 70A filled with the ink liquid supplied from the ink tank 44, and filled with the ink liquid supplied from the ink liquid filling unit 70A. An ink droplet ejection unit 72 that ejects ink droplets according to pressure, and a switching valve 75 that switches so that one of the ink liquid filling unit 70A and the ink droplet ejection unit 72 communicates with the feedback path 48 are provided. Yes.

  In the recording head 50 according to the present embodiment, the ink droplet ejection section 72 communicates with the ink liquid filling section 70B filled with the ink liquid discharged from the ink droplet ejection section 72, and the supply path 46 is filled with the ink liquid. The upper surface of the portion 70A communicates with the ink liquid filling portion 70A, and the return path 48 can communicate with the ink liquid filling portions 70A and 70B via the switching valve 75 on each upper surface of the ink liquid filling portions 70A and 70B. .

  A pump 76 is provided in the return path 48, and the ink liquid filled in the ink liquid filling unit 70 </ b> A or the ink liquid filling unit 70 </ b> B is discharged by the pump 76 to the return path 48. Further, the supply path 46 and the return path 48 are formed of a flexible material so as not to hinder the movement of the image forming unit 12 in the main scanning direction.

  The ink droplet ejection unit 72 according to the present embodiment has a nozzle 78 that ejects each ink droplet, and includes a pressure chamber 80 that ejects the supplied ink liquid from the nozzle 78 in accordance with the applied pressure. . Further, the ink droplet discharge section 72 is provided with a bypass flow path 82 for flowing the ink liquid from the ink liquid filling section 70A to the ink liquid filling section 70B without going through the pressure chamber 80, and from the ink liquid filling section 70A. The ink liquid flowing to the ink liquid filling unit 70B has a predetermined ratio between the flow rate of the ink liquid flowing through the pressure chamber 80 and the flow rate of the ink liquid flowing through the bypass channel 82. Yes.

  The switching valve 75 according to the present embodiment causes the ink liquid filling unit 70A to communicate with the feedback path 48 when power is supplied, and the ink droplet ejection unit 72 and the feedback path when power is not supplied. It is comprised with the solenoid valve which makes 48 communicate. That is, when the image forming unit 12 is moved to the home position, the switching valve 75 is supplied with electric power via the connectors 64A and 64B so that the ink liquid filling unit 70A and the return path 48 communicate with each other. When the image forming unit 12 is located at a position other than the home position, the power is not supplied, so that the ink droplet ejection unit 72 and the return path 48 are switched to communicate with each other.

  Furthermore, the switching valve 75 according to the present embodiment is electrically connected to the connector 64A via the switch 84.

  In the ink liquid filling unit 70A according to the present embodiment, a filter 86 that removes foreign matters mixed in the liquid supplied to the ink liquid filling unit 70A is disposed. As shown in FIG. 3, the filter 86 is disposed so as to be inclined so that the upper part is on the right side with respect to the vertical plane.

  If air bubbles are generated in the ink liquid supplied to the ink liquid filling unit 70 </ b> A, after the air bubbles are attached to the filter 86, the air bubbles are not peeled off from the filter 86 or are not attached to the filter 86. After drifting in the ink liquid, the ink liquid filling part 70A may be accumulated above. In this case, the amount of ink liquid filled in the ink liquid filling unit 70A is reduced. Therefore, the ink liquid filling unit 70A according to the present embodiment includes a liquid level sensor 88 that detects the height of the liquid level of the ink liquid filled in the ink liquid filling unit 70A.

  The liquid level sensor 88 according to the present embodiment is connected to the floating body 88A which floats the liquid level and the floating body 88A, and the angle θ formed with the upper surface of the ink liquid filling unit 70A changes according to the height of the liquid level. The cable 88B is provided, and the height of the liquid level is detected by the angle θ.

  In the ink jet recording apparatus 10 according to the present embodiment, as shown in FIGS. 4A and 4B, the angle θ increases as the liquid level of the ink liquid filling unit 70A decreases. When the angle θ is equal to or smaller than a predetermined angle indicating that the liquid level is so high that it is not necessary to discharge the air (bubbles) in the ink liquid filling unit 70A, the angle θ is shown in FIG. Thus, the switch 84 is turned off, and even if the connector 64A and the connector 64B are electrically connected, power is not supplied to the solenoid valve. On the other hand, when the angle θ exceeds the predetermined angle, the switch 84 is turned on as shown in FIG. 4B, and power is supplied to the switching valve 75 via the connector 64A and the connector 64B. It becomes possible. That is, the switch 84 is turned on when the liquid level detected by the liquid level sensor 88 is less than or equal to a predetermined height, and when the liquid level detected by the liquid level sensor 88 exceeds a predetermined height. It will be in an off state.

  FIG. 5 shows an electrical configuration of the inkjet recording apparatus 10.

  As shown in the figure, the inkjet recording apparatus 10 includes a system controller 100, a print controller 102, a communication interface 104, an image memory 106, a ROM (Read Only Memory) 108, a motor driver 110, a heater driver 112, a motor driver 114, And a recording head driver 116.

  The system controller 100 includes a CPU (Central Processing Unit) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. That is, the system controller 100 controls the print control unit 102, the communication interface 104, the image memory 106, the ROM 108, the motor driver 110, the heater driver 112, and the switching valve power supply unit 66, and the host controller 118. Communication control, read / write control of the image memory 106 and ROM 108, and the like, and a control signal for controlling output and non-output of power to the motor 120, the heater 122, and the connector 64B of the transport system is generated. Note that various data such as image data stored in the image memory 106 are transmitted to the print control unit 102 when performing control to form an image on the recording paper 14.

  The communication interface 104 is an interface unit with a host device 118 that is used by a user to instruct the inkjet recording apparatus 10 to form an image, and is equipped with a buffer memory for speeding up communication. Yes. The inkjet recording apparatus 10 according to the present embodiment uses USB (Universal Serial Bus) as the communication interface 104, but is not limited to this, and is not limited to IEEE (Institute of Electrical and Electronics Engineers) 1394, Ethernet ( (Registered trademark), a serial interface such as a wireless network, or a parallel interface such as Centronics may be applied.

  The image memory 106 is a storage unit that stores image data and the like transmitted from the host device 118 via the communication interface 104, and various data are read and written through the system controller 100. The image memory 106 is used as a temporary storage area for various data, and is also used as a program development area and a calculation work area for the CPU. In the inkjet recording apparatus 10 according to the present embodiment, a memory made of a semiconductor element is applied as the image memory 106. However, the present invention is not limited to this, and a magnetic medium such as a hard disk may be applied.

  The ROM 108 stores programs executed by the CPU of the system controller 100 and various data necessary for control. The inkjet recording apparatus 10 according to the present embodiment uses a non-rewritable storage means as the ROM 108, but is not limited to this, and a rewritable storage such as an EEPROM (Electrically Erasable Programmable Read Only Memory). Means may be applied.

  The motor driver 110 is a drive circuit that drives the conveyance motor 120 in accordance with a control signal from the system controller 100, and the heater driver 112 drives the heater 122 used in the post-drying unit 40 in accordance with the control signal from the system controller 100. It is a driver to let you.

  The switching valve power supply unit 66 switches the switching valve 75 by outputting power to the switching valve 75 to the connector 64B in accordance with a control signal from the system controller 100.

  The print control unit 102 performs various processes and corrections for generating ink discharge control data (hereinafter referred to as “ink discharge data”) from image data transmitted from the system controller 100 according to the control of the system controller 100. In addition to functioning as signal processing means for performing the above-described processing, the print head 50 is controlled via the print head driver 116 and the carriage motor 62 is controlled via the motor driver 114 which is a drive circuit for driving the carriage motor 62.

  The print head driver 116 is a drive circuit for driving the print head 50 in accordance with an instruction from the print control unit 102, and discharges ink droplets from the nozzles 78 based on the ink discharge data transmitted from the print control unit 102. Are generated and output to the recording head 50.

  Next, the operation of the inkjet recording apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a flow of a valve switching program executed by the CPU of the system controller 100 when the image forming process is completed. The program is stored in advance in the storage area of the ROM 108.

  In step 200, the process waits until the image forming unit 12 reaches the home position. When the image forming unit 12 reaches the home position, the connector 64A and the connector 64B are electrically connected. In the inkjet recording apparatus 10 according to the present embodiment, as an example, a sensor (not shown) is provided at the home position, and this sensor determines whether or not the image forming unit 12 has reached the home position. For example, it may be determined that the image forming unit 12 has reached the home position when a predetermined time has elapsed after the image forming process is completed.

  In the next step 202, a control signal is output to the switching valve power supply unit 66 so as to start outputting power to the connector 64B. By this control, when the switch 84 is in the ON state, power is supplied to the switching valve 75 via the connectors 64A and 64B. When electric power is supplied to the switching valve 75, the ink liquid filling unit 70A communicates with the return path 48, and the ink liquid in the ink liquid filling unit 70A and the ink tank together with the air accumulated in the upper part of the ink liquid filling unit 70A. Accordingly, the air accumulated in the ink liquid filling unit 70A is discharged from the ink liquid filling unit 70A.

  In the next step 204, the process waits until a predetermined time elapses when the air in the ink liquid filling unit 70A is completely discharged.

  In the next step 206, a control signal is output to the switching valve power supply unit 66 so as to stop the output of power to the connector 64B, and this program is terminated.

  As described above in detail, in the ink jet recording apparatus 10 according to the present embodiment, the ink forming unit 70A in which the image forming unit 12 is filled with the ink supplied from the ink tank 44 that stores the ink. Any one of the ink droplet ejection unit 72 that is filled with the ink liquid supplied from the ink liquid filling unit 70A and ejects ink droplets according to the applied pressure, and the ink liquid filling unit 70A and the ink droplet ejection unit 72 A switching valve 75 is provided to switch one side so as to communicate with a return path 48 for returning the ink liquid to the ink tank 44. When the image forming unit 12 is moved to the home position, the home position of the apparatus main body is provided. When the power is supplied to the switching valve 75 by the connector 64A provided in the connector, the ink liquid filling unit 70A and the return path 48 communicate with each other. When the switching valve 75 is switched and the image forming unit 12 is located at a position other than the home position, the switching valve 75 is switched so that the ink droplet discharge unit 72 and the return path 48 communicate with each other. Bubbles generated in the liquid can be discharged, and the image forming unit 12 that discharges droplets while moving can be reduced in size and weight.

  Further, a liquid level sensor 88 that detects the height of the liquid level filled in the ink liquid filling unit 70A is provided, and the switching valve 75 is switched when the liquid level detected by the liquid level sensor 88 is equal to or lower than a predetermined height. Therefore, unnecessary return to the ink tank 44 with respect to the liquid filled in the ink liquid filling unit 70A can be prevented.

  In addition, since the filter 86 for removing the foreign matter mixed in the supplied ink liquid is provided in the ink liquid filling unit 70A, it is possible to prevent ink droplet ejection failure caused by the foreign matter being mixed.

  As mentioned above, although this invention was demonstrated using said each embodiment, the technical scope of this invention is not limited to the range as described in each said embodiment. Various modifications or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the modifications or improvements are added are also included in the technical scope of the present invention.

  For example, in each of the above-described embodiments, the case where the liquid level sensor 88 that detects the height of the liquid level based on the angle θ formed by the cable 88B and the upper surface of the ink liquid filling unit 70A is used as the liquid level sensor 88 has been described. The present invention is not limited to this, and other liquid level sensors such as a liquid level sensor that includes a pair of electrodes and detects the liquid level by immersing the ink liquid in the pair of electrodes are used. It is good also as a form.

  In each of the above embodiments, the case where the switching valve 75 is switched at the home position when the liquid level detected by the liquid level sensor 88 is equal to or lower than the predetermined height has been described. However, the present invention is not limited to this. The switching valve 75 may be switched at the home position regardless of the liquid level.

  In each of the above embodiments, the case where the home position is the right end in FIG. 2 has been described. However, the present invention is not limited to this, and the home position is set to another position such as the left end in FIG. It is good also as a form.

  Further, in each of the above-described embodiments, the case where the position for supplying electric power to the switching valve 75 is the home position has been described. However, the present invention is not limited to this, and for example, FIG. The right side position may be a position for supplying power to the switching valve 75, and the position for supplying power to the switching valve 75 may be a position different from the home position.

  Moreover, although the case where the switching valve is an electromagnetic valve has been described in the above embodiment, the present invention is not limited to this, and for example, as shown in FIG. A mechanical switching valve configured by a valve body 150 located at a first position where the return path 48 communicates and at a second position where the ink droplet discharge unit 72 communicates with the feedback path 48 may be used.

  In the case of this configuration, the home position is provided with a moving member 152 that switches the valve body 150 by moving the valve body 150 from the second position to the first position by pressing the valve body 150.

  FIG. 7A shows a case where the valve body 150 is located at the second position, and the ink droplet discharge section 72 and the return path 48 are communicated with each other. On the other hand, FIG. 7B shows a case where the image forming unit 12 has reached the home position, and the valve body 150 is moved by being pressed by the moving member 152 and is located at the first position. Yes, the ink liquid filling unit 70A and the return path 48 are communicated with each other. In addition, the liquid level sensor 88 is provided in the ink liquid filling unit 70A, and when the liquid level detected by the liquid level sensor 88 is less than a predetermined height, the moving member 152 is moved to a position where the valve body 150 is not pressed. It is good.

  Moreover, although each said embodiment demonstrated the case where electric power was supplied via the connectors 64A and 64B to the switching valve 75 used as the electromagnetic valve, this invention is not limited to this, For example, electromagnetic It is good also as a form which supplies electric power to the switching valve 75 made into the non-contact electromagnetic valve by induction | guidance | derivation.

10 Inkjet recording device (droplet ejection device)
12 Image forming unit (droplet discharge head)
44 Ink tank (reservoir)
48 Return path 58 Carriage belt (moving means)
64B connector B (switching means)
70A Ink liquid filling part (liquid filling part)
72 Ink droplet ejection part (Droplet ejection part)
75 Switching valve 86 Filter 88 Liquid level sensor (detection means)

Claims (5)

A liquid filling unit that is filled with a liquid supplied from a storage unit that stores liquid, and a liquid droplet discharge unit that is filled with the liquid supplied from the liquid filling unit and that discharges liquid droplets according to an applied pressure. And a droplet discharge head provided with a switching valve for switching so that any one of the liquid filling unit and the droplet discharge unit communicates with a return path for returning the liquid to the storage unit;
Moving means for moving the droplet discharge head in a predetermined direction with respect to the apparatus main body;
Provided in a predetermined position of the apparatus main body, and when the droplet discharge head is moved to the predetermined position by the moving means, the switching valve is switched so that the liquid filling unit and the return path communicate with each other; Switching means for switching the switching valve so that the droplet discharge section and the feedback path communicate with each other when the droplet discharge head is located at a position other than the predetermined position;
A droplet discharge device comprising: A detection means for detecting the height of the liquid level filled in the liquid filling unit;
2. The liquid droplet ejection apparatus according to claim 1, wherein when the liquid level detected by the detection unit is equal to or lower than a predetermined height, the switching unit switches the switching valve.   The droplet discharge device according to claim 1, wherein the liquid filling unit is provided with a filter that removes foreign matters mixed in the supplied liquid. An electromagnetic valve that connects the liquid filling unit and the return path when electric power is supplied, and connects the droplet discharge unit and the return path when electric power is not supplied. Consisting of
The droplet discharge device according to any one of claims 1 to 3, wherein the switching unit includes a supply unit that switches the switching valve by supplying electric power to the switching valve. The switching valve is constituted by a valve body located at a first position for communicating the liquid filling part and the return path, and a second position for communicating the droplet discharge part and the return path,
4. The droplet discharge device according to claim 1, wherein the switching unit is configured by a moving member that switches the valve body by moving the valve body from the second position to the first position. 5. .

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