JP2008272997A - Ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a prior art collection pump that the diaphragm must be enlarged or a plurality of collection pumps must be installed when the flow rate of ink to be collected is increased by employing a plurality of nozzles or enlarging the ejection opening of nozzle. <P>SOLUTION: An ink collection pump is provided in the print head of an ink jet recorder. The ink collection pump is provided with a diaphragm and liquid chambers on both sides of the diaphragm so that suction-delivery can be performed on the surface while delivery-suction can be performed on the rear surface and both suction and delivery are performed twice by single reciprocation movement. Consequently, the flow rate can be doubled by single operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that draws characters and patterns on a substrate to be printed, for example, conveyed on a production line, using particle ink.

  Generally, a continuous ink jet recording apparatus is provided with an ink container for storing ink in a main body, and the ink in the ink container is supplied to a print head by a supply pump. The ink supplied to the print head is vibrated and continuously ejected from the nozzles to form particles.

  Among the ink particles, the ink particles used for printing are charged and deflected to fly to a desired position, and the ink particles not used for printing are not charged and deflected and collected by a gutter. And return to the ink container by the recovery pump. As described above, ink is always circulated during operation of the apparatus.

  A recovery pump that is housed in a print head is known. The structure of the recovery pump is a diaphragm type, with one side being a liquid chamber and the other being a diaphragm drive. This recovery pump has the ability to recover a small flow rate of ink particles ejected from the nozzle, and is miniaturized because it is stored in a small space in the print head.

JP 2006-255981 A

  In the conventional recovery pump, when the ink recovery flow rate is increased, for example, a plurality of nozzles or a nozzle outlet is increased in diameter, the diaphragm must be enlarged or a plurality of conventional recovery pumps must be installed. For this reason, the print head must be enlarged.

  In order to solve the above problems, an ink jet recording apparatus of the present invention has a diaphragm driven by an ink recovery pump under the control of the operation control unit, and liquid chambers provided on both sides in the deformation direction corresponding to both the front and back surfaces of the diaphragm. Is.

  The ink jet recording apparatus has a configuration in which a diaphragm type recovery pump provided in the head is provided with a liquid chamber on the other surface of the diaphragm. As a result, the diaphragm can be reciprocated once, and the surface can be aspirated and discharged, and the back surface can be aspirated and aspirated. With this reciprocating once, both the aspiration and the ejection can be performed twice. Flow rate is possible. As a result, it is possible to easily cope with an increase in the ink recovery flow rate.

  By incorporating the above means, it is possible to provide a plurality of nozzles and large-diameter nozzles without increasing the size of a conventional print head.

  Examples of the present invention will be described below.

  FIG. 2 shows the configuration of an ink jet recording apparatus according to an embodiment of the present invention. This ink jet recording apparatus includes a main body 600 containing a control system and a circulation system, a print head 610 having nozzles that eject ink and create ink particles, and a cable connecting the circulation system and the control system of the main body 600 and the print head 610. 620, and the main body 600 and the print head 610 are connected via the cable 620.

  The main body 600 is provided with a liquid crystal panel 630 that allows a user to input printing contents, printing specifications, etc., and display control contents, apparatus operating conditions, and the like. It connects with the operation control part of the control system which has a circuit.

  The print head 610 is covered with a stainless steel cover. Inside the print head 610 is stored a printing unit (described later) that creates ink particles and controls the flying of the ink particles. The holes 615 provided on the bottom surface of the cover are for passing ink particles.

  FIG. 3 shows an ink circulation path of an ink jet recording apparatus according to an embodiment of the present invention. The main body 600 has an ink container 1, an ink supply pump 3, a filter 4, and an ink pressure regulating valve 5 as a path for supplying the ink 2 to the nozzle 10, and these are connected in order.

  Further, the cleaning liquid supply path for supplying the cleaning liquid 6 to the nozzle 10 includes a cleaning liquid container 7 and a cleaning liquid supply pump 8, which are sequentially connected in the same manner as the ink supply path.

  Both paths pass through the cable 620 and connect to the three-way switching electromagnetic valve 9 of the print head 610. The three-way switching electromagnetic valve 9 switches the supply liquid to the nozzle 10 to either the ink 2 or the cleaning liquid 6 based on control of a control unit (not shown).

  During operation of the apparatus, the ink 2 is supplied to the nozzle 10 by exciting the three-way switching electromagnetic valve 9 to open the supply path side of the ink 2. The nozzle 10 includes vibration means (not shown), and the ink 2 vibrated by the vibration means is formed into particles (ink droplets) when ejected from the nozzle 10 and flies as ink particles 11.

  When the ink particles 11 are converted into particles, they are selectively charged by the charging electrode 12 provided at the subsequent stage of the nozzle 10. The charged ink particles 11 are further subjected to a deflection force corresponding to the amount of charge in an electric field formed by the deflection electrode 16 at the subsequent stage. The ink particles 11 whose flying direction is changed by the deflection force jump over the gutter 13 and reach the printed matter 17 to be attached.

  On the other hand, the ink particles 11 that are not charged by the charging electrode travel straight in the electric field formed by the deflection electrode 16 and are collected by the gutter 13. Since the recovery electromagnetic valve 14 is excited during operation of the apparatus to open the ink recovery path, the ink 2 collected by the gutter 13 is sucked by the ink recovery pump 15 provided inside the print head 610. In the present embodiment, an example in which the ink 2 sucked and pressurized by the ink recovery pump 15 is returned to the ink container 1 of the main body 600 through a return path which is an ink recovery path in the cable 620 is shown.

  Next, the structure of a conventional diaphragm type ink recovery pump will be described with reference to FIG. The ink recovery pump shown in FIG. 4 includes a main body case 40 and a diaphragm 41 that reciprocates within the main body case 40. This ink recovery pump is provided with a liquid chamber 42 including a recess of the main body case 40 and a diaphragm 41.

  An ink-in side port 45 communicating with the liquid chamber 42 and an ink-out side port 46 similarly communicating with the liquid chamber 42 are provided for the liquid chamber 42. An in-side check valve 43 is provided between the ink-in side port 45 into which the ink 2 is introduced into the liquid chamber 42 and the liquid chamber 42. In addition, an out-side check valve 44 is provided between the ink-out side port 46 through which the ink 2 discharged from the liquid chamber 42 passes and the liquid chamber 42.

  The ink recovery pump shown in FIG. 4 connects the ink-in side port 45 so as to communicate with the gutter 13 and connects the ink-out side port 46 so as to communicate with the ink container 1.

  FIG. 5 shows an operation in which the ink recovery pump 15 sucks the ink 2 from the gutter 13. When the diaphragm 41 is concave, that is, when the diaphragm 41 is deformed to the opposite side of the liquid chamber 42 and the volume of the liquid chamber 42 is increased, negative pressure is generated in the liquid chamber 42 and the in-side check valve 43 is opened. The When the in-side check valve 43 is opened, the ink 2 collected by the gutter 13 is sucked into the liquid chamber 42 through the ink-in side port 45.

  On the other hand, the out-side check valve 44 is in close contact with the main body case 40 due to the negative pressure of the liquid chamber 42 and blocks the negative pressure of the liquid chamber 42 from being transmitted to the ink-out side port 46.

  FIG. 6 shows an operation in which the ink recovery pump 15 pumps the ink 2 to the ink container 1. When the diaphragm 41 is convex, that is, when the diaphragm 41 is deformed toward the liquid chamber 42 and the volume of the liquid chamber 42 increases, the liquid chamber 42 generates a positive pressure, and the out-side check valve 44 is opened. When the out-side check valve 44 is opened, the ink 2 sucked into the liquid chamber 42 is discharged to the ink container 1 through the ink-out side port 46.

  On the other hand, the in-side check valve 43 is in close contact with the main body case 40 by the positive pressure of the liquid chamber 42, and blocks the positive pressure of the liquid chamber 42 from being transmitted to the ink-in side port 45.

  Thus, the ink 2 collected in the gutter 13 is sucked and sent to the ink container 1 by the reciprocating motion of the diaphragm 41 in the liquid chamber 42.

  However, as described in the above problem, when the ink recovery flow rate is increased, for example, when a plurality of nozzles or a nozzle outlet is made large in diameter, the capacity of the ink recovery pump must be increased. However, in order to increase the pump capacity, it is necessary to increase the size of the diaphragm or to install a plurality of conventional recovery pumps, so that the print head must be enlarged.

  The ink recovery pump of this embodiment will be described with reference to FIGS. The ink recovery pump 15 of this embodiment is a pump provided with liquid chambers on both sides in the deformation direction corresponding to both the front and back surfaces of the diaphragm. The ink recovery pump 15 is a piezoelectric diaphragm type.

  7 and 8, a pump body 57 composed of two upper and lower structures is provided with a diaphragm 41 having a reciprocating function between them. An upper liquid chamber 51 and a lower liquid chamber 52 are formed in the pump body 57 with the diaphragm 41 as a boundary.

  The ink recovery pump 15 has an upper ink-in side port 47 and an upper ink-out side port 49 so as to communicate with the upper liquid chamber 51, and an upper in-side check valve 48, An upper out check valve 50 is provided in the upper ink out port 49.

  Similarly, a lower ink-in side port 54 and a lower ink-out side port 56 are provided so as to communicate with the lower liquid chamber 52. The lower ink-in side port 54 has a lower in-side check valve 53 and a lower ink-out side. A lower-out check valve 55 is provided at the port 56.

  The upper ink-in side port 47 and the lower ink-in side port 54 are connected so as to communicate with the gutter 13, and the upper ink-out side port 49 and the lower ink-out side port 56 are connected so as to communicate with the ink container 1. .

  The flow of the ink 2 when the diaphragm 41 is recessed toward the lower liquid chamber 52 will be described with reference to FIG. As shown in FIG. 7, when the diaphragm 41 is recessed toward the lower liquid chamber 52, the volume of the upper liquid chamber 51 is increased, negative pressure is generated inside the upper liquid chamber 51, and the upper in-side check valve 48. Is released. When the upper in-side check valve 48 is opened, the ink 2 collected by the gutter 13 is sucked through the upper ink-in side port 47.

  At this time, the upper out side check valve 50 comes into close contact with the pump body 57 due to the negative pressure of the upper liquid chamber 51, and blocks the negative pressure of the upper liquid chamber 51 from being transmitted to the upper ink out side port 49. .

  On the other hand, when the diaphragm 41 is recessed toward the lower liquid chamber 52, the volume of the lower liquid chamber 52 decreases in the lower liquid chamber 52. Then, a positive pressure is generated inside the lower liquid chamber 52, and the lower out side check valve 55 is opened. When the lower out side check valve 56 is opened, the ink recovery pump 15 discharges the ink 2 in the lower liquid chamber 52 to the ink container 1. The lower in-side check valve 53 is in close contact with the pump body 57 due to the positive pressure of the lower liquid chamber 52, and blocks the lower liquid chamber 52 from being transmitted to the lower ink-in side port 54.

  Next, the flow of the ink 2 when the diaphragm 41 is convex toward the upper liquid chamber 51 will be described with reference to FIG. As shown in FIG. 8, when the diaphragm 41 is convex toward the upper liquid chamber 51, the volume of the upper liquid chamber 51 is reduced, positive pressure is generated inside the upper liquid chamber 51, and the upper out side check valve 50. Is released. By opening the upper-side check valve 50, the ink in the upper liquid chamber 51 is pushed out to the ink container 1.

  The upper in-side check valve 48 is in close contact with the pump body 57 due to the positive pressure in the upper liquid chamber 51, and blocks the positive pressure in the upper liquid chamber 51 from being transmitted to the upper ink-in side port 47.

  On the other hand, when the diaphragm 41 is convex toward the upper liquid chamber 51, the volume of the lower liquid chamber 52 increases in the lower liquid chamber 52. A negative pressure is generated inside the lower liquid chamber 52, and the lower in-side check valve 53 is opened. When the lower in-side check valve 53 is opened, the ink recovery pump 15 sucks the ink 2 collected by the gutter 13 through the lower ink-in side port 54. The lower out side check valve 55 is in close contact with the pump body 57 due to the negative pressure in the lower liquid chamber 52, and blocks the negative pressure in the lower liquid chamber 52 from being transmitted to the lower ink out side port 56.

  The upper ink-in side port 47 of the upper liquid chamber 51 and the lower ink-in side port 56 of the lower liquid chamber 52 may merge and communicate with one gutter 13 or separately communicate with each gutter 13. May be.

  Similarly, the upper ink-out side port 49 of the upper liquid chamber 51 and the lower ink-out side port 54 of the lower liquid chamber 52 may join and communicate with the ink container 1 or communicate with the ink container 1 individually. May be.

  According to the above description, in the ink recovery pump 15 of the present embodiment, when the diaphragm 41 is recessed toward the lower liquid chamber 52, the upper liquid chamber 51 sucks the ink 2 and the lower liquid chamber 52 discharges the ink 2. To do. When the diaphragm 41 is convex toward the upper liquid chamber 51, the upper liquid chamber 51 ejects the ink 2 and the lower liquid chamber 52 sucks the ink 2. For this reason, the flow rate twice as large as that of the conventional ink recovery pump can be flowed by one reciprocation of the diaphragm 41.

  As a result, when a plurality of nozzles, for example, two nozzles, are installed, even if the flow rate is twice that of the conventional one, two ink recovery pumps 15 are not installed, and one can be handled. As a result, the total size of the ink recovery pump 15 can be reduced, and a plurality of nozzles and large-diameter nozzles can be provided without increasing the size of the conventional print head 610. If a plurality of nozzles are built in one print head, 2 to 3 nozzles are desirable. Further, ink may be supplied from different ink containers to each nozzle. In this case, a plurality of ink recovery paths are also required, and ink recovered from different gutters is sent to separate ink containers by the ink recovery pump 15.

1 is a simplified diagram of an ink recovery pump according to an embodiment of the present invention. 1 is a simplified diagram of an ink circulation path of an ink jet recording apparatus according to an embodiment of the present invention. 1 is an external view of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 6 is a simplified diagram of a conventional ink recovery pump. FIG. 10 is a simplified diagram illustrating an ink suction operation of a conventional ink recovery pump. FIG. 10 is a simplified diagram illustrating an ink discharge operation of a conventional ink recovery pump. FIG. 3 is a simplified diagram showing ink discharge / suction operation of an ink recovery pump according to an embodiment of the present invention. FIG. 3 is a simplified diagram showing ink discharge / suction operation of an ink recovery pump according to an embodiment of the present invention.

Explanation of symbols

1 Ink container 2 Ink
3 Ink supply pump 4 Filter 5 Ink pressure regulating valve 6 Cleaning liquid 7 Cleaning liquid container 8 Cleaning liquid supply pump 9 Three-way switching solenoid valve 10 Nozzle 11 Ink particle 12 Charging electrode 13 Gutter 14 Recovery solenoid valve 15 Ink recovery pump 16 Deflection electrode 17 Printed matter 40 Main body Case 41 Diaphragm 42 Liquid chamber 43 In-side check valve 44 Out-side check valve 45 Ink-in side port 46 Ink-out side port 47 Upper ink-in side port 48 Upper in-side check valve 49 Upper ink-out side port 50 Upper out Side check valve 51 Upper liquid chamber 52 Lower liquid chamber 53 Lower in-side check valve 54 Lower ink-in side port 55 Lower out-side check valve 56 Lower ink-out side port 57 Pump main body 600 Main body 610 Print head 615 Hole 620 Cable 630 LCD panel

Claims (6)

  The main body includes an ink container that stores ink, an ink supply pump that supplies the ink, and an operation control unit that controls operation, and a print head that sends out the particleized ink is supplied from the main body. A nozzle for ejecting ink; a charging electrode for charging the ink that has been atomized; a deflection electrode for generating an electric field that deflects the flying direction of the charged ink particles; and a gutter for collecting ink particles that have not been used for printing. And an ink recovery pump for sending the collected ink particles to the ink container, and a cable for connecting the main body and the print head is an ink supply path for supplying the ink from the main body to the print head And an ink collection path for returning the ink particles collected by the gutter to the ink container, and various signal lines connecting the operation control unit and the print head. That in the ink jet recording apparatus, the ink collection pump and a diaphragm driven by the control of the operation control unit, a liquid chamber provided in the deformation direction both sides of the diaphragm, an ink jet recording apparatus having a.   2. The ink jet recording apparatus according to claim 1, wherein a diaphragm of the ink recovery pump is a piezoelectric diaphragm.   3. The ink jet recording apparatus according to claim 1, wherein each of the liquid chambers has an in-side port for introducing ink, and each of the liquid chambers is connected to a flow path communicating with the gutter, and the flow path includes the gutter and the in-port. An ink jet recording apparatus having a merging portion that merges with a side port.   3. The ink jet recording apparatus according to claim 1, wherein each of the liquid chambers has an out-side port that discharges ink, and is connected to a flow path that communicates with the ink container, and the ink container and the out-side port; An ink jet recording apparatus having a confluence portion that merges between the two.   3. The ink jet recording apparatus according to claim 1, wherein a plurality of the print heads are provided, and each of the liquid chambers has an in-side port for introducing ink, and is connected to communicate with another gutter. An inkjet recording apparatus.   3. The ink jet recording apparatus according to claim 1, wherein a plurality of the print heads are provided, an ink container for supplying ink to the print heads and a plurality of ink supply paths are also provided, and each of the liquid chambers discharges ink. An ink jet recording apparatus having an out-side port and communicating with different ink containers.

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