JP2010069669A - Droplet delivering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide configuration of a droplet circulation system which can be miniaturized without causing leakage of a droplet from a droplet delivering portion. <P>SOLUTION: Ink reservoired in a reservoir tank 12 is sucked up by a circulation pump 18 to be delivered to a circulation path 16, and is made to circulate in the circulation path 16 to return to the reservoir tank 12. A first circulation part 16A having a first diameter and a second circulation part 16B having a second diameter smaller than the first diameter are provided in the circulation path 16. The first circulation part 16A is connected to an ink inflow port 14A of an ink chamber 14 of a recording head, the second circulation part 16B is connected to an ink ejection port 14B of the ink chamber 14 of the recording head, and flow velocity of the ink is increased in the second circulation part 16B, whereby the ink ejection port 14B of the ink chamber 14 of the recording head is set to a negative pressure state. Thus, the ink is sucked from the ink ejection port 14B of the ink chamber 14 of the recording head to the second circulation part 16B of the circulation path 16, and is made to flow into the ink chamber 14 of the recording head from the first circulation part 16A through the ink inflow port 14A of the recording head. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet discharge device, and more particularly, to a droplet discharge device that discharges droplets such as ink.

  As a droplet discharge device, for example, an ink jet printer that forms an image by discharging ink onto a medium such as image receiving paper is widely used.

  In order to eject droplets from a head that ejects droplets, it is necessary to supply a liquid to be ejected to the head.

  As a circulation system for discharging droplets to the head, for example, a supply tank, a head, and a return tank are provided, and the supply tank, the head, the return tank, and the supply tank are connected so that the ink circulates in this order, By using a circulation loop of the ink circulation system and providing a valve between the supply tank and the return tank, and performing pressure control such as making the return tank negative with a pump while the valve is closed, the ink is discharged from the head. There is one that circulates ink so that ink is supplied from the supply tank to the head by sucking out the ink (for example, Patent Document 1).

  Another method has been proposed in which ink is supplied from a supply tank to a head by a pump (for example, Patent Documents 2 to 5).

In addition, there is a type in which ink is supplied to the head from a tank above the head by a head difference, and ink is collected from the head by a head difference in a return tank provided on the lower side (Patent Document 6).
Japanese Patent No. 3387806 Japanese Patent No. 4071156 Japanese Patent No. 3631085 Japanese Patent No. 3523511 Special table 2008-513245 gazette JP 2005-502498 A

  However, in order to prevent liquid droplets from leaking from the nozzles that eject liquid droplets provided on the head, it is necessary to set the pressure at the nozzle portion to a pressure lower than atmospheric pressure. Tanks are required, and a plurality of valves and the like for pressure control must be provided.

  The present invention has been made in consideration of the above-described facts, and an object of the present invention is to constitute a droplet circulation system that can be miniaturized without leakage of droplets from a droplet discharge portion.

  In order to achieve the above object, according to the first aspect of the present invention, the liquid circulates at a first predetermined flow rate and a storage means that stores the liquid and includes a delivery port and a return port for the stored liquid. Having a first circulation part and a second circulation part in which the liquid circulates at a second flow rate faster than the first flow rate, and sending the liquid stored in the storage means from the delivery port, A circulation path for circulating the liquid so as to return to the storage means from the return port, a circulation means for circulating the liquid in the circulation path, and supply of the liquid for discharging the droplets and discharging the droplets It is characterized by comprising droplet discharge means for connecting a mouth and the first circulation part and for connecting a liquid outlet and the second circulation part.

  According to the first aspect of the present invention, the storage means stores the liquid and is provided with the outlet and return port for the stored liquid.

  In addition, the circulation path is provided with a first circulation part in which the liquid circulates at a predetermined first flow rate and a second circulation part in which the liquid circulates at a second flow rate faster than the first flow rate. The liquid stored in the storage means is sent out from the delivery port, and the liquid is circulated through the circulation path so as to return from the return port to the storage means.

  The circulation of the liquid in the circulation path is performed by a circulation means. For example, a pump or the like can be applied as the circulation means.

  Further, the droplet discharge means discharges droplets. In the droplet discharge means, a liquid supply port for discharging droplets and a first circulation unit are connected, and a liquid discharge port and a second circulation unit are connected.

  That is, when the liquid in the circulation path is circulated by the circulation means, the liquid stored in the storage means is sent from the delivery port to the circulation path, and returns from the return port to the storage means. At this time, in the circulation path, the first circulation part circulates at the first flow rate, and the second circulation part accelerates the liquid flow rate, and the liquid circulates at the second flow rate faster than the first flow rate. Since the supply port of the droplet discharge means is connected to the first circulation section and the discharge port of the droplet discharge means is connected to the second circulation section, the liquid is discharged by the second flow rate of the second circulation section. A negative pressure is generated at the discharge port of the droplet discharge unit, and the droplet is sucked out from the droplet discharge unit, whereby the liquid flows from the first circulation section into the supply port of the droplet discharge unit. Accordingly, it is possible to supply the liquid for discharging the droplets to the droplet discharge means.

  Further, since the liquid is supplied to the droplet discharge means by the negative pressure, it is possible to prevent the liquid from leaking from the droplet discharge means.

  Further, since the first circulation unit and the second circulation unit are simply provided in the circulation path and connected to the droplet discharge means, the size can be reduced.

  The invention according to claim 2 stores the liquid, and includes a storage means having a stored liquid delivery port and a return port, a first circulation unit in which the liquid circulates at a predetermined first flow rate, And a second circulation part that circulates the liquid at a second flow rate that is faster than the first flow rate. The liquid stored in the storage unit is sent out from the delivery port, and the storage unit is supplied from the return port. A circulation path for circulating the liquid so as to return to the circulation path, a circulation means for circulating the liquid in the circulation path, a liquid supply port for discharging the liquid droplets, and the delivery port for discharging the liquid droplets It is characterized in that it comprises a droplet discharge means that connects and connects the liquid outlet and the second circulation part.

  According to the second aspect of the present invention, the storage means stores the liquid, and is provided with the outlet and return port for the stored liquid.

  In addition, the circulation path is provided with a first circulation part in which the liquid circulates at a predetermined first flow rate and a second circulation part in which the liquid circulates at a second flow rate faster than the first flow rate. The liquid stored in the storage means is sent out from the delivery port, and the liquid is circulated through the circulation path so as to return from the return port to the storage means.

  The circulation of the liquid in the circulation path is performed by a circulation means. For example, a pump or the like can be applied as the circulation means.

  Further, the droplet discharge means discharges droplets. In the droplet discharge means, a liquid supply port for discharging droplets is connected to a delivery port of the storage means, and a liquid discharge port is connected to the second circulation unit.

  That is, when the liquid in the circulation path is circulated by the circulation means, the liquid stored in the storage means is sent from the delivery port to the circulation path, and returns from the return port to the storage means. At this time, in the circulation path, the first circulation part circulates at the first flow rate, and the second circulation part accelerates the liquid flow rate, and the liquid circulates at the second flow rate faster than the first flow rate. Since the supply port of the droplet discharge means is connected to the delivery port of the storage means, and the discharge port of the droplet discharge means is connected to the second circulation part, the liquid is discharged by the second flow rate of the second circulation part. A negative pressure is generated at the discharge port of the droplet discharge unit, and the droplet is sucked out from the droplet discharge unit, whereby the liquid flows from the outlet of the storage unit to the supply port of the droplet discharge unit. Accordingly, it is possible to supply the liquid for discharging the droplets to the droplet discharge means.

  Further, since the liquid is supplied to the droplet discharge means by the negative pressure, it is possible to prevent the liquid from leaking from the droplet discharge means.

  Further, since the first circulation unit and the second circulation unit are simply provided in the circulation path and connected to the droplet discharge means, the size can be reduced.

  The invention according to claim 2 is provided at a connection portion between the discharge port of the droplet discharge means and the second circulation part, as in the invention according to claim 3, and the liquid flowing through the second circulation part is provided. A differential pressure generator for generating a negative pressure at the discharge port by pressure may be further provided.

  Moreover, the 1st circulation part in the invention of any one of Claims 1-3 WHEREIN: As for the 1st circulation part in the invention of Claim 4, a 1st circulation part is a diameter in a circulation path. Is set to a predetermined first diameter, and the second circulation section is set to a second diameter smaller than the first diameter in the circulation path, thereby reducing the flow velocity in the first circulation section. It is possible to set the first flow rate and the second flow rate at the second circulation section.

  According to the fifth aspect of the present invention, the liquid is stored, the storage means having the stored liquid delivery port and the return port, and the liquid stored in the storage means is sent out from the delivery port, and the return is performed. A circulation path for circulating the liquid so as to return to the storage means from the mouth; a circulation means for circulating the liquid in the circulation path; and a liquid supply port for discharging the liquid droplets and discharging the liquid droplets Droplet discharge means that connects the delivery port and connects the liquid discharge port and the circulation path, and is provided in the discharge port and the circulation path. The liquid outlet is connected to the discharge port by the pressure of the liquid flowing through the circulation path. And a differential pressure generating means for generating a negative pressure.

  According to the fifth aspect of the present invention, the storage means stores the liquid and is provided with the outlet and return port for the stored liquid.

  Further, the liquid stored in the storage unit is sent out from the delivery port, and the liquid is circulated through the circulation path so as to return from the return port to the storage unit.

  The circulation of the liquid in the circulation path is performed by a circulation means. For example, a pump or the like can be applied as the circulation means.

  Further, the droplet discharge means discharges droplets. In the droplet discharge means, a liquid supply port for discharging droplets and a delivery port of the storage means are connected, and a liquid discharge port and a circulation path are connected.

  Then, in the differential pressure generating means provided at the connection portion between the discharge port and the circulation path, a negative pressure is generated at the discharge port by the pressure of the liquid flowing through the circulation path.

  That is, when the liquid in the circulation path is circulated by the circulation means, the liquid stored in the storage means is sent from the delivery port to the circulation path, and returns from the return port to the storage means. At this time, since the differential pressure generating means is provided at the connection portion between the circulation path and the discharge port of the droplet discharge means, a negative pressure is generated at the discharge port of the droplet discharge means due to the pressure of the liquid flowing through the circulation path. Then, the liquid droplets are sucked out from the liquid droplet discharge means, whereby the liquid flows from the outlet of the storage means to the supply port of the liquid droplet discharge means. Accordingly, it is possible to supply the liquid for discharging the droplets to the droplet discharge means.

  Further, since the liquid is supplied to the droplet discharge means by the negative pressure, it is possible to prevent the liquid from leaking from the droplet discharge means.

  Furthermore, since the differential pressure generating means is simply provided in the circulation path and connected to the droplet discharge means, the size can be reduced.

  As described above, according to the present invention, there is an effect that it is possible to configure a droplet circulation system that can be miniaturized without leakage of droplets from a droplet discharge portion.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to an ink jet printer.

  An ink jet printer according to an embodiment of the present invention records an image on a recording medium such as paper by ejecting ink droplets from a recording head that ejects ink.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an ink circulation system for supplying ink to a recording head of an ink jet printer according to the first embodiment of the present invention.

  As shown in FIG. 1, the ink circulation system 10 of the ink jet printer according to the first embodiment includes a storage tank 12 that stores ink, and the storage tank 12 stores ink to be supplied to the recording head. Is done. The stored ink is supplied to an ink chamber 14 provided in the recording head, and the ink supplied to the ink chamber 14 is ejected as ink droplets from the recording head.

  The storage tank 12 is provided with a delivery port 12A for delivering ink, and a return port 12B for returning the circulated ink delivered from the delivery port 12A. A circulation path 16 for circulating ink is connected to the delivery port 12A and the return port 12B of the storage tank 12, and the ink stored in the storage tank 12 is sent from the delivery port 12A to the circulation path 16 for circulation. After circulating through the path 16, the ink circulates to the return port 12 </ b> B of the storage tank 12.

  In the circulation path 16, a circulation pump 18 for circulating ink through the circulation path 16 is provided in the vicinity of the delivery port 12 </ b> A of the storage tank 12. By driving the circulation pump 18, ink is sucked out from the delivery port 12 </ b> A of the storage tank 12 and pushed out to the circulation path 16. The ink circulates in the circulation path 16 and returns from the return port 12B of the storage tank 12 to the storage tank 12.

  A circulation path 16 through which ink circulates from the circulation pump 18 to the return port 12B of the storage tank 12 includes a first circulation portion 16A having a predetermined first diameter, and a second diameter smaller than the first diameter. The second circulation part 16B is provided. That is, the first circulation unit 16A circulates ink at a predetermined first flow rate corresponding to the first diameter, and the second circulation unit 16B responds to the second diameter, which is faster than the first flow rate. Ink circulates at the second flow rate.

  The first circulation portion 16A is connected to the ink inlet 14A of the ink chamber 14 of the recording head, and the second circulation portion 16B is connected to the ink outlet 14B of the ink chamber 14 of the recording head.

  The discharge performance of the circulation pump, the first diameter of the first circulation part 16A, the second diameter of the second circulation part 16B, the passage of the ink inlet 14A of the recording head, and the passage of the ink discharge port 14B of the recording head. The ink pushed out by the circulation pump 18 circulates from the first circulation part 16A to the storage tank 12 through the second circulation part 16B, and is discharged from the recording head by the second flow velocity of the second circulation part 16B. The negative pressure of 14B is set so that the ink can flow from the first circulation portion 16A to the ink inlet 14A of the recording head.

  Further, the ink circulation system 10 shown in FIG. 1 may be entirely mounted on the recording head, or only a part of the circulation path 16 and the ink chamber 14 may be mounted on the recording head.

  Next, the operation of the ink circulation system 10 of the inkjet printer according to the first embodiment of the present invention configured as described above will be described.

  When the power supply of the ink jet printer is turned on or when an ink supply is instructed by a control unit (not shown) that controls the ink jet printer, the circulation pump 18 is started to drive.

  When the circulation pump 18 starts to be driven, the ink stored in the storage tank 12 is sucked up by the circulation pump 18 and discharged to the circulation path 16, and the ink circulates in the circulation path 16.

  The ink flowed to the circulation path 16 by the circulation pump 18 circulates through the circulation path 16 along the arrow in FIG. 1 and returns to the storage tank 12.

  At this time, the ink circulates in a first diameter predetermined in the first circulation portion 16A of the circulation path 16, and subsequently, in the second diameter of the second circulation portion 16B smaller than the first diameter. The ink circulates. In other words, the first circulation unit 16A circulates ink at the first flow rate, and then the second circulation unit 16B circulates ink at the second flow rate that is faster than the first flow rate. Here, the first circulation section 16A is connected to the ink inlet 14A of the ink chamber 14 of the recording head, and the second circulation section 16B is connected to the ink outlet 14B of the ink chamber 14 of the recording head. As the ink flow velocity is accelerated in the circulation section 16B, the ink discharge port 14B of the ink chamber 14 of the recording head becomes negative pressure. As a result, ink is sucked from the ink discharge port 14B of the ink chamber 14 of the recording head to the second circulation portion 16B of the circulation path 16. Then, when ink is sucked out from the ink discharge port 14B of the ink chamber 14, the ink flows from the first circulation section 16A into the ink chamber 14 of the recording head through the ink inlet 14A of the recording head. Accordingly, the ink flowing in the circulation path 16 also flows into the ink chamber 14 of the recording head, and the ink can be supplied to the recording head.

  Further, since the ink discharge port 14B of the recording head has a negative pressure, ink flows into the ink chamber 14 from the ink inlet 14A of the recording head, so that the ink chamber 14 of the recording head also has a negative pressure. Accordingly, since the pressure inside the recording head can be made lower than the atmosphere, ink can be prevented from leaking from the recording head.

  As described above, in this embodiment, the first circulation unit 16A and the second circulation unit 16B are provided in the circulation path 16, and the first circulation unit 16A and the ink chamber 14 of the recording head are connected to each other. The ink can be supplied to the recording head simply by connecting the ink chamber 14 of the recording head and circulating the ink in the circulation path 16 by the circulation pump 18, so that the ink can be supplied to the recording head with a simple configuration. It becomes. Further, since only the first circulation part 16A and the second circulation part 16B are provided in the circulation path 16, the configuration of the ink circulation system 10 can be reduced in size.

(Second Embodiment)
Next, an ink jet printer according to the second embodiment of the present invention will be described. FIG. 2 is a diagram showing a configuration of an ink circulation system for supplying ink to the recording head of the ink jet printer according to the second embodiment of the present invention. The same parts as those in the first embodiment will be described with the same reference numerals.

  As in the first embodiment, the ink circulation system 11 of the ink jet printer according to the second embodiment also includes a storage tank 12 for storing ink, as shown in FIG. Ink for supply is stored. The stored ink is supplied to an ink chamber 14 provided in the recording head, and the ink supplied to the ink chamber 14 is ejected as ink droplets from the recording head.

  The storage tank 12 is provided with a delivery port 12A for delivering ink, and a return port 12B for returning the circulated ink delivered from the delivery port 12A. A circulation path 16 for circulating ink is connected to the delivery port 12A and the return port 12B of the storage tank 12, and the ink stored in the storage tank 12 is sent from the delivery port 12A to the circulation path 16 for circulation. After circulating through the path 16, the ink circulates to the return port 12 </ b> B of the storage tank 12.

  In the circulation path 16, a circulation pump 18 for circulating ink through the circulation path 16 is provided in the vicinity of the delivery port 12 </ b> A of the storage tank 12. By driving the circulation pump 18, ink is sucked out from the delivery port 12 </ b> A of the storage tank 12 and pushed out to the circulation path 16. Then, the ink circulates in the circulation path 16 and returns to the storage tank 12 from the return port 12B of the storage tank 12.

  In the circulation path 16 through which the ink circulates from the circulation pump 18 to the return port 12B of the storage tank 12, the first circulation section 16A having a predetermined first diameter and the first And a second circulating portion 16B having a second diameter smaller than the diameter. That is, the first circulation unit 16A circulates ink at a predetermined first flow rate corresponding to the first diameter, and the second circulation unit 16B responds to the second diameter, which is faster than the first flow rate. Ink circulates at the second flow rate.

  An inflow path 15 connected to an ink inlet 14A provided in the ink chamber 14 of the recording head is connected in the vicinity of the outlet 12A of the storage tank 12 and between the outlet 12A and the circulation pump 18. Has been.

  A second circulation portion 16B of the circulation path 16 is connected to the ink discharge port 14B of the ink chamber 14 of the recording head.

  The discharge performance of the circulation pump 18, the first diameter of the first circulation unit 16A, the second diameter of the second circulation unit 16B, the ink inlet 14A of the recording head, and the ink discharge port 14B of the recording head. The ink pushed out by the circulation pump 18 circulates from the first circulation part 16A to the storage tank 12 through the second circulation part 16B, and the ink of the recording head by the second flow rate of the second circulation part 16B. By setting the discharge port 14B to a negative pressure, the relationship is set such that ink can flow from the storage tank 12 to the ink inlet 14A of the recording head.

  Further, the ink circulation system 11 shown in FIG. 2 may be entirely mounted on the recording head, or only a part of the circulation path 16 and the ink chamber 12 may be mounted on the recording head.

  Next, the operation of the ink circulation system 11 of the ink jet printer according to the second embodiment of the present invention configured as described above will be described.

  When the power supply of the ink jet printer is turned on or when an ink supply is instructed by a control unit (not shown) that controls the ink jet printer, the circulation pump 18 is started to drive.

  When the circulation pump 18 starts to be driven, the ink stored in the storage tank 12 is sucked up by the circulation pump 18 and discharged to the circulation path 16, and the ink circulates in the circulation path 16.

  The ink flowed to the circulation path 16 by the circulation pump 18 circulates in the circulation path 16 along the arrow in FIG. 2 and returns to the storage tank 12.

  At this time, as in the first embodiment, in the first circulation portion 16A of the circulation path 16, the ink circulates in a predetermined first diameter, and then the second circulation portion smaller than the first diameter. Ink circulates in the second diameter of 16B. That is, the first circulation unit 16A circulates ink at a first flow rate, and then the second circulation unit 16B circulates ink at a second flow rate that is faster than the first flow rate, and the second circulation unit 16B. Since the ink flow velocity is accelerated, the ink discharge port 14B of the ink chamber 14 of the recording head connected to the second circulation unit 16B has a negative pressure. As a result, ink is sucked into the circulation path 16 from the ink outlet 14B of the ink chamber 14 of the recording head. Then, ink is sucked from the ink chamber 14 to the ink discharge port 14B, so that the ink flows from the storage tank 12 into the ink chamber 14 of the recording head through the inflow path 15 and the ink inlet 14A of the recording head. Accordingly, the ink stored in the storage tank 12 also flows into the ink chamber 14 of the recording head, and the ink can be supplied to the recording head.

  Further, since the ink discharge port 14B of the recording head has a negative pressure, ink flows into the ink chamber 14 from the ink inlet 14A of the recording head, so that the ink chamber 14 of the recording head also has a negative pressure. Accordingly, since the pressure inside the recording head can be made lower than the atmosphere, ink can be prevented from leaking from the recording head.

  Even with this configuration, the ink can be supplied to the recording head with a simple configuration as in the first embodiment, and the configuration of the ink circulation system 11 can be reduced in size.

(Third embodiment)
Next, an ink jet printer according to a third embodiment of the present invention will be described. The third embodiment is a modification of the second embodiment.

  In the present embodiment, a differential pressure generator used in a bus pump or the like is provided for the ink circulation system 11 of the ink jet printer according to the second embodiment.

  FIG. 3 is a diagram showing an example of a differential pressure generator applied to the ink circulation system of the ink jet printer according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected and demonstrated about the same structure as 1st Embodiment and 2nd Embodiment.

  The differential pressure generator 20 applied to the third embodiment applies a configuration in which water is sucked up by negative pressure, such as a bus pump, and in this embodiment, the second circulation unit 11 in the second embodiment and A differential pressure generator 20 is applied to a connection portion between the ink discharge port 14B of the ink chamber 14 of the recording head.

  As shown in FIG. 3, the differential pressure generator 20 is configured so that the second circulation unit 16 </ b> B has a different diameter from the second circulation unit 16 </ b> A and the circulation path 16 connected to the return port 12 </ b> B of the storage tank 12. The shape is inserted into the circulation path 16 connected to the return port 12B.

  A connecting portion between the ink discharge port 14B of the recording head and the second circulating portion 16B has a chamber-shaped portion 22 that stores a predetermined amount of ink.

  In this way, by configuring the differential pressure generator 20, the ink accelerated by the second circulation unit 16 </ b> B is ejected vigorously to the circulation path 16 connected to the return port 12 </ b> B of the storage tank 12. Then, a negative pressure is generated in the chamber-shaped portion 22, and ink is sucked out from the ink discharge port 14B of the recording head to the circulation path 16 connected to the return port 12B of the storage tank 12. Accordingly, as in the second embodiment, ink is sucked from the ink chamber 14 to the ink discharge port 14B, whereby the ink of the recording head is transferred from the storage tank 12 via the inflow path 15 and the ink inlet 14A of the recording head. Ink flows into the chamber 14. Accordingly, the ink stored in the storage tank 12 also flows into the ink chamber 14 of the recording head, and the ink can be supplied to the recording head.

  Further, since the ink discharge port 14B of the recording head has a negative pressure, ink flows into the ink chamber 14 from the ink inlet 14A of the recording head, so that the ink chamber 14 of the recording head also has a negative pressure. Accordingly, since the pressure inside the recording head can be made lower than the atmosphere, ink can be prevented from leaking from the recording head.

  In the third embodiment, as a configuration in which the differential pressure generator 20 is provided with respect to the second embodiment, the liquid is accelerated by the first circulation unit 16A and the second circulation unit 16B. However, the present invention is not limited to this. Instead, for example, as shown in FIG. 4, the first circulation unit 16A and the second circulation unit 16B may be omitted.

  Further, in the first embodiment, the example in which the second circulation unit 16B is disposed on the downstream side in the liquid circulation direction of the first circulation unit 16A has been described. However, the present invention is not limited to this, and for example, as illustrated in FIG. In addition, a first circulation part 16A is provided downstream of the second circulation part 16B in the liquid circulation direction, the ink inlet 14A of the recording head and the first circulation part 16A are connected, and the ink discharge port 14B of the recording head is connected to the second outlet. The circulation unit 16B may be connected, or the first circulation unit 16A and the second circulation unit 16B are connected in parallel to connect the ink inlet 14A of the recording head and the first circulation unit 16A. You may make it connect the ink discharge port 14B of a recording head, and the 2nd circulation part 16B.

  In each of the above embodiments, the ink circulation system of the recording head of the inkjet printer that discharges ink has been described as an example. However, the present invention is not limited to this. For example, colored ink is discharged onto a polymer film. Various industrial applications such as the production of color filters for displays performed, the formation of EL display panels performed by discharging organic EL solution onto the substrate, and the etching process by discharging the solution when creating printed circuit boards, etc. The present invention is applicable to a general droplet discharge apparatus.

FIG. 2 is a diagram illustrating a configuration of an ink circulation system for supplying ink to a recording head of the ink jet printer according to the first embodiment of the present invention. It is a figure which shows the structure of the ink circulation system for supplying ink to the recording head of the inkjet printer concerning 2nd Embodiment of this invention. It is a figure which shows an example of the differential pressure generator applied to the ink circulation system of the inkjet printer concerning 3rd Embodiment of this invention. It is a figure which shows the modification of the ink circulation system of the inkjet printer concerning 3rd Embodiment of this invention. FIG. 3 is a diagram illustrating an example of a case where a first circulation unit and a second circulation unit are arranged at opposite positions in the ink circulation system for supplying ink to the recording head of the inkjet printer according to the first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ink circulation system 12 Storage tank 12A Outlet 12B Return port 14 Ink chamber 14A Ink inlet 14B Ink outlet 16 Circulation path 16A First circulation part 16B Second circulation part 18 Circulation pump 20 Differential pressure generator

Claims (5)

Reserving means that stores liquid and includes a delivery port and a return port for the stored liquid;
A first circulation part that circulates the liquid at a predetermined first flow rate; and a second circulation part that circulates the liquid at a second flow rate faster than the first flow rate. A circulation path for circulating the liquid so as to be sent out from the delivery port and returned from the return port to the storage means;
A circulation means for circulating the liquid in the circulation path;
A droplet discharge means for discharging a droplet, connecting a liquid supply port for discharging the droplet and the first circulation unit, and connecting a liquid discharge port and the second circulation unit;
A droplet discharge device comprising: Reserving means that stores liquid and includes a delivery port and a return port for the stored liquid;
A first circulation part that circulates the liquid at a predetermined first flow rate; and a second circulation part that circulates the liquid at a second flow rate faster than the first flow rate. A circulation path for circulating the liquid so as to be sent out from the delivery port and returned from the return port to the storage means;
A circulation means for circulating the liquid in the circulation path;
A droplet discharge means for discharging a droplet, connecting a liquid supply port for discharging the droplet and the delivery port, and connecting a liquid discharge port and the second circulation unit;
A droplet discharge device comprising:   The differential pressure generator further provided in the connection part of the said discharge port and the said 2nd circulation part, and generating a negative pressure in the said discharge port with the pressure of the liquid which flows through the said 2nd circulation part is provided. Droplet discharge device.   The first circulation unit sets a diameter in the circulation path to a predetermined first diameter, and the second circulation unit sets the circulation path to a second diameter smaller than the first diameter. The droplet discharge device according to any one of claims 1 to 3. Reserving means that stores liquid and includes a delivery port and a return port for the stored liquid;
A circulation path for circulating the liquid so that the liquid stored in the storage means is sent out from the delivery port and returned from the return port to the storage means;
A circulation means for circulating the liquid in the circulation path;
A droplet discharge means for discharging a droplet, connecting a liquid supply port for discharging the droplet and the delivery port, and connecting a liquid discharge port and the circulation path;
Differential pressure generating means provided at a connection portion between the discharge port and the circulation path, and generating a negative pressure at the discharge port by the pressure of the liquid flowing through the circulation path;
A droplet discharge device comprising:

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