JP2012176580A - Liquid ejection head and liquid ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extrude ink from a pressure chamber by targeting a single nozzle opening.SOLUTION: Drive signals are individually applied to second piezoelectric elements 35 of a second pressure generating chamber 26 corresponding to a first pressure generating chamber 25 (nozzle opening 32) where the ink is to be discharged so as to increase pressure within the second pressure generating chamber 26. The ink (air) is just sent to the first pressure generating chamber 25 where the ink is to be discharged via a first check valve 54.

Description

  The present invention relates to a liquid ejecting head that ejects liquid from a nozzle opening and a liquid ejecting apparatus.

As an ink jet recording head that is a typical example of a liquid ejecting head that ejects liquid droplets, for example, a flow path forming substrate in which a pressure chamber is formed, a piezoelectric element provided on one side of the flow path forming substrate, and a flow path There is known one provided with a nozzle opening plate provided on the other surface of the formation substrate and having nozzle openings for discharging ink droplets (see, for example, Patent Document 1). In a recording apparatus (liquid ejecting apparatus) equipped with an ink jet recording head, a rubber cap is pressed against the nozzle opening plate to protect the nozzle opening of the nozzle opening plate and to clean the ink flow path except during printing. The nozzle opening is covered.

A plurality of nozzle openings are provided in the nozzle opening plate, and a pressure chamber and a piezoelectric element are provided corresponding to each nozzle opening. Each pressure chamber is supplied with ink from a common reservoir. When cleaning the ink flow path, a plurality of nozzle openings are sucked all at once, and deteriorated ink, ink attached to the nozzle openings, and the like are discharged. Further, pressure is applied to each pressure chamber from the upstream reservoir side, and pressurized fluid is ejected simultaneously from a plurality of nozzle openings to discharge the deteriorated ink, the ink adhered to the nozzle openings, and the like.

In a recording apparatus equipped with a conventional ink jet recording head, when ink channels are cleaned, ink is sucked (discharged) from a plurality of nozzle openings, so that all undegraded ink is treated as waste ink. become. For this reason, the ink is consumed wastefully.

Such a problem exists not only in an ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

JP 2006-21503 A (FIGS. 1 and 2)

The present invention has been made in view of the above circumstances, and provides a liquid ejecting head and a liquid ejecting apparatus that can push out a fluid from a pressure chamber with a single nozzle opening and can fill the pressure chamber with a single nozzle opening. The purpose is to do.

In order to achieve the above object, a liquid jet head according to the present invention includes a first pressure chamber communicating with a nozzle opening, a second pressure chamber provided on the upstream side of the first pressure chamber, and the first pressure chamber. A first check valve provided between the second pressure chambers and allowing only a fluid flow from the second pressure chamber to the first pressure chamber; and provided upstream of the second pressure chamber; A second check valve that allows only a fluid flow from the upstream side to the second pressure chamber; and a second check valve that is provided corresponding to the first pressure chamber. First pressure generating means for discharging fluid from the nozzle opening;
And a second pressure generating means that is provided corresponding to the second pressure chamber and sends a fluid to the first pressure chamber by applying a pressure fluctuation to the first pressure chamber.
Thus, normally, the first pressure generating means applies pressure fluctuation to the first pressure chamber (or the second pressure generating means adds pressure fluctuation to the second pressure chamber), and the fluid is discharged from the nozzle opening. When discharging and cleaning, and when filling the first pressure chamber with ink,
The second pressure generating means applies pressure fluctuation to the second pressure chamber, and the second check valve prevents the fluid from flowing upstream, and the fluid (including air) in the second pressure chamber is supplied with the first pressure. Send to the room. For this reason, it becomes possible to push out the fluid from the pressure chamber with the nozzle opening alone, and to fill the pressure chamber with the fluid with the nozzle opening alone, thereby suppressing wasteful fluid consumption. Initial filling of fluid is possible without providing dedicated power.

As a liquid jet head including a first pressure chamber and a second pressure chamber,
JP-A-1-169650, JP-A-2001-338772, JP-A-2009-226929, and the like are known. These techniques are techniques that include a first pressure chamber and a second pressure chamber, and control the ink droplets to be discharged while maintaining a high driving frequency. For this reason, it is a technique which does not have the idea of providing a check valve and sending fluid only to the first pressure chamber side, and can be said to be a technique different from the field of the present invention.

In the liquid jet head according to the aspect of the invention, the plurality of nozzle openings may be provided, the first pressure chamber and the second pressure chamber may be provided for each of the plurality of nozzle openings, and an upstream side of the second pressure chamber may be , A reservoir of fluid discharged from the plurality of nozzle openings, and the second pressure generating means is individually driven, so that the fluid is individually sent from the second pressure chamber to the first pressure chamber. It is characterized by that.
Thereby, even if the reservoir side has a negative pressure, the fluid can be pushed out from the first pressure chamber by the single nozzle opening and the first pressure chamber can be filled by the single nozzle opening.

In the liquid jet head according to the aspect of the invention, the fluid may be individually ejected from the nozzle opening when the fluid is individually sent from the second pressure chamber to the first pressure chamber.
The liquid ejecting head according to the invention is characterized in that the fluid is filled into the first pressure chamber by individually sending the fluid from the second pressure chamber to the first pressure chamber.
As a result, the fluid is individually sent from the second pressure chamber to the first pressure chamber by the nozzle opening alone, so that the first
The ink flow path is cleaned by extruding the fluid from the pressure chamber, and the fluid (including air) is individually sent from the second pressure chamber to the first pressure chamber by the nozzle opening alone, thereby supplying the fluid to the first pressure chamber. Fill.

In order to achieve the above object, a liquid ejecting apparatus according to an aspect of the invention includes the liquid ejecting head and a fluid source that supplies fluid to the upstream side of the second pressure chamber of the liquid ejecting head. Accordingly, it is possible to provide a liquid ejecting apparatus including a liquid ejecting head that can push out the fluid from the pressure chamber with the nozzle opening alone and can fill the pressure chamber with the fluid with the nozzle opening alone.

1 is a schematic configuration diagram of an ink jet recording apparatus. FIG. 3 is an exploded perspective view of an ink ejecting head. FIG. 3 is a cross-sectional view of an ink ejecting head.

FIG. 1 is an overall configuration of an ink jet recording apparatus according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing a schematic configuration of an ink ejecting head, and FIG. 3 is a cross section showing a schematic configuration of the ink ejecting head. It is.

  An ink jet recording apparatus will be described with reference to FIG.

As shown in the drawing, an ink jet recording apparatus 1 as a liquid ejecting apparatus has a carriage 3 on which an ink cartridge 2 is mounted and an ink ejecting head 5 as a liquid ejecting head attached to the carriage 3. The carriage 3 is connected to a stepping motor 7 via a timing belt 6 and is guided by a guide bar 8 to reciprocate in the paper width direction (main scanning direction) of the recording paper 9. The carriage 3 has a box shape that opens to the top, and is attached so that the nozzle opening surface of the ink ejection head 5 is exposed on the surface (lower surface) facing the recording paper 9, and the ink cartridge 2 is accommodated. Yes.

The ink ejecting head 5 moves on the carriage 3, ink is supplied from the ink cartridge 2 to the ink ejecting head 5, and ink droplets are ejected onto the upper surface of the recording paper 9 while moving the carriage 3. Images and characters are printed using a dot matrix (positions where ink is ejected).

In FIG. 1, reference numeral 10 denotes a nozzle opening of the ink ejecting head 5 that is sealed while printing is stopped, thereby preventing the nozzle opening from being dried and applying a negative pressure to the nozzle opening surface of the ink ejecting head 5 for cleaning. A cap for operation, 11 is a wiper blade for wiping the nozzle opening surface of the ink jet head 5, 12 is a waste ink storage unit for storing waste ink sucked by the cleaning operation, and 13 is an ink jet recording apparatus. 1 is a control device that controls the operation of 1.

  The ink ejecting head will be described with reference to FIGS.

An elastic film 22 is provided on one surface of a flow path forming substrate 21 made of, for example, silicon that constitutes the ink ejecting head 5, and the flow path forming substrate 21 is partitioned by a plurality of partition walls 23 and a partition wall 24. In addition, a first pressure generation chamber 25 as a first pressure chamber and a second pressure generation chamber 26 as a second pressure chamber are arranged in parallel. An upstream partition wall 27 is provided on one end side of the flow path forming substrate 21, and the upstream partition wall 27 provides a communication portion 28 that serves as a common ink chamber for the first pressure generation chamber 25 and the second pressure generation chamber 26. Is formed.

A nozzle opening plate 31 is fixed to the opening surface side (lower surface side in the drawing) of the flow path forming substrate 21 with an adhesive, a heat welding film, or the like. A nozzle opening 32 communicating with the first pressure generating chamber 25 is formed in the nozzle opening plate 31. The nozzle opening plate 31 is, for example,
It is made of glass ceramics, silicon single crystal substrate, stainless steel or the like.

As described above, the elastic film 22 is formed on the side opposite to the opening surface of the flow path forming substrate 21, and the lower electrode film and the piezoelectric layer are formed on the elastic film 22 corresponding to the first pressure generating chamber 25. A first piezoelectric element 34 is provided as a first pressure generating means composed of the upper electrode film. Further, on the elastic film 22 corresponding to the second pressure generating chamber 26, there is provided a second piezoelectric element 35 as second pressure generating means composed of a lower electrode film, a piezoelectric layer, and an upper electrode film. Yes.

In addition, although the example which applied the piezoelectric element as a pressure generation means was given and demonstrated, as a pressure generation means, the piezoelectric element which laminated | stacked the thin film, the piezoelectric element of a bulk state, a heat generating element, laminated | stacked piezoelectric material and an electrode plate member Various vibration elements such as a longitudinal vibration type piezoelectric element can be applied.

The first piezoelectric element 34 is provided with an electrode 36, the second piezoelectric element 35 is provided with an individual electrode 37, and is connected to a drive IC (not shown) or the like. When a drive signal is applied to the first piezoelectric element 34, pressure fluctuation occurs in the first pressure generating chamber 25 via the elastic film 22. When a drive signal is applied to the second piezoelectric element 35, pressure fluctuation occurs in the second pressure generation chamber 26 via the elastic film 22. The electrode 36 may be a common electrode for all the first piezoelectric elements 34 or may be an individual electrode for each first piezoelectric element 34.

A protective substrate 38 is bonded onto the flow path forming substrate 21, and the first piezoelectric element 3 is attached to the protective substrate 38.
A piezoelectric element protection unit 39 is provided to protect the fourth and second piezoelectric elements 35. The first piezoelectric element 34 and the second piezoelectric element 35 are disposed inside the piezoelectric element protection unit 39 and are protected in a state where they are not easily affected by the external environment. The protective substrate 38 is provided with a reservoir 40 that communicates with the communication portion 28. The upper part of the reservoir 40 is sealed with a sealing film 30. Examples of the material of the protective substrate 38 include glass, ceramic material, metal, resin, and the like, but it is preferable that the protective substrate 38 be formed of a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 21.

The nozzle opening plate 31 is formed by joining an upper plate 41 and a lower plate 42, and a nozzle opening 32 is formed across the upper plate 41 and the lower plate 42. A first channel recess 43 is formed in the lower plate 42 corresponding to the partition wall 24, and a first outlet 44 and a first inlet 45 are formed in the upper plate 41 before and after the first channel recess 43. Has been. A second channel recess 46 is formed in the lower plate 42 corresponding to the second partition wall 27, and a second outlet 47 and a second inlet 48 are formed in the upper plate 41 before and after the second channel recess 46. Is formed.

The first pressure generating chamber 25 and the second pressure generating chamber 25 are connected to the nozzle opening plate 31 corresponding to the partition wall 24.
A first flow path 51 communicating with the pressure generation chamber 26 is formed. In addition, a second flow path 52 that communicates the second pressure generation chamber 26 and the communication portion 28 (upstream side) is formed in the nozzle opening plate 31 at a portion corresponding to the second partition wall 27.

A first check valve 54 is provided at the first outlet 44 of the first flow path 51, and the first check valve 54 is a second check valve 54.
Ink flow from the pressure generating chamber 26 to the first pressure generating chamber 25 is allowed. Second flow path 52
The second outlet 47 is provided with a second check valve 55, and the second check valve 55 is allowed to flow ink from the communicating portion 28 (upstream side) to the second pressure generating chamber 26 side.

The first check valve 54 and the second check valve 55 are formed of a thin film, and the thin film constituting the first check valve 54 is joined between the partition wall 24 and the upper plate 41, and the second check valve 55 is The constituting thin film is joined between the second partition wall 27 and the upper plate 41. The first check valve 54 and the second check valve 54
As the check valve 55, a check valve including a valve body such as a ball or a float material may be applied.

When normal printing is performed by the ink jet recording apparatus 1 including the ink ejecting head 5 described above, a pressure signal is applied to the first pressure generating chamber 25 by applying a drive signal to the first piezoelectric element 34, and the communication unit 28. Ink is sent to the first pressure generating chamber 25 through the second pressure generating chamber 26 and the ink in the first pressure generating chamber 25 is ejected from the nozzle opening 32. Or second
A drive signal is also applied to the piezoelectric element 35 to change the pressure in the second pressure generating chamber 26 and to change the pressure in the first pressure generating chamber 25, and to send ink from the communicating portion 28 to the second pressure generating chamber 26. The ink in the second pressure generation chamber 26 is sent to the first pressure generation chamber 25 and the first pressure generation chamber 25 is supplied.
The ink inside is ejected from the nozzle opening 32.

When discharging the deteriorated ink remaining in the first pressure generating chamber 25 or discharging the ink adhering to the nozzle opening 32, the first pressure generating chamber 25 (nozzle opening 3) to be discharged
2), a driving signal is individually applied to the second piezoelectric element 35 of the second pressure generating chamber 26 corresponding to 2)
The pressure in the pressure generation chamber 26 is increased. The fluid in the second pressure generating chamber 26 is prevented from moving toward the communicating portion 28 by the second check valve 55, and the first target that is the target of ink discharge through the first check valve 54.
It is sent only to the pressure generation chamber 25. As a result, the ink in one first pressure generation chamber 25 is individually pushed out from the nozzle openings 32, and the deteriorated ink and the ink attached to the nozzle openings 32 are discharged.

Accordingly, it is possible to push out ink from the first pressure generating chamber 25 for the single nozzle opening 32, and it is not necessary to push out ink from all the first pressure generating chambers 25 at the time of cleaning, thereby suppressing wasteful ink consumption. And cleaning can be performed. Further, it is not necessary to separately provide power for cleaning.

And in the state which blocked | circulated the flow of the ink (fluid) to the communicating part 28 side by the 2nd check valve 55,
Since the ink (including air) in the second pressure generation chamber 26 can be sent to the first pressure generation chamber 25, the ink is initially filled by the pressure fluctuation in the second pressure generation chamber 26 without providing a dedicated power. It can be carried out.

In the above-described embodiment, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention is widely intended for the entire liquid ejecting head, and ejects liquid other than ink. Of course, the present invention can also be applied to a liquid ejecting head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device, 2 Ink cartridge, 5 Ink jet head, 21 Flow path formation board | substrate, 22 Elastic film, 23 Partition, 24 Partition wall, 25
1st pressure generation chamber, 26 2nd pressure generation chamber, 27 2nd partition wall, 28 Communication part,
30 sealing film, 31 nozzle opening plate, 32 nozzle opening, 34 first piezoelectric element, 35 second piezoelectric element, 36 electrode, 37 individual electrode, 38 protective substrate, 3
9 Piezoelectric protection part, 40 reservoir, 41 upper plate, 42 lower plate,
43 first channel recess, 44 first outlet, 45 first inlet, 46 second channel recess, 47 second outlet, 48 second inlet, 51 first channel, 52 second channel,
54 1st check valve, 55 2nd check valve

Claims (5)

A first pressure chamber communicating with the nozzle opening;
A second pressure chamber provided upstream of the first pressure chamber;
A first check valve provided between the first pressure chamber and the second pressure chamber and allowing only a fluid flow from the second pressure chamber to the first pressure chamber;
A second check valve provided on the upstream side of the second pressure chamber and allowing only the flow of fluid from the upstream side to the second pressure chamber;
First pressure generating means that is provided corresponding to the first pressure chamber, and causes the first pressure chamber to vary in pressure to discharge fluid from the nozzle opening;
A liquid ejecting head, comprising: a second pressure generating unit that is provided corresponding to the second pressure chamber and sends a fluid to the first pressure chamber by changing a pressure in the first pressure chamber. The liquid ejecting head according to claim 1,
A plurality of the nozzle openings are provided, and the first pressure chamber and the second pressure chamber are provided for each of the plurality of nozzle openings,
The upstream side of the second pressure chamber is a reservoir of fluid discharged from the plurality of nozzle openings,
The liquid ejecting head, wherein the fluid is individually sent from the second pressure chamber to the first pressure chamber by individually driving the second pressure generating unit. The liquid ejecting head according to claim 2,
The liquid ejecting head according to claim 1, wherein the fluid is individually ejected from the nozzle opening when the fluid is individually sent from the second pressure chamber to the first pressure chamber. The liquid ejecting head according to claim 2 or 3,
The liquid ejecting head, wherein the fluid is filled into the first pressure chamber by individually sending the fluid from the second pressure chamber to the first pressure chamber. The liquid jet head according to claim 1,
And a fluid source for supplying fluid to the upstream side of the second pressure chamber of the liquid ejecting head.

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