JP2011201225A - Liquid jetting head, liquid jetting head unit and liquid jetting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jetting head, liquid jetting head unit and liquid jetting apparatus, which surely opens and closes a nozzle opening and suppresses the deviation of liquid landing positions with reduced cost.SOLUTION: The liquid jetting head includes: a nozzle opening 13 for jetting a liquid; a pressure generator 16 for jetting the liquid from the nozzle opening 13 by generating a pressure change in a liquid passage communicated with the nozzle opening 13; and an opening and closing unit 100 provided in the liquid passage, which opens and closes the nozzle opening 13 in the liquid passage.

Description

The present invention relates to a liquid ejecting head that ejects liquid from a nozzle opening, a liquid ejecting head unit, and a liquid ejecting apparatus, and more particularly, an ink jet recording head that ejects ink as liquid,
The present invention relates to an ink jet recording head unit and an ink jet recording apparatus.

A liquid ejecting apparatus typified by an ink jet recording apparatus such as an ink jet printer or a plotter uses a liquid stored in a liquid storing means such as a liquid cartridge or a liquid tank.
A liquid ejecting head that can be ejected as droplets is provided.

Here, the liquid ejecting head includes a pressure generating chamber that communicates with the nozzle opening, and a pressure generating unit that causes a pressure change in the pressure generating chamber to discharge droplets from the nozzle opening. And as a pressure generating means mounted on the liquid jet head, for example, a longitudinal vibration type piezoelectric element,
Examples include a flexural vibration type piezoelectric element, a heating element, and one using electrostatic force.

In these liquid ejecting heads, bubbles included in the liquid may remain in the flow path when the liquid cartridge is replaced or printing defects such as missing dots may occur. Therefore, the liquid ejecting apparatus is provided with a cap member connected to a suction device that sucks the liquid in the flow path through the nozzle opening.

According to this cap member, by performing a suction operation of capping the end face of the liquid ejecting head and sucking the liquid in the flow path from the nozzle opening, the ink is filled in the flow path and printing defects such as missing dots are caused. Can be prevented. Further, in a standby state in which printing is not performed, the nozzle opening is covered with a cap member to suppress drying of ink near the nozzle opening.

However, as the liquid ejecting head becomes larger (nozzle openings are multi-rowed), it is necessary to enlarge the cap member to cover all the nozzle openings, and the ink jet recording apparatus becomes larger. For this reason, there has been proposed a liquid ejecting apparatus that provides a small cap member that covers a part of the nozzle openings without covering all the nozzle openings, and performs a suction operation of all the nozzle openings while moving the cap member ( For example, see Patent Document 1).

In such a configuration of Patent Document 1, since all the nozzle openings cannot be covered with the cap member at the same time, drying of ink near the nozzle openings at the time of non-printing cannot be suppressed.

For this reason, there has been proposed an ink jet recording head that opens and closes a nozzle opening by providing a plug portion in the flow path of the nozzle opening and moving the ejection surface provided with the nozzle opening (
For example, see Patent Document 2).

JP 2009-12371 A JP 2009-12372 A

However, as in Patent Document 2, when the ejection surface is moved, a bellows-like movable area for moving the ejection surface is necessary, and it is difficult to wipe or wipe the ink adhering to the movable area with a rubber blade. Thus, there is a problem that it is difficult to clean the ejection surface normally. In addition, when ink adheres to the bellows-like movable range and is solidified, there is a problem that the ejection surface cannot move normally and the nozzle opening cannot be opened and closed.

Furthermore, since the ejection surface is moved, it is difficult to always perform the same operation, and there is a problem that variations in the ink ejection direction occur and landing position deviation is likely to occur.

Further, the bellows-like movable range needs to be durable by repeated driving, and there is a problem that the cost becomes high by using a highly durable material.

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.

In view of such circumstances, the present invention can reliably open and close the nozzle opening,
An object of the present invention is to provide a liquid ejecting head, a liquid ejecting head unit, and a liquid ejecting apparatus that reduce the cost by suppressing landing position deviation.

An aspect of the present invention that solves the above problems includes a nozzle opening that ejects liquid, a pressure generating unit that causes a pressure change in the liquid flow path communicating with the nozzle opening, and ejects the liquid from the nozzle opening. The liquid ejecting head includes: an opening / closing means provided in the liquid channel and configured to open and close the nozzle opening in the liquid channel.
In such an aspect, cleaning such as wiping of the discharge surface can be easily performed by opening and closing the nozzle opening from the inside of the liquid flow path without moving the discharge surface. Further, since the ejection surface is not moved, it is possible to suppress occurrence of landing position deviation due to deviation of the liquid flight direction. Furthermore, the nozzle opening can be closed at a desired timing to suppress the drying of the liquid in the vicinity of the nozzle opening, thereby suppressing defects such as missing dots. In addition, a bellows-like member that operates the discharge surface on the discharge surface side becomes unnecessary, and it is not necessary to use a high-cost material, so that the cost can be reduced.

Here, the opening / closing means is controlled by the opening / closing control means, and when the liquid is ejected from the nozzle opening, the opening / closing control means opens the nozzle opening by the opening / closing means, and from the nozzle opening. When the liquid is not ejected, the nozzle opening is preferably controlled to be closed by the opening / closing means. According to this, it is possible to close nozzle openings that are not used for ejection, suppress drying of the liquid in the vicinity of the nozzle openings, and suppress defects such as missing dots.

The pressure generating means is for displacing the diaphragm that defines the liquid flow path, and the opening / closing means is extended to a region where the diaphragm is opposed to the nozzle opening. It is preferable to include an opening / closing portion provided in a region that does not vibrate by driving of the generating unit, and a moving unit that deforms the diaphragm in the region provided with the opening / closing portion. According to this, the nozzle opening can be reliably opened and closed by the movement of the opening and closing unit.

Moreover, it is preferable that the said opening-and-closing part has a cone shape provided with the vertex toward the said nozzle opening. According to this, when the liquid is discharged, the opening / closing part does not get in the way, and the nozzle opening can be reliably closed by the opening / closing part.

The moving means may include an opening / closing part pressure chamber provided on the opposite side of the diaphragm from the opening / closing part, and pressure adjusting means for adjusting the pressure in the opening / closing part pressure chamber. preferable. According to this, the opening / closing part can be reliably moved by adjusting the pressure in the opening / closing part pressure chamber by the pressure adjusting means.

Further, the moving means includes an adsorption plate made of a magnetic material provided on the diaphragm provided with the opening / closing portion, and an electromagnet provided on the opposite side of the opening / closing portion of the diaphragm. It is preferable to do. According to this, the opening / closing part can be reliably moved by the electromagnet.

According to another aspect of the invention, there is provided a liquid ejecting head unit including a plurality of liquid ejecting heads according to the above aspects.
According to this aspect, it is possible to reliably open and close the nozzle opening, and it is possible to realize a liquid ejecting head unit with reduced cost by suppressing landing position deviation.

According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head unit or the liquid ejecting head according to the above aspect.
In such an aspect, the nozzle opening can be reliably opened and closed, and the landing position deviation can be suppressed, and the liquid ejecting apparatus with reduced cost can be realized.

FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. FIG. 4 is an enlarged cross-sectional view of a main part illustrating the operation of the recording head according to the first embodiment. FIG. 4 is an enlarged cross-sectional view of a main part illustrating the operation of the recording head according to the first embodiment. 1 is a perspective view illustrating a schematic configuration of a recording apparatus according to Embodiment 1. FIG. FIG. 3 is a block diagram illustrating a control configuration of the recording apparatus according to the first embodiment. FIG. 9 is an enlarged cross-sectional view of a main part showing a modification of the recording head according to the first embodiment. 6 is a cross-sectional view of a recording head according to Embodiment 2. FIG. FIG. 9 is an enlarged cross-sectional view of a main part illustrating the operation of a recording head according to a second embodiment. 6 is a cross-sectional view of a recording head according to Embodiment 3. FIG. FIG. 9 is an enlarged cross-sectional view of a main part illustrating the operation of a recording head according to a third embodiment. 6 is a cross-sectional view of a recording head according to Embodiment 4. FIG. FIG. 9 is an enlarged cross-sectional view of a main part illustrating the operation of a recording head according to a fourth embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1A is a longitudinal sectional view of a pressure generation chamber of an ink jet recording head which is an example of a liquid jet head according to Embodiment 1 of the present invention, and FIG. 1B is an ink jet recording head. FIG. 2 and FIG. 3 are enlarged cross-sectional views of the main part of FIG. 1 (a).

As shown in FIG. 1, the ink jet recording head 10 of this embodiment includes a flow path forming substrate 12 in which a plurality of pressure generation chambers 11 are arranged in parallel, and a plurality of nozzle openings 13 communicating with the pressure generation chambers 11. It has a nozzle plate 14 that is drilled, a vibration plate 15 that is provided on the surface of the flow path forming substrate 12 opposite to the nozzle plate 14, and a piezoelectric element 16 that is provided on the vibration plate 15.

As shown in FIG. 1B, a plurality of pressure generating chambers 11 are partitioned by a partition wall 17 and arranged in parallel in the width direction of the flow path forming substrate 12. Further, as shown in FIG. 1A, a manifold 18 communicating with the plurality of pressure generation chambers 11 penetrates the flow path formation substrate 12 on one end side in the longitudinal direction of the pressure generation chamber 11 of the flow path formation substrate 12. Is provided. And each pressure generating chamber 1
1 and the manifold 18 are connected to each other via an ink supply path 19. In this embodiment, the ink supply path 19 is formed with a width narrower than that of the pressure generation chamber 11, and plays a role of maintaining a constant flow path resistance of ink flowing from the manifold 18 into the pressure generation chamber 11. .

Further, in this embodiment, the pressure generation chamber 11 is formed without penetrating the flow path forming substrate 12, and the flow path forming substrate 1 is disposed on the end side opposite to the manifold 18 of the pressure generation chamber 11.
A nozzle opening communication path 22 is formed so as to pass through 2 and communicate with the nozzle opening 13. That is, in the present embodiment, the manifold 18 and the ink supply path 19 are provided inside the recording head 10.
A liquid flow path including the pressure generation chamber 11 and the nozzle opening communication path 22 is provided.

A nozzle plate 14 is bonded to one surface side of the flow path forming substrate 12. As described above, each nozzle opening 13 communicates with each pressure generating chamber 11 via a nozzle opening communication path 22 provided in the flow path forming substrate 12. A diaphragm 15 is joined to the other surface side of the flow path forming substrate 12, that is, the opening surface side of the pressure generation chamber 11, and the pressure generation chamber 11 and the manifold 18 are sealed by the vibration plate 15. And the diaphragm 15 corresponding to the pressure generation chamber 11
On the top, the piezoelectric element 16 is fixed in a state in which the tip portion is in contact therewith. In the piezoelectric element 16, piezoelectric layers 25, individual internal electrodes 26 and common internal electrodes 27 are alternately stacked, and an inactive region that does not contribute to piezoelectric deformation is fixed to a fixed substrate 28. Further, a drive circuit 29 such as a drive IC is mounted on the inactive region of the piezoelectric element 16, for example, a chip-on-film (CO
A circuit board 30 made of F) is connected. Each wiring of the circuit board 30 is connected to the individual internal electrode 26 and the common internal electrode 27 constituting the piezoelectric element 16 by, for example, solder, anisotropic conductive material or the like on the base end side.

Further, on the vibration plate 15, a head case 32 having an accommodating portion 31 that accommodates a piezoelectric element 16 that is a pressure generating means for causing a pressure change in the pressure generating chamber 11 while being fixed to a fixed substrate 28 is fixed. Has been.

The vibration plate 15 with which the tip of the piezoelectric element 16 abuts is, for example, an elastic film 33 made of an elastic member such as a resin film, and a support plate 34 made of, for example, a metal material that supports the elastic film 33. It is formed of a composite plate, and the elastic film 33 side is bonded to the flow path forming substrate 12. For example, in the present embodiment, the elastic film 33 is made of a PPS (polyphenylene sulfide) film having a thickness of several μm, and the support plate 34 is a stainless steel plate (S) having a thickness of about several tens of μm.
US). In addition, an island portion 35 with which the tip end portion of the piezoelectric element 16 abuts is provided in a region of the diaphragm 15 facing each pressure generating chamber 11. That is, a first thin portion 36 having a thickness smaller than that of the other regions is formed in a region of the diaphragm 15 facing the peripheral portion of each pressure generating chamber 11, and an island is formed inside each of the first thin portions 36. A portion 35 is provided. Further, the diaphragm 15
Similar to the thin portion 36, a compliance portion 37 that is substantially composed only of the elastic film 33 is provided in the region facing the manifold 18 by removing the support plate 34. A space 38 that is a space that allows deformation of the compliance portion 37 is formed in a portion of the head case 32 that faces the compliance portion 37. This compliance section 3
7 has a function of absorbing the pressure change by deforming the elastic film 33 of the compliance portion 37 when the pressure change in the manifold 18 occurs, and maintaining the pressure in the manifold 18 constantly.

Further, in the present embodiment, in the region facing the nozzle opening 13 of the vibration plate 15, similarly to the first thin portion 36, the second support plate 34 is removed and the second plate configured only by the elastic film 33. Thin part 3
9 is provided. An opening / closing part pressure chamber 40, which is a space allowing deformation of the second thin part 39, is provided in a portion of the head case 32 that faces the second thin part 39. The pressure adjusting means 111 constituting the pressure adjusting means 111 described later in detail is connected through a communication passage 41 provided in the head case 32. In this embodiment, such an opening / closing part pressure chamber 40 is provided as a continuous space over the direction in which the nozzle openings 13 are arranged side by side.

Then, a second thin portion 39 provided in a region facing the nozzle opening 13 of the diaphragm 55.
Is provided with an opening / closing part 101 constituting the opening / closing means 100.

As shown in FIG. 2, the opening / closing part 101 is made of a material such as metal or resin, for example, and the diaphragm 1
5 has a conical shape fixed to the second thin portion 39 opposed to the five nozzle openings 13. The opening / closing part 101 has a bottom surface fixed to the elastic film 33 of the diaphragm 15 so that the tip thereof is positioned at the center of each nozzle opening 13. Since such an opening / closing part 101 needs to be provided corresponding to the arrangement of the nozzle openings 13, the opening / closing part 101 can be formed using, for example, the nozzle plate 14. As a forming method using the nozzle plate 14 of the opening / closing part 101, for example, the photocurable resin is filled in the nozzle openings 13 of the nozzle plate 14, and the photocurable resin is irradiated with light from the oblique direction of the nozzle openings 13. A conical opening / closing portion 101 can be formed. If the opening / closing part 101 formed in this way is adhered to the sheet-like elastic film 33 before being taken out from the nozzle opening 13, the opening / closing part 101 can be arranged on the elastic film 33 at the same interval as the nozzle opening 13.

Further, the head case 32 having the accommodating portion 31 is fixed on the diaphragm 15 as described above, and the piezoelectric element 16 is positioned and fixed in the accommodating portion 31 of the head case 32 with high accuracy. .

Further, the head case 32 is provided with a moving means 110 constituting the opening / closing means 100. The moving means 110 deforms the second thin portion 39 provided with the opening / closing portion 101 to move the opening / closing portion 101 so that the nozzle opening 13 is opened / closed by the opening / closing portion 101. In the present embodiment, the moving means 110 includes an opening / closing part pressure chamber 40 provided in a region facing the second thin portion 39 of the head case 32 and a pressure for adjusting the pressure in the opening / closing part pressure chamber 40. Adjusting means 111.

Furthermore, the opening / closing part pressure chamber 40 of the moving means 110 and the pressure adjusting means 111 are a communication path 41 communicating with the opening / closing part pressure chamber 40 of the head case 32, and a pipe member 1 connected to the communication path 41.
12 is connected. The pressure adjusting unit 111 pressurizes the opening / closing part pressure chamber 40, and includes, for example, a blower pump that blows gas into the opening / closing part pressure chamber 40.

In such a moving means 110, as shown in FIG. 2, the pressure adjusting means 111 (see FIG. 1).
When the pressure is not applied to the pressure chamber 40 for the opening / closing section, the opening / closing section 101 is connected to the nozzle opening 1.
The nozzle opening 13 is opened without moving to the third side.

On the other hand, as shown in FIG. 3, when the pressure adjusting means 111 (see FIG. 1) applies pressure to the opening / closing portion pressure chamber 40, the second thin portion 39 of the diaphragm 15 is moved to the nozzle opening 13 side. The nozzle opening 13 is closed by the opening / closing part 101.

That is, by adjusting the pressure in the opening / closing part pressure chamber 40 by the pressure adjusting means 111, the nozzle opening 13 is opened without moving the opening / closing part 101 toward the nozzle opening 13, or the opening / closing part 101 is moved to the nozzle. The nozzle opening 13 can be closed by moving to the opening 13 side.

Thus, the moving means 110 is opened and closed by the opening / closing part 101 at a desired timing.
By closing the nozzle, it is possible to suppress drying of the ink in the vicinity of the nozzle opening 13 during non-printing, and to suppress variation in the ink flying direction due to thickening due to drying of the ink, thereby preventing occurrence of landing position deviation. it can.

In addition, the opening / closing part 101 provided in the nozzle opening communication path 22 that is a liquid flow path moves without moving the discharge surface of the nozzle opening 13 (the surface on the ink droplet discharge side that the nozzle opening 13 opens). Since the nozzle opening 13 can be opened and closed, the ink jet recording head 1
The ink attached to the discharge surface can be removed by wiping the 0 discharge surface with a blade member. As a result, it is possible to suppress the ink adhering to the ejection surface from solidifying and hindering the opening and closing of the nozzle openings 13 and the landing positions of the ink droplets from shifting.

In the present embodiment, the opening / closing part pressure chamber 40 is provided as a continuous space in the direction in which the nozzle openings 13 are arranged in parallel, so that the moving unit 110 opens and closes all the nozzle openings 13 simultaneously. However, the present invention is not particularly limited to this, and for example, the pressure chamber 40 for the opening / closing portion is connected to the nozzle opening 1
If each nozzle opening 13 is provided independently, each nozzle opening 13 can be opened and closed independently. Of course, by providing the opening / closing part pressure chamber 40 for each nozzle opening group composed of two or more nozzle openings 13, the nozzle openings 13 can be opened and closed for each nozzle opening group. By the way,
When the opening / closing part pressure chamber 40 is provided for each nozzle opening 13 or for each nozzle opening group, the pressure adjusting means 111 is provided for each opening / closing part pressure chamber 40 or each opening / closing part pressure chamber 40 and the pressure adjusting means. 1
11 may be provided so that the pressure of each open / close section pressure chamber 40 is adjusted independently by opening and closing the valve.

In such a recording head 10, as shown in FIG. 2, ink droplets are ejected in a state where the opening / closing part 101 opens the nozzle opening 13. Specifically, when ink is supplied to the manifold 18 from a cartridge, which will be described later, the ink is distributed to each pressure generating chamber 11 via the ink supply path 19. Actually, the piezoelectric element 16 is contracted by applying a voltage to the piezoelectric element 16. As a result, the diaphragm 15 is deformed together with the piezoelectric element 16 to expand the volume of the pressure generating chamber 11, and ink is drawn into the pressure generating chamber 11. After the ink is filled up to the nozzle opening 13, the voltage applied to the individual internal electrode 26 and the common internal electrode 27 of the piezoelectric element 16 is released according to the recording signal supplied through the circuit board 30. To do. As a result, the piezoelectric element 16 is expanded to return to the original state, and the diaphragm 15 is also displaced to return to the original state. As a result, the volume of the pressure generation chamber 11 contracts, the pressure in the pressure generation chamber 11 increases, and ink droplets are ejected from the nozzle openings 13.

The recording head 10 according to this embodiment constitutes a part of an ink jet recording head unit having an ink flow path communicating with a cartridge, and is mounted on the ink jet recording apparatus. FIG. 4 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 4, the ink jet recording apparatus I includes an ink jet recording head unit 1 (hereinafter also referred to as a head unit 1) having a plurality of recording heads 10.
The head unit 1 is provided with detachable cartridges 2A and 2B constituting ink supply means, and a carriage 3 on which the head unit 1 is mounted is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. It has been. The head unit 1 ejects, for example, a black ink composition and a color ink composition.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the head unit 1 is mounted is moved along the carriage shaft 5. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

In such an ink jet recording apparatus I, bubbles remain in the flow path due to bubbles included in the ink during the printing operation when the ink cartridges 2A and 2B are initially installed or replaced,
Since the bubbles absorb pressure fluctuations in the flow path (especially, a pressure generation chamber described later), ink droplets are not normally ejected, and printing defects such as missing dots may occur. for that reason,
In the non-printing region of the ink jet recording apparatus I, a suction unit 130 that sucks bubbles from the nozzle openings 13 together with the ink in the liquid flow path is provided.

The suction unit 130 includes a cap member 131 that covers the nozzle opening 13 of the recording head 10 and a suction device 133 such as a vacuum pump connected to the cap member 131 via a tube 132.

The cap member 131 is provided opposite to the ejection surface from which the ink of the recording head 10 is ejected. The cap member 131 is not sized to cover all of the plurality of nozzle openings, but is sized to selectively cover one to a plurality of nozzle openings. In this embodiment, the cap member 131 is made shorter than the length of the head unit 1 in the main scanning direction, and the carriage 3 is moved in the main scanning direction with respect to the cap member 131, so that the narrow cap member 131 is used. All the nozzle openings 13 can be sequentially capped. As a result, the cap member 131 need not be large enough to cover all the nozzle openings 13, and the ink jet recording apparatus I can be downsized.

In the suction means 130 having such a configuration, the cap member 131 is brought into contact with the ejection surface of the recording head 10, and the suction device 133 performs a suction operation, whereby the inside of the cap member 131 is set to a negative pressure, and the liquid is discharged from the nozzle opening 13. The ink in the flow path is sucked together with bubbles to perform a suction operation.
Then, as described above, by moving the carriage 3 in the main scanning direction while performing the suction operation, the suction operation of all the nozzle openings 13 can be performed by the suction means 130.

In the non-printing area, a blade member 140 made of rubber or the like that wipes the ejection surface of the recording head 10 is provided. The blade member 140 is provided at such a height that it slides in contact with the ejection surface of the nozzle plate 14 while being elastically deformed by the movement of the recording head 10 in the main scanning direction. The blade member 140 is ejected by moving the recording head 10 in the main scanning direction. The surface of the blade member 140
Can be wiped by.

Further, the ink jet recording apparatus I is provided with a control device 50 that controls the operation of the ink jet recording apparatus I, as will be described in detail later.

Here, a control configuration for controlling such a recording head 10 will be described. Note that FIG.
FIG. 3 is a block diagram showing a control configuration of an ink jet recording head.

As shown in FIG. 5, in the ink jet recording apparatus I, a recording head 10 that is a mechanism unit that actually performs printing, and a suction unit 13 that sucks ink from a nozzle opening 13 of the recording head 10.
0, and a control device 5 that controls the operation of the recording head 10, the opening / closing means 100, and the suction means 130.
0.

The control device 50 includes a print control unit 51, a print position control unit 52, a suction control unit 53, and an opening / closing control unit 54.

The printing control unit 51 controls the printing operation of the recording head 10 and applies a driving pulse to the piezoelectric element 16 via a driving circuit 29 provided in the recording head 10 in response to the input of a printing signal, for example. Ink is ejected to the head 10.

The printing position control means 52 performs positioning in the main scanning direction and the sub scanning direction during printing or cleaning operation of the recording head 10 (suction operation by the cap member 131 and wiping operation by the blade member). Specifically, the printing position control means 52 drives the drive motor 6 to move the carriage 3 in the main scanning direction to position the recording head 10 in the main scanning direction, and drives a paper feed motor (not shown) to drive the platen. The recording head 10 is positioned with respect to the recording sheet S in the sub-scanning direction by rotating 8 and moving the recording sheet S in the sub-scanning direction. The printing position control means 52 moves the recording sheet S in the sub-scanning direction while moving the carriage 3 on which the recording head 10 is mounted in the main scanning direction during printing. Also,
During the cleaning operation, the carriage 3 on which the recording head 10 is mounted is moved to the non-printing area, so that wiping by a blade member and suction means 130 provided in the non-printing area are performed.
The suction operation by etc. is performed.

The suction control unit 53 controls the suction operation of the suction unit 130. That is, the suction control means 53 operates the suction device 133 of the suction means 130 at a predetermined timing, and the suction means 1
A suction operation for sucking ink in the vicinity of the nozzle openings 13 of the recording head 10 by 30 is performed. Specifically, the suction control unit 53 moves the recording head 10 to a position opposite to the cap member 131 via the printing position control unit 52, and drives the suction device 133 by capping the recording head 10 with the cap member 131. The suction operation is performed.

Further, in the present embodiment, the cap member 131 is not sized to cover all of the plurality of nozzle openings 21 but is sized to selectively cover one to a plurality of nozzle openings 13. Therefore, during the suction operation, the cap member 131 and the recording head 10 are connected to the nozzle opening 1.
3 is performed while relatively moving in the parallel direction of 3. The recording head 10 (carriage 3) is moved relative to the cap member 131 by moving in the main scanning direction. According to such a method, since the capping area of the cap member 131 can be reduced,
The cap member 131 can be downsized, and the ink jet recording apparatus I can be downsized.

The opening / closing control means 54 is a timing at which ink is ejected from the recording head 10, that is,
The driving of the pressure adjusting means 111 of the opening / closing means 100 is stopped in accordance with the timing at which the print signal is output from the printing control means 51, and the opening / closing part pressure chamber 40 is opened to the atmosphere, thereby opening and closing the opening / closing part 101. The nozzle opening 13 is opened away from the opening 13 (see FIG. 2). Further, the opening / closing control means 54 drives the pressure adjusting means 111 to pressurize the inside of the opening / closing section pressure chamber 40 when printing is not performed, that is, when a print signal is not output from the printing control means 51. Then, the nozzle opening 13 is closed from the liquid channel side by the opening / closing part 101 (see FIG. 3).

Incidentally, when the nozzle opening 13 is opened by the opening / closing part 101, the pressure adjusting means 11 is used.
1 is not only released to the atmosphere but also the internal gas is sucked so that the opening / closing portion pressure chamber 40 has a negative pressure.
The opening can be performed in a short time and reliably.

As described above, in the present embodiment, since the nozzle opening 13 is opened and closed by the opening / closing means 100 provided in the recording head 10, the nozzle opening 13 is not covered by the cap member 131, but near the nozzle opening 13. Ink drying can be suppressed, and ink ejection defects such as clogging due to the dried ink can be suppressed. In addition, the cap member 131
As described above, since a small-sized one that does not cover all the nozzle openings 13 can be used, and a protective cap that covers all the nozzle openings 13 is not required separately from the cap member 131, the ink jet recording apparatus I can be reduced in size. Can be

Further, since the nozzle opening 13 can be opened and closed by the opening / closing means 100 provided in the recording head 10 without using a cap member 131 or a protective cap as in the prior art, the carriage 3 can be moved without discharging ink. The nozzle opening 13 can be opened and closed at a desired timing, for example, during the operation. Incidentally, when the nozzle opening 13 is covered and closed with a cap member 131 or a protective cap, the cap member 131 or the protective cap is provided in the non-printing area, and therefore the carriage 3 must be moved to the non-printing area. However, according to the opening / closing means 100 of the present embodiment, since the nozzle opening 13 can be closed even while the carriage 3 is moving, the nozzle opening 13 can be reliably protected and the cap member 131 can be protected. In comparison with the above, drying of the ink can be more effectively suppressed.

In this embodiment, the nozzle opening 13 is closed by the opening / closing means 100 when ink is not ejected, and the opening / closing means 100 is opened by the opening / closing means 100 when ink is ejected. The nozzle opening 13 is interlocked with the opening and closing of the nozzle opening 13.
The ink meniscus may be drawn into the pressure generating chamber 11 side. Such an example is shown in FIG. FIG. 6 is an enlarged cross-sectional view showing a main part of a modification of the ink jet recording head according to Embodiment 1 of the present invention.

As shown in FIG. 6A, in a state where ink is ejected, that is, in a state where the opening / closing means 100 opens the nozzle opening 13, the ink meniscus A exists on the ejection surface side of the nozzle opening 13. Yes.

When the nozzle opening 13 is closed by the opening / closing means 100, the piezoelectric element 16 is driven to make the pressure in the pressure generating chamber 11 negative. As a result, as shown in FIG. 6B, the ink meniscus A in the nozzle opening 13 moves backward toward the pressure generating chamber 11. After the ink meniscus A of the nozzle opening 13 is thus retracted, the nozzle opening 13 is closed by the opening / closing means 100 (opening / closing portion 101) as shown in FIG. When the ink is discharged, after the opening / closing means 100 opens the nozzle opening 13, the ink meniscus A in the nozzle opening 13 is returned to the position shown in FIG. Good.

Thus, when the nozzle opening 13 is closed by the opening / closing means 100, the nozzle opening 13
By retracting the ink meniscus A toward the pressure generation chamber 11, the amount of ink remaining between the opening / closing portion 101 and the nozzle opening 13 can be reduced when the opening / closing portion 101 closes the nozzle opening 13. it can. Incidentally, when the nozzle opening 13 is closed by the opening / closing part 101 without retracting the meniscus A, the ink in the nozzle opening 13 is pushed out to the ejection surface side by the opening / closing part 101 and exposed to the outside, thereby drying and thickening. May occur. In this embodiment, when the nozzle opening 13 is closed, the meniscus A is retracted into the pressure generation chamber 11 to reduce the ink that remains between the opening / closing portion 101 and the nozzle opening 13 and is exposed to the outside. And
Due to drying and thickening of the remaining ink, it is possible to reduce the occurrence of an ink landing position deviation or the like during ink ejection.

The movement of the ink meniscus A in the nozzle opening 13 is controlled by the open / close control means 54.
However, it can be performed by controlling the print control means 51 to drive the piezoelectric element 16.

(Embodiment 2)
FIG. 7 is a cross-sectional view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 2 of the present invention. FIG. 8 is an enlarged cross-sectional view of the main part showing the operation of the ink jet recording head according to Embodiment 2. FIG. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

As shown in the drawing, in the ink jet recording head 10A of the present embodiment (hereinafter also referred to as recording head 10A), as an opening / closing means 100A, an opening / closing portion 101A and a moving means 110A.
And.

As shown in FIG. 8A, the opening / closing part 101 </ b> A is provided with a size that closes the nozzle opening 13 when the diaphragm 15 (second thin part 39) is not deformed.

The moving means 110A includes an opening / closing part pressure chamber 40, a pressure adjusting means 111A, and a communication passage 41 and a pipe member 112 communicating the opening / closing part pressure chamber 40 and the pressure generating means 111A.

The pressure adjusting means 111A is composed of, for example, a vacuum pump for sucking the gas in the opening / closing part pressure chamber 40, and as shown in FIG. 8B, the pressure adjusting means 111A is a gas in the opening / closing part pressure chamber 40. , The inside of the pressure chamber 40 for the opening / closing part is set to a negative pressure. Thus, by making the pressure chamber 40 for opening / closing part into a negative pressure, the second thin part 39 can be deformed, the opening / closing part 101A can be separated from the nozzle opening 13, and the nozzle opening 13 can be opened.

In such a configuration, the nozzle opening 13 can be closed by the opening / closing portion 101A as shown in FIG. 8A even when the power source of the ink jet recording apparatus I is cut off. It is possible to suppress drying of the ink in the vicinity of the nozzle opening 13 in the cut state.

(Embodiment 3)
FIG. 9 is a cross-sectional view of an ink jet recording head that is an example of a liquid ejecting head according to Embodiment 3 of the present invention. FIG. 10 is an enlarged cross-sectional view showing the main part of the operation of the ink jet recording head according to Embodiment 3. FIG. In addition, the same code | symbol is attached | subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate | omitted.

As shown in FIG. 9, the opening / closing means 100 </ b> B of the recording head 10 </ b> B of the present embodiment includes the opening / closing unit 10.
1A and moving means 110B.

The moving means 110B is a pressure adjusting means 11 comprising an opening / closing part pressure chamber 40 and a blower pump.
1, a communication passage 41, a pipe member 112, and an external communication hole 42 that allows the opening / closing part pressure chamber 40 to communicate with the outside.

In such moving means 110B, as shown in FIG. 10, when gas is blown into the opening / closing part pressure chamber 40 by the pressure adjusting means 111, the gas blown into the opening / closing part pressure chamber 40 is transferred to the external communication hole 42. It is discharged to the outside through. At this time, the second thin portion 39 becomes negative pressure by Bernoulli's theorem, the second thin portion 39 is drawn into the opening / closing portion pressure chamber 40, and the opening / closing portion 101 </ b> A is separated from the nozzle opening 13. The opening 13 is opened.

Further, when closing the nozzle opening 13, the opening / closing part 101 closes the nozzle opening 13 by stopping the blowing by the pressure adjusting means 111.

(Embodiment 4)
FIG. 11 is a cross-sectional view of an ink jet recording head that is an example of a liquid ejecting head according to Embodiment 4 of the present invention, and FIG. 12 is an enlarged cross-sectional view of the main part showing the operation of the ink jet recording head of Embodiment 4. It is. In addition, the same code | symbol is attached | subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate | omitted.

As shown in FIG. 11, the recording head 10C of the embodiment is provided with an opening / closing means 100C, and the opening / closing means 100C includes an opening / closing part 101A and a moving means 110C.

The moving unit 110 </ b> C includes a suction plate 113 made of a magnetic material provided in the second thin portion 39, and an electromagnet 114 that sucks the suction plate 113 with electromagnetic force.

The suction plate 113 is made of a magnetic material such as iron provided on the head case 32 side of the second thin portion 39 of the vibration plate 15.

The electromagnet 114 is provided at a position facing the suction plate 113 of the opening / closing part pressure chamber 40 </ b> A of the head case 32 at a position away from the suction plate 113.

Then, as shown in FIG. 12, the suction plate 113 is attracted by the electromagnetic force of the electromagnet 114, so that the opening / closing part 101 </ b> A is separated from the nozzle opening 13 and the nozzle opening 13 is opened.

Further, when ink is not ejected, the opening / closing portion 101A closes the nozzle opening 13 as shown in FIG. 11 by releasing the suction of the suction plate 113 by the electromagnet 114.

That is, in the present embodiment, the suction plate 11 is used as a moving unit that moves the opening / closing part 101A.
3 and an electromagnet 114 are provided. In the case where the recording head 10C is provided with the opening / closing unit 101 of the first embodiment described above, the suction plate 1 is caused by the electromagnetic force of the electromagnet 114.
A permanent magnet, an electromagnet, or the like may be provided as the attracting plate 113 so that 13 repels the electromagnet 114.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

In each of the above-described embodiments, the piezoelectric layer 25, the individual internal electrode 26, and the common internal electrode 27 are alternately stacked as the pressure generating means for causing a pressure change in the flow path (pressure generating chamber 11) in the axial direction. However, the pressure generating means is not particularly limited to this, and the piezoelectric layers 25, the individual internal electrodes 26, and the common internal electrodes 27 are alternately stacked. Thus, a lateral vibration type piezoelectric element in which one end portion in the stacking direction is brought into contact with the island portion may be used.

As the pressure generating means, for example, a lower electrode, a piezoelectric layer formed of a piezoelectric material, and an upper electrode may be formed and a thin film type piezoelectric element formed by a lithography method may be used.
A thick film type piezoelectric element formed by a method such as attaching a green sheet can also be used. Also, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are discharged from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. In addition, it is possible to use a device in which a diaphragm is deformed by electrostatic force and droplets are ejected from a nozzle opening.

In the ink jet recording apparatus I described above, the head unit 1 having the plurality of recording heads 10 is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line type recording apparatus in which the head 10 is fixed and printing is performed simply by moving the recording sheet S such as paper in the sub-scanning direction.

In the example described above, the head unit 1 having a plurality of recording heads 10 is mounted on the ink jet recording apparatus I. However, one recording head 10 may be mounted on each head unit 1. In addition, one or a plurality of recording heads 10 may be directly mounted on the ink jet recording apparatus I.

In the above-described embodiment, an ink jet recording head has been described as an example of a liquid ejecting head. However, the present invention is widely intended for all liquid ejecting heads and ejects liquids 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,
Examples thereof include an electrode material ejecting head used for forming an electrode such as an organic EL display and FED (field emission display), and a bio-organic matter ejecting head used for biochip production.

I ink jet recording apparatus (liquid ejecting apparatus), 1 ink jet recording head unit (liquid ejecting head unit), 10, 10A, 10B, 10C ink jet recording head (liquid ejecting head), 11 pressure generating chamber, 12 flow path formation Board, 1
3 nozzle opening, 16 piezoelectric element (pressure generating means), 30 circuit board, 50 control device, 54 opening / closing control means, 100, 100A, 100B, 100C opening / closing means,
101, 101A Opening / closing section, 110, 110A, 110B, 110C Moving means, 11
1, 111A pressure adjusting means, 113 suction plate, 114 electromagnet

Claims (9)

A nozzle opening for jetting liquid;
Pressure generating means for causing a pressure change in a liquid flow path communicating with the nozzle opening and ejecting liquid from the nozzle opening;
A liquid ejecting head, comprising: an opening / closing means provided in the liquid flow path for opening and closing the nozzle opening in the liquid flow path. The opening / closing means is controlled by an opening / closing control means, and the opening / closing control means opens the nozzle opening by the opening / closing means when ejecting liquid from the nozzle opening,
The liquid ejecting head according to claim 1, wherein when the liquid is not ejected from the nozzle opening, the opening and closing means controls the nozzle opening to be closed. The pressure generating means is for displacing a diaphragm defining the liquid flow path;
The opening / closing means includes an opening / closing part provided in a region where the diaphragm extends to a region opposite to the nozzle opening and is not vibrated by driving the pressure generating unit, and vibration in a region where the opening / closing unit is provided. The liquid ejecting head according to claim 1, further comprising a moving unit that deforms the plate. The liquid ejecting head according to claim 3, wherein the opening / closing portion has a conical shape with a vertex provided toward the nozzle opening. An opening / closing part pressure chamber provided on the opposite side of the opening / closing part of the diaphragm;
The liquid ejecting head according to claim 3, further comprising a pressure adjusting unit that adjusts a pressure in the pressure chamber for the opening and closing unit. The moving means includes an adsorption plate made of a magnetic material provided on the diaphragm provided with the opening / closing portion, and an electromagnet provided on the opposite side of the opening / closing portion of the diaphragm. The liquid jet head according to claim 3, wherein: A liquid ejecting head unit comprising a plurality of liquid ejecting heads according to claim 1.   A liquid ejecting apparatus comprising the liquid ejecting head unit according to claim 7. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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