JP2016049677A - Liquid discharge head and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head which can suppress cross talk between a plurality of pressure chambers, and decrease changes in a liquid discharge state; and a liquid discharge device including the liquid discharge head.SOLUTION: A liquid discharge head 7 includes: a plurality of discharge outlets 16 for discharging liquid; a plurality of pressure chambers 11 which includes pressure generating means 21 and is connected with the discharge ports 16; common liquid chambers 12a and 12b; and a plurality of liquid channels 15a and 15b which respectively connect the pressure chambers 11 to the common liquid chambers 12a and 12b. In the inside of the liquid channels 15a and 15b, a plurality of dampers 17 are respectively provided.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid discharge head and a liquid discharge apparatus.

  In inkjet recording, in which recording is performed by discharging liquid ink onto a recording medium, higher definition and higher speed recording is desired. Therefore, a liquid discharge head in which a plurality of discharge ports for discharging liquid are two-dimensionally arranged Is widely used. The liquid discharge head is provided with a plurality of pressure chambers communicating with the plurality of discharge ports, and pressure generating means including piezo elements and the like are arranged in each pressure chamber.

  Patent Document 1 describes a liquid discharge head that includes a plurality of two-dimensionally arranged discharge ports, a plurality of pressure chambers that communicate with the respective discharge ports, and a common liquid chamber that communicates with the plurality of pressure chambers. Has been. In this liquid discharge head, a diaphragm is disposed at the boundary between the common liquid chamber and the pressure chamber, and a part of the diaphragm functions as a thin damper portion that absorbs pressure fluctuations.

  Patent Document 2 also describes a liquid discharge head including a plurality of discharge ports arranged two-dimensionally, a plurality of pressure chambers communicating with the respective discharge ports, and a common liquid chamber. In this liquid discharge head, the common liquid chamber is located between the discharge port and the pressure chamber, and the damper is provided between the portion where the common liquid chamber is provided and the portion where the discharge port is formed. The pressure chambers are arranged in a plurality of rows, and the driving means of each pressure chamber is controlled so as to drive the pressure generating means of the pressure chambers in the rows adjacent to each other at different timings.

JP 2007-307774 A JP 2013-91215 A

  In a liquid discharge head in which a plurality of pressure chambers are arranged at high density, mutual interference (crosstalk) occurs in which pressure fluctuations generated when the pressure generating means of the pressure chamber is driven interfere with adjacent pressure chambers. As a result, the liquid discharge state changes and the recording quality deteriorates. Further, when a large number of pressure generating means are driven simultaneously, the peak value of the driving power increases, and the liquid discharge state changes due to the accompanying voltage drop and the recording quality deteriorates.

In the liquid discharge head described in Patent Document 1, a part of a diaphragm constituting a wall serving as a boundary between a pressure chamber and a common liquid chamber is used as a damper portion. This damper part can suppress a pressure fluctuation to some extent. However, since the damper portion constitutes the wall surface of the common liquid chamber communicating with the plurality of pressure chambers, the effect of reducing crosstalk between adjacent pressure chambers is small. In particular, the crosstalk caused by the back flow of the liquid generated in addition to the crosstalk caused by the propagation of the pressure wave between the pressure chambers cannot be suppressed much by the damper portion of Patent Document 1.
Specifically, when the liquid in the pressure chamber is pressurized by the pressure generating means and discharged from the discharge port, the liquid flows backward and flows from the pressure chamber to the common liquid chamber through the liquid channel. The degree of pressure increase in the vicinity of the liquid flow path due to the reverse flow varies depending on the number of pressure generating means that are driven simultaneously. That is, the discharge state of the liquid from the discharge port varies depending on the number of pressure generating units driven at the same time, and the meniscus of the liquid at the discharge port corresponding to the pressure generation unit that has not been driven fluctuates. The state is affected. Further, immediately after the liquid is discharged, the liquid is supplied toward the discharge port from which the liquid has been discharged, so that a liquid flows in the liquid flow path and the pressure is reduced. Such pressure fluctuations due to the flow of liquid and the resulting fluctuations in the discharge state cannot be prevented simply by suppressing the direct propagation of pressure waves.

  In the liquid discharge head of Patent Document 2, a large number of discharge ports are arranged in a plurality of (for example, four) rows and driven at different timings for each row, so that the peak value of drive power can be kept low. Furthermore, pressure fluctuations that occur as the pressure generating means is driven are alleviated. However, in the same column, since the pressure generating means of these pressure chambers are driven simultaneously with a plurality of pressure chambers connected to the same common liquid chamber, crosstalk is inevitable.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid discharge head that can suppress crosstalk between a plurality of pressure chambers and has a small fluctuation in the liquid discharge state, and a liquid discharge apparatus including the liquid discharge head.

  The liquid discharge head of the present invention includes a plurality of discharge ports for discharging liquid, a plurality of pressure chambers including pressure generating means connected to the discharge ports, a common liquid chamber, and each pressure chamber as a common liquid chamber. A plurality of liquid flow paths connected to each other and a plurality of dampers provided inside the liquid flow paths are included.

  According to the present invention, since the damper is provided inside the liquid flow path between the pressure chamber and the common liquid chamber, both efficient liquid discharge and suppression of crosstalk between adjacent pressure chambers can be achieved. Efficient liquid discharge is impossible as in the configuration in which the damper is provided in the pressure chamber, and crosstalk between adjacent pressure chambers cannot be suppressed much as in the configuration in which the damper is provided in the common liquid chamber. There is nothing.

  According to the present invention, it is possible to provide a liquid discharge head in which crosstalk between a plurality of pressure chambers is suppressed and the liquid discharge state is small and a liquid discharge apparatus including the liquid discharge head.

It is a schematic diagram which shows the liquid discharge apparatus of one Embodiment of this invention. FIG. 2 is a schematic view of the liquid discharge head unit of the liquid discharge apparatus shown in FIG. 1 as viewed from the discharge port side. FIG. 5 is a perspective view, a cross-sectional view, and a cross-sectional view of a modification as seen from the discharge port side of the liquid discharge head shown in FIG. It is the perspective view and sectional drawing seen from the discharge outlet side of the liquid discharge head of the 2nd Embodiment of this invention. FIG. 5 is a waveform diagram showing drive signals supplied to the liquid ejection head shown in FIG. 4. It is sectional drawing of the modification of the liquid discharge head of 2nd Embodiment. It is the perspective view seen from the discharge outlet side of the liquid discharge head of the 3rd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows an example of the liquid ejection apparatus of the present invention. According to this liquid ejection apparatus, the recording paper 1 that is a recording medium is fed in the direction of the arrow by the paper feed roller 2 that is a conveying means. A platen 3 that supports the recording paper 1 is provided in the conveyance path of the recording paper 1. At a position facing the platen 3, a recording unit that performs recording by discharging liquid onto the recording paper 1 is provided. In the recording unit of the present embodiment, four liquid discharge head units 4 are provided. Each liquid discharge head unit 4 performs ink jet recording by discharging cyan, magenta, yellow, and black liquid inks onto the recording paper 1 on the platen 3. The liquid discharge head unit 4 has pressure generating means including a piezo element or a heat generating element, and is connected to a driving means 5 for electrically driving the pressure generating means. Each driving means 5 electrically drives the pressure generating means based on an image signal or the like sent from the controller 6.

  FIG. 2 shows a view of one liquid discharge head unit 4 as viewed from the discharge port side. The liquid discharge head unit 4 has a configuration in which a plurality of liquid discharge heads 7 are arranged in a staggered manner. Each liquid discharge head 7 has 2000 discharge ports, and can record 1200 dpi (1200 dots per inch (about 2.54 cm)).

  3A is a perspective view of the main part of the liquid discharge head 7 as seen from the discharge port side, and FIG. 3B is a cross-sectional view taken along the line S-S. In the liquid ejection head 7, an ejection port plate 9 having ejection ports 16 is laminated on one surface of the element substrate 8. A common liquid chamber plate 10 is laminated on the other surface of the element substrate 8. On one surface of the element substrate 8, a pressure chamber 11 is constituted by the element substrate 8 and the discharge port plate 9. On the other surface of the element substrate 8, common liquid chambers 12 a and 12 b are configured by the element substrate 8 and the common liquid chamber plate 10. And the through-hole part 13a, 13b which penetrates the element board | substrate 8 in the thickness direction, extends between one surface and the other surface, and one end communicates with the common liquid chambers 12a, 12b is formed. On one surface of the element substrate 8, individual flow path portions 14 a and 14 b communicating with the other end of the through-hole portions 13 a and 13 b and the pressure chamber 11 are further formed. The through-hole portions 13 a and 13 b and the individual flow path portions 14 a and 14 b constitute liquid flow paths 15 a and 15 b that connect the common liquid chambers 12 a and 12 b and the pressure chamber 11. In the present embodiment, two liquid channels (a set of a through-hole portion and an individual channel portion) are connected to one pressure chamber 11, and one of them is an inflow liquid channel 15a, The other is the outflow liquid channel 15b. That is, two paths for liquid inflow and liquid outflow are formed for one pressure chamber 11. As will be described later, the element substrate 8 of the present embodiment mainly has a configuration in which a support substrate 24 and a flow path wall substrate 25 are laminated, and a pressure generating means 21 formed from a formation substrate is configured inside. ing. In FIG. 3A, the discharge port plate 9 is omitted, and only the discharge port 16 is indicated by an imaginary line for easy viewing.

  FIG. 3A shows only four rows of discharge ports 16 and pressure chambers 11, but the entire liquid discharge head 7 is provided with a large number (for example, 40 rows) of discharge ports 16 and pressure chambers 11. ing. One of the inner walls of the pressure chamber 11 of the present embodiment is constituted by a pressure generating means 21. The pressure generating means 21 is obtained by attaching a piezoelectric element and an electrode to a diaphragm. An electrical wiring 22 is connected to the electrode of each pressure generating means 21.

  A damper 17 is provided inside each of the liquid flow paths 15a and 15b of the present embodiment. Specifically, a substantially U-shaped frame member 18 is provided on a portion of the element substrate 8 constituting the inner walls of the through holes 13a and 13b of the liquid flow paths 15a and 15b. One end of the frame member 18 is closed by a flexible membrane 19. Further, the discharge port plate 9 is laminated on the element substrate 8, whereby the other end portion of the frame member 18 is closed by the discharge port plate 9. In this way, the cavity 20 is formed by the inner walls of the liquid flow paths 15a and 15b, the frame member 18, the membrane 19, and the discharge port plate 9 so as to prevent the liquid from entering. A damper 17 is mainly constituted by the hollow portion 20 and the flexible membrane 19. That is, as the air enclosed in the cavity 20 expands and contracts, the membrane 19 is elastically deformed so as to enter the cavity 20 or elastically deforms toward the outside of the cavity 20. You can also Therefore, for example, pressure fluctuation generated in the pressure chamber 11 is absorbed by elastic deformation of the flexible membrane 19 so that the air inside the cavity 20 contracts or expands, and the common flow chamber 15a, 15b is used to absorb the pressure fluctuation. It is not transmitted to 12a, 12b.

  As shown in FIG. 3B, the through holes 13 a and 13 b of the liquid flow paths 15 a and 15 b are provided in the element substrate 8. Among these, the through-hole portion 13a of the inflowing liquid channel 15a has two inner diameters, the portion connected to the common liquid chamber 12a has a large diameter, and the portion connected to the individual channel portion 14a has a small diameter. . Thereby, the flow resistance with respect to the gas which flows into the pressure chamber 11 from the common liquid chamber 12a via the inflow liquid flow path 15a is small. The through-hole portion 13b of the outflow liquid channel 15b is connected to the individual channel portion 14b from the common liquid chamber 12b with a constant diameter. Since the through-hole portions 13a and 13b and the individual flow channel portions 14a and 14b intersect each other substantially perpendicularly, the inflow liquid flow channel 15a and the outflow liquid flow channel 15b are partially bent at a right angle. is there.

  In this liquid discharge head 7, the liquid (for example, liquid ink) accommodated in the common liquid chamber 12a for inflow passes through the inflow liquid flow path 15a (the through-hole portion 13a and the individual flow path 13b) to the pressure chamber. 11 flows in. When an electrical signal is supplied from the controller 6 and the driving means 5 to the piezo element of the pressure generating means 21 via the electric wiring 22, the pressure generating means 21 applies pressure to the liquid in the pressure chamber 11. That is, the pressure generating means 21 is deformed so as to reduce the volume of the pressure chamber 11 by piezoelectric deformation of the piezoelectric element constituting the pressure generating means 21 and pressurizes the liquid in the pressure chamber 11. The pressurized liquid is discharged from the pressure chamber 11 to the outside through the discharge port 16 and adheres to, for example, the recording paper 1 to form an image. In this way, the piezoelectric element of the pressure generating means 21 provided facing the pressure chamber 11 is driven by applying the drive waveform signal generated by the driving means 5. It goes without saying that there are cases where the piezo element is actually driven and cases where the signal is not supplied and not driven depending on the image to be recorded.

After the liquid is discharged, the electric signal is not supplied to the piezo element of the pressure generating means 21, the diaphragm returns from the deformed state to the initial state, and the pressure chamber 11 expands accordingly and returns to the volume before the deformation. . Thus, in the process in which the diaphragm returns to the initial state, vibration and pressure fluctuation occur in the liquid in the pressure chamber 11. If this vibration or pressure fluctuation is transmitted to the liquid in the adjacent pressure chamber 11 via the common liquid chambers 12a and 12b, good discharge of the liquid may be hindered.
Therefore, in the present embodiment, the damper 17 is provided inside the liquid flow paths 15a and 15b. Vibrations and pressure fluctuations generated inside the pressure chamber 11 after liquid discharge are absorbed by the dampers 17 in the liquid flow paths 15a and 15b, specifically by elastic deformation of the membrane 19 and reduction or expansion of the volume of the cavity 20. Is done. Therefore, vibrations and pressure fluctuations are not easily transmitted to the common liquid chambers 12a and 12b, and the liquid discharge of the adjacent pressure chambers 11 is not affected via the common liquid chambers 12a and 12b. In this way, the interaction (crosstalk) that affects the adjacent pressure chambers 11 due to the liquid ejection of a certain pressure chamber 11 is suppressed. Thereby, when the liquid discharge head 7 of the present embodiment is used for ink jet recording, the influence of crosstalk on the recorded image can be reduced.

If a damper is provided inside the pressure chamber 11 itself, the pressure is absorbed by the damper even if the pressure is applied to discharge the liquid, so that the liquid cannot be efficiently discharged, and the liquid discharge head 7 has good performance. Cannot be obtained. On the other hand, if a damper is provided in the common liquid chambers 12a and 12b, vibrations and pressure fluctuations cannot be prevented from being transmitted to the portion where the liquid flow paths 15a and 15b connected to the adjacent pressure chambers 11 are joined, thereby reducing crosstalk. Does not contribute much.
On the other hand, in the present embodiment, the damper 17 is provided inside the liquid flow path 15 between the pressure chamber 11 and the common liquid chambers 12a and 12b, so that efficient liquid discharge is not hindered and crosstalk is achieved. Can be reduced.

In the present embodiment, liquid continuously flows from the inflow common liquid chamber 12a into the pressure chamber 11 through the inflow liquid channel 15a, and the liquid in the pressure chamber 11 flows out through the outflow liquid channel 15b. A circulation structure that continuously flows out to the common liquid chamber 12b is configured. Specifically, the liquid in the inflow common liquid chamber 12a is maintained at a weak negative pressure of about −300 Pa by an ink supply device (not shown), and the liquid in the outflow common liquid chamber 12b is several hundred more than that. The pressure is kept low by about Pa. Thereby, even when the piezo element is not driven, the liquid flows from the inflow common liquid chamber 12a through the inflow liquid channel 15a, the pressure chamber 11, and the outflow liquid channel 15b. It slowly flows toward the liquid chamber 12b. Therefore, there are problems such as ejection failure due to thickening of the liquid due to evaporation from the ejection port 16 when liquid ejection is not being performed, and ejection failure due to bubbles being accumulated in the pressure chamber 11 due to continuous liquid ejection or the like. Occurrence can be suppressed.
However, the common liquid chamber 12a for inflow and the common liquid chamber 12b for outflow can be maintained at the same pressure, and the two common liquid chambers can be used without distinction between inflow and outflow.

A method for manufacturing the liquid discharge head 7 of this embodiment will be described.
The element substrate 8 of the present embodiment is a stacked body of a plurality of substrates. First, power is supplied to the piezoelectric element on one surface of a support substrate 24 (for example, Si substrate) which is one member constituting the element substrate 8. Electrical wiring 22 is formed. Moreover, the through-hole parts 13a and 13b are formed by making the hole which penetrates the support substrate 24 in the thickness direction.

  Next, a SiN film is formed by sputtering on a formation substrate for forming a diaphragm. On the SiN film, a piezoelectric element and an electrode (for example, an electrode made of Ti, Pt, Au, etc.) are formed and patterned to form the pressure generating means 21. Further, a dry film that becomes the gap member 23 for holding the piezoelectric element and the SiN film at an oscillating interval is laminated and patterned.

Then, the support substrate 24 is attached to the dry film 23 patterned on the formation substrate. At this time, the electrode of the pressure generating means 21 and the electric wiring 22 are connected by bump connection. After the formation substrate is attached to the support substrate 24, the formation substrate is chemically cut from the side opposite to the surface on which the piezoelectric element is formed. For example, the formation substrate is melted by dry etching to leave only the SiN film as the vibration plate. Thus, the pressure generating means 21 including the diaphragm (SiN film), the piezoelectric element, and the electrode is formed.
Simultaneously with the formation of the vibration plate, the membrane 19 is dry-etched in the same manner as the vibration plate in the partition wall portion between the recesses that are adjacent individual flow path portions 14a and 14b on one surface of the support substrate 24. Form.

  Subsequently, the pressure chamber 11 and the flow path wall substrate 25 serving as the side walls of the individual flow path portions 14a and 14b are further stacked on the stacked body of the pressure generating means 21 and the membrane 19 and the support substrate 24, which are formed substrates, and patterned. To do. The side wall formed by patterning the flow path wall substrate 25 and the vibration plate form a recess that becomes the pressure chamber 11, and the individual flow path portion 14 a is formed by the similarly formed side wall and the surface of the support substrate 24. , 14b are formed. The concave portions that become the individual flow path portions 14a and 14b are formed at positions that communicate with one end portions of the through-hole portions 13a and 13b. Further, by cutting the flow path wall substrate 25, a substantially U-shaped frame member 18 is formed at a position facing the membrane 19 made of the formation substrate, and the membrane 19 is formed at one end of the substantially U-shaped frame member 18. Make sure they are in close contact. In this way, the element substrate 8 which is mainly a laminated body of the support substrate 24 and the channel wall substrate 25 and includes the pressure generating means 21 inside is manufactured.

  Thereafter, the discharge port plate 9 having the discharge ports 16 at positions facing the respective pressure chambers 11 is attached to the surface side of the element substrate 8 on which the vibration plate is formed. At this time, the discharge port plate 9 closes a recess formed on one surface of the element substrate 8 to form the pressure chamber 11 and the individual flow path portions 14 a and 14 b, and the frame member 18 attached to the element substrate 8. Block the other end of the. Thereby, a cavity 20 surrounded by the frame member 18, the membrane 19, and the discharge port plate 9 is formed. The cavity 20 and the membrane 19 constitute the damper 17.

The liquid discharge head 7 formed in this way can absorb the vibration and pressure fluctuation generated in the pressure chamber 11 by the damper 17 as described above, and suppress the crosstalk between the adjacent pressure chambers 11. Can do. When a plurality of the liquid discharge heads 7 are incorporated to form a liquid discharge apparatus as shown in FIG. 1, a good image can be formed on the recording paper 1 with high definition and high speed.
In the liquid discharge head 7, the membrane 19 of the damper 17 is formed by a formation substrate in the same manner as the diaphragm. Further, the frame member 18 which becomes the side wall of the cavity 20 of the damper 17 and partially surrounds the cavity 20 is formed by the flow path wall substrate 25 similarly to the inner walls of the pressure chamber 11 and the individual flow paths 14a and 14b. . Thereby, the damper 17 can be manufactured easily. The damper 17 may be provided with pores.

The configuration in which the element substrate 8 is mainly a stacked body of the support substrate 24, the formation substrate, and the flow path wall substrate 25 has been described. However, the configuration is not limited to such a configuration. For example, instead of the channel wall substrate 25, the pressure chamber 11 and the inner walls of the individual channel parts 14a and 14b may be formed in the discharge port plate 9. In that case, the flow path wall substrate 25 becomes unnecessary.
In the embodiment described above, the diaphragm is formed by dry etching. However, a configuration in which a diaphragm formed in a desired thickness and shape in advance is attached to the support substrate 24 may be employed. In that case, a formation substrate is not necessary. Furthermore, since the inner walls of the pressure chamber 11 and the individual flow path portions 14a and 14b can be formed on the support substrate 24, the flow path wall substrate 25 is also unnecessary.

  In the present invention, the damper 17 may be provided in at least one of the liquid flow paths 15a and 15b. Even if the damper 17 is provided only in one of the liquid flow paths 15a and 15b, a certain degree of effect can be obtained in suppressing crosstalk between the adjacent pressure chambers 11. Further, the above-described liquid circulation structure is not employed, and the common liquid chamber for outflow 12b and the outflow liquid channel 15b may not be provided. In that case, inflow and outflow of the liquid between one common liquid chamber 12a and one pressure chamber 11 are performed only through the liquid flow chamber 15a. Even in this configuration, the crosstalk between the adjacent pressure chambers 11 can be suppressed by forming the damper 17 in the liquid channel 15a.

  The pressure generating means of this embodiment can reduce the volume of the pressure chamber 11 and has a diaphragm and a piezoelectric element. However, the present invention is not limited to this configuration. For example, a heating element that can raise the pressure in the pressure chamber 11 by the foaming pressure by heating and foaming the liquid may be provided as the pressure generating means. In that case, if there is a member that supports the heat generating element, a diaphragm for reducing the volume of the pressure chamber 11 is not necessary.

  FIG. 3C shows a modification of the present embodiment. In this modification, the membrane 19 of the damper 17 is formed by a dry film that constitutes the gap member 23. That is, when patterning the dry film, patterning is performed so that the dry film is left at the position of the membrane 19 at the same time as the position of the gap member 23. Then, the membrane 19 is formed by processing the dry film into a thin film. By doing so, the damper 17 can be easily manufactured without complicating the manufacturing process.

FIG. 4A is a perspective view of the main part of the liquid discharge head 7 according to the second embodiment of the present invention as viewed from the discharge port side, and FIG. 4B is a sectional view taken along the line S-S. Show. Description of substantially the same parts as those of the liquid discharge head 7 of the first embodiment will be omitted.
As shown in FIG. 4A, in the liquid ejection head 7 of the present embodiment, the four pressure chambers 11 are connected to one inflow through-hole portion 13a via the inflow individual flow path portion 14a. . Similarly, the four pressure chambers 11 are connected to one outflow through-hole portion 13b via the outflow individual flow path portion 14b. That is, in the present embodiment, the four pressure chambers 11 are combined and connected to one inflow liquid passage 15a or outflow liquid passage 15b. However, the combination of the four pressure chambers 11 connected to the inflow through hole 13a is different from the combination of the four pressure chambers 11 connected to the outflow through hole 13b. That is, any of the pressure chambers 11 is connected to the other three pressure chambers 11 connected via the inflow liquid channel 15a and the other three pressure chambers 11 connected via the outflow liquid channel 15b. But everything is different. By doing so, the influence of the interaction (crosstalk) between the pressure chambers 11 is dispersed, and the influence on the image formed by the liquid ejection is reduced. In addition, a damper 17 is provided in each of the inflow through hole 13a and the outflow through hole 13b.

  In the present embodiment, since the four pressure chambers 11 are connected to one inflow through-hole portion 13a, a large number of small inflow through-hole portions 13a are provided instead of a large number of small inflow through-hole portions 13a. Therefore, the flow resistance is small, and driving at a high frequency is easily realized. The configuration of the present embodiment is particularly effective because a large number of pressure chambers 11 are regularly arranged two-dimensionally (in the X direction and the Y direction) and arranged at high density. The same applies to the outflow through-hole portion 13b.

As shown in FIG. 4B, the inflow through-hole portion 13 a and the outflow through-hole portion 13 b are provided in the element substrate 8. The inflow through-hole portion 13a has an inner diameter formed in two stages, a portion connected to the inflow common liquid chamber 12a has a large diameter, and a portion connected to the individual flow path portion 14a has a small diameter. Thereby, the flow resistance with respect to the gas which flows into the pressure chamber 11 from the common liquid chamber 12a via the inflow liquid flow path 15a is small. The through-hole portion 13b of the outflow liquid channel 15b is connected to the individual channel portion 14b from the common liquid chamber 12b with a constant diameter. Since the through-hole portions 13a and 13b and the individual flow channel portions 14a and 14b intersect each other substantially perpendicularly, the inflow liquid flow channel 15a and the outflow liquid flow channel 15b are partially bent at a right angle. is there.
The damper 17 provided inside the liquid flow paths 15a and 15b of the present embodiment includes a cavity 20 formed by the inner walls of the liquid flow paths 15a and 15b, the frame member 18, the membrane 19, and the discharge port plate 9. A flexible membrane 19 is used. The membrane 19 is formed from a forming substrate in the same manner as the diaphragm constituting the pressure generating means 21.

  The piezoelectric element of the pressure generating means 21 provided in each pressure chamber 11 is driven by applying a driving waveform signal generated by the driving means 5. The piezo elements of the pressure generating means 21 facing the four pressure chambers 11 connected to one through-hole 13a are driven at different timings. As an example, the piezoelectric elements of the pressure generating means 21 corresponding to the discharge ports 16a, 16b, 16c, and 16d shown in FIG. 4A are driven in the order described above. Here, for convenience, the order of driving the piezo elements will be described with reference to the reference numerals of the ejection ports corresponding to the piezo elements. FIG. 5 shows an example of the generation state of the drive signal by the drive means 5. In the example shown in FIG. 5, the drive signal is composed of a negative voltage, and the signals a, b, c, d are applied to the piezoelectric elements corresponding to the ejection ports 16 a, 16 b, 16 c, 16 d, respectively. Needless to say, depending on the image to be recorded, there is a case where the drive is actually performed and a case where the drive is stopped and the signal is not driven.

  As a specific example of the present embodiment, when the length of one side of one square pixel is A, the interval in the X direction between the discharge ports 16a and 16b adjacent to each other in the left-right direction (X direction) in the drawing. Is 40A, and the interval in the vertical direction of the drawing (Y direction) is 0.25A. When the resolution is 1200 dpi, A = 21.167 μm. The interval between the discharge ports 16a and 16c adjacent to each other in the Y direction is A, and the interval in the Y direction is (5 + 0.5) A. The interval between the discharge port 16a and the discharge port 16d opposed to each other in the diagonal direction in the drawing is 41A, and the vertical interval (Y direction) in the drawing is (5 + 0.75) A. In this configuration, when recording is performed by ejecting liquid while moving the recording paper 1 relative to the liquid ejection head 7 in the Y direction, the time when the recording paper 1 advances by the distance A is T. In that case, the timing is shifted by approximately (1/4) T, and the piezoelectric elements respectively corresponding to the discharge ports 16a, 16b, 16c, and 16d are driven in this order. Then, liquid can be ejected with high accuracy without causing a landing error due to time-division driving. The intervals between the discharge ports 16a and 16c adjacent to each other in the Y direction and the interval between the discharge ports 16b and 16d are 5.5A everywhere, and the discharge ports are regularly arranged without generating a useless space. Is done. As described above, such a regular arrangement is realized by determining the driving order of the piezo elements so as to alternate in the X direction with the inflow through-hole portions 13a interposed therebetween.

  FIG. 6 shows a modification of the present embodiment. In this modified example, the membrane 19 of the damper 17 is formed of a dry film constituting the gap member 23, as in the configuration shown in FIG. That is, the membrane 19 is patterned simultaneously with the gap member 23. Therefore, the damper 17 can be easily manufactured without complicating the manufacturing process.

FIG. 7 shows a main part of the liquid discharge head 7 according to the third embodiment of the present invention. Description of substantially the same parts as those of the liquid discharge head 7 of the first embodiment will be omitted.
In the liquid discharge head 7 of the present embodiment, the two pressure chambers 11 are connected to one inflow through-hole portion 13a via the inflow individual flow path portion 14a. Similarly, the two pressure chambers 11 are connected to one outflow through-hole portion 13b via the outflow individual flow path portion 14b. A damper 17 is provided in each of the inflow through hole 13a and the outflow through hole 13b.
In the present embodiment, the driving unit 5 alternately drives the piezo elements corresponding to the ejection ports 16a and the piezo elements corresponding to the ejection ports 16b at substantially equal intervals. Assuming that the length of one side of one square pixel is A, the same piezo element is driven with at least a time for the recording paper 1 to advance by the distance A. The interval in the Y direction between the discharge ports 16a adjacent in the Y direction is 6A, and the interval in the X direction is A. The interval between the discharge ports 16b is also the same as the interval between the discharge ports 16a. And the space | interval of the X direction between the discharge port 16a corresponding to the pressure chamber 11 connected to the same inflow through-hole part 13a and the discharge port 16b is 40A, and the space | interval of the Y direction is 0.5A. According to this configuration, liquid discharge can be performed with high accuracy without causing a landing error or the like due to time-division driving. Also in this embodiment, since the plurality of pressure chambers 11 connected to the same inflow through hole 13a and outflow through hole 13b are not simultaneously driven, the adverse effect of crosstalk is sufficiently reduced. can do.

When a plurality of pressure chambers are connected to one through-hole portion as in the second and third embodiments, pressure generating means corresponding to the plurality of pressure chambers connected to the same through-hole portion are provided. They are not driven at the same time, and are driven at different timings.
Also in the second and third embodiments, the inflow liquid passage 15a and the outflow liquid passage 15b are connected to the pressure chamber 11 so that a circulation structure can be formed. However, the common liquid chamber 12b for outflow and the liquid flow path 15b for outflow are not provided, and the inflow and outflow of liquid between the common liquid chamber 12a and the pressure chamber 11 are performed only through the liquid flow path 15a. You can also. Even with this configuration, the crosstalk between the adjacent pressure chambers 11 can be suppressed by forming the damper 17 in the liquid channel 15a.

  As described above, according to the liquid discharge head of the present invention and the liquid discharge apparatus using the same, even if a plurality of discharge ports are arranged at high density, the influence of crosstalk between the pressure chambers is small and accurate. Liquid discharge can be performed. Thereby, it is possible to form a high-definition and beautiful image at a high speed by discharging liquid ink onto a recording medium such as the recording paper 1. In particular, in the case of a liquid ejection device that forms a color image, by suppressing crosstalk between pressure chambers, a high-definition image can be formed without color unevenness. In addition, this liquid ejecting apparatus can be widely used as a high-performance production apparatus that forms a wiring pattern by accurately ejecting conductive liquid ink onto a recording material such as a resin substrate.

7 Liquid discharge head 11 Pressure chambers 12a and 12b Common liquid chambers 13a and 13b Through-hole portions 14a and 14b Individual flow channel portions 15a and 15b Liquid flow channel 16 Discharge port 17 Damper 18 Frame member 19 Membrane 20 Cavity portion 21 Pressure generating means

Claims (14)

  A plurality of discharge ports for discharging liquid, a plurality of pressure chambers including pressure generating means connected to the discharge ports, a common liquid chamber, and a plurality of pressure chambers each connecting the pressure chambers to the common liquid chamber And a plurality of dampers respectively provided inside the liquid channel.   The liquid channel for inflow and the liquid channel for outflow are connected to one of the pressure chambers, and the damper is connected to the liquid channel for inflow and the liquid channel for outflow. The liquid discharge head according to claim 1, wherein the liquid discharge head is provided on at least one of them.   The discharge port and the pressure chamber are formed on one surface of the element substrate, the common liquid chamber is formed on the other surface of the element substrate, and the liquid flow path penetrates the element substrate. The liquid discharge head according to claim 1, further comprising: a through-hole portion extending between the one surface and the other surface; and an individual flow path portion connecting the through-hole portion and the pressure chamber. .   The liquid discharge head according to claim 3, wherein one pressure chamber is connected to one through-hole portion.   The liquid ejection head according to claim 3, wherein a plurality of the pressure chambers are connected to one through-hole portion.   The inflow through-hole portion and the outflow through-hole portion, and the inflow through-hole portion and the outflow through-hole portion are connected to each of the pressure chambers. 6. The combination of the plurality of pressure chambers connected to the through-hole portion for use is different from the combination of the plurality of pressure chambers connected to the through-hole portion for outflow. Liquid discharge head.   The liquid ejection head according to claim 3, wherein the damper is provided inside the through-hole portion.   The damper includes a cavity partly surrounded by a frame member provided inside the liquid flow path, and a membrane that covers a part of the cavity together with the frame member. The liquid discharge head according to any one of the above.   The liquid ejection head according to claim 8, wherein the frame member surrounding a part of the cavity is formed of the same member as a part of the inner wall of the pressure chamber.   10. The liquid ejection head according to claim 8, wherein the membrane is formed of the same member as a diaphragm constituting the pressure generating unit.   The liquid ejection head according to claim 10, further comprising: a gap member that holds the diaphragm so as to vibrate, wherein the membrane includes the same member as the gap member.   The liquid discharge head according to claim 1, wherein the pressure generating unit includes a piezo element.   13. A liquid ejection apparatus comprising: the liquid ejection head according to claim 1; and a driving unit that electrically drives the pressure generation unit.   The liquid ejecting apparatus according to claim 13, wherein the driving unit supplies a driving signal to each of the pressure generating units of each of the plurality of pressure chambers connected to one through-hole portion at different timings. .

Images