JP2012192668A - Liquid injection head and liquid injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid injection head capable of more stably suppressing pressure fluctuation in a flow passage in the liquid injection head, and a liquid injection device.SOLUTION: An ink introduction passage 25 includes: a lateral passage 35 extending in a direction orthogonal to a vertical direction; and a pressure relief chamber 26 formed at a vertical upper side from the lateral passage. Gas in the ink introduction passage is introduced to the pressure relief chamber, and pressure fluctuation in the ink introduction passage is alleviated by the elastic deformation of the introduced gas. Thus, the transmission of the pressure fluctuation to a nozzle 30 side is suppressed.

Description

  The present invention relates to a liquid ejecting head used in a liquid ejecting apparatus such as an ink jet recording apparatus, and a liquid ejecting apparatus including the same, and in particular, introduces liquid stored in a liquid storing member into a pressure chamber to generate pressure. The present invention relates to a liquid ejecting head that ejects liquid in a pressure chamber from a nozzle by driving means, and a liquid ejecting apparatus.

  The liquid ejecting apparatus includes a liquid ejecting head and ejects various liquids from the ejecting head. As this liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet printer or an ink jet plotter, but recently, various types of manufacturing have been made by taking advantage of the ability to accurately land a very small amount of liquid on a predetermined position It is also applied to devices. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or FED (surface emitting display), a chip for manufacturing a biochip (biochemical element) Applied to manufacturing equipment. The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  As this type of liquid ejecting head, one using a cartridge-type liquid storage member that is easy to be put on the distribution and easy to handle has been developed. For example, ink jet printers (hereinafter simply referred to as printers) that use ink cartridges that enclose liquid ink are widely used. In this configuration, when an ink cartridge is attached to a recording head that is a type of liquid ejecting head, the ink introduction needle (liquid introduction needle) of the recording head is inserted into the ink cartridge, thereby the ink introduction needle. Ink in the ink cartridge is introduced to the recording head side through an ink introduction hole (liquid introduction hole) opened on the front end side of the recording head. The ink introduced into the recording head is introduced into a common liquid chamber (also referred to as a reservoir or a manifold) through an introduction path inside the head. The ink introduced into the common liquid chamber is supplied to a plurality of pressure chambers communicating with the common liquid chamber. Then, a pressure fluctuation is generated in the pressure chamber by driving a piezoelectric vibrator or a heat generating element which is a kind of pressure generating means, and ink is ejected from a nozzle communicating with the pressure chamber by controlling the pressure fluctuation. .

  Here, excessive positive pressure or negative pressure may be generated in the ink cartridge due to temperature change or pressure change, and when the pressure propagates from the ink cartridge to the nozzle of the recording head, the meniscus formed on the nozzle is changed. It can be destroyed. That is, the meniscus may be excessively drawn to the pressure chamber side from the inner peripheral surface of the nozzle, or may swell outward from the opening surface on the injection side of the nozzle. As described above, when the meniscus is not formed at a predetermined position on the inner peripheral surface of the nozzle, there is a possibility that the ink is not ejected normally. Further, there is a possibility that ink is erroneously ejected from the nozzle. In order to solve such problems, the ink cartridge (ink tank) is provided with a pressure control valve capable of opening the air layer inside the cartridge to the atmosphere, and when an excessive pressure is generated in the ink cartridge due to a temperature change or the like. A configuration has been proposed in which the pressure fluctuation in the ink cartridge is suppressed by opening the pressure control valve (see, for example, Patent Document 1).

JP 2008-162217 A

  However, the above configuration is a mechanism for making the pressure inside the cartridge constant, and it is difficult to keep the volume of the air layer in the space closed by the pressure control valve constant. For this reason, in the said structure, there existed a possibility that the impact relaxation capability of a pressure fluctuation might become unstable.

  The phenomenon as described above exists not only in the exemplified recording head but also in other liquid ejecting heads that adopt a configuration in which the liquid stored in the liquid storage member is introduced.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting head and a liquid ejecting apparatus that can more stably suppress pressure fluctuation in the introduction flow path. There is to do.

The liquid ejecting head of the present invention has been proposed in order to achieve the above object. The liquid ejecting head supplies liquid to the common liquid chamber through the liquid introducing path from the liquid introducing portion into which the liquid is introduced, and the pressure generating means is operated. A liquid ejecting head capable of causing a pressure fluctuation in a pressure chamber communicating with the common liquid chamber, and ejecting the liquid in the pressure chamber as a droplet from a nozzle by the pressure fluctuation;
The liquid introduction path includes a liquid passage extending in a direction intersecting the vertical direction, and a pressure relaxation chamber formed above the liquid passage in the vertical direction,
The gas in the liquid introduction path is introduced into the pressure relaxation chamber.

  According to the present invention, since the gas in the liquid introduction path is introduced into the pressure relaxation chamber, the pressure fluctuation in the liquid introduction path is mitigated by elastic deformation of the introduced gas, whereby the pressure fluctuation is transmitted to the nozzle side. It is suppressed. As a result, it is possible to reduce adverse effects on the meniscus in the nozzle.

  Moreover, in the said structure, it is desirable to employ | adopt the structure provided with the adjustment mechanism which maintains the quantity of the gas in the said pressure relaxation chamber in the predetermined range.

In this configuration, the adjustment mechanism includes an inflow port through which liquid and gas can flow from the liquid introduction path into the pressure relaxation chamber, and an air supply / exhaust port that is disposed vertically above the inflow port and through which gas can pass. And an air supply / exhaust valve capable of opening and closing the air supply / exhaust port, and an air supply / exhaust means capable of supplying or exhausting gas from the pressure relief chamber through the air supply / exhaust port,
When the amount of gas in the pressure relaxation chamber is between a predetermined upper limit value and a lower limit value, the supply / exhaust valve is closed, and when the amount of gas in the pressure relaxation chamber falls below a lower limit value, When the air supply / exhaust valve is opened, gas is supplied from the air supply / exhaust means to the pressure relief chamber through the air supply / exhaust port, and the gas supply / exhaust valve is opened when the gas in the pressure relief chamber exceeds the upper limit. In addition, it is desirable to adopt a configuration in which the gas in the pressure relaxation chamber is discharged to the supply / exhaust means side through the supply / exhaust port.

  According to this configuration, since the amount of gas in the pressure relaxation chamber is maintained within a certain range by the adjustment mechanism, it is possible to always stably ensure the effect of relaxing the pressure fluctuation caused by the gas in the pressure relaxation chamber. In addition, since the gas (bubbles) in the liquid introduction path is introduced into the pressure relaxation chamber and discharged to the outside when exceeding a certain amount, bubbles are generated in the flow path in the liquid ejecting head. Is suppressed. As a result, problems such as blockage of the flow path and pressure loss due to bubbles are reduced, and the reliability of the liquid ejecting head can be improved.

Further, the ceiling surface of the liquid passage is inclined upward from the upstream side toward the downstream side,
It is desirable to adopt a configuration in which the gas in the liquid introduction path is guided to the pressure relaxation chamber side along the ceiling surface.

  According to this configuration, the gas in the liquid introduction path can be more smoothly and surely introduced into the pressure relaxation chamber.

The liquid ejecting apparatus of the present invention supplies the liquid to the common liquid chamber through the liquid introduction path from the liquid introduction portion into which the liquid in the liquid storage member is introduced, and the pressure that is communicated with the common liquid chamber by the operation of the pressure generating means. A liquid ejecting apparatus capable of causing a pressure fluctuation in a chamber and ejecting the liquid in the pressure chamber as a droplet from a nozzle by the pressure fluctuation;
The liquid introduction path includes a liquid passage extending in a direction intersecting the vertical direction, and a pressure relaxation chamber formed above the liquid passage in the vertical direction,
The gas in the liquid introduction path is introduced into the pressure relaxation chamber.

FIG. 3 is a perspective view illustrating a configuration of a printer. FIG. 3 is a schematic diagram illustrating configurations of an ink cartridge and a recording head. It is a schematic diagram explaining the opening / closing operation | movement of an air supply / exhaust valve.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following, an ink jet recording head (hereinafter referred to as a recording head) mounted on an ink jet recording apparatus (hereinafter referred to as a printer) will be described as an example of the liquid jet head of the present invention.

  FIG. 1 is a perspective view showing the configuration of the printer 1. The printer 1 includes a carriage 4 to which a recording head 2 is attached and an ink cartridge 3 that is a kind of liquid storage member is detachably attached, and a platen 5 disposed below the recording head 2 during a recording operation. The carriage 4 moves in the sub-scanning direction orthogonal to the main scanning direction, and the carriage moving mechanism 7 for reciprocating the carriage 4 in the paper width direction of the recording paper 6 (a kind of the recording medium and the landing target), that is, the main scanning direction. And a transport mechanism 8.

  The carriage 4 is attached while being supported by a guide rod 9 installed in the main scanning direction, and is configured to move in the main scanning direction along the guide rod 9 by the operation of the carriage moving mechanism 7. ing. The position of the carriage 4 in the main scanning direction is detected by the linear encoder 10. The linear encoder 10 is a kind of position information output means, and outputs an encoder pulse corresponding to the scanning position of the recording head 2 to a control unit (not shown) as position information in the main scanning direction.

  A home position serving as a base point for scanning of the carriage is set in an end area outside the recording area within the movement range of the carriage 4. A capping member 11 that seals the nozzle formation surface 24 (see FIG. 2) of the recording head 2 and a wiper member 12 that wipes the nozzle formation surface are disposed at the home position in the present embodiment. The printer 1 is bi-directional between when the carriage 4 moves from the home position toward the opposite end and when the carriage 4 returns from the opposite end to the home position. So-called bidirectional recording in which characters, images, etc. are recorded on the recording paper 6 is possible.

FIG. 2 is a cross-sectional view schematically showing the configuration of the ink cartridge 3 and the recording head 2.
The ink cartridge 3 includes a box-like case 15 made by molding, for example, thermoplastic plastic, and a housing chamber 16 is formed in the case 15. In the storage chamber 16, an ink holding material 17 is stored. The ink holding material absorbs and holds ink which is a kind of liquid in the present invention. As the ink holding material 17, for example, a sponge-like foam material is preferably used. A needle insertion portion 18 into which the ink introduction needle 23 of the recording head 2 is inserted is formed on the bottom surface portion of the ink cartridge 3. A ring-shaped packing 19 is provided at the opening portion of the inner peripheral surface of the needle insertion portion 18. When the ink introduction needle 23 is inserted into the needle insertion portion 18, the packing 19 is in close contact with the outer peripheral surface of the ink introduction needle 23 in a liquid-tight state, and the ink stored in the ink cartridge 3 leaks to the outside of the cartridge. To prevent it from coming out. The ink cartridge 3 (liquid storage member) is not limited to the exemplified one, and various configurations can be used.

  The recording head 2 in this embodiment includes a synthetic resin head case 21 and a cartridge mounting portion 22 provided on the upper surface of the head case 21 (the surface opposite to the nozzle forming surface 24 on which the nozzles are formed). And an ink introduction needle 23 (corresponding to the liquid introduction needle in the present invention) provided upright on the cartridge mounting portion 22. Further, inside the head case 21, an ink introduction path 25 (corresponding to a liquid introduction path in the present invention), a pressure relaxation chamber 26 provided in the middle of the ink introduction path 25, and a reservoir 27 (common in the present invention). A liquid chamber, an ink supply port 28, a pressure chamber 29, and an ink flow path leading to the nozzle 30 and a piezoelectric vibrator 31 functioning as a kind of pressure generating means.

  The ink introduction needle 23 is a hollow needle-like member whose tip side is formed in a tapered shape (conical shape). An ink introduction hole 32 for introducing ink in the ink cartridge 3 is formed at the tip of the ink introduction needle 23. When the ink introduction needle 23 is inserted into the needle insertion portion 18 of the ink cartridge 3, the ink stored in the cartridge is introduced into the needle flow path 33 through the ink introduction hole 32. The proximal end portion (the end portion opposite to the distal end portion) of the ink introduction needle 23 has a conical shape in which the inner diameter gradually increases from the distal end side toward the proximal end side. The ink introduction needle 23 is fixed to the peripheral edge of the upstream opening of the ink introduction path 25 in the cartridge mounting portion 22 by welding or the like with a filter 34 interposed. The filter 34 filters the ink introduced into the needle flow path 33 of the ink introduction needle 23 and supplies it to the ink introduction path 25 side.

  The ink introduction path 25 is a series of flow paths having one end (upstream end) opened to the cartridge mounting portion 22 and the other end communicating with the reservoir 27. A lateral passage 35 (corresponding to a liquid passage in the present invention) extending in a direction intersecting the vertical direction is provided in the middle of the ink introduction passage 25. In the present embodiment, the bottom surface of the lateral passage 35 extends parallel to the nozzle forming surface 24, while the ceiling surface (upper surface) 35 'of the lateral passage 35 rises from the upstream side to the downstream side with respect to the bottom surface. Inclined. The pressure relaxation chamber 26 is formed above the inclined upper end of the ceiling surface 35 'in the vertical direction. The pressure relaxation chamber 26 and the lateral passage 35 communicate with each other via an inflow port 36. The bubbles (gas) mixed in the ink in the ink introduction path 25 are guided to the pressure relaxation chamber 26 along the inclination of the ceiling surface 35 ′ by the buoyancy. Thereby, bubbles can be introduced into the pressure relaxation chamber 26 more smoothly and more reliably.

  The pressure relaxation chamber 26 is an empty portion into which gas (bubbles) mixed in the ink in the ink introduction path 25 is introduced. In the pressure relaxation chamber 26, a supply / exhaust port 37 through which gas can pass is formed above the inflow port 36 in the vertical direction, specifically, on the upper surface of the pressure relaxation chamber 26. The pressure relaxation chamber 26 is provided with an adjustment mechanism 38 that can adjust the amount of gas in the pressure relaxation chamber 26. The details of the pressure relaxation chamber 26 and the adjustment mechanism 38 will be described later.

  The ink that has flowed down the ink introduction path 25 is introduced into the reservoir 27. The reservoir 27 is an empty portion common to the plurality of pressure chambers 29 and is provided for each ink type, that is, for each ink color. Each pressure chamber 29 communicates with the reservoir 27 via the ink supply port 28. Therefore, the ink in the reservoir 27 is supplied to the pressure chamber 29 through the ink supply port 28, respectively. The ink supply port 28 is formed with a narrower width than the pressure chamber 29, and gives a certain flow path resistance to the ink flowing from the reservoir 27 into the pressure chamber 29. The pressure chamber 29 is formed as an elongated chamber in a direction perpendicular to the direction in which the nozzles 30 are arranged (nozzle row direction).

  A flexible working surface 40 is provided on the upper surface of the pressure chamber 29. A piezoelectric vibrator 31 is disposed on the surface of the operating surface 40 opposite to the pressure chamber 29. The piezoelectric vibrator 31 is, for example, a so-called flexural vibration mode piezoelectric vibrator, and includes a piezoelectric body 42 sandwiched between a drive electrode 41 and a common electrode 43. When a drive voltage (drive pulse) is applied to the drive electrode 41 of the piezoelectric vibrator 31, an electric field corresponding to the potential difference is generated between the drive electrode 41 and the common electrode 43. This electric field is applied to the piezoelectric body 42 and deforms according to the strength of the electric field to which the piezoelectric body 42 is applied. That is, as the potential of the drive electrode 41 is increased, the central portion of the piezoelectric body 42 is bent toward the inside of the pressure chamber 29 (on the nozzle 30 side), and the working surface 40 is deformed so as to reduce the volume of the pressure chamber 29. On the other hand, as the electric potential of the drive electrode 41 is lowered, the central portion of the piezoelectric body 42 is bent to the outside of the pressure chamber 29 (the side away from the nozzle 30), and the working surface 40 is deformed so as to increase the volume of the pressure chamber 29. . In addition to the piezoelectric vibrator, an electrostatic actuator, a magnetostrictive element, a heating element, or the like can be used as the pressure generating means.

  When the piezoelectric vibrator 31 is operated as described above, the volume of the pressure chamber 29 can be changed. As a result, pressure fluctuations occur in the ink in the pressure chamber 29, so that ink can be ejected from the nozzles 30 using the pressure fluctuations. For example, when the piezoelectric vibrator 31 is charged to expand the pressure chamber 29 and then the piezoelectric vibrator 31 is suddenly discharged to contract the pressure chamber 29, the pressure chamber 29 expands and flows into the pressure chamber 29. The ink is rapidly pressurized, and ink droplets are ejected from the nozzle 30.

  In the recording head 2 according to the present invention, a pressure relaxation chamber 26 is provided in the middle of the ink introduction path 25, and bubbles (air) that are gases mixed in the ink in the ink introduction path 25 are guided to the pressure relaxation chamber 26. In addition to being captured, the gas in the pressure relaxation chamber 26 is characterized by absorbing the pressure fluctuation generated in the ink in the ink introduction path 25. That is, even when an impact is applied to the ink cartridge 3 when the ink cartridge 3 is replaced or the like, even when the pressure of the ink in the ink introduction path 25 changes abruptly, the pressure relaxation chamber corresponds to the pressure fluctuation. Pressure fluctuations are absorbed by the gas in 26 being expanded or compressed. That is, when the pressure in the ink introduction path 25 becomes higher than normal, the gas in the pressure relaxation chamber 26 is compressed, or when the pressure in the ink introduction path 25 becomes lower than normal, the pressure By expanding the gas in the relaxation chamber 26, the pressure fluctuation of the ink in the ink introduction path 25 is relaxed. Thereby, it is possible to suppress the pressure fluctuation from being transmitted to the nozzle 30 side, and it is possible to reduce the adverse effect of the nozzle 30 on the meniscus.

In the present embodiment, the amount of gas in the pressure relaxation chamber 26 is adjusted by the adjustment mechanism 38 in order to always ensure the above-described pressure fluctuation relaxation action stably.
FIG. 3 is a schematic diagram for explaining the operation of the adjustment mechanism 38.
The adjustment mechanism 38 is connected to the float 45 that is displaced according to the height of the ink level in the pressure relaxation chamber 26, the air supply / exhaust valve 46 provided in the air supply / exhaust port 37, and the air supply / exhaust port 37 in an airtight state. And an air pump 48 (a kind of air supply / exhaust means in the present invention, see FIG. 2) connected to the air passage 47. The opening of the air supply / exhaust port 37 is a storage portion 49 in which the air supply / exhaust valve 46 is stored. A part of the inner peripheral surface of the accommodating portion 49 is bent in an arc shape in which the central portion in the gas passage direction is located outside the both end portions in the same direction. Since the arc portions are formed in a pair so as to face each other on the inner peripheral surface of the accommodating portion 49, the portions of the accommodating portion 49 have a bracket shape in a cross-sectional view. The length of the arc is determined by the displacement of the float 45 in accordance with the change in the gas amount within the specified range (that is, the change in the liquid level associated therewith) in order to maintain the gas amount in the pressure relaxation chamber 26 within the specified range. It is determined based on the rotation amount (rotation angle) of the air supply / exhaust valve 46 corresponding to the amount.

  The air supply / exhaust valve 46 is a plate-like member accommodated in the accommodating portion 49 so as to be rotatable about the rotation shaft 51. A sliding portion 50 is provided in a portion of the air supply / exhaust valve 46 that faces the inner peripheral surface of the accommodating portion 49. This sliding part 50 consists of elastic materials, such as rubber | gum and an elastomer. In the state where the supply / exhaust valve 46 is stored in parallel with the liquid level in the storage portion 49, the sliding portions 50 on both sides abut against the inner peripheral surface (arc portion) of the storage portion 49, respectively. Prevent gas from passing through. Further, one end portions of a pair of connection legs 52a and 52b are rotatably connected to both sides of the rotation shaft 51 of the air supply / exhaust valve 46, respectively. The float 45 is a resin sphere in which a gas such as air is enclosed, and is fixed to the tip of the arm 54. The arm 54 is pivotally supported in the pressure relaxation chamber 26 so as to be rotatable about a rotation shaft 53 provided near the end opposite to the float 45. In addition, the other end portions of the connection legs 52a and 52b are rotatably connected to both sides of the rotation shaft 53 of the arm 54, respectively.

  By configuring the adjustment mechanism 38 in this way, the change in the liquid level of the ink in the pressure relaxation chamber 26, that is, the displacement (up or down) of the float 45 due to the change in the volume of the gas, the arm 54 and the connecting foot portion. The air supply / exhaust port 37 can be opened and closed by being transmitted to the air supply / exhaust valve 46 through 52a, 52b and rotating the air supply / exhaust valve 46. Hereinafter, this point will be described.

  When the amount of gas in the pressure relaxation chamber 26 is within a certain range, as shown in FIG. 3A, the sliding portions 50 on both sides of the air supply / exhaust valve 46 are arranged on the inner peripheral surface (arc portion) of the accommodating portion 49. ), The passage of gas at the air supply / exhaust port 37 is blocked and the valve is closed. On the other hand, when air bubbles mixed in the ink in the ink introduction path 25 are introduced into the pressure relaxation chamber 26 from the inflow port 36, the gas in the pressure relaxation chamber 26 flows as shown in FIG. As the amount gradually increases, the ink level in the pressure relaxation chamber 26 drops. Along with this, the float 45 descends, so that the arm 54 pivots clockwise in the figure around the pivot shaft 53. As a result, the connection foot 52b on the float 45 side with respect to the rotation shaft 53 is lowered, whereas the connection foot 52a on the opposite side of the float 45 with respect to the rotation shaft 53 is raised, whereby the air supply / exhaust valve 46 rotates clockwise in the drawing around the rotation shaft 53 while sliding the sliding portions 50 on both sides on the inner peripheral surface (arc portion) of the accommodating portion 49. When the amount of gas in the pressure relaxation chamber 26 exceeds a predetermined upper limit value and the rotation angle of the exhaust valve 46 exceeds a specified value, the sliding portions 50 are respectively separated from the inner peripheral surface of the housing portion 49. Leave.

  Thereby, it will be in the valve opening state in which the passage of gas in the air supply / exhaust port 37 is possible. In this state, the air pump 48 is activated to generate a negative pressure, and the gas in the pressure relaxation chamber 26 is discharged from the air supply / exhaust port 37 through the ventilation path 47. When the gas in the pressure relaxation chamber 26 is discharged, the liquid level rises accordingly, so that the float 45 rises and the air supply / exhaust valve 46 rotates counterclockwise around the rotation shaft 53. When the amount of gas in the pressure relaxation chamber 26 falls within a certain range, as shown in FIG. 3A, the sliding portions 50 of the air supply / exhaust valve 46 are placed on the inner peripheral surface of the accommodating portion 49. Each abuts to return to the closed state.

  Further, when the amount of gas in the ink introduction path 25 decreases due to the gas in the ink introduction path 25 being dissolved in the ink or being discharged from the wall surface of the head case 21 to the outside, FIG. ), The ink level in the pressure relaxation chamber 26 increases as the amount of gas decreases. Along with this, the float 45 rises, so that the arm 54 rotates about the rotation shaft 53 counterclockwise in the drawing. Thereby, the air supply / exhaust valve 46 rotates counterclockwise in the figure around the rotation shaft 53 while sliding the sliding portions 50 on the inner peripheral surface of the accommodating portion 49. Then, when the amount of gas in the pressure relaxation chamber 26 falls below a predetermined lower limit value and the rotation angle of the exhaust valve 46 exceeds a specified value, each sliding portion 50 starts from the inner peripheral surface of the accommodating portion 49. Leave. Thereby, it will be in the valve opening state in which the passage of gas in the air supply / exhaust port 37 is possible. In this state, the air pump 48 is activated and gas is introduced into the pressure relaxation chamber 26 from the air supply / exhaust port 37 through the air passage 47. When gas is introduced into the pressure relaxation chamber 26 from the air pump 48 side, the liquid level is lowered accordingly, so that the float 45 is lowered and the air supply / exhaust valve 46 rotates clockwise around the rotary shaft 53. Move. When the amount of gas in the pressure relaxation chamber 26 falls within a certain range, as shown in FIG. 3A, the sliding portions 50 of the air supply / exhaust valve 46 are placed on the inner peripheral surface of the accommodating portion 49. Each abuts to return to the closed state.

  As described above, in the present embodiment, the amount of gas in the pressure relaxation chamber 26 is maintained within a certain range by the adjustment mechanism 38, so that the action of relaxing the pressure fluctuation due to the gas in the pressure relaxation chamber 26 is always stabilized. It can be secured. In addition, since the gas (bubbles) in the ink introduction path 25 is introduced into the pressure relaxation chamber 26 and discharged to the outside when exceeding a certain amount, bubbles are generated in the flow path in the recording head 2. Occurrence is suppressed. Thereby, problems such as blockage of the flow path due to air bubbles and pressure loss are reduced, and the reliability of the recording head 2 can be improved.

  By the way, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the description of the scope of claims.

  For example, the adjustment mechanism 38 is not limited to the configuration illustrated in the above embodiment as long as the supply / exhaust port 37 can be opened and closed according to the amount of gas (the height of the liquid level). For example, it is also possible to employ a configuration in which the upper and lower limits of the ink level in the pressure relaxation chamber 26 are detected by an optical sensor or the like, and the air supply / exhaust port 37 is opened or closed by an electromagnetic valve or the like according to the detection of the optical sensor. it can.

  Furthermore, the present invention is not limited to the recording head 2 as long as it is a liquid ejecting head that adopts a configuration for introducing liquid from a liquid storage member, and various ink jet recording apparatuses such as a plotter, a facsimile machine, a copier, The present invention can also be applied to a liquid ejecting head mounted on a liquid ejecting apparatus other than the recording apparatus, such as a display manufacturing apparatus, an electrode manufacturing apparatus, or a chip manufacturing apparatus. In the display manufacturing apparatus, a solution of each color material of R (Red), G (Green), and B (Blue) is ejected from the color material ejecting head. Moreover, in an electrode manufacturing apparatus, a liquid electrode material is ejected from an electrode material ejection head. In the chip manufacturing apparatus, a bioorganic solution is ejected from a bioorganic ejecting head.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording head, 3 ... Ink cartridge, 21 ... Head case, 23 ... Ink introduction needle, 25 ... Ink introduction path, 26 ... Pressure relaxation chamber, 30 ... Nozzle, 35 ... Side passage, 36 ... Inlet 37 ... Air supply / exhaust port, 38 ... Adjustment mechanism, 45 ... Float, 46 ... Air supply / exhaust valve, 47 ... Air passage, 48 ... Air pump, 49 ... Housing part, 50 ... Sliding part, 51 ... Rotating shaft, 52 ... Connection foot, 53 ... rotating shaft, 54 ... arm

Claims (5)

The liquid is supplied from the liquid introduction part into which the liquid is introduced to the common liquid chamber through the liquid introduction path, and a pressure fluctuation is generated in the pressure chamber communicating with the common liquid chamber by the operation of the pressure generating means. A liquid ejecting head capable of ejecting a liquid as a droplet from a nozzle,
The liquid introduction path includes a liquid passage extending in a direction intersecting the vertical direction, and a pressure relaxation chamber formed above the liquid passage in the vertical direction,
A liquid ejecting head, wherein a gas in the liquid introduction path is introduced into the pressure relaxation chamber.   The liquid ejecting head according to claim 1, further comprising an adjustment mechanism that maintains an amount of gas in the pressure relaxation chamber within a predetermined range. The adjustment mechanism includes an inflow port through which liquid and gas can flow from the liquid introduction path into the pressure relaxation chamber, a supply / exhaust port arranged vertically above the inflow port, through which gas can pass, and the supply / exhaust air An air supply / exhaust valve capable of opening and closing the opening and an air supply / exhaust means capable of supplying or exhausting gas to or from the pressure relaxation chamber through the air supply / exhaust port,
When the amount of gas in the pressure relaxation chamber is between a predetermined upper limit value and a lower limit value, the supply / exhaust valve is closed, and when the amount of gas in the pressure relaxation chamber falls below a lower limit value, When the air supply / exhaust valve is opened, gas is supplied from the air supply / exhaust means to the pressure relief chamber through the air supply / exhaust port, and the gas supply / exhaust valve is opened when the gas in the pressure relief chamber exceeds the upper limit. The liquid jet head according to claim 2, wherein the gas in the pressure relaxation chamber is discharged to the supply / exhaust means side through the supply / exhaust port. The ceiling surface of the liquid passage is inclined upward from the upstream side toward the downstream side,
The liquid according to any one of claims 1 to 3, wherein the gas in the liquid introduction path is configured to be guided to the pressure relaxation chamber side along the ceiling surface. Jet head. Liquid is supplied to the common liquid chamber through the liquid introduction path from the liquid introduction portion into which the liquid in the liquid storage member is introduced, and pressure fluctuation is caused in the pressure chamber that leads to the common liquid chamber by the operation of the pressure generating means. A liquid ejecting apparatus capable of ejecting liquid in the pressure chamber as droplets from a nozzle by fluctuation,
The liquid introduction path includes a liquid passage extending in a direction intersecting the vertical direction, and a pressure relaxation chamber formed above the liquid passage in the vertical direction,
A liquid ejecting apparatus, wherein the gas in the liquid introduction path is introduced into the pressure relaxation chamber.

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