JP2008173961A - Liquid injection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid injection apparatus which prevents a failure from occurring owing to gas mixing, by trapping, collecting, and recovering the gas mixed into a liquid flow path without carrying out a cleaning operation. <P>SOLUTION: Upper part filter chamber 55a is formed which traps gas mixed in a liquid in the way of an ink flow path, and a gas recovery space 60 is formed via a partition wall partitioning and forming the upper filter chamber 55a. There is provided a pressure difference adding means for lowering a pressure in the gas recovery space 60 compared with one in the upper filter chamber 55a, and the partition wall between the upper filter chamber 55a and the gas recovery space 60 is made transmitting partition walls 61. Gas in the upper filter chamber 55a is transmitted through the transmitting partition wall 61, and recovered to the gas recovery space 60, by the pressure difference. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus such as an ink jet printer, and in particular, introduces liquid stored in a liquid storage member into a pressure chamber via a liquid flow path, and introduces the liquid introduced into the pressure chamber from a nozzle opening. The present invention relates to a liquid ejecting apparatus including a liquid ejecting head that ejects droplets.

  A typical example of a liquid ejecting apparatus that includes a liquid ejecting head capable of ejecting liquid and ejects various liquids from the liquid ejecting head is, for example, for recording paper as an ejection target (recording medium) An image recording apparatus such as an ink jet printer that performs recording by discharging and landing ink droplets can be given. In recent years, it is applied not only to this image recording apparatus but also to various manufacturing apparatuses. For example, in a display manufacturing apparatus such as a liquid crystal display, a plasma display, an organic EL (Electro Luminescence) display, or an FED (surface emitting display), various liquid materials such as coloring materials and electrodes are used for pixel formation regions and electrode formation. A liquid ejecting apparatus is used for discharging to an area or the like.

  In the liquid ejecting apparatus, the liquid ejecting head and the liquid storing member (liquid supply source) are mounted on a carriage, and the liquid in the liquid storing member is ejected as droplets from the liquid ejecting head while moving the carriage. Some are configured to do this (on-carriage type).

  Further, for example, in a liquid ejecting apparatus that uses a relatively large amount of liquid at a time, such as a business printer that prints on large format recording paper, a liquid supply source (ink cartridge) as a liquid storage member is used. A relay unit that is arranged on the main body side and introduces ink from the liquid supply source into the liquid ejecting head (an ink pressure adjusting unit; also functions as a pressure adjusting valve that controls pressure fluctuation during ink supply). Is mounted on the liquid ejecting head, the liquid supply source and the relay unit are connected by a flexible liquid supply tube, and the ink from the liquid supply source is supplied into the liquid ejecting head through the liquid supply tube. A configuration (off-carriage type) is employed (Patent Document 1).

  In a configuration using an ink cartridge typified by such a liquid supply source, the ink flow path (liquid flow path) from the ink introduction needle inserted into the ink cartridge to the nozzle opening of the recording head is filled with ink. However, it is difficult to completely prevent the gas from entering the ink flow path by replacing the ink cartridge. In particular, in the off-carriage type that supplies ink from the ink cartridge to the inside of the liquid ejecting head through the liquid supply tube, the outside air permeates the wall surface of the liquid supply tube and dissolves in the ink. Ink may be saturated. For this reason, the gas that has newly entered the ink flow path cannot be dissolved in the ink, or the gas that has been dissolved due to a change in temperature may become bubbles and be mixed into the ink in the ink flow path. The bubbles that have entered the ink flow path in this way gradually grow and become large, and if the excessively grown bubbles move to the pressure chamber side by the flow of ink, the bubbles absorb the pressure fluctuation during the discharge operation. May cause problems such as pressure loss due to ink and insufficient supply of ink due to air bubbles blocking the flow path.

In order to prevent such a malfunction due to the mixing of bubbles, the above-described liquid ejecting head periodically performs a cleaning operation for generating an ink flow having a flow rate several times that during the recording operation, and the bubbles in the ink flow path Is discharged. In order to discharge the gas mixed in the ink other than the cleaning operation, a gas permeable film is provided on the side surface of the common liquid chamber (common liquid chamber) communicating with the pressure chamber, and the liquid of the gas permeable film is It has been proposed that a chamber is provided on the side opposite to the side in contact with the chamber, and a negative pressure is generated in the chamber to degas the liquid in the common liquid chamber, thereby suppressing the generation of bubbles in the pressure chamber ( Patent Document 2).
JP 2005-219229 A JP 2006-95878 A

  However, in the configuration of the invention of Patent Document 2, if the pressure difference between the common liquid chamber and the chamber is not large (for example, at least 50 kPa at room temperature, desirably 80 kPa to approximately vacuum), the gas in the common liquid chamber is gas. Since it cannot permeate through a permeable membrane, a large-scale decompression means is required. In addition, if this pressure difference is too large, the water vapor mixed in the ink will escape and the ink in the ink flow path will thicken, so the pressure in the chamber is controlled while monitoring using a pressure gauge or the like. There was a need to do. In addition, a gas permeable film made of a fluorine-based thin film or a silicon-based thin film has a problem that the transmittance is reduced when ink is spread. Furthermore, if air bubbles are inadvertently mixed into the ink flow path when the ink cartridge is not sufficiently deaerated in the common liquid chamber, the air bubbles enter the adjacent pressure chamber before melting into the ink, causing a problem. There was a fear.

  Further, in the gas permeable membrane, when the pressure difference is increased, the gas permeable membrane cannot withstand the pressure and may be damaged or bend according to the pressure fluctuation, so that the ink is ejected from the nozzle opening of the liquid ejecting head. There was also a risk of being ejected carelessly. In addition, pressure loss occurs due to the gas permeable membrane absorbing pressure fluctuations when ink is ejected from the nozzle openings in the liquid ejecting head, thereby reducing the amount and speed of the ejected ink. There was also the possibility of adversely affecting the properties.

  And in order to employ | adopt a gas-permeable film | membrane, the attachment work process of the said film | membrane was needed, and there existed a problem which manufacturing efficiency etc. deteriorated. Further, since the rigidity of the membrane portion is weak, a support column (support member) is required to reinforce the peripheral portion, and by providing this support column, the flow channel resistance in the flow channel increases, the discharge frequency, etc. Could have an adverse effect on Furthermore, in order to arrange this support column, it is necessary to consider the balance between the deaeration efficiency, the head rigidity, and the flow path resistance of the common liquid chamber, which is difficult to design.

  The present invention has been made in view of such circumstances, and an object of the present invention is to collect and collect the gas mixed in the liquid flow path without performing a cleaning operation, and collect the gas. It is an object of the present invention to provide a liquid ejecting apparatus capable of preventing the occurrence of problems caused by the above.

The liquid ejecting apparatus of the present invention has been proposed in order to achieve the above object, and the liquid stored in the liquid storage member is introduced into the pressure chamber through the liquid flow path, and the liquid is generated by the operation of the pressure generating means. A liquid ejecting apparatus including a liquid ejecting head capable of ejecting from a nozzle opening,
In the middle of the liquid flow path, a gas trap space capable of capturing the gas mixed in the liquid is formed, and a gas recovery space is formed via a partition wall forming the gas trap space. And a pressure difference adding means for lowering the pressure in the gas recovery space compared to the pressure in the gas trap space, and the partition wall between the gas trap space and the gas recovery space is defined as a transmission partition wall. ,
According to the pressure difference, the gas in the gas trap space is transmitted through the permeation partition wall and recovered in the gas recovery space.

  According to the above configuration, the gas trap vacant part capable of capturing the gas mixed in the liquid is formed in the middle of the liquid flow path, and the gas is interposed via the partition wall forming the gas trap vacant part. A partition between the gas trap space and the gas recovery space is provided with a pressure difference adding means for forming a recovery space and making the pressure in the gas recovery space lower than the pressure in the gas trap space. The wall is a permeation partition wall, and the gas in the gas trap space due to the pressure difference passes through the permeation partition wall and is collected in the gas recovery space. It is possible to reliably capture and collect the trapped gas, and to collect the trapped gas mainly in the gas recovery cavity. For this reason, it is possible to prevent as much as possible problems caused by bubbles mixed into the pressure chamber. As a result, since the frequency of performing the cleaning operation for discharging the bubbles can be reduced, the consumption of ink accompanying the cleaning operation can be reduced.

In this configuration, it is desirable that the permeation partition wall is a rigid wall having a rigidity capable of retaining a shape even when subjected to a pressure change by at least the pressure difference adding means.
In this configuration, it is preferable that the permeation partition wall is constituted by a part of a structure that forms the liquid flow path.

  According to this configuration, since the permeable partition wall is a rigid wall, it is possible to suppress deformation and breakage of the permeable partition wall and bleeding of the liquid when a pressure difference is generated by the pressure difference adding means. Further, it is possible to prevent inadvertent discharge of the liquid due to the bending of the transmission partition wall in accordance with the pressure fluctuation by the pressure difference adding means. Further, it is possible to suppress pressure loss when the liquid is ejected from the nozzle opening by the liquid ejecting head.

  Further, in the above configuration, the structure including the permeable partition wall is made of a material different from other structures that divide the liquid flow path, and has a higher gas permeability than the other structures. It is desirable to form using.

  According to this configuration, gas permeability can be ensured for the permeation partition wall, and airtightness can be further ensured for the other partition walls. Thereby, the gas in the gas trap space can be removed more efficiently.

  Further, the permeation partition wall is integrally formed using the same material as the structure that partitions the liquid flow path, and is made thinner than a portion of the partition wall that partitions the liquid flow path that is in contact with outside air. Is also possible.

  According to this configuration, since the permeable partition wall is integrally formed using the same material as the structure that divides the liquid flow path, the step of separately forming and attaching the permeable partition wall can be omitted. It becomes possible to improve the gas permeability.

  In each of the above configurations, it is desirable that the pressure difference adding means sets the pressure difference to be equal to or higher than a saturated water vapor pressure at an ambient temperature around the gas trap empty space.

  In this configuration, it is desirable that the pressure difference is set to be greater than 0 kPa and not greater than 30 kPa.

  In each of the above-described configurations, it is desirable to include pressure difference maintaining means that enables the pressure difference to be maintained even when the apparatus is not in operation.

  According to this configuration, since the pressure difference maintaining means that enables the pressure difference to be maintained even when the apparatus is not in operation is provided, the pressure difference can be maintained over a long period of time. For this reason, even if it does not enlarge a pressure difference compared with the past, the bubble in a bubble trap empty part can be collect | recovered gradually over a long period of time. Thereby, the deformation | transformation of the permeation | transmission division wall and the bleeding of a liquid which generate | occur | produce by making this pressure difference large can be suppressed more reliably. Therefore, it is possible to prevent the occurrence of problems such as a decrease in gas permeability caused by ink bleeding.

  In each of the above-described configurations, it is desirable that the pressure difference adding means makes the pressure in the gas trap space higher than the atmospheric pressure and higher than the pressure in the gas recovery space.

  In each of the above-described configurations, it is preferable that the pressure difference adding means depressurizes the pressure in the gas recovery cavity to a lower pressure than the pressure in the gas trap cavity.

In the above configuration, a sealing member for sealing the nozzle forming surface of the liquid jet head is provided,
A suction pump for decompressing the inside of the sealing void formed by the nozzle forming surface is connected to the sealing member via a suction path,
The decompression means is preferably configured by connecting a suction path leading to the gas recovery cavity in parallel with a suction path of the suction pump.

  According to this configuration, since the pressure reducing means is configured by connecting the suction path leading to the gas recovery empty portion in parallel with the suction path of the suction pump, the suction pump normally used for the cleaning operation is used. The pressure inside the gas recovery space can be reduced. Therefore, it is not necessary to separately provide a pressure reducing means as a pressure difference adding means. Further, since the gas recovery empty portion can be depressurized also by suction accompanying a cleaning operation or the like, it is not necessary to perform suction only for newly depressurizing the gas recovery empty portion.

  In each of the above-described configurations, the volume of gas trapped in the gas trap space is recovered in the gas recovery space and reduced, and the volume of gas trapped in the gas trap space is the liquid flow path. It is desirable to make it faster than the volume increase rate that increases in combination with the gas flowing into the gas trap cavity from the upstream side.

  According to this structure, it can suppress that the gas of a gas trap empty part increases to the volume which causes a malfunction, and can reduce possibility that a bubble will mix in a pressure chamber. Therefore, there is no possibility that a problem due to gas mixing into the pressure chamber occurs.

  In each of the above configurations, a filter chamber in which a filter for filtering the liquid in the liquid channel is disposed is formed in the middle of the liquid channel, and an empty portion upstream of the filter in the filter chamber is formed. It is desirable to use a gas trap space.

  According to this configuration, it is not necessary to separately form a gas trap space for capturing and collecting gas in the liquid channel.

  In each of the above configurations, it is preferable that the gas trap empty portion is disposed in the middle of the liquid flow path formed in the liquid ejecting head.

  According to this configuration, the gas in the liquid channel near the pressure chamber can be reliably captured and recovered, and the possibility that the gas is mixed into the pressure chamber can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the 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 present embodiment, an ink jet printer (hereinafter simply referred to as a printer) typified by an image recording apparatus that is one form of the liquid ejecting apparatus will be described as an example.

  FIG. 1 is a plan view showing the configuration of a printer equipped with a recording head according to the present invention. The printer 1 includes a housing 2 and a platen 3 disposed in the housing 2, and is mounted on the platen 3 by a paper feed roller (none of which is shown) that is rotated by driving a paper feed motor. A recording paper (a kind of recording medium or discharge target: not shown) is conveyed. A guide rod 4 is installed in the housing 2 in parallel with the platen 3, and a carriage 6 equipped with a recording head 5 is slidably supported on the guide rod 4. The carriage 6 is connected to a timing belt 10 installed between a driving pulley 8 that is rotated by driving of a pulse motor 7 and an idler pulley 9 that is provided on the opposite side of the housing 2 from the driving pulley 8. Has been. The carriage 6 is configured to reciprocate in the main scanning direction perpendicular to the paper feeding direction along the guide rod 4 by driving the pulse motor 7.

  A capping mechanism 12 is disposed at a home position that is a non-recording area (non-ejection range) of the printer 1. The capping mechanism 12 has a tray-like cap member 12 ′ (a kind of sealing member in the present invention) that can come into contact with the nozzle forming surface of the recording head 5. In this capping mechanism 12, the space in the cap member 12 ′ functions as a sealing void, and the nozzle opening 13 (see FIG. 3) of the recording head 5 faces the nozzle forming surface in the sealing void. It is configured to be in close contact. The capping mechanism 12 is connected to a pump unit 14 including a suction pump, and the operation of the pump unit 14 can create a negative pressure in the sealed space. Then, when the pump unit 14 is operated in close contact with the nozzle forming surface and the inside of the sealing empty portion (sealed space) is made negative pressure, the ink in the recording head 5 is sucked from the nozzle opening 13 and the cap member 12 ′. It is discharged in the sealed empty space. That is, the capping mechanism 12 is configured to perform a cleaning operation for forcibly sucking and discharging ink and bubbles by generating an ink flow at a flow rate several times that during the recording operation in the recording head 5 (in the ink flow path). It has become.

  A cartridge holder 18 on which the ink cartridge 17 is detachably mounted is provided on one side of the housing 2 adjacent to the home position. In the present embodiment, a total of four ink cartridges 17 (a kind of liquid storage member in the present invention) are mounted on the cartridge holder 18. The ink cartridge 17 is connected to an air pump 20 via an air tube 19, and air from the air pump 20 is supplied into each ink cartridge 17. Then, the pressure in the ink cartridge 17 by the air causes ink to be supplied (pressure-fed) to the recording head 5 side through the ink supply tube 21 (a kind of member constituting the liquid flow path in the present invention). It is configured.

  The ink supply tube 21 is a long hollow member having flexibility, and is formed corresponding to each ink cartridge 17 (each color). Further, an FFC (flexible flat cable) 22 for transmitting a drive signal and the like from the control unit on the printer 1 body side to the recording head 5 side is wired between the printer 1 body side and the recording head 5 side. .

  Next, the recording head mounted on the printer 1 will be described. 2 is an exploded perspective view of the recording head, FIG. 3 is a cross-sectional view of the main part of the head main body of the recording head, and FIG. 4 is a perspective view of the recording head.

  The recording head 5 in the present embodiment includes a head body 5 ′, an ink pressure adjustment unit 24, a first case 25, and a second case 26 as main components. The head main body 5 ′ includes an introduction needle unit 27, a head case 28, a vibrator unit 29, a flow path unit 30, a drive substrate 31, a relay substrate 32, a head cover 33, and the like.

  The head case 28 is a hollow box-like member. As shown in FIG. 3, the flow path unit 30 is fixed to the front end surface (lower surface), and the fixing member 34 formed inside vibrates. The relay unit 32 and the introduction needle unit 27 are disposed on the base end surface (upper surface) side opposite to the flow path unit 30 in which the child unit 29 is accommodated. The vibrator unit 29 includes a plurality of piezoelectric vibrators 35 (a kind of pressure generating means in the present invention) arranged in a comb-teeth shape, and a wiring member (not shown) for supplying a drive signal to the piezoelectric vibrators 35. And a fixing plate 36 for fixing the piezoelectric vibrator 35. The piezoelectric vibrator 35 is joined to a flexible surface (vibrating plate) that partitions the pressure chamber 37 in the flow path unit 30. The piezoelectric vibrator 35 is expanded and contracted by supplying a drive signal to expand or contract the volume of the pressure chamber 37, thereby causing a pressure variation in the ink in the pressure chamber 37, and controlling the pressure variation. Ink droplets can be ejected from the nozzle openings 13.

  The flow path unit 30 is an adhesive in a state in which constituent members such as a nozzle formation substrate 38 (see FIG. 3) having a nozzle row in which the nozzle openings 13 are arranged and a flow path formation substrate 39 that forms an ink flow path are laminated. And a series of ink flow paths (liquid flow paths) from the common ink chamber 40 (common liquid chamber) to the nozzle opening 13 through the ink supply port and the pressure chamber 37. Is a unit member forming one type). The pressure chamber 37 in the flow path unit 30 is formed for each nozzle opening 13 and is configured such that ink is supplied from the ink pressure adjustment unit 24 side through the common ink chamber 40. The flow path unit 30 is joined to the front end surface of the head case 28, and a metal head cover 33 is attached by a fastening member 33 'so as to surround the peripheral edge portion from the outside of the joined flow path unit 30. . The head cover 33 protects the flow path unit 30 and the head case 28, adjusts the nozzle forming substrate 38 of the flow path unit 30 to a ground potential, and reduces noise caused by static electricity generated from a kind of recording paper of the recording medium. It serves to prevent obstacles.

  The drive board 31 includes a connector 41 for connecting the FFC 22, and is configured to receive a drive signal from the control unit side through the FFC 22 and supply the drive signal to the piezoelectric vibrator 35 side. Two connectors 41 are respectively attached. The drive board 31 is connected to the relay board 32 via a flexible cable 42 and is attached to a board fixing portion 25 ′ of the first case 22 described later. The relay substrate 32 is a substrate for relaying a signal path between the drive substrate 31 and the piezoelectric vibrator 35, and is on the base end surface (the surface opposite to the surface of the nozzle forming substrate 38) side of the head case 28. Be placed.

  In addition to the relay substrate 32, an introduction needle unit 27 is disposed on the base end surface of the head case 28. The introduction needle unit 27 is molded from a synthetic resin or the like, and a plurality of ink introduction needles 44 (liquid introduction needles) are attached to the upper surface of the introduction needle unit 27 with a filter 43 interposed therebetween. In addition, an adjustment unit disposing portion 45 for disposing the ink pressure adjusting unit 24 is provided on the upper surface of the introduction needle unit 27, that is, the surface opposite to the surface of the nozzle forming substrate 38 of the head body 5 '. ing. When the ink pressure adjustment unit 24 is attached to the adjustment unit arrangement portion 45, the ink introduction needle 44 is inserted into the ink pressure adjustment unit 24. Further, a focusing channel corresponding to each ink introduction needle 44 is formed on the lower surface side of the introduction needle unit 27 (not shown). This focusing flow path is an ink flow path for supplying ink from the ink introduction needle 44 to the pressure chamber 37 side. When the recording head 5 is housed in the carriage 6, the introduction needle unit 27 is disposed on the carriage 6, and the ink introduction needle 44 is erected upward from the bottom surface of the carriage 6. The ink introduction needle 44 will be described in detail later.

  The ink pressure adjusting unit 24 is connected to the ink supply tube 21 via an attachment 48 (see FIG. 1) connected to the upper surface, and introduces ink from the ink supply tube 21 to the pressure chamber 37 side of the recording head 5. . In the present embodiment, as shown in FIGS. 1 and 2, a total of four ink pressure adjustment units 24 correspond to each ink cartridge 17 (each color) or each ink supply tube 21. The adjustment unit placement unit 45 is attached. An introduction needle insertion portion 49 is provided at the bottom of each ink pressure adjustment unit 24, and when the ink pressure adjustment unit 24 is placed on the adjustment unit placement portion 45, the ink introduction needle is placed in the introduction needle insertion portion 49. 44 is inserted. Further, on the upper surface of the ink pressure adjusting unit 24, a flow path connecting portion 50 to which the attachment 48 is connected protrudes upward. In addition, ink distribution channels (not shown) corresponding to the channel connection portions 50 of the respective ink pressure adjustment units 24 are defined in the attachment 48 so that ink from the ink supply tube 21 side can be drawn. Each ink pressure adjusting unit 24 is distributed and supplied through the ink distribution flow path.

  The ink pressure adjusting unit 24 opens and closes a valve (self-sealing valve) according to the internal pressure fluctuation, and controls the introduction of ink to the head body 5 ′ (pressure chamber 37) side of the recording head 5. It has a function. That is, in a non-recording state where ink is not ejected by the recording head 5 (a state where ink is not consumed), the ink pressure adjustment unit 24 closes the valve so as not to introduce ink to the head body 5 'side. On the other hand, when the recording head 5 consumes ink by ejecting ink droplets during the recording operation (ejection operation) and the pressure inside the ink pressure adjustment unit 24 decreases, the ink pressure adjustment unit 24 opens the valve and the head Ink is introduced into the main body 5 '. Therefore, the ink pressure adjusting unit 24 controls the ink introduced to the head main body 5 ′ (pressure chamber 37) side as described above, so that the amount of change in the ink pressure can be made as small as possible. The state can be stabilized. That is, the ink pressure adjusting unit 24 has a function of adjusting the pressure of the ink introduced into the pressure chamber 37 of the recording head 5.

  As shown in FIG. 2, the first case 25 is a sleeve-like member that is surrounded by four side walls and opened up and down. The planar shape of the opening of the first case 25 is formed in a substantially rectangular shape, and the internal space thereof includes an accommodation empty portion 52 for accommodating the ink pressure adjustment unit 24 arranged on the adjustment unit arrangement portion 45. It has become. In addition, substrate fixing portions 25 ′ for attaching the drive substrate 31 are formed on two opposing side walls of the first case 25, respectively.

  As shown in FIGS. 2 and 4, the second case 26 includes a base surface 55 that can cover the upper opening of the accommodation space 52 in the first case 25, and an array of the ink pressure adjustment units 24 on the base surface 55. It is a member having a substantially gate-shaped or U-shaped cross section formed by side wall portions 56 extending downward from both side edge portions in a direction orthogonal to the direction. The base surface 55 covers the ink pressure adjustment unit 24 exposed from the upper opening of the accommodation space 52 of the first case 25. Further, the side wall portion 56 covers the drive substrate 31 fixed to the substrate fixing portion 25 ′ of the first case 25.

  In the base surface 55, an exposed opening 57 that can expose the flow path connection portion 50 is provided at a portion corresponding to the flow path connection portion 50 of the ink pressure adjustment unit 24 accommodated in the accommodation space 52. . In the present embodiment, since two flow path connection portions 50 are provided for each ink pressure adjustment unit 24, a total of eight exposure openings 57 corresponding to four ink pressure adjustment units 24 are provided.

Next, the configuration of the ink introduction needle 44 will be described.
FIG. 5 is a cross-sectional view in the longitudinal direction of the needle showing the configuration of the ink introduction needle in the present embodiment. The ink introduction needle 44 is a hollow needle-like member having an internal space as an ink introduction path 53 (a kind of liquid flow path), and includes a straight portion 54 and a filter chamber 55 formed continuously to the base end of the straight portion 54. And is roughly configured.

  The straight portion 54 is a hollow cylindrical member that is inserted into the introduction needle insertion portion 49 of the ink pressure adjusting unit 24, and a conical pointed portion 56 that is formed in a tapered shape is formed at the tip portion thereof. ing. A plurality of ink introduction holes 57 that allow the outside of the ink introduction needle 44 and the ink introduction path 53 to communicate with each other are formed in the pointed end portion 56. That is, as described above, when the ink introduction needle 44 (straight portion 54) is inserted into the ink pressure adjusting unit 24, the ink supplied from the ink cartridge 17 to the ink pressure adjusting unit 24 through the ink supply tube 21 is supplied. Can be introduced into the ink introduction path 53 through the ink introduction hole 57. In the present embodiment, the configuration in which the ink introduction hole 57 is opened in the pointed portion 56 is illustrated. However, for example, the configuration in which the ink introduction hole 57 is opened in the side surface of the ink introduction needle 44 downstream from the pointed portion 56. Can also be adopted.

  As shown in FIG. 5, the filter chamber 55 is formed in the middle of the ink introduction path 53 on the downstream side of the straight portion 54 with a disk-like filter 43 interposed therebetween, and is located on the upstream side of the filter 43. The upper filter chamber 55a in the skirt-shaped enlarged diameter portion 55 'that gradually increases in diameter from the upstream (upper end opening) side toward the downstream side is located downstream of the filter 43 and downstream from the upstream (upper end opening) side. The lower filter chamber 55b gradually decreases in diameter toward the (lower end opening) side. In the lower filter chamber 55b, a head flow path 58 is continuously formed in a lower end minimum diameter portion (lower end opening) that is gradually reduced in diameter from the inner diameter of the upper end opening on the filter 43 side. That is, the filter chamber 55 is upstream of the head flow path 58 communicating with the common ink chamber 33 (pressure chamber 37), and other ink such as the ink introduction path 53 and the head flow path 58 on the ink introduction needle 44 side. The diameter is larger than the flow path. The area of the upper end opening of the upper filter chamber 55a is made equal to the area of the lower end opening of the straight portion 54, while the area of the lower end opening is the effective filtration area of the filter 43 disposed immediately below the area (the ink is actually received in the filter 43). The area of the passable area). Further, the area of the upper end opening of the lower filter chamber 55 b is aligned with the effective filtration area of the filter 43 disposed immediately above, while the area of the lower end opening is aligned with the area of the upper end opening of the head channel 58. Therefore, the filter chamber 55 is configured so that the ink from the straight portion 54 side can smoothly flow toward the head flow path 38 side through the filter 43.

  The filter 43 disposed inside the filter chamber 55 has a function of filtering the ink in the ink flow path (liquid flow path), and makes the effective filtration product larger than the cross-sectional area of the other ink flow paths. As a result, the channel resistance of the ink channel is reduced. Further, the filter 43 in the present embodiment has a function of making it difficult for air bubbles mixed in the ink flow path to pass therethrough and trapping them in the empty portion (in the upper filter chamber 55a) of the upstream filter chamber 55. Therefore, the upper filter chamber 55a also functions as a gas trap cavity that can capture the gas mixed in the ink in the ink flow path.

  The ink introduction needle 44 configured as described above is attached to the introduction needle unit 27 by ultrasonic welding, for example, with the lower end opening of the upper filter chamber 55a of the filter chamber 55 facing the filter 43. Thereby, the lower end opening of the upper filter chamber 55 a and the upper end opening of the lower filter chamber 55 b communicate with each other in a liquid-tight state through the filter 43. That is, the ink introduction path 53 of the ink introduction needle 44 communicates with the head flow path 58 on the head case 28 side in a liquid-tight state, and the ink introduction path 53 and the head flow path 58 function as a liquid flow path in the present invention. To do.

  By the way, in the printer 1 of the present embodiment, when the ink cartridge 17 is attached, gas may enter the ink flow path. This gas normally dissolves in the ink that has been degassed in advance, but may become bubbles due to a change in environmental temperature or a change in atmospheric pressure, and may float in the ink flow path. Further, in the off-carriage type, as described above, the ink flow path from the cartridge 7 to the recording head 5 is constituted by the relatively long ink supply tube 21, and therefore, from the wall surface of the ink supply tube 21. Gas may enter and melt into the ink in the ink flow path, causing the ink to become saturated. In this state, the gas newly entered from the outside is difficult to dissolve in the saturated ink, so that it becomes bubbles and floats in the ink flow path. Thus, the air bubbles floating in the ink flow path gradually flow to the downstream side by the ink flow by the recording operation or the like, and flow into the filter chamber 55 formed in the middle of the ink flow path. Here, since the filter 43 of this embodiment makes it difficult for air bubbles to pass through, the air bubbles are caught by the filter 43 and stay in the upper filter chamber 55a as it is. Furthermore, as described above, the filter chamber 55 according to the present embodiment has a gentler ink flow velocity by expanding the diameter of the ink flow path than the other ink flow paths, so that it is difficult to move the inflowing bubbles to the downstream side of the filter 43. , Can be retained upstream. Therefore, it is possible to collect and capture the air bubbles that have flowed into the filter chamber 55 from the upstream in the empty space on the upstream side of the filter 43, that is, the upper filter chamber 55a. If the upper filter chamber 55a is configured as a gas trap space in this way, there is no need to separately form a gas trap space for capturing and collecting gas in the ink flow path. Further, the upper filter chamber 55a (ink introduction needle 44) of the present embodiment is disposed on the carriage 6, and is disposed in the middle of the ink flow path of the recording head 5 and closest to the pressure chamber 37. Therefore, the bubbles in the ink flow path near the pressure chamber 37 can be reliably captured, and the possibility that the bubbles are mixed into the pressure chamber 37 can be reduced.

  Therefore, in order to prevent problems caused by the gas mixed in the ink, in the printer 1 of this embodiment, as shown in FIG. 5, the skirt-shaped enlarged diameter portion 55 ′ defining the upper filter chamber 55 a is formed. A gas recovery empty portion 60 is formed on the outer periphery of the upper filter chamber 55a with a partition wall on the inner peripheral side interposed therebetween, so that gas can permeate through the partition wall between the upper filter chamber 55a and the gas recovery empty portion 60. The partition wall 61 is used, and the gas recovery space 60 is made to have a lower pressure than the pressure in the upper filter chamber 55a by the pressure difference adding means, and the gas (bubble A) trapped in the upper filter chamber 55a by this pressure difference. Is recovered in the gas recovery cavity 60 through the permeation partition wall 61.

  The permeation partition wall 61 of the upper filter chamber 55a is the same material as the other partition walls partitioning the upper filter chamber 55a, the straight portion 54, and the like, and is a material that allows gas to pass through, such as POM (polyacetal), It is integrally formed of PP (polypropylene), PPE (polyphenylene ether), or the like, and is thinner than the other partition walls and the portion of the straight wall 54 in contact with the outside air. That is, the transmission partition wall 61 is formed by thinning at least a part of the partition wall that partitions the upper filter chamber 55a. In other words, the permeation partition wall 61 is configured by a part of the structure that forms the liquid flow path. Thereby, the process of separately molding and attaching the permeation partition wall 61 can be omitted, and the gas permeability can be enhanced as compared with other partition walls. In the present embodiment, the experimental results show that the transmission efficiency is suitable when the area of the transmission partition wall 61 is about 1 cm 2 and the thickness is about 1 mm. Also, in the material, the gas permeability coefficient is 5 cc · mm / m 2 · day · atm or more, and the moisture permeability coefficient is preferably 2 g · mm / m 2 · day · atm or less. It is possible to use materials other than the above materials. Further, the permeation partition wall 61 may be formed using a material having a higher gas permeability than other partition walls that partition the upper filter chamber 55a.

  The gas recovery cavity 60 is an annular cavity surrounded by a permeation partition wall 61 and a partition wall on the outer peripheral side of the skirt-shaped enlarged diameter portion 55 ′, and will be described later via a suction path 63 (see FIG. 6). It is comprised so that it may communicate with a pressure difference addition means. The gas recovery empty portion 60 does not need to be formed so as to surround the entire upper filter chamber 55a, and may be formed in a state of surrounding a part of the upper filter chamber 55a. In short, any shape may be used as long as it has a gas recovery space located outside the upper filter chamber 55a and can be formed with the permeation partition wall 61 interposed therebetween.

  Next, pressure difference adding means for reducing the pressure in the gas recovery cavity 60 to a lower pressure than the pressure in the upper filter chamber 55a will be described. FIG. 6 is a schematic diagram for explaining the pressure reducing means as the pressure difference adding means of the present embodiment.

  The pressure difference adding means of the present embodiment includes a pressure reducing means for reducing the pressure in the gas recovery cavity 60 to a pressure lower than the pressure in the upper filter chamber 55a. The decompression means connects the suction path 63 communicating with the gas recovery cavity 60 in parallel with the cap suction path 64 for decompressing the inside of the cap member 12 ′, and decompresses the interior of the gas recovery cavity 60 by the cleaning operation pump unit 14. You may comprise.

  As shown in FIG. 6, the decompression means is provided in the middle of the suction path 63 and the pump unit 14 capable of decompressing the gas recovery cavity 60 from the gas recovery cavity 60 through the suction path 63. And a check valve 70 that allows ventilation from the collection empty portion 60 to the pump unit 14 and prevents the reverse. The suction path 63 is connected to the cap suction path 64 via the branch connection portion 65, and the space from the branch connection portion 65 to the carriage 6 is constituted by a flexible hollow tube member.

  With this configuration, when the pump unit 14 is operated and the cap suction path 64 is sucked and depressurized, the inside of the gas recovery cavity 60 can be depressurized via the suction path 63 branched from the cap suction path 64. it can. Thereby, the pressure in the gas collection | recovery empty part 60 can be made low pressure compared with the pressure in the upper filter chamber 55a. Due to this pressure difference, the bubbles trapped in the upper filter chamber 55 a can be recovered in the gas recovery cavity 60 through the permeation partition wall 61. Then, the upper filter chamber 55a functions as a gas trap space, so that bubbles floating in the ink flow path are reliably captured and collected in the space upstream of the filter 43, and the captured bubbles are collected. The gas can be recovered in the gas recovery empty portion 60 with priority. For this reason, it is possible to prevent problems that occur due to air bubbles entering the pressure chamber 37. As a result, since the frequency of performing the cleaning operation for discharging the bubbles can be reduced as compared with the prior art, it is possible to reduce the consumption of ink accompanying the cleaning operation.

  Further, when the gas recovery empty portion 60 is decompressed by using the pump unit 14 that is normally used for the cleaning operation as described above, it is not necessary to separately provide a decompression means. Further, since the gas recovery empty portion 60 can be depressurized together with the cleaning operation, it is not necessary to perform individual suction only for reducing the pressure in the gas recovery empty portion 60. Furthermore, since the suction path 63 from the branch connection portion 65 to the cap suction path 64 to the carriage 6 is constituted by a tube member, the movement of the carriage 6 is not restricted.

  Regarding this pressure difference adding means, by providing a check valve 70 in the middle of the suction path 63, the gas in the gas recovery cavity 60 flows only in the direction of depressurization. The pressure can be maintained. And since this check valve 70 opens only at the time of the operation | movement of a pressure reduction means, it maintains a valve closing state in a normal state. Therefore, the check valve 70 also functions as a pressure difference maintaining unit that can maintain the pressure difference between the upper filter chamber 55a and the gas recovery empty portion 60 regardless of whether the apparatus is not operating or operating.

  Thus, since the pressure difference between the gas recovery empty portion 60 and the upper filter chamber 55a can be maintained over a long period of time, the bubbles in the upper filter chamber 55a can be maintained without increasing the pressure difference as compared with the conventional case. Can be gradually recovered over a long period of time. Accordingly, it is possible to suppress the bleeding and deformation of the ink on the transmission partition wall 61 that is generated by increasing the pressure difference. Therefore, it is possible to prevent the occurrence of problems such as a decrease in gas permeability caused by ink bleeding.

  Further, when the pressure difference adding means is configured as described above, the pressure supplied into the gas recovery empty portion 60 by setting the pressure threshold value for opening the check valve 70, setting the suction time of the pump unit 14, or the like. Can be easily adjusted. Further, since the ink pressure in the upper filter chamber 55a can be adjusted to be constant by the ink pressure adjusting unit 24, the pressure difference adding means adjusts the pressure in the gas recovery cavity 60 to thereby recover the gas. It is possible to appropriately set the pressure difference between the empty portion 60 and the upper filter chamber 55a. In the present embodiment, it is desirable to set this pressure difference to be equal to or higher than the saturated water vapor pressure at the ambient temperature around the upper filter chamber 55a. Specifically, for example, it is preferable to set this pressure difference to 5 kPa or more.

  In the present embodiment, the volume reduction rate at which the volume of the bubbles trapped in the upper filter chamber 55a is recovered and reduced in the gas recovery cavity 60 is reduced, and the volume of the gas trapped in the upper filter chamber 55a is the ink flow. It is set to be faster than the volume increase rate that increases (grows) together with the bubbles flowing in from the upstream side of the path. Specifically, the pressure difference is adjusted so that the gas permeation amount per 24 hours (one day) of the partition permeation wall is, for example, 0.05 mm 3 / day or more and the water vapor permeation amount is 0.10 mg / day or less. P (for example, about 5 kPa), area S (for example, about 1 cm 2) of the partition transmission wall (transmission region), thickness T (for example, about 1 mm), gas permeability coefficient K of the material (for example, about 5 cc · mm / m 2 · day · atm) Or above) or by adjusting the balance of the moisture permeability coefficient k (for example, about 2 g · mm / m 2 · day · atm or less). This balance is not limited to the above numerical values, and can be set as appropriate based on the expression “transmission amount ∝ S · K (or k) · P / T”.

  By setting in this way, it is possible to suppress the bubbles in the upper filter chamber 55a from increasing to the volume causing the malfunction, and the possibility that the bubbles will be mixed into the pressure chamber 37 can be reduced, so that the bubbles are mixed into the pressure chamber 37. This eliminates the possibility of problems arising from the above.

  Moreover, in the said embodiment, although the pressure difference maintenance means comprised including the pressure reduction means which pressure-reduces the inside of the gas collection | recovery empty part 60 was illustrated, this invention is not limited to this. For example, the inside of the upper filter chamber 55a as the gas trap empty portion may be pressurized by a pressurizing unit that pressurizes the inside of the ink flow path. Specifically, the gas recovery empty portion 60 and the upper filter chamber 55a are formed in the same manner as in the above-described embodiment, and the atmosphere recovery path that connects the gas recovery empty portion 60 and the outside is provided, and the ink in the cartridge 13 is pressurized. A plate-like nozzle sealing member made of an elastic member capable of sealing all the nozzle openings 13 in one of the home positions on the one side or the non-recording region on the other side opposite to the air pump 20 to be supplied. (Both not shown). As a result, the air pump 20 is operated in a state where the nozzle opening 13 is sealed by the nozzle sealing member, and the pressure inside the ink flow path from the cartridge 13 to the nozzle opening is increased to a pressure higher than the atmospheric pressure. By pressurizing, the pressure in the gas recovery cavity 60 can be made lower than the pressure in the upper filter chamber 55a. Then, the gas in the upper filter chamber 55a can be recovered in the gas recovery cavity 60 by the pressure difference generated by the pressurizing means, and can be discharged to the outside through the atmosphere open path. Further, when the pressure by the air pump 20 is kept applied to the ink flow path when not in operation, and the nozzle opening 13 is sealed by the nozzle sealing member, the pressure in the gas recovery cavity 60 and the upper filter chamber 55a are reduced. The pressure difference from the internal pressure can be maintained. Therefore, it can function as a pressure difference maintaining means that can maintain this pressure difference even when not in operation. Note that it is desirable that the pressurization by the air pump 20 as the pressure difference adding means is set within a range that does not cause the permeation partition wall 61 to cause problems such as ink bleeding.

  In the above embodiment, the example in which the nozzle opening 13 is sealed by the nozzle sealing member when the ink in the ink flow path is pressurized by the pressurizing unit has been described. However, the present invention is not limited thereto. In short, any configuration may be used as long as the ink in the upper filter chamber 55a on the upstream side can be pressurized by closing the ink flow path on the downstream side of the filter chamber 55. For example, in each of the above embodiments, the ink pressure adjustment unit 24 disposed on the upstream side of the filter chamber 55 is disposed on the downstream side of the filter chamber 55, and a valve (self-sealing) provided in the ink pressure adjustment unit 24 is provided. The inside of the filter chamber 55 may be pressurized by closing the ink flow path downstream of the filter chamber 55 with a valve.

  In each of the above embodiments, an example has been described in which the upper filter chamber 55a formed integrally with the ink introduction needle 44 is a gas trap cavity that can trap air bubbles in the ink flow path. It is not limited to. In short, any configuration may be used as long as it is formed in the middle of the ink flow path and can capture bubbles. For example, as shown in FIG. 7, a filter chamber 55 having the same configuration as that of each of the above embodiments may be formed in the middle of the ink flow path, and this upper filter chamber 55a may be used as a gas trap empty portion. Further, the gas trap empty portion is not limited to the filter chamber 55, and may be constituted by an empty portion capable of capturing bubbles using buoyancy. Specifically, as shown in FIG. 8, a dome-shaped trap chamber 69 that is wider than the other portion is formed in the middle of the ink flow path, and an inlet flow is formed on one side of the floor surface of the trap chamber 69. An outlet passage 71 is formed on the other side of the passage 70, and a gas recovery cavity 60 is provided above the permeation partition wall 61 that forms a dome-shaped ceiling of the trap chamber 69. It is good also as a structure to form. With this configuration, the bubbles A contained in the ink passing through the inlet channel 70 and the outlet channel 71 rise by buoyancy and stay in contact with the lower surface of the dome-shaped transmission partition wall 61. . Further, since the trap chamber 69 is wider than the other ink flow paths, the flow rate of ink becomes gentle, and the bubbles A floating upward do not easily flow to the lower outlet flow path 71 side. Thereby, it is easy to trap the bubbles A above the trap chamber 69.

  FIG. 9 is a diagram for explaining the configuration of another embodiment of the present invention, and is a cross-sectional view of the main part of an ink pressure adjusting unit 24 which is a kind of members constituting the liquid flow path in the present invention. In this figure, the configuration on the downstream side of the self-sealing valve is shown enlarged.

  In the present embodiment, the gas recovery empty portion 60 is provided in the ink pressure adjustment unit 24. The ink pressure adjustment unit 24 is configured by laminating a plurality of structures. In the present embodiment, the first structure 74 and the upper filter for partitioning the gas recovery cavity 60 from above in FIG. It consists of a total of three structures: a second structure 75 for partitioning the chamber 55a and a third structure 76 for partitioning the lower filter chamber 55b.

  The third structure 76 is formed by recessing the joint surface with the second structure 75 in the shape of a mortar or funnel in the opposite direction to form the lower filter chamber 55b, and the downstream end of the lower filter chamber 55b. Are connected to the recording head 5 side to form a communication channel 78. Further, at a position slightly lowering from the upstream opening of the lower filter chamber 55b to the downstream side, a stepped portion 77 protruding in a stepped shape in the cross section toward the center of the diameter is present in the entire upstream opening of the lower filter chamber 55b. The filter 43 is attached by joining the peripheral edge of the lower surface of the filter 43 to the upper surface of the stepped portion 77 by ultrasonic welding or the like.

  The second structure 75 has a surface corresponding to the lower filter chamber 55b of the third structure 55b facing the opposite surface (bonding surface with the first structure 74) on the bonding surface with the third structure 55b. Thus, the upper filter chamber 55a is formed by being recessed into a rectangular cross section. The opening shape of the upper filter chamber 55 a is aligned with the upstream opening shape of the lower filter chamber 55 b of the third structure 76. And by laminating | stacking the 2nd structure 75 and the 3rd structure 76, the upper filter chamber 55a and the lower filter chamber 55b are connected in series, and the filter chamber 55 is divided.

  The second structure 75 is formed with an introduction path 81 for introducing ink from a self-sealing valve (not shown) into the upper filter chamber 55a. Furthermore, the joint surface of the second structure 75 with the first structure 74 is recessed toward the upper filter chamber 55a to form the recess 79 so that the thickness of the boundary wall with the upper filter chamber 55a is reduced. It is configured. This boundary wall functions as the transmission partition wall 61. That is, it can be said that the permeation partition wall 61 is configured by a part of the structure that forms the liquid flow path.

  The permeation partition wall 61 is secured between the filter chamber 55 (upper filter chamber 55a) and the gas recovery cavity 60 while ensuring the rigidity that can maintain the shape even when subjected to a pressure change by the pressure difference adding means. It is desirable to use a rigid wall having a thickness that allows gas exchange, that is, gas permeation due to the pressure difference. Specifically, the thickness of the transmission partition wall 61 is set to about 10% to 50% of the average thickness of other portions. The material of the second structure 75 including the permeable partition wall 61 is formed using a material having higher gas permeability than the materials of the other structures 74 and 76. Specifically, plastics such as m-PPE (modified polyphenylene ether) or PP (polypropylene) or alloys thereof can be used. On the other hand, the other structures 74 and 76 are made of materials having low gas permeability, such as PPS (polyphenylene sulfide), m-PPE / PPS alloy (alloy of modified polyphenylene ether and polyphenylene sulfide), liquid crystal polymer, EVOH (ethylene- It is desirable to use a vinyl alcohol copolymer resin). Thereby, about the permeation | separation partition wall 61, while ensuring gas permeability, airtightness can be made more reliable in another partition wall. As a result, the gas in the gas trap space (upper filter chamber 55a) can be removed more efficiently. Of course, the materials of the structural bodies 74, 75, and 76 may be the same.

  The first structure 74 has a recess 80 formed by recessing the joint surface of the second structure 75 with the first structure 74 on the opposite surface side. The opening shape of the recess 80 is aligned with the opening shape of the recess 79 of the second structure 75. When the first structure 74 and the second structure 75 are stacked, the recess 79 and the recess 80 are arranged in series. And a gas recovery cavity 60 is formed. The gas recovery empty portion 60 in the present embodiment is a common empty portion for the filter chamber 55 formed for each ink flow path in the plurality of ink flow paths. The gas recovery cavity 60 is provided in a state adjacent to the upper filter chamber 55a through the transmission partition wall 61. The gas recovery empty portion 60 is connected to a pressure reducing means (pressure difference adding means) such as the pump unit 14 through a check valve 70 and a suction path 63.

  In the above configuration, when the pump unit 14 is operated to reduce the pressure in the gas recovery cavity 60, the pressure in the gas recovery cavity 60 can be reduced compared to the pressure in the upper filter chamber 55a. At this time, it is desirable to set the pressure difference to be equal to or higher than the saturated water vapor pressure at the ambient temperature around the upper filter chamber 55a. Specifically, for example, this pressure difference is preferably set to 5 kPa or more and 30 kPa or less. Due to this pressure difference, the bubbles A trapped in the upper filter chamber 55a can be recovered in the gas recovery cavity 60 via the permeation partition wall 61. That is, also in the present embodiment, it is possible to obtain the same effects as those in the above embodiment. Even if the pressure difference is set to 5 kPa or less, the same effect can be obtained if the pressure difference is kept for a long time, so that the pressure difference should be larger than 0 kPa.

  In the present embodiment, the second structural body 75 including the transmission partition wall 61 is made of a material different from the other structural bodies 74 and 76 that partition the liquid flow path, and is more gas than other structural bodies. Although the example formed using the material with high permeability was shown, it is not restricted to this. Each structure 74, 75, 76 may be formed as an integral structure. That is, as in the first embodiment, the permeation partition wall 61 is integrally formed using the same material as the structure that partitions the liquid flow path, and more than the portion (partition wall) in contact with the outside air. A thinning configuration can also be employed.

  As described above, in each of the embodiments described above, a part of the structure forming the liquid flow path is the permeable partition wall 61, and the permeable partition wall 61 is compared with the conventional configuration using a gas permeable film such as silicon. Since the rigidity is increased, it is possible to suppress deformation and breakage of the transmission partition wall 61 when a pressure difference is generated by the pressure difference adding means. Further, it is possible to prevent inadvertent ink discharge due to the bending of the transmission partition wall 61 in accordance with the pressure fluctuation by the pressure difference adding means. Furthermore, since the deformation of the transmission partition wall 61 is suppressed, pressure loss when the recording head 5 ejects ink from the nozzle openings 13 can be suppressed. In addition, a support column (support member) for securing rigidity as in the conventional configuration is not necessary.

  In each of the above embodiments, an example in which the present invention is applied to the printer 1 that is a kind of an off-carriage type liquid ejecting apparatus has been described. Of course, the present invention is also applied to an on-carriage type liquid ejecting apparatus. Is possible. That is, it is also suitable for a configuration in which the ink cartridge 17 is accommodated in the accommodating space of the carriage 6 instead of the ink pressure adjusting unit 24. In this case, it is desirable to provide a gas trap void and a gas recovery void in the ink introduction needle.

  In addition, the present invention is not limited to the printer 1, and any display manufacturing apparatus, electrode manufacturing apparatus, or chip manufacturing can be used as long as the liquid stored in the liquid storage member is introduced into the liquid ejecting head through the liquid flow path. The present invention can also be applied to liquid ejecting apparatuses such as apparatuses and micropipettes.

FIG. 2 is a plan view illustrating a configuration of a printer. FIG. 3 is an exploded perspective view of a recording head. FIG. 3 is a cross-sectional view of a main part of a head body of a recording head. It is a perspective view of a recording head. It is sectional drawing of the needle longitudinal direction which shows the structure of an ink introduction needle | hook. It is a schematic diagram explaining the pressure reduction means as a pressure difference addition means of this embodiment. It is sectional drawing which shows the modification of a filter chamber and a gas collection | recovery empty part. It is sectional drawing which shows the modification of a gas trap empty part and a gas collection | recovery empty part. It is principal part sectional drawing explaining the structure of the ink pressure adjustment unit in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Housing | casing, 3 ... Platen, 4 ... Guide rod, 5 ... Recording head, 5 '... Head main body, 6 ... Carriage, 7 ... Pulse motor, 8 ... Drive pulley, 9 ... Sliding pulley, 10 ... timing belt, 12 ... capping mechanism, 12 '... cap member, 13 ... nozzle opening, 14 ... pump unit, 17 ... ink cartridge, 18 ... cartridge folder, 19 ... air tube, 20 ... air pump, 21 ... ink supply tube, 22 ... FFC, 24 ... ink pressure adjusting unit, 25 ... first case, 25 '... substrate fixing part, 26 ... second case, 27 ... introducing needle unit, 28 ... head case, 29 ... vibrator unit, 30 ... flow Road unit, 31... Drive board, 32. Relay board, 33... Head cover, 33 ′ ... fastening member, 34. 36 ... Fixed plate, 37 ... Pressure chamber, 38 ... Nozzle forming substrate, 39 ... Flow path forming substrate, 40 ... Common ink chamber, 41 ... Connector, 42 ... Flexible cable, 43 ... Filter, 44 ... Ink introduction needle, 45 ... Adjustment unit arrangement part, 48 ... attachment, 49 ... introduction needle insertion part, 50 ... flow path connection part, 52 ... accommodation empty part, 53 ... ink introduction path, 54 ... straight part, 55 ... filter chamber, 55 '... skirt shape Expanded portion, 55a ... upper filter chamber, 55b ... lower filter chamber, 56 ... tip end portion, 57 ... ink introduction hole, 58 ... head flow path, 60 ... gas recovery empty portion, 61 ... permeation partition wall, 63 ... suction path 64 ... cap suction path, 65 ... branch connection, 69 ... trap chamber, 70 ... inlet channel, 71 ... outlet channel, 74 ... first structure, 75 ... second structure, 76 ... second structure , 77 ... Step 78 ... communicating passage, 79 ... recess

Claims (14)

A liquid ejecting apparatus including a liquid ejecting head capable of introducing a liquid stored in a liquid storing member into a pressure chamber through a liquid flow path and ejecting the liquid from a nozzle opening by an operation of a pressure generating unit,
In the middle of the liquid flow path, a gas trap space capable of capturing the gas mixed in the liquid is formed, and a gas recovery space is formed via a partition wall forming the gas trap space. And a pressure difference adding means for lowering the pressure in the gas recovery space compared to the pressure in the gas trap space, and the partition wall between the gas trap space and the gas recovery space is defined as a transmission partition wall. ,
The liquid ejecting apparatus according to claim 1, wherein the gas in the gas trap cavity is collected by the gas recovery cavity through the transmission partition wall by the pressure difference.   The liquid ejecting apparatus according to claim 1, wherein the permeation partition wall is configured by a rigid wall having rigidity capable of retaining a shape even when subjected to a pressure change by at least the pressure difference adding unit.   The liquid ejecting apparatus according to claim 1, wherein the permeable partition wall is configured by a part of a structure that forms the liquid flow path.   The structure including the permeation partition wall is formed of a material that is different from other structures that partition the liquid flow path and has higher gas permeability than the other structures. The liquid ejecting apparatus according to claim 3.   The permeation partition wall is integrally formed using the same material as the structure that partitions the liquid flow path, and is thinner than a portion of the partition wall that partitions the liquid flow path that is in contact with outside air. The liquid ejecting apparatus according to claim 3.   6. The liquid jet according to claim 1, wherein the pressure difference adding unit sets the pressure difference to be equal to or higher than a saturated water vapor pressure at an ambient temperature around a gas trap empty space. apparatus.   The liquid ejecting apparatus according to claim 6, wherein the pressure difference is greater than 0 kPa and equal to or less than 30 kPa.   8. The liquid ejecting apparatus according to claim 1, further comprising a pressure difference maintaining unit that makes it possible to maintain the pressure difference even when the apparatus is not in operation.   9. The pressure difference adding unit according to any one of claims 1 to 8, wherein the pressure in the gas trap space is set to be higher than atmospheric pressure and higher than the pressure in the gas recovery space. The liquid ejecting apparatus according to claim 1.   9. The liquid ejecting apparatus according to claim 1, wherein the pressure difference adding unit reduces the pressure in the gas recovery empty portion to a pressure lower than the pressure in the gas trap empty portion. A sealing member for sealing the nozzle forming surface of the liquid jet head;
A suction pump for decompressing the inside of the sealing void formed by the nozzle forming surface is connected to the sealing member via a suction path,
11. The liquid ejecting apparatus according to claim 10, wherein the decompression unit is configured by connecting a suction path leading to the gas recovery empty portion in parallel with a suction path of the suction pump.   The volume of the gas trapped in the gas trap cavity is reduced from the upstream side of the liquid flow path by the volume reduction rate at which the volume of the gas trapped in the gas trap cavity is recovered and reduced in the gas recovery cavity. 12. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is faster than a volume increase rate that increases in combination with a gas flowing into the trap empty portion.   A filter chamber in which a filter for filtering the liquid in the liquid channel is disposed is formed in the middle of the liquid channel, and an empty portion upstream of the filter in the filter chamber is defined as a gas trap empty portion. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.   The liquid ejecting apparatus according to claim 1, wherein the gas trap empty portion is disposed in the middle of a liquid flow path formed in the liquid ejecting head.

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