JP2010208186A - Defoaming mechanism and liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve defoaming speed in a liquid jet apparatus. <P>SOLUTION: The defoaming mechanism includes a defoaming chamber for capturing air bubbles in liquid, a deformable partition part having gas permeability, and a pressure adjusting chamber adjacent to the defoaming chamber via the partition part, whose in-chamber pressure changes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for removing bubbles from a liquid flowing in a liquid ejecting apparatus.

  In an ink jet printer, if bubbles occur in ink in an ink supply path from an ink supply unit such as an ink cartridge to a recording head, printing defects such as missing dots may be caused. Therefore, it is required to remove bubbles (defoaming) from the ink. As a mechanism for performing this defoaming, a chamber (defoaming chamber) in which ink is temporarily stored and bubbles are trapped is adjacent to the decompression chamber via a gas-permeable partition, and the pressure in the decompression chamber is adjusted. A mechanism for removing bubbles trapped in a defoaming chamber by reducing the pressure below the pressure has been proposed (Patent Document 1).

JP 2006-95878 A

  However, the conventional defoaming mechanism has a problem that bubbles in the ink cannot be sufficiently removed. Such a problem may occur not only in an ink jet printer but also in a liquid ejecting apparatus that ejects an arbitrary liquid such as a lubricating oil or a resin liquid.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and to improve a defoaming speed in a liquid ejecting apparatus.

[Application Example 1] A defoaming mechanism for removing bubbles from a liquid flowing in a liquid supply path of a liquid ejecting apparatus, which has a defoaming chamber for capturing bubbles in the liquid, and has gas permeability. A defoaming mechanism comprising: a deformable partition wall; and a pressure adjusting chamber that is adjacent to the defoaming chamber via the partition wall and in which a chamber pressure can be changed.

  In the defoaming mechanism of Application Example 1, the partition wall between the defoaming chamber and the pressure regulating chamber can be deformed, so that when the pressure in the pressure regulating chamber becomes lower than the pressure in the defoaming chamber, the pressure regulating chamber expands to the pressure regulating chamber side. When the pressure in the pressure adjusting chamber becomes higher than the pressure in the defoaming chamber, the pressure adjusting chamber can be deformed so as to swell toward the defoaming chamber. Therefore, many bubbles can be captured by deforming the partition wall so as to swell toward the pressure adjusting chamber, and the defoaming speed can be improved. In addition, the liquid can be pushed out to the downstream side of the defoaming chamber by deforming the partition wall so as to swell toward the defoaming chamber.

[Application Example 2] The defoaming mechanism according to Application Example 1, wherein the partition wall portion has flexibility, and the central portion of the partition wall portion is displaced more largely than the surrounding portion.

  With such a configuration, when the pressure in the pressure adjusting chamber becomes lower than the pressure in the defoaming chamber, the partition wall deforms in a mountain shape toward the pressure adjusting chamber, so a large amount of bubbles are trapped in the central part of the partition wall. can do.

Application Example 3 In the defoaming mechanism according to Application Example 1 or Application Example 2, the defoaming mechanism according to Application Example 1 or Application Example 2 further includes an abutting member disposed inside the pressure adjustment chamber and capable of contacting the partition wall, The defoaming mechanism has elasticity and deforms in contact with the contact member when the pressure in the pressure adjusting chamber is lower than the pressure in the defoaming chamber.

  With such a configuration, the partition wall portion has elasticity, so that it expands when deformed and increases the surface area. Therefore, when the pressure in the pressure adjusting chamber is lower than the pressure in the defoaming chamber, the surface area of the partition wall can be increased to increase the defoaming speed.

Application Example 4 The defoaming mechanism according to Application Examples 1 to 3, wherein the defoaming chamber has a bellows shape.

  With this configuration, the partition wall expands toward the pressure adjusting chamber when the pressure in the pressure adjusting chamber becomes lower than the pressure in the defoaming chamber, and degassed when the pressure in the pressure adjusting chamber becomes higher than the pressure in the defoaming chamber. It can be deformed to contract toward the chamber side.

Application Example 5 A liquid ejecting apparatus including the defoaming mechanism according to any one of Application Examples 1 to 4.

  With such a configuration, a large amount of bubbles existing in the liquid can be captured and quickly removed in the liquid ejecting apparatus.

It is explanatory drawing which shows schematic structure of the printer 500 provided with the carriage 100 as a defoaming mechanism of this invention. FIG. 4 is an explanatory diagram illustrating detailed configurations of the carriage 100 and the recording head 150 during decompression, and an enlarged view of the carriage 100 and the recording head 150 viewed in the −X direction. 3 is an explanatory diagram illustrating a detailed configuration of the carriage 100 and the recording head 150 in a negative pressure maintaining state. FIG. FIG. 4 is an explanatory diagram illustrating states of the carriage 100 and the recording head 150 when ink is ejected and after ink has flowed. It is an enlarged view which shows the structure of the degassing chamber 92 vicinity in a 2nd Example. It is an enlarged view which shows the structure of the degassing chamber 92 vicinity in a 3rd Example.

A. First embodiment:
A1. Device configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a printer 500 including a carriage 100 as a defoaming mechanism of the present invention. The printer 500 is an ink jet printer that can eject inks of four colors (black, cyan, magenta, and yellow). The printer 500 includes an ink cartridge IC1 for black ink, an ink cartridge IC2 for cyan ink, an ink cartridge IC3 for magenta ink, an ink cartridge IC4 for yellow ink, a carriage 100, a recording head 150, a guide rod 260, A platen 270, four ink supply pumps 220a, 220b, 220c, and 220d, and a pressure reducing pump 300 are provided.

  The printer 500 is a so-called off-carriage type printer in which four ink cartridges IC1 to IC4 are mounted on the printer body. The ink cartridge IC1 is connected to the carriage 100 via a tube t1, an ink supply pump 220a, and a tube t11. Similarly, the ink cartridge IC2 is connected to the tube t2, the ink supply pump 220b and the tube t12, the ink cartridge IC3 is connected to the tube t3, the ink supply pump 220c and the tube t13, and the ink cartridge IC4 is connected to the tube t4. The ink supply pump 220d and the tube 14 are connected to the carriage 100, respectively. The decompression pump 300 is connected to the carriage 100 via a tube t5. Each of the ink cartridges IC1 to IC4 is attached to a main body frame (not shown) of the printer 500 by a cartridge holder (not shown).

  The ink supply pump 220a supplies the black ink in the ink cartridge IC1 to the carriage 100. Similarly, the ink supply pump 220b carries cyan ink in the ink cartridge IC2, the ink supply pump 220c carries magenta ink in the ink cartridge IC3, and the ink supply pump 220d carries yellow ink in the ink cartridge IC4. 100. The decompression pump 300 is used in common for each color (black, cyan, magenta, yellow).

  The guide rod 260 is disposed above the platen 270 along the longitudinal direction (Z-axis direction) of the platen 270. The carriage 100 is supported so as to be movable in the longitudinal direction of the platen 270 along the guide rod 260, and is driven by a carriage motor (not shown) via a timing belt (not shown). The recording head 150 is disposed on the bottom surface of the carriage 100 and ejects ink droplets downward from a number of nozzles (not shown) as the carriage 100 reciprocates in the longitudinal direction. At this time, the recording paper P is conveyed on the platen 270 by a paper feed mechanism (not shown), whereby an image or the like is formed on the recording paper P.

  FIG. 2A is an explanatory diagram showing a detailed configuration of the carriage 100 and the recording head 150 during decompression. FIG. 2B is an enlarged view of the carriage 100 and the recording head 150 shown in FIG. 2A and 2B show the carriage 100 and the recording head 150 when the decompression pump 300 is driven and the later-described second pressure chamber 89 and decompression chamber 80 are decompressed. In FIG. 2A, functional units related to black ink are shown, but the same applies to functional units related to inks of other colors. In FIG. 2B, for convenience of illustration, some of the functional units illustrated in FIG. 2A are omitted.

  As shown in FIG. 2A, the carriage 100 includes an air chamber 87, a first partition wall 88a, a first pressure chamber 77, a valve chamber 70, a first pressure regulating valve 71, and a defoaming chamber 92. A defoaming partition wall 90, a decompression chamber 80, a second pressure chamber 89, a second partition wall portion 88b, a second pressure regulating valve 81, three ink channels 69, 79, and 95, and a negative And a pressure supply path 68.

  The atmosphere chamber 87 communicates with the atmosphere via the atmosphere communication hole 99. The first partition wall portion 88a has flexibility and can be displaced in the vertical direction. The partition wall portion 88b can be formed of, for example, a film made of synthetic resin or rubber, and a cantilevered thin plate member (not shown) that can be displaced together with the film. The first partition wall 88 a forms a part of the bottom surface of the atmosphere chamber 87 and forms the ceiling surface of the first pressure chamber 77.

  The first pressure chamber 77 temporarily stores black ink to be supplied to the defoaming chamber 92. The first pressure chamber 77 communicates with the defoaming chamber 92 through the ink flow path 79. The first pressure chamber 77 is provided with an ink inlet 76, and communicates with a valve chamber 70 described later via the ink inlet 76. The valve chamber 70 communicates with the ink flow path 69. The valve chamber 70 accommodates the first pressure regulating valve 71.

  The first pressure regulating valve 71 is used to control the flow rate and pressure of black ink. The first pressure regulating valve 71 includes a pressure adjusting spring 73, a valve body 72, a seal member 75, and a support rod 74. The pressure adjustment spring 73 is connected to the bottom surface of the valve chamber 70 and the lower surface of the valve body 72. The valve body 72 is urged by the pressure adjusting spring 73 in the direction toward the ceiling surface (upward) in the valve chamber 70. The valve body 72 is displaceable between an open position where the first pressure chamber 77 and the valve chamber 70 are in communication with each other and a sealing position where the valve chamber 70 is in non-communication according to the expansion and contraction of the pressure adjustment spring 73. . Specifically, when the ink is discharged from the first pressure chamber 77, the force that pushes down the valve body 72 (the pressing force of the support rod 74 by the partition wall portion 88a and the pressure in the first pressure chamber 77) is reduced. When it becomes larger than the force that pushes up 72 (the pressure in the valve chamber 70 and the biasing force of the pressure adjusting spring 73), it is displaced toward the open position. Further, when ink flows into the first pressure chamber 77 and the force for pushing down the valve body 72 becomes smaller than the force for pushing up the valve body 72, the ink is displaced toward the sealing position. In the example of FIG. 2A, the valve body 72 is located at the sealing position. The seal member 75 is disposed on the upper surface of the valve body 72 and seals the ink from flowing from the valve chamber 70 to the first pressure chamber 77 when the valve body 72 is disposed at the sealing position. The support rod 74 is disposed across the valve chamber 70 and the first pressure chamber 77, and has one end joined to the valve body 72 and the other end joined to the partition wall portion 88a.

  The defoaming chamber 92 temporarily stores the ink flowing from the ink flow path 79 and captures the bubbles rising in the ink at the ceiling portion. The defoaming chamber 92 includes a filter 93 for ink filtration inside. The defoaming chamber 92 communicates with the ink flow path 79 on the upper side of the filter 93. The defoaming chamber 92 also communicates with the ink flow path 95.

  The defoaming partition wall 90 is made of a gas-permeable sheet-like member, and allows the air bubbles trapped in the defoaming chamber 92 to permeate into the decompression chamber 80. As the sheet-like member, for example, a thin film such as polyacetal, polypropylene, or polyphenylene ether can be employed. The defoaming partition wall 90 has an edge bonded to the side surface at the upper end of the defoaming chamber 92, and forms the ceiling surface of the defoaming chamber 92 and part of the bottom surface of the decompression chamber 80.

  The defoaming partition wall 90 is deformed according to the pressure difference between the defoaming chamber 92 and the decompression chamber 80 and is displaced between the defoaming chamber 92 and the decompression chamber 80. Specifically, when the pressure in the defoaming chamber 92 is higher than the pressure in the decompression chamber 80, the defoaming partition wall 90 is displaced upward (the decompression chamber 80 side) and moves toward the decompression chamber 80 side. Deforms like a mountain. When the pressure in the defoaming chamber 92 is lower than the pressure in the decompression chamber 80, the defoaming chamber 92 is displaced downward (defoaming chamber 92 side) and deforms in a mountain shape toward the defoaming chamber 92 side. Here, the defoaming partition wall portion 90 is configured to be displaced more vertically as it approaches the center portion of the defoaming partition wall portion 90. This can be realized, for example, by bending and adhering the sheet member without applying strong tension when adhering the edge portion of the sheet-like member constituting the defoaming partition wall 90 to the side surface of the defoaming chamber 92. .

  The decompression chamber 80 is a chamber that receives bubbles (gas) that have passed through the defoaming partition wall 90. The decompression chamber 80 is disposed above the defoaming chamber 92, and is disposed adjacent to the defoaming chamber 92 via the defoaming partition wall 90. The decompression chamber 80 includes a communication hole 86 on the ceiling surface (the surface opposite to the surface on which the defoaming partition wall 90 is disposed), and communicates with the second pressure chamber 89 via the communication hole 86.

  The second pressure chamber 89 is used to supply the negative pressure supplied from the decompression pump 300 to the decompression chamber 80. The second pressure chamber 89 is disposed above the decompression chamber 80 and communicates with the tube t <b> 5 via the negative pressure supply path 68. The second pressure chamber 89 is disposed adjacent to the atmospheric chamber 87 via a partition wall 88b that forms a ceiling portion. In addition, the partition part 88b has the same structure as the above-mentioned partition part 88a. However, the partition wall portion 88a and the partition wall portion 88b are not in contact with each other and can be displaced (bent) independently.

  The second pressure regulating valve 81 is disposed across the second pressure chamber 89 and the decompression chamber 80 and is used to control the supply of negative pressure from the second pressure chamber 89 to the decompression chamber 80. The second pressure regulating valve 81 has the same configuration as the first pressure regulating valve 71 described above. That is, the second pressure regulating valve 81 includes a valve body 82, a pressure adjustment spring 83, a seal member 85, and a support rod 84. The valve body 82 can be displaced between an open position where the second pressure chamber 89 and the decompression chamber 80 are in communication with each other and a sealing position where the second pressure chamber 89 and decompression chamber 80 are not in communication. Is being energized. In the example of FIG. 2 (A), the valve body 82 is disposed at the open position. The seal member 85 seals the communication hole 86 and maintains the negative pressure in the decompression chamber 80 when the valve body 82 is disposed at the sealing position. The support rod 84 has one end joined to the valve body 82 and the other end joined to the partition wall portion 88b.

  As shown in FIG. 2B, a defoaming chamber forming member 101 that forms a defoaming chamber 92 is disposed at the lower portion of the carriage 100. The defoaming chamber forming member 101 includes a defoaming chamber 92c for cyan ink, a defoaming chamber 92m for magenta ink, and a yellow ink for the defoaming chamber 92 for black ink. A defoaming chamber 92y is formed. The configurations of the defoaming chamber 92c, the defoaming chamber 92m, and the defoaming chamber 92y are the same as the configuration of the defoaming chamber 92 described above.

  In addition to the above-described defoaming partition wall 90, a defoaming partition wall 90c corresponding to the defoaming chamber 92c is arranged on the ceiling portion of the defoaming chamber forming member 101 (the boundary with the decompression chamber 80). ing. Similarly, a defoaming partition wall portion 90m corresponding to the defoaming chamber 92m and a defoaming partition wall portion 90y corresponding to the defoaming chamber 92y are disposed on the ceiling portion of the defoaming chamber forming member 101, respectively. ing. Of the ceiling portion of the defoaming chamber forming member 101, the other portions excluding the four defoaming partition walls 90, 90c, 90m, 90y form a rigid surface 91 having no flexibility. One end of the pressure adjustment spring 83 is connected to the rigid surface 91. Therefore, the pressure adjustment spring 83 can expand and contract independently of the displacement of the four defoaming partition wall portions 90, 90c, 90m, and 90y.

  The four defoaming partition walls 90, 90 c, 90 m and 90 y all face the decompression chamber 80. Accordingly, when the decompression chamber 80 becomes negative pressure, these defoaming partition wall portions 90, 90c, 90m, 90y are all displaced upward, and the bubbles trapped in the corresponding defoaming chambers 92, 92c, 92m, 92y It passes through BL and flows out into the decompression chamber 80.

  Returning to FIG. 2A, the recording head 150 is disposed on the bottom surface of the carriage 100 and ejects ink toward the recording paper P (FIG. 1). The recording head 150 includes a nozzle plate 152 and an ink discharge channel 154. The ink discharge channel 154 communicates with the ink channel 95 of the carriage 100 and guides the ink discharged from the defoaming chamber 92 to the nozzle plate 152. The nozzle plate 152 includes a number of nozzles (not shown).

  The above-described carriage 100 corresponds to the defoaming mechanism in the claims. The defoaming partition wall 90 corresponds to the partition wall in the claims, the decompression chamber 80 corresponds to the pressure adjustment chamber in the claims, and the printer 500 corresponds to the liquid ejecting apparatus in the claims.

A2. Defoaming action:
FIG. 3 is an explanatory diagram showing detailed configurations of the carriage 100 and the recording head 150 in the negative pressure maintaining state. FIG. 3 shows the carriage 100 and the recording head 150 in a state where the inside of the decompression chamber 80 is maintained at a negative pressure. 3 is the same as that in FIG. 2A described above. Hereinafter, the defoaming operation in the printer 500 will be described with reference to FIGS.

  After the printing operation is completed in the printer 500, a defoaming operation is performed. First, the decompression pump 300 (FIG. 2A) is driven, and the second pressure chamber 89 is decompressed to a negative pressure. At this time, the second partition wall portion 88b bends downward (second pressure chamber side) due to the difference between the pressure (atmospheric pressure) of the atmospheric chamber 87 and the pressure (negative pressure) of the second pressure chamber 89. Accordingly, the support rod 84 is displaced downward, and the valve body 82 moves to the open position. As a result, since a negative pressure is supplied to the decompression chamber 80 through the communication hole 86, the bubbles BL trapped in the ceiling portion of the defoaming chamber 92 permeate the defoaming partition wall 90 and enter the decompression chamber 80. Inflow. Here, when the decompression chamber 80 has a negative pressure, the pressure in the decompression chamber 80 becomes lower than the pressure in the defoaming chamber 92, so that the defoaming partition wall 90 is displaced upward (the decompression chamber 80 side). At this time, the central portion of the defoaming partition wall portion 90 is displaced more than the surrounding portion, and the defoaming partition wall portion 90 is deformed in a mountain shape toward the decompression chamber 80 side.

  The decompression pump 300 stops after being driven for a predetermined period. Thereafter, an opening valve (not shown) connected to the tube t5 is opened, and the second pressure chamber 89 is opened to the atmosphere. Then, since the pressure difference between the second pressure chamber 89 and the atmospheric chamber 87 disappears, as shown in FIG. 3, the second partition wall portion 88b and the support rod 84 are displaced upward, and the valve body 82 is positioned at the sealing position. To do. As a result, since the inside of the decompression chamber 80 is maintained at a negative pressure, the bubbles BL trapped in the defoaming chamber 92 are continuously removed. At this time, the defoaming partition wall 90 maintains a mountainous state. Therefore, compared with a configuration in which the defoaming partition wall portion is not deformed, the contact area of the defoaming partition wall portion 90 with the defoaming chamber 92 is increased, so that more bubbles are trapped and a higher defoaming speed is obtained. Is realized.

A3. Ink supply operation:
FIG. 4A is an explanatory diagram illustrating a state of the carriage 100 and the recording head 150 during ink ejection. At the time of printing, when ink is ejected from the nozzles (not shown) provided on the nozzle plate 152 and the ink is consumed, the pressure in the defoaming chamber 92 decreases, and the defoaming partition wall 90 moves downward (defoaming It bends to the chamber 92 side. Similarly, since the amount of ink in the first pressure chamber 77 also decreases, the pressure in the first pressure chamber 77 decreases. Then, the pressure in the first pressure chamber 77 becomes lower than the pressure (atmospheric pressure) in the atmospheric chamber 87, and the partition wall 88 b is deflected to the inside of the first pressure chamber 77 and displaced downward by this pressure difference. Along with this, the valve body 72 is pushed down via the support rod 74. When the urging force of the pressure adjustment spring 73 is overcome and the valve body 72 is positioned at the open position, the ink inlet 76 is opened and the ink flows into the first pressure chamber 77.

  FIG. 4B is an explanatory diagram showing the state of the carriage 100 and the recording head 150 after ink has flowed into the first pressure chamber 77 from the opened ink inlet 76. When ink flows into the first pressure chamber 77 and the chamber pressure increases, the partition wall portion 88b is displaced upward. Accordingly, when the valve body 72 moves to the sealing position again, the inflow of ink into the first pressure chamber 77 is stopped, and the supply of ink to the recording head 150 is stopped. As described above, the printer 500 is configured such that the consumed amount of ink appropriately flows into the recording head 150 by opening and closing the first pressure regulating valve 71 according to the consumption of ink.

  The printer 500 is configured to eject ink in order to discharge bubbles and thickened ink accumulated in nozzles (not shown) after the initial ink filling. When the ink is ejected, the defoaming partition wall 90 is displaced downward as in FIG. 4A to push the ink vigorously into the ink flow path 95. Therefore, bubbles and thickened ink in the nozzle are easily discharged from the nozzle to the outside.

  As described above, in the carriage 100, the defoaming partition wall 90 is displaced toward the decompression chamber 80 when the decompression chamber 80 becomes negative pressure, and deforms in a mountain shape. Therefore, the contact area of the defoaming partition wall 90 with the defoaming chamber 92 and the decompression chamber 80 can be increased, and the defoaming amount (defoaming speed) per unit time can be increased. Further, since the volume of the defoaming chamber 92 increases due to the displacement of the defoaming partition wall 90, a large amount of bubbles can be trapped. Further, since the defoaming partition wall 90 is displaced toward the defoaming chamber 92 when ink is discharged, the ink in the defoaming chamber 92 is transferred to the recording head 150 via the ink channel 95. We can push out strongly. Therefore, bubbles and thickened ink accumulated in the nozzle can be easily discharged.

B. Second embodiment:
FIG. 5A is a first enlarged view showing a configuration in the vicinity of the defoaming chamber 92 in the second embodiment. FIG. 5B is a second enlarged view showing the configuration in the vicinity of the defoaming chamber 92 in the second embodiment. FIG. 5A shows the configuration near the defoaming chamber 92 when ink is not ejected in the negative pressure maintaining state, and FIG. 5B shows the configuration near the defoaming chamber 92 when ink is ejected. ing. 5A and 5B show the configuration in the vicinity of the defoaming chamber 92 for black ink, the defoaming chambers for other colors of ink (defoaming chambers 92c, 92m, and 92y). Is the same.

  The carriage 100a according to the second embodiment is different from the carriage 100 in that the defoaming partition wall 60 is formed in a bellows shape and the support member 62 is provided on the ceiling of the defoaming partition wall 60. Unlike (FIGS. 1 to 3), other configurations are the same as those of the first embodiment.

  The defoaming partition wall 60 of the second embodiment is composed of a cylindrical side surface 61 and a support member 62 that closes one opening of the side surface 61. The opening where the support member 62 is not disposed on the side surface 61 faces the defoaming chamber 92. The side surface 61 is comprised by the sheet-like member which has the gas permeability formed in the bellows shape. By this bellows structure, the side surface 61 can be expanded upward and contracted downward. The support member 62 is more rigid than the sheet-like member that forms the side surface 61. The support member 62 can be configured, for example, by stacking a synthetic resin thin plate or a plurality of sheet members. The side surface 61 corresponds to a partition wall in the claims.

  As shown in FIG. 5 (A), when the decompression chamber 80 is decompressed and maintained in a negative pressure state, the pressure in the decompression chamber 80 becomes lower than the pressure in the defoaming chamber 92, so that the support member 62 is displaced upward. The side surface 61 extends. As a result, the contact area between the defoaming chamber 92 and the decompression chamber 80 on the side surface 61 increases, and the bubbles trapped in the defoaming chamber 92 pass through the side surface 61 and flow into the decompression chamber 80. The support member 62 may be formed of a gas permeable member. In this case, trapped bubbles pass through the side surface 61 and the support member 62 and flow into the decompression chamber 80.

  As shown in FIG. 5B, when ink is ejected and the pressure in the defoaming chamber 92 becomes lower than the pressure in the decompression chamber 80, the support member 62 is displaced downward and the side surface 61 contracts. As a result, the contact area of the side surface 61 with the defoaming chamber 92 and the decompression chamber 80 decreases. At this time, since the support member 62 is displaced downward, the ink in the defoaming chamber 92 can be pushed out to the recording head 150 via the ink flow path 95. Therefore, in the ink discharge after the initial ink filling, bubbles accumulated in the nozzles and the thickened ink can be easily discharged.

  The carriage 100a of the second embodiment having the above configuration has the same effect as the carriage 100 of the first embodiment.

C. Third embodiment:
FIG. 6A is a first enlarged view showing a configuration in the vicinity of the defoaming chamber 92 in the third embodiment. FIG. 6B is a second enlarged view showing the configuration near the defoaming chamber 92 in the third embodiment. 6A shows a configuration near the defoaming chamber 92 when ink is not ejected in the negative pressure maintaining state, and FIG. 6B shows a configuration near the defoaming chamber 92 when ink is ejected. ing. 6A and 6B show the configuration near the defoaming chamber 92 for black ink, the defoaming chambers for other colors of ink (defoaming chambers 92c, 92m, and 92y). Is the same.

  The carriage 100b according to the third embodiment is different in that the defoaming partition wall portion is formed of a stretchable member and the decompression chamber 80 includes three extending portions 51 to 53. Unlike 100 (FIGS. 1 to 3), other configurations are the same as those of the first embodiment.

  In the third embodiment, the defoaming partition wall 90a is composed of a sheet-like member having elasticity. As such a sheet-like member, for example, a sheet-like member formed by thinly extending an elastomer can be employed. As the elastomer, for example, silicon rubber or butyl rubber can be employed. Since the defoaming partition wall 90a has elasticity, it can be displaced upward (the decompression chamber 80 side) or downward (the defoaming chamber 92 side) similarly to the first embodiment.

  The three extended portions 51 to 53 are all highly rigid columnar members, and can be formed of, for example, metal (SUS, aluminum, etc.), synthetic resin, or the like. These extended portions 51 to 53 are arranged such that the longitudinal direction is the X-axis direction, and both ends are supported by the side walls of the decompression chamber 80. In addition, in the example of FIG. 6 (A), (B), the cross section of the three extended parts 51-53 is represented. These extended portions 51 to 53 are arranged above the rigid surface 91 along the horizontal direction (Z-axis direction). The three extended portions 51 to 53 correspond to the contact members in the claims.

  When the decompression chamber 80 has a negative pressure, the defoaming partition wall 90a is displaced upward and abuts against the extended portions 51 to 53. In this case, in the defoaming partition wall 90a, the edge portion and the portion between the extended portions 51 to 53 are extended and displaced upward. As a result, as shown in FIG. 6A, the defoaming partition wall 90a is deformed so that the cross section has a corrugated shape. At this time, since the surface area of the defoaming partition wall 90a increases, the defoaming speed increases.

  On the other hand, when the ink is consumed by the ink ejection, the defoaming partition wall 90a is displaced downward as shown in FIG. 6B, and the ink in the defoaming chamber 92 is passed through the ink flow path 95. To the recording head 150. At this time, like the first embodiment, the defoaming partition wall 90a is displaced more downward as it is closer to the center.

  The carriage 100b of the third embodiment having the above configuration has the same effect as the carriage 100 of the first embodiment. Further, when the decompression chamber 80 becomes negative pressure, the defoaming partition wall 90a is expanded by the extending portions 51 to 53, so that the surface area of the defoaming partition 90a is increased and the defoaming speed is increased. Can be raised.

D. Variation:
In addition, elements other than the elements claimed in the independent claims among the constituent elements in each of the above embodiments are additional elements and can be omitted as appropriate. The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

D1. Modification 1:
In each of the above-described embodiments, the bottom surface of the decompression chamber 80 and the ceiling surface of the defoaming chamber 92 are integrally formed by the defoaming partition walls 90, 60, and 90a. The bottom surface and the ceiling surface of the defoaming chamber 92 can be formed by separate members. For example, the bottom surface of the decompression chamber 80 and the ceiling portion of the defoaming chamber 92 are each covered with a gas-permeable sheet-like member so that the bottom surface of the decompression chamber 80 and the ceiling portion of the defoaming chamber 92 are in contact with each other. In addition, the decompression chamber 80 and the defoaming chamber 92 can be combined. That is, generally, a deformable partition wall having gas permeability can be employed as the partition wall in the defoaming mechanism and the liquid ejecting apparatus of the present invention.

D2. Modification 2:
In the second embodiment described above, the number of stretched portions is three, but may be any number. Moreover, although the extended parts 51-53 were arrange | positioned along with the horizontal direction, it can replace with this and can also arrange | position so that the distance (height) from the rigid surface 91 may mutually differ. Moreover, although the extended parts 51-53 were arrange | positioned so that a longitudinal direction might turn into an X-axis direction, it can replace with this and can also be arrange | positioned so that a longitudinal direction may turn into a Z-axis direction. In this case, in addition to the defoaming partition wall portion 90a for the black ink, the defoaming partition wall portions for the inks of other colors can be extended by the extending portions 51 to 53. Moreover, although the shape of the extended parts 51-53 was a cylindrical shape, it can replace with this and can be made into arbitrary shapes, such as a triangular prism and an elliptical column. That is, in general, any contact member that can contact the partition wall can be employed as the contact member in the defoaming mechanism and the liquid ejecting apparatus of the present invention.

D3. Modification 3:
In each of the above-described embodiments, the example in which the defoaming mechanism is applied to the carriages 100, 100a, and 100b has been described. However, instead of this, the defoaming mechanism can be configured separately from the carriage. For example, in each embodiment, the defoaming mechanism can be configured by providing a defoaming chamber and a decompression chamber in the middle of the tubes t11 to t14.

D4. Modification 4:
In each of the above-described embodiments, the type of ink ejected by the printer 500 is four colors. However, instead of this, any type of ink can be ejected. The printer of each embodiment is an off-carriage type printer, but instead of this, a so-called on-carriage type printer in which an ink cartridge is mounted on a carriage can be adopted.

D5. Modification 5:
In each of the above-described embodiments, degassing is performed by negative pressure. However, instead of this, degassing by pressurization may be performed. For example, the defoaming mechanism is provided in an ink supply path (from the first pressure regulating valve 71 to the ink cartridge IC1) from the ink cartridge IC1 to the carriage 100, and is configured to supply ink by pressurization. Bubbles can also be trapped and defoamed in the defoaming chamber 92). In this configuration, since the pressure in the defoaming chamber 92 can be made higher than the pressure in the decompression chamber 80, the defoaming partition wall portion can be displaced upward (the decompression chamber 80 side) as in each embodiment. it can. Even in such a configuration, the same effects as those of the embodiments can be obtained.

D6. Modification 6:
Similarly to the defoaming partition wall 90a in the third embodiment, the defoaming partition wall 90 in the first embodiment described above can also be configured by a sheet-like member having elasticity such as an elastomer. In this configuration, the defoaming partition wall 90 is displaced upward and deformed like a first embodiment when the decompression chamber 80 has a negative pressure, and the third embodiment and the third embodiment. Similarly, it stretches upward and the surface area increases. Therefore, as in the third embodiment, the defoaming speed can be increased compared to the configuration in which the defoaming partition wall portion does not expand.

D7. Modification 7:
In each of the above-described embodiments, the ink jet printer has been described. However, the present invention is not limited to this, and can be applied to any liquid ejecting apparatus that ejects liquid other than ink. For example, image recording devices such as facsimile machines, color material ejection heads used in the manufacture of color filters such as liquid crystal displays, electrodes such as organic EL (Electro Luminescence) displays and surface emission displays (Field Emission Display, FED) Electrode material injection device used for forming, liquid injection device for injecting liquid containing bio-organic matter used for biochip manufacturing, sample injection device as a precision pipette, lubricating oil injection device, resin liquid injection device Etc. In addition, transparent resin liquids such as UV curable resins to form liquid injection devices that inject lubricating oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate, or a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate or the like may be employed. The present invention can be applied to any one of the various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets.

  In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in the state when the substance is in a liquid phase, and may be in a liquid state with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts) ) And a liquid as one state of the substance, as well as particles in which functional material particles made of solid materials such as pigments and metal particles are dissolved, dispersed or mixed in a solvent. In addition, typical examples of the liquid include ink and liquid crystal as described in the above embodiments. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot-melt inks.

    DESCRIPTION OF SYMBOLS 14 ... Tube, 51 ... Expanding part, 60 ... Defoaming partition part, 61 ... Side surface, 62 ... Supporting member, 68 ... Negative pressure supply path, 69 ... Ink flow path, 70 ... Valve chamber, 71 ... First tone Pressure valve, 72 ... valve body, 73 ... pressure adjusting spring, 74 ... support rod, 75 ... seal member, 76 ... ink inlet, 77 ... first pressure chamber, 79 ... ink flow path, 80 ... decompression chamber, 81 ... Second pressure regulating valve, 82 ... Valve, 83 ... Pressure adjusting spring, 84 ... Support rod, 85 ... Seal member, 86 ... Communication hole, 87 ... Air chamber, 88a ... First partition part, 88b ... Second partition part 89 ... second pressure chamber, 90, 90c, 90m, 90y ... defoaming partition, 91 ... rigid surface, 92, 92c, 92m, 92y ... defoaming chamber, 93 ... filter, 95 ... ink flow path, 99 ... air communication hole, 100, 100a, 100b ... carriage, 101 ... defoaming Forming member, 150 ... recording head, 152 ... nozzle plate, 154 ... ink ejection flow path, 220a to 200d ... ink supply pump, 260 ... guide rod, 270 ... platen, 300 ... pressure reducing pump, 500 ... printer, P ... Recording paper, IC1 to IC4 ... ink cartridge, t1 to t5 ... tube, BL ... air bubbles, t11 to t13 ... tube

Claims (5)

A defoaming mechanism for removing bubbles from a liquid flowing in a liquid supply path of a liquid ejecting apparatus,
A defoaming chamber for trapping bubbles in the liquid;
A gas-permeable, deformable partition wall, and
Adjacent to the defoaming chamber via the partition wall, a pressure adjusting chamber in which the indoor pressure can change,
A defoaming mechanism. The defoaming mechanism according to claim 1,
The partition wall has flexibility,
In the partition wall, the defoaming mechanism in which the central portion is displaced more greatly than the surrounding portion. The defoaming mechanism according to claim 1 or 2, further comprising:
An abutting member disposed inside the pressure regulating chamber and capable of abutting against the partition;
The said partition part has a stretching property, and when the pressure of the said pressure regulation chamber falls rather than the pressure of the said defoaming chamber, it deabuts and abuts against the said contact member, and is a deaeration mechanism. In the defoaming mechanism according to any one of claims 1 to 3,
The defoaming chamber has a bellows shape.   A liquid ejecting apparatus comprising the defoaming mechanism according to claim 1.

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