JP2010221538A - Liquid supply mechanism and liquid ejection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress settling of particles of a substance in liquid residing between a pump for supplying liquid and a pressure regulation valve in a liquid ejection device having the pressure regulating valve. <P>SOLUTION: A liquid supply mechanism is adapted to supply liquid to a recording head having two liquid reserve chambers which are adjacent to each other and respectively reserve liquid and the pressure regulation valve that generates a communicating state or a non-communicating state between the two liquid reserve chambers depending on a pressure change of at least one of the two liquid reserve chambers. The liquid supply mechanism includes the pump for performing supplying or sucking of liquid, a check valve which is placed between the pump and the pressure regulating valve so as to prevent a liquid from flowing to the upstream side, and a volume variable section which is placed between the pump and the pressure regulating valve and has a variable volume. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for supplying a liquid to a liquid ejecting apparatus.

  In an off-carriage type ink jet printer in which the ink cartridge is mounted on the printer body, when a layout in which the recording head (nozzle plate) is arranged at a position lower than the ink cartridge is adopted, ink leakage from the nozzle due to a water head difference is prevented. It is necessary to suppress it. Therefore, a printer has been proposed that reduces the ink flow path in the recording head to suppress ink leakage and supplies the recording head with an amount of ink discharged when the ink is discharged from the nozzle. For example, an ink storage chamber is provided in the recording head, and a pressure adjusting valve (opens when the pressure in the ink storage chamber decreases due to ink jetting) at the inlet of the ink storage chamber. There has been proposed a printer in which a valve that closes when it rises (Patent Document 1).

JP 2005-186344 A

  In general, in a printer provided with the pressure adjusting valve, the ink flow path between the pump for supplying ink to the recording head and the pressure adjusting valve is long. Therefore, when pigment-based ink is used in the printer, there is a problem that a large amount of pigment particles settle between the pump and the pressure regulating valve because the specific gravity of the pigment particles contained in the ink is large. However, in the past, the actual situation is that sufficient measures have not been taken for the sedimentation of pigment particles in the ink flow path between the pump and the pressure regulating valve. This problem can occur not only in an ink jet printer but also in any liquid ejecting apparatus that ejects liquid such as lubricating oil or resin liquid.

  An object of the present invention is to suppress sedimentation of component particles in a liquid between a liquid supply pump and a pressure adjustment valve in a liquid ejecting apparatus including a pressure adjustment valve.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] Two liquid storage chambers that are adjacent to each other and store a liquid, and pressure that communicates or does not communicate between the two liquid storage chambers according to a change in pressure in at least one of the two liquid storage chambers A liquid supply mechanism for supplying the liquid to a recording head having a regulating valve, which is disposed between the pump for supplying and sucking the liquid, and between the pump and the pressure regulating valve. A liquid supply mechanism comprising: a check valve that suppresses the flow of the liquid; and a volume variable unit that is disposed between the pump and the pressure adjustment valve and capable of changing a volume.

  In the liquid supply mechanism of Application Example 1, since the variable volume portion is disposed between the pump and the pressure regulating valve, an amount of liquid corresponding to the variable volume in the variable volume portion is supplied using the pump. By sucking, the liquid can flow between the pump and the pressure regulating valve. Therefore, sedimentation of component particles in the liquid between the pump and the pressure regulating valve can be suppressed. Further, since the check valve is disposed between the pump and the pressure adjustment valve, it is possible to suppress the pressure adjustment valve from being opened when the liquid is supplied and sucked using the pump. Further, since a pump capable of supplying liquid is used, this pump can be used as a pump for supplying an amount of liquid ejected from the recording head. Therefore, it is possible to reduce the manufacturing cost of the liquid supply mechanism as compared with a configuration including a dedicated pump in order to suppress sedimentation of component particles in the liquid.

Application Example 2 In the liquid supply mechanism according to Application Example 1, the liquid supply mechanism further includes a flexible liquid flow path disposed between the check valve and the pressure regulating valve, and the check valve includes: A liquid supply mechanism, comprising: a valve chamber that contains the liquid; and a flexible valve body that is disposed in the valve chamber, wherein the volume changing unit includes the liquid channel.

  With such a configuration, an amount of liquid corresponding to the volume that increases or decreases due to the displacement of the liquid flow path and the valve body can be supplied and sucked using the displacement of the pump and the valve body. Further, since the liquid supply path itself can change its volume, the liquid supply mechanism can be downsized compared to a configuration in which a room for changing the liquid storage amount is provided separately from the liquid supply path.

Application Example 3 The liquid supply mechanism according to Application Example 2, wherein the valve body has a bent portion that is flexible and bends in the flow direction of the liquid.

  With such a configuration, the volume of the variable volume portion can be changed using the bending of the bent portion.

Application Example 4 In the liquid supply mechanism according to Application Example 1, the volume variable unit is a liquid storage chamber that is disposed upstream of the check valve and has a flexible sheet member. .

  With such a configuration, it is possible to change the volume of the variable volume portion using the bending of the sheet member.

Application Example 5 In the liquid supply mechanism according to Application Example 4, the check valve and the volume variable section are disposed in the recording head.

  With such a configuration, sedimentation of component particles in the liquid can be suppressed between a relatively long distance pump and the recording head.

Application Example 6 A liquid ejecting apparatus including the liquid supply mechanism according to any one of Application Examples 1 to 5.

  With such a configuration, in the liquid ejecting apparatus, the sedimentation of the component particles in the liquid between the pump and the pressure regulating valve can be suppressed, so that the liquid concentration ejected from the recording head can be made uniform.

3 is an explanatory diagram illustrating a schematic configuration of a printer 500 as a liquid ejecting apparatus to which the liquid supply mechanism according to the first embodiment of the invention is applied. FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of the printer 500 when storing ink. 2 is a cross-sectional view schematically showing a cross section of a printer 500 during ink ejection. FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of the printer 500 in a left state. FIG. 5 is a cross-sectional view schematically showing a cross section of the printer 500 during ink suction in the stirring operation. FIG. 5 is a cross-sectional view schematically showing a cross section of the printer 500 when ink is supplied in a stirring operation. It is sectional drawing which shows typically the cross section of the printer 500a at the time of the ink storage in a 2nd Example. It is sectional drawing which shows typically the cross section of the printer 500a at the time of the ink ejection in a 2nd Example. It is sectional drawing which shows typically the cross section of the printer 500a of the leaving state in a 2nd Example. It is sectional drawing which shows typically the cross section of the printer 500a at the time of the ink suction in the stirring operation of a 2nd Example. It is sectional drawing which shows typically the cross section of the printer 500a at the time of the ink supply in the stirring operation of a 2nd Example.

A. First embodiment:
A1. Device configuration:
FIG. 1 is an explanatory diagram illustrating a schematic configuration of a printer 500 as a liquid ejecting apparatus to which the liquid supply mechanism according to the first embodiment of the invention is applied.

  The printer 500 of the first embodiment is an ink jet printer that can eject inks of four colors (black, cyan, magenta, yellow). The printer 500 includes a black ink ink cartridge IC1, a cyan ink cartridge IC2, a magenta ink cartridge IC3, a yellow ink cartridge IC4, a carriage 100, a recording head 150, and a guide rod 260. , Platen 270, four ink supply sections 400, 401, 402, 403, four ink outlet pipes 30, 31, 32, 33, four pipes 120, 121, 122, 123, and negative pressure generating section 300. And a control board 700.

  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 the ink outlet tube 30, the ink supply unit 400, and the piping 120. Similarly, the ink cartridge IC2 passes through the ink outlet tube 31, the ink supply unit 401, and the pipe 121, and the ink cartridge IC3 passes through the ink outlet tube 32, the ink supply unit 402, and the pipe 122, and the ink cartridge IC4. Are connected to the carriage 100 via an ink outlet pipe 33, an ink supply unit 403, and a pipe 123, respectively. 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). Note that all other components except the carriage 100 are mounted on the main body frame of the printer 500.

  The ink supply unit 400 supplies the black ink in the ink cartridge IC1 to the carriage 100 via the pipe 120. Similarly, the ink supply unit 401 supplies cyan ink in the ink cartridge IC2, the ink supply unit 402 supplies magenta ink in the ink cartridge IC3, and the ink supply unit 403 supplies yellow ink in the ink cartridge IC4 to the carriage 100, respectively. To do. Here, each color ink is a pigment-based ink, and pigment particles corresponding to each color (for example, an azo compound in a yellow pigment) are dispersed in a solvent.

  The negative pressure generating unit 300 is connected to four ink supply units 400 to 403 and is used for supplying ink to the carriage 100 in these ink supply units 400 to 403. The negative pressure generator 300 is also used to supply negative pressure to the carriage 100. Note that an ink flow path and a negative pressure supply path (not shown), which will be described later, are accommodated in the four pipes 120 to 123.

  The guide rod 260 is disposed along the longitudinal direction of the platen 270. The carriage 100 is supported so as to be reciprocable 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 from a number of nozzles (not shown) as the carriage 100 reciprocates. At this time, the recording paper P is conveyed on the platen 270 by a paper feeding mechanism (not shown), and an image or the like is formed on the recording paper P.

  The control board 700 includes a CPU (Central Processing Unit) 710 and a memory 720. The control board 700 is electrically connected to the carriage 100 and the negative pressure generator 300. The memory 720 stores a print control program and an agitation control program, and the CPU 710 functions as the print control unit 711 by executing the print control program. The print control unit 711 controls the recording head 150 and the negative pressure generation unit 300 to control ink ejection. Similarly, the CPU 710 functions as the stirring control unit 712 by executing the stirring control program. The stirring control unit 712 controls a stirring operation described later.

  The negative pressure generation unit 300 is connected to the four ink supply units 400 to 403, and supplies negative pressure to these ink supply units 400 to 403.

  FIG. 2 is a cross-sectional view schematically showing a cross section of the printer 500 during ink storage. The example of FIG. 2 shows the internal structure related to the supply of black ink, but the same applies to the internal structure related to the supply of ink of other colors. In the example of FIG. 2, for the sake of illustration, the relative positional relationship between the carriage 100 and the ink cartridge IC1 and the orientation of the carriage 100 and the ink cartridge IC1 are different from those in FIG. In the example of FIG. 2, in the state where the printer 500 is placed, the upward direction in the vertical direction coincides with the + Y direction.

  The ink outlet tube 30 has an ink outlet needle 250 at the tip, and communicates with the inside of the ink cartridge IC1 through the ink outlet needle 250.

  The ink supply unit 400 includes a first check valve 420, a pump 440, and three ink flow paths 34, 35, and 37. The ink flow path 34 allows the ink outlet pipe 30 and the first check valve 420 to communicate with each other. The ink flow path 35 allows the first check valve 420 and the pump 440 to communicate with each other. The ink flow path 37 allows the pump 440 and the piping 120 (an ink flow path 38 described later) to communicate with each other.

  The first check valve 420 is used to suppress the back flow of ink to the ink cartridge IC1. The first check valve 420 includes the valve chamber 20, the valve body 22, and the coil spring 21. The valve chamber 20 contains black ink. The valve body 22 is a thin plate-like member, and is disposed so as to be displaceable up and down in the valve chamber 20. In the example of FIG. 2, the valve body 22 is located at the uppermost position. The valve body 22 is connected to the coil spring 21 at the central portion, and is urged by the coil spring 21 in a direction to be pressed against the bottom surface 29 of the valve chamber 20. A communication hole 28 is provided in the center of the valve body 22. The communication hole 28 is closed when the valve body 22 is pressed against the bottom surface 29, and is configured to open when the valve body 22 is away from the bottom surface 29 as shown in FIG.

  The pump 440 sucks ink from the ink cartridge IC1 and pressurizes and supplies the ink to the downstream side. The pump 440 is used when performing a stirring operation described later. The pump 440 includes a pump chamber 40, a diaphragm 42, and a coil spring 41. The diaphragm 42 is a thin plate-like member having flexibility, and is arranged so as to be able to be displaced up and down in the pump chamber 40. In the example of FIG. 2, the diaphragm 42 is disposed at a position closest to the ceiling surface 48. The diaphragm 42 is connected to the coil spring 41 at the central portion, and is urged by the coil spring 41 in a direction in which the diaphragm 42 is pressed against the bottom surface 49 of the pump chamber 40. The pump chamber 40 is connected to the ink flow path 35 at the bottom surface 49, and can store ink in the space below the diaphragm 42. The pump chamber 40 is connected to the ink flow path 37 at the bottom surface 49. The pump chamber 40 is connected to the negative pressure supply path 352 on the ceiling surface 48, and the space above the diaphragm 42 is connected to the negative pressure generating unit 300 via the negative pressure supply path 352.

  The negative pressure generation unit 300 includes a suction pump and an atmosphere release mechanism (not shown), performs a suction operation using the suction pump when driven, stops the suction operation when stopped, and sets the suction destination to atmospheric pressure. Two negative pressure supply paths 352 and 354 are connected to the negative pressure generator 300.

  An ink flow path 38 and a negative pressure supply path 356 are provided inside the pipe 120. The ink flow path 38 is connected to the ink flow path 37. The negative pressure supply path 356 is connected to the negative pressure supply path 354. The pipe 120 is made of a rubber tube so as to correspond to the reciprocating motion of the carriage 100 during printing.

  The carriage 100 includes four ink flow paths 39, 50, 51, 95, a variable volume chamber 600, an atmosphere communication path 613, a second check valve 620, an atmosphere chamber 87, an atmosphere communication hole 99, A first pressure chamber 77, a valve chamber 70, a pressure regulating valve 71, a defoaming chamber 92, a defoaming partition wall 90, a decompression chamber 80, a second pressure chamber 89, and a negative pressure supply path 55. And an atmospheric pressure valve 81.

  The volume variable chamber 600 stores ink and is used in a stirring operation described later. The variable volume chamber 600 includes a flexible film 610 inside, and is connected to the ink flow path 38 at the bottom surface 614 of the variable volume chamber 600. The film 610 is joined to the side surface 611 of the variable volume chamber 600, and the central portion is configured to be vertically displaceable. In the example of FIG. 2, the film 610 is located at the lowest position. The variable volume chamber 600 is connected to the atmosphere communication path 613 on the ceiling surface 612 and communicates with the atmosphere via the atmosphere communication path 613. In the variable volume chamber 600 having the above configuration, the ink storage amount increases when the film 610 is displaced upward and decreases when the film 610 is displaced downward.

  The second check valve 620 is used to suppress the backflow of ink to the upstream side. The second check valve 620 is connected to the variable volume chamber 600 via the ink flow path 39 and is connected to a later-described valve chamber 70 via the ink flow path 50. The second check valve 620 includes a valve chamber 621, a valve body 624, and a coil spring 623. The valve chamber 621 contains ink. The valve body 624 is a thin plate-like member, and is disposed so as to be vertically displaceable within the valve chamber 621. In the example of FIG. 2, the valve body 624 is located at the lowest position. The valve body 624 is connected to a coil spring 623 at the central portion, and is biased by the coil spring 623 in a direction to be pressed against the bottom surface 629 of the valve chamber 621. A communication hole 628 is provided in the center of the valve body 624. As shown in FIG. 2, the communication hole 628 is closed when the valve body 624 is pressed against the bottom surface 629, and is configured to open when the valve body 624 is away from the bottom surface 629.

  The atmosphere chamber 87 communicates with the atmosphere via the atmosphere communication hole 99. The first pressure chamber 77 temporarily stores ink. The first pressure chamber 77 is adjacent to the atmospheric chamber 87 through a partition wall portion 88a that is a ceiling portion. The partition wall portion 88a has flexibility and can be displaced in the vertical direction. The partition wall portion 88a can be formed of, for example, a film made of synthetic resin, rubber, or the like and a cantilever (not shown) thin plate member that can be displaced together with the film. The first pressure chamber 77 includes an ink inlet 76, and can communicate with a valve chamber 70 described later via the ink inlet 76. The first pressure chamber 77 communicates with the defoaming chamber 92 via the ink flow path 51.

  The valve chamber 70 contains the pressure regulating valve 71 and accommodates ink. The pressure regulating valve 71 causes the valve chamber 70 and the first pressure chamber 77 to communicate or not communicate with each other according to a change in pressure of at least one of the valve chamber 70 and the first pressure chamber 77. The pressure adjustment valve 71 includes a valve body 72, a pressure adjustment spring 73, a seal member 75, and a support rod 74. One end of a support rod 74 is joined to the center of the valve body 72, and a seal member 75 is disposed so as to surround this joined portion. The valve body 72 is disposed so as to be vertically displaceable within the valve chamber 70. The valve body 72 and the bottom surface 79 of the valve chamber 70 are connected by a pressure adjusting spring 73, and the valve body 72 is urged by the pressure adjusting spring 73 in a direction to be pressed against the ceiling surface 78 of the valve chamber 70. In the example of FIG. 2, the valve body 72 is located at the uppermost position. At this time, the seal member 75 contacts the ceiling surface 78 of the valve chamber 70 and seals the ink inlet 76.

  The valve body 72 includes a force that pushes down the valve body 72 (pressing force of the support rod 74 by the partition wall portion 88a and pressure in the first pressure chamber 77) and force that pushes up the valve body 72 (pressure and pressure in the valve chamber 70). The biasing force of the adjusting spring 73). When the pushing force becomes larger than the pushing force, the valve body 72 is displaced downward, the ink inlet 76 is opened, and the valve chamber 70 and the first pressure chamber 77 communicate with each other.

  The support rod 74 is included in the first pressure chamber 77 and the valve chamber 70, and is joined to the partition wall 88 a at the end on the side not joined to the valve body 72.

  The defoaming chamber 92 is used to temporarily store the ink flowing in from the ink flow path 51 and collect and remove bubbles in the ink in the defoaming partition wall 90. The defoaming chamber 92 includes a filter 93 inside. The filter 93 filters impurities in the ink and suppresses inflow of large bubbles into the recording head 150. The ink stored in the defoaming chamber 92 is supplied to the recording head 150 via the filter 93 and the ink flow path 95.

  The defoaming partition wall 90 is formed of a gas-permeable sheet-like member, and allows the bubbles trapped in the defoaming chamber 92 to pass through and flow into the decompression chamber 80.

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

  The second pressure chamber 89 is used to supply the negative pressure supplied from the negative pressure generator 300 to the decompression chamber 80. The second pressure chamber 89 is connected to the negative pressure supply path 55. The negative pressure supply path 55 is connected to the negative pressure supply path 356 in the pipe 120. The second pressure chamber 89 is adjacent to the atmospheric chamber 87 through the partition wall portion 88b. The second partition wall portion 88b has the same configuration as the first partition wall portion 88a described above.

  The atmospheric pressure valve 81 is included in the second pressure chamber 89 and the decompression chamber 80, and allows the second pressure chamber 89 and the decompression chamber 80 to communicate or not communicate with each other. The atmospheric pressure valve 81 has the same configuration as the pressure adjustment valve 71 described above. That is, the atmospheric pressure 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, the valve body 82 is disposed in the open position. The seal member 85 seals the communication hole 86 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.

  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 ink supply unit 400, the variable volume chamber 600, and the second check valve 620 described above correspond to the liquid supply mechanism in the claims. The valve chamber 70 and the first pressure chamber 77 are the two liquid storage chambers in the claims, the second check valve 620 is the check valve in the claims, and the variable volume chamber 600 is the variable volume portion in the claims. The film 610 corresponds to a sheet member in claims.

A2. Ink supply operation:
Hereinafter, an ink supply operation to the carriage 100 will be described with reference to FIGS. 2 and 3. FIG. 3 is a cross-sectional view schematically showing a cross section of the printer 500 during ink ejection. First, an operation of storing ink to be supplied to the carriage 100 in the pump 440 will be described with reference to FIG.

  The print control unit 711 (FIG. 1) drives the negative pressure generating unit 300 (FIG. 2) to perform a suction operation via the negative pressure supply paths 352 and 354. Then, the space above the diaphragm 42 becomes negative pressure in the pump chamber 40, and the diaphragm 42 overcomes the urging force of the coil spring 41 and is elastically deformed and displaced upward. As a result, the pump 440 performs a suction operation, and sucks ink stored in the space above the valve body 22 in the valve chamber 20 via the ink flow path 35. In the first check valve 420, the valve body 22 overcomes the urging force of the coil spring 21 and is elastically deformed to be displaced upward. At this time, the communication hole 28 is opened in the valve body 22, and the first check valve 420 is opened. Therefore, the black ink in the ink cartridge IC1 flows into the first check valve 420 (valve chamber 20) via the ink outlet needle 250, the ink outlet pipe 30, and the ink flow path 34, and further the ink flow. It flows into the pump 440 (the space below the diaphragm 42) through the passage 35.

  In addition to the ink suction operation from the ink cartridge IC1 described above, the suction operation of the ink stored in the variable volume chamber 600 is also performed. Specifically, as the diaphragm 42 is displaced upward, the ink stored in the space below the film 610 in the variable volume chamber 600 is sucked into the pump 440 via the two ink flow paths 37 and 38. The At this time, the pressure in the lower space (on the ink flow path 38 side) across the film 610 in the variable volume chamber 600 is lower than the pressure in the upper space (atmospheric pressure), so the film 610 is displaced downward. Here, in the second check valve 620, the valve body 624 is sucked through the ink flow path 39, but is pressed against the bottom surface 629, so that the communication hole 628 is closed. Accordingly, the ink flow through the second check valve 620 is suppressed, and the ink upstream of the second check valve 620 is not sucked by the pump 440.

  When the ink is ejected from the nozzles (not shown) provided on the nozzle plate 152 and the ink is consumed after the ink storage operation to the pump 440 is completed, the chamber pressure of the first pressure chamber 77 is reduced. It decreases by. Then, as shown in FIG. 3, due to the differential pressure between the decompressed chamber pressure and the pressure (atmospheric pressure) of the atmospheric chamber 87, the partition wall portion 88 a bends to the inside of the first pressure chamber 77 and is displaced downward. 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 displaced downward, the ink inlet 76 is opened and the ink flows into the first pressure chamber 77.

  At this time, the print controller 711 (FIG. 1) stops the suction operation of the pump 440 (FIG. 3). Then, in the pump 440, the diaphragm 42 is pushed downward by the urging force of the coil spring 41, and the ink stored in the pump 440 is pressurized and supplied to the ink flow path 37. The ink supplied to the ink flow path 37 flows into the second check valve 620 via the two ink flow paths 38 and 39. At this time, the film 610 of the variable volume chamber 600 is displaced upward.

  In the second check valve 620, since pressurized ink is supplied, the valve body 624 overcomes the urging force of the coil spring 623 and is displaced upward, and the communication hole 628 is opened. Accordingly, the pressurized ink flows into the valve chamber 70 through the communication hole 628 and the ink flow path 50, and further flows into the first pressure chamber 77 through the opened ink inlet 76.

  When ink flows into the first pressure chamber 77 and the chamber pressure increases, the partition wall portion 88a is displaced upward. Along with this, when the valve body 72 moves upward again to seal the ink inlet 76, 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 so that the consumed amount of ink appropriately flows into the recording head 150 by opening and closing the pressure adjustment valve 71 according to the consumption of ink.

  FIG. 4 is a cross-sectional view schematically showing a cross section of the printer 500 in the neglected state. After finishing the printing operation, the printer 500 performs the ink storage operation to the pump 440 described above to prepare for the next printing operation (ink ejection operation). When left in this state for a long time, or when the printer 500 is turned off and left for a long time, pigment particles in the ink settle in each ink flow path in the printer 500. In particular, since the two ink flow paths 37 and 38 located between the pump 440 and the carriage 100 are long, a large amount of ink exists. Accordingly, the pigment particles settle in the ink flow paths 37 and 38. Therefore, the printer 500 is configured to suppress the sedimentation of pigment particles in the ink by performing a stirring operation described later.

  When printing is not performed and the ink is left for a long time, the gas dissolved in the ink is released to the atmosphere through the wall surface of the ink flow path. Accordingly, the diaphragm 42 of the pump 440 is slightly displaced downward as shown in FIG. Note that the film 610 of the variable volume chamber 600 maintains a state of being displaced upward.

A3. Defoaming action:
Hereinafter, the defoaming operation in the printer 500 will be briefly described. The negative pressure is supplied to the second pressure chamber 89 via the two negative pressure supply paths 354 and 55 by driving the negative pressure generating unit 300 during ink storage (FIG. 2). Then, the second partition wall portion 88b bends downward due to the pressure difference between the pressure in the second pressure chamber 89 and the pressure in the atmospheric chamber 87 (atmospheric pressure), so that the support rod 84 and the valve element 82 are pushed down. The communication hole 86 is opened. Therefore, the decompression chamber 80 has a negative pressure. At this time, the bubbles collected on the defoaming partition wall 90 side in the defoaming chamber 92 permeate the defoaming partition wall 90 and flow into the decompression chamber 80 due to the differential pressure between the decompression chamber 80 and the defoaming chamber 92. And removed from the defoaming chamber 92. Further, the second pressure chamber 89 becomes atmospheric pressure due to the stop of the negative pressure generating unit 300 at the time of ink ejection described above (FIG. 3). Therefore, the pressure difference between the second pressure chamber 89 and the atmospheric chamber 87 disappears, the support rod 84 and the valve body 82 are displaced upward, and the communication hole 86 is sealed. Therefore, the decompression chamber 80 is maintained at a negative pressure, and the bubbles in the defoaming chamber 92 are continuously removed. Note that a negative pressure is also supplied to the second pressure chamber 89 during ink suction in the stirring operation described above. However, since the driving period of the pump 440 is short, the second partition wall portion 88b is hardly displaced and the atmospheric pressure valve 81 is not opened.

A4. Stirring action:
FIG. 5 is a cross-sectional view schematically showing a cross section of the printer 500 during ink suction in the stirring operation. FIG. 6 is a cross-sectional view schematically showing a cross section of the printer 500 when ink is supplied in the stirring operation. In the printer 500, when printing is not performed for a long time with the power off, the stirring operation is periodically performed. The stirring operation is also performed when the printer 500 is turned on. The reason why the stirring operation is performed when the power is turned on is that the power is generally left for a long time when the power is turned off. This stirring operation is realized by sucking and supplying ink using the pump 440.

  Specifically, first, the agitation controller 712 (FIG. 1) drives the negative pressure generator 300 (FIG. 5). Accordingly, as shown in FIG. 5, the diaphragm 42 is displaced upward, and the pump 440 performs an ink suction operation. At this time, the displacement amount of the diaphragm 42 is small and the suction force of the pump 440 is weak. However, since the rigidity of the film 610 in the variable volume chamber 600 is weak, the film 610 is displaced downward by the suction operation of the pump 440. Therefore, the ink in the variable volume chamber 600 and the ink in the two ink flow paths 37 and 38 flow toward the pump 440. By the ink flow, the ink is stirred in the two ink flow paths 37 and 38, and the precipitation of the pigment component is suppressed. At this time, since the second check valve 620 maintains a closed state, ink upstream from the second check valve 620 is not sucked. Accordingly, the pressure regulating valve 71 is opened, and the suction of the ink on the defoaming chamber 92 or the recording head 150 side to the upstream side is suppressed.

  In contrast, the rigidity of the valve body 22 of the first check valve 420 is stronger than that of the film 610, and the coil spring 21 is pressed in the direction in which the valve body 22 of the first check valve 420 is pressed against the bottom surface 29. The urging force is acting. Therefore, the valve body 22 is not displaced by the weak suction force of the pump 440 and maintains a state of being pressed against the bottom surface 29. Therefore, ink is not supplied from the ink cartridge IC1 to the pump 440.

  Next, the stirring control unit 712 stops the negative pressure generating unit 300. In addition, since the upward displacement of the diaphragm 42 during the suction is small, the stirring control unit 712 drives the negative pressure generating unit 300 for a short period and then stops it. The driving period of the negative pressure generating unit 300 can be obtained and set in advance through experiments or the like. In addition, it can also be set as the structure which detects that the diaphragm 42 was located in the uppermost position with a sensor, and stops the negative pressure generation part 300. FIG. With such a configuration, useless driving of the negative pressure generating unit 300 can be suppressed.

  As the negative pressure generating unit 300 stops, the diaphragm 42 is displaced downward as shown in FIG. 6, and the pump 440 performs an ink supply operation. The ink supplied from the pump 440 is supplied to the variable volume chamber 600 through the two ink flow paths 37 and 38. In this case, the film 610 in the variable volume chamber 600 is displaced upward, and the supplied ink is stored in the variable volume chamber 600. On the other hand, the ink supply to the first check valve 420 is blocked by the valve body 22. Therefore, the amount of ink sucked from the variable volume chamber 600 to the pump 440 by the ink suction operation (FIG. 5) in the above-described stirring operation is returned to the variable volume chamber 600 by this ink supply operation (FIG. 6). By the ink flow, the ink is stirred in the two ink flow paths 37 and 38, and the precipitation of the pigment component is suppressed. Here, since the rigidity of the film 610 is weaker than that of the valve body 624 of the second check valve 620, and the urging force of the coil spring 623 is applied to the valve body 624, the film 610 is supplied by supplying ink. In contrast to the displacement, the valve body 624 is not displaced. Therefore, in the second check valve 620, the communication hole 628 is kept closed.

  As described above, the printer 500 according to the first embodiment includes the variable volume chamber 600 having the flexible film 610 with low rigidity between the pump 440 and the pressure adjustment valve 71, so that the volume can be changed. Ink corresponding to a variable volume in the chamber 600 can be caused to flow between the pump 440 and the variable volume chamber 600 using the pump 440. Therefore, the sedimentation of the pigment particles in the ink flow paths 37 and 38 can be suppressed. Further, since the printer 500 includes the second check valve 620 between the pump 440 and the pressure adjustment valve 71, the opening and closing of the pressure adjustment valve 71 accompanying the stirring operation can be suppressed. Therefore, ink can be prevented from leaking from the recording head 150 during the stirring operation. In addition, since the pump for stirring operation and the pump 440 for supplying ink to the carriage 100 are used together, the manufacturing cost of the printer 500 can be reduced compared to a configuration including a pump dedicated for stirring operation separately from the pump 440. The printer 500 can be reduced in size.

B. Second embodiment:
B1. Device configuration:
FIG. 7 is a cross-sectional view schematically showing a cross section of the printer 500a during ink storage in the second embodiment. In the printer 500a of the second embodiment, the ink supply unit 400a includes the third check valve 460, and the carriage 100a does not include the variable volume chamber 600 and the second check valve 620. Unlike the printer 500 (FIGS. 1 to 6), the other structure is the same as that of the first embodiment in that the ink flow path 38a has flexibility.

  The ink supply unit 400 a includes a third check valve 460 on the downstream side of the pump 440. The third check valve 460 is connected to the pump 440 via the ink flow path 37. The third check valve 460 suppresses the back flow of ink to the pump 440 and suppresses the pressure adjustment valve 71 from being opened by the ink suction operation of the pump 440. The third check valve 460 includes a valve chamber 60, a valve body 62, and a coil spring 61. The valve chamber 60 stores ink. The valve body 62 is disposed so as to be vertically displaceable within the valve chamber 20. In the example of FIG. 2, the valve body 62 is located at the lowest position. The valve body 62 is connected to the coil spring 61 at the central portion, and is biased by the coil spring 61 in a direction to be pressed against the bottom surface 69 of the valve chamber 60. A communication hole 68 is provided in the center of the valve body 62. In the state where the valve element 62 is pressed against the bottom surface 29 as shown in FIG. 7, the communication hole 68 does not allow the ink flow path 37 and the space above the valve element 62 to communicate with each other. The ink flow path 37 and the upper space of the valve body 62 are configured to communicate with each other in a state of being away from the center. In the valve body 62, a bent portion 63 having flexibility and a cross-sectional shape is formed around the communication hole 68. The bent portion 63 can be in one of a state protruding upward and a state protruding downward. In the example of FIG. 7, the bent portion 63 is in a state of protruding downward. The change (displacement) of the state of the bent portion 63 can be performed independently of the displacement of the valve body 62.

  The ink flow path 38a disposed in the pipe 120 has flexibility, and expands or contracts according to the pressure of the ink to be stored, and the cross-sectional area can change. As such an ink flow path 38a, for example, a thin tube formed of an elastomer such as butyl rubber or silicon rubber can be employed. The ink flow path 38 a is connected to the space above the valve body 62 in the valve chamber 60 of the third check valve 460. In the carriage 100 a, the valve chamber 70 is connected to the ink flow path 38 a through the ink flow path 50.

  In the second embodiment, the third check valve 460 corresponds to the check valve in the claims. Further, the ink flow path 38a is a liquid flow path in the claims, the valve chamber 60 is a valve chamber in the claims, the valve body 62 is a valve body in the claims, and the space above the valve body 62 in the valve chamber 60 and the ink flow. The path 38a corresponds to the variable volume portion in the claims.

B2. Ink supply operation:
As in the first embodiment, when the negative pressure generator 300 (FIG. 7) is driven, ink is supplied from the ink cartridge IC1 to the pump 440. At this time, in the third check valve 460, the valve body 62 is pressed against the bottom surface 69 by the suction operation of the pump 440, so that the communication hole 68 remains closed. Accordingly, the ink upstream of the third check valve 460 is not sucked by the pump 440. Here, the bending portion 63 protrudes downward due to the suction force of the pump 440.

  FIG. 8 is a cross-sectional view schematically showing a cross section of the printer 500a during ink ejection in the second embodiment. Similar to the first embodiment, when ink is ejected, the amount of ink in the first pressure chamber 77 is reduced and the pressure regulating valve 71 is opened. Further, when the negative pressure generating unit 300 stops, the ink flows out from the pump 440 to the ink flow path 37.

  In the third check valve 460, since pressurized ink is supplied, the valve body 62 is displaced upward and the communication hole 68 is opened. Accordingly, the pressurized ink is supplied to the ink flow path 38a via the third check valve 460. At this time, the ink flow path 38a expands and the cross-sectional area increases. Then, as in the first embodiment, ink is supplied to the first pressure chamber 77 through the ink flow path 50, the valve chamber 70, and the ink inlet 76, the pressure adjustment valve 71 is closed, and the ink supply is completed. .

  FIG. 9 is a cross-sectional view schematically showing a cross section of the printer 500a in a neglected state in the second embodiment. After being left for a long period of time, the diaphragm 42 of the pump 440 is displaced slightly downward from the uppermost position as in the first embodiment. The ink flow path 38a is also slightly contracted, but is not shown for convenience of explanation. In such a neglected state, the agitating operation is performed in the printer 500a of the second embodiment as in the first embodiment.

  FIG. 10 is a cross-sectional view schematically showing a cross section of the printer 500a during ink suction in the stirring operation of the second embodiment. FIG. 11 is a cross-sectional view schematically showing a cross section of the printer 500a when ink is supplied in the stirring operation of the second embodiment.

  As shown in FIG. 10, in the stirring operation of the second embodiment, first, the diaphragm 42 is displaced upward as in the first embodiment, and the ink suction operation of the pump 440 is performed. Since the bent portion 63 of the third check valve 460 is less rigid than the valve body 22 of the first check valve 420, the bent portion 63 protrudes downward due to the suction operation of the pump 440. Accordingly, the ink in the ink flow path 37 flows toward the pump 440. Here, since the rigidity of the ink flow path 38a is weak, the ink flow path 38a contracts, and the ink stored in the ink flow path 38a flows toward the third check valve 460 (valve chamber 60). . At this time, since the ink supplied from the ink flow path 38a is accommodated in the space above the valve body 62, the pressure in the valve chamber 70 does not change. Therefore, the pressure adjustment valve 71 does not open, and the ink downstream of the pressure adjustment valve 71 does not flow toward the third check valve 460.

  Next, an ink supply operation is performed in the pump 440 as in the first embodiment. At this time, as shown in FIG. 11, the bent portion 63 of the third check valve 460 protrudes upward due to its low rigidity, and the ink flowing out from the pump 440 passes through the ink flow path 37. The valve chamber 60 is accommodated below the bent portion 63. Accompanying the displacement of the bent portion 63, the ink stored in the space above the bent portion 63 in the valve chamber 60 is supplied to the ink flow path 38a. When ink is supplied from the valve chamber 60, the ink flow path 38a expands and stores the supplied ink.

  The printer 500a of the second embodiment having the above configuration has the same effect as the printer 500 of the first embodiment. In addition, since the mechanism for stirring operation is not provided in the carriage 100a, the manufacturing cost of the carriage 100a can be suppressed and the carriage 100a can be downsized. Further, since the ink flow path 38a itself expands and contracts to change the volume and change the ink storage amount, the printer main body and the carriage 100a can be made smaller than the configuration in which the room for changing the ink storage amount is provided. Can be

C. 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.

C1. Modification 1:
In the first embodiment, the variable volume chamber 600 and the second check valve 620 are disposed in the carriage 100, but may be disposed in the printer main body instead. In this case, by connecting the variable volume chamber 600 to the pump 440 via the ink flow path 37, sedimentation of pigment particles in the ink flow path 37 can be suppressed. In such a configuration, the printer main body corresponds to the liquid supply mechanism and the liquid supply device in the claims. In the second embodiment, the third check valve 460 is disposed in the printer main body. Instead, the third check valve 460 is disposed in the carriage 100a (for example, between the ink flow path 50 and the valve chamber 70). It can also be arranged. That is, in general, a check valve and a variable volume portion arranged between the pump and the pressure regulating valve can be employed in the liquid supply mechanism and the liquid ejecting apparatus of the present invention.

C2. Modification 2:
In the first embodiment, the variable volume chamber 600 increases or decreases the amount of ink stored as the film 610 is displaced up and down, but the present invention is not limited to such a configuration. For example, it is possible to employ a configuration in which a piston that moves up and down in the variable volume chamber 600 is arranged and the amount of ink stored is increased or decreased by moving the piston up and down. That is, in general, a variable volume portion whose volume can be changed can be employed in the liquid supply mechanism and the liquid ejecting apparatus of the present invention.

C3. Modification 3:
In the second embodiment, the valve body 62 has the bent portion 63. Instead, the valve body 62 is formed flat using a thin film member having an elastomer as a base material, and the ink pressure is increased. It can also be configured to bend depending on.

C4. Modification 4:
In the first and second embodiments, the diaphragm 42 is disposed at the uppermost position during ink suction in the stirring operation. Alternatively, the diaphragm 42 may be disposed at a position lower than the uppermost position. In the first and second embodiments, the position of the diaphragm 42 in the neglected state is a position slightly lowered from the uppermost position, but the present invention is not limited to this. For example, the present invention can be applied even when the diaphragm 42 is located at the lowest position. Specifically, for example, when the stirring operation is performed in a state where the diaphragm 42 is located at the lowest position, first, the negative pressure generating unit 300 is driven for a short time, and the diaphragm 42 is slightly displaced upward. Then, the negative pressure generator 300 is stopped and the diaphragm 42 is lowered downward. Even in this case, the ink flows in the two ink flow paths 37 and 38, and the sedimentation of the pigment particles can be suppressed. In this configuration, the period during which the first check valve 420 is not opened by the suction force of the pump 440 can be obtained by experiment and set as the period for driving the negative pressure generating unit 300.

C5. Modification 5:
In the first and second embodiments, the pump 440 is a diaphragm pump. However, any type of pump that can supply and suck ink, such as a gear pump and a piston pump, can be used instead. . In the first and second embodiments, the pump 440 is also used as a pump for supplying ink to the carriages 100 and 100a and a stirring operation pump, but instead, a pump for each application is used. Can also be provided. That is, in general, a pump that supplies and sucks liquid can be employed in the liquid supply mechanism and the liquid ejecting apparatus of the present invention.

C6. Modification 6:
In the second embodiment, the entire ink flow path 38a is expanded and contracted, but instead, only a part of the flow path may be expanded and contracted. For example, such a configuration can be realized by configuring only a part of the ink flow path 38a as a portion having flexibility and a small thickness.

C7. Modification 7:
In the first and second embodiments, four types of ink were used, but any type of ink can be used instead. For example, metallic ink can be adopted. When metallic ink is employed, sedimentation of component particles (for example, aluminum) in the ink can be suppressed in the ink flow paths 37 and 38.

C8. Modification 8:
In the first and second embodiments, the printers 500 and 500a are off-carriage type printers. Instead, a so-called on-carriage type printer in which an ink cartridge is mounted on a carriage may be employed.

C9. Modification 9:
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.

  IC1 to IC4 ... ink cartridge, 20 ... valve chamber, 21 ... coil spring, 22 ... valve body, 28 ... communication hole, 29 ... bottom surface, 30-33 ... ink outlet tube, 34-39, 38a, 50, 51, 95 ... Ink flow path, 40 ... pump chamber, 41 ... coil spring, 42 ... diaphragm, 48 ... ceiling surface, 49 ... bottom surface, 55 ... negative pressure supply path, 60 ... valve chamber, 61 ... coil spring, 62 ... valve body, 63 ... bent , 68 .. communication hole, 69 .. bottom surface, 70... Valve chamber, 71... Pressure regulating valve, 72 .. valve body, 73 .. pressure regulating spring, 74 .. support rod, 75. DESCRIPTION OF SYMBOLS 1st pressure chamber, 78 ... Ceiling surface, 79 ... Bottom surface, 80 ... Decompression chamber, 81 ... Pressure valve, 82 ... Valve body, 83 ... Pressure adjustment spring, 84 ... Support rod, 85 ... Seal member, 86 ... Communication hole , 87 ... atmospheric chamber, 88 ... 1st partition part, 88b ... 2nd partition part, 89 ... 2nd pressure chamber, 90 ... Degassing partition part, 92 ... Defoaming chamber, 93 ... Filter, 99 ... Air communication hole, 100, 100a ... Carriage, 120-123 ... Piping, 150 ... Recording head, 152 ... Nozzle plate, 154 ... Ink ejection flow path, 250 ... Ink discharge needle, 260 ... Guide rod, 270 ... Platen, 300 ... Negative pressure generating unit, 352, 354, 356 ... negative pressure supply path, 400 to 403, 400a ... ink supply section, 420 ... first check valve, 440 ... pump, 460 ... third check valve, 500, 500a ... printer, 600 ... variable volume chamber, 610 ... Film, 611 ... Side, 612 ... Ceiling, 613 ... Atmospheric communication path, 614 ... Bottom, 620 ... Second check valve, 621 ... Valve chamber, 623 ... Coil spring, 624 ... Valve body, 6 8 ... communication hole, 629 ... bottom, 700 ... control board, 711 ... print control unit, 712 ... agitation control unit, 720 ... memory, P ... recording paper

Claims (6)

Two liquid storage chambers that store liquids adjacent to each other, and a pressure regulating valve that communicates or disconnects the two liquid storage chambers according to a change in pressure in at least one of the two liquid storage chambers. A liquid supply mechanism for supplying the liquid to a recording head having:
A pump for supplying and suctioning the liquid;
A check valve disposed between the pump and the pressure regulating valve to suppress the flow of the liquid to the upstream side;
A volume variable portion that is disposed between the pump and the pressure regulating valve and capable of changing a volume;
A liquid supply mechanism. The liquid supply mechanism according to claim 1, further comprising:
A flexible liquid flow path disposed between the check valve and the pressure regulating valve;
The check valve has a valve chamber for storing the liquid and a flexible valve body disposed in the valve chamber,
The volume variable unit is a liquid supply mechanism including the liquid channel. The liquid supply mechanism according to claim 2, wherein
The said valve body is a liquid supply mechanism which has a bending part which has flexibility and bends in the flow direction of the said liquid. The liquid supply mechanism according to claim 1,
The volume variable section is a liquid supply mechanism that is a liquid storage chamber that is disposed upstream of the check valve and includes a flexible sheet member. The liquid supply mechanism according to claim 4, wherein
The non-return valve and the variable volume portion are liquid supply mechanisms arranged in the recording head.   A liquid ejecting apparatus comprising the liquid supply mechanism according to any one of claims 1 to 5.

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