JP2011251495A - Liquid ejection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection apparatus capable of suppressing gas from being mixed with liquid and supplying the liquid to a liquid ejection head.SOLUTION: The liquid ejection apparatus includes: a recording head 26 ejecting ink to paper; an ink flow path 32 capable of supplying the ink from the upstream side being the side of an ink cartridge 31 to the downstream side being the side of the recording head 26; a one-way valve 51 provided at a pressure adjustment position PT in the ink flow path 32 and permitting the passage of the ink from the upstream side to the downstream side; a maintenance pump 61 connected to a pressure changing position PH on the downstream side from the pressure adjustment position PT in the ink flow path 32 and performing a pressure reduction operation and a pressurization operation; and an opening-closing valve capable of closing a connection flow path. The maintenance pump 61 performs the pressure reduction operation in such a state that the first stop valve is opened to suck the ink from a connection port, and then, performs the pressurization operation to discharge the ink from the connection port. After that, the maintenance pump performs the pressure reduction operation in such a state that the first opening-closing valve is closed and keeps such a state that drive is stopped after the pressure reduction operation is performed.

Description

  The present invention relates to a liquid ejecting apparatus such as an ink jet printer.

  Conventionally, ink jet printers are widely known as liquid ejecting apparatuses that eject liquid onto a target. This printer performs printing (image formation) on a target by ejecting ink (liquid) supplied to a recording head (liquid ejecting head) from a nozzle formed on the recording head.

  In such a printer, when bubbles are generated in the ink in the recording head, it is impossible to eject the ink from the nozzles, and the print quality is deteriorated. Therefore, in such a printer, for example, as described in Patent Document 1, by supplying ink from the ink cartridge side that stores ink to the recording head side under pressure, air bubbles are pushed out of the nozzle opening and discharged together with the ink. The nozzle recovery process (pressure cleaning) is performed.

JP 2007-152725 A

  By the way, in Patent Document 1, ink is pressurized and supplied by displacing a flexible film by air pressure. However, in a film having flexibility, the gas barrier property is low, and the gas that has permeated through the film is dissolved in the ink, and the dissolved gas may be generated as bubbles.

  In addition, since the possibility of gas permeating into the ink increases as the surface area of the flow path increases, the gas may be more dissolved in the ink when the pressurizing portion is larger than the flow path as in Patent Document 1. There is.

  Therefore, as in Patent Document 1, not the pressure supply based on the displacement of the film, but the flow path between the recording head and the ink cartridge is branched, and the decompression operation and the pressure operation are performed at the end of the branched flow path. A method of supplying pressure by connecting a possible pump is conceivable. However, even when ink is supplied under pressure using a pump, there is a possibility that gas may be dissolved in the ink remaining in the branched flow path.

  The present invention has been made in view of the above problems, and an object thereof is to provide a liquid ejecting apparatus capable of suppressing the gas from being dissolved in the liquid and supplying the liquid to the liquid ejecting head. It is in.

  In order to achieve the above object, a liquid ejecting apparatus of the present invention includes a liquid ejecting head that ejects liquid to a target, and a liquid that flows from an upstream side that is a liquid supply source side to a downstream side that is the liquid ejecting head side A liquid supply channel that can be supplied, a one-way valve that is provided at a first position in the liquid supply channel and that allows the liquid to pass from the upstream side to the downstream side, and the first channel in the liquid supply channel. A connection port provided at a second position downstream of the position 1, a pump connected to a connection flow path extending from the connection port and performing a pressure reducing operation and a pressure operation, and the pump and the connection port. An opening / closing valve disposed between the opening and closing the connection flow path, and the pump performs a pressure reducing operation while the opening / closing valve is opened to perform a pressure operation after sucking the liquid from the connection port. Discharging the liquid from the connection port, Maintaining a reduced pressure state when the said drive stop stops the drive after depressurization operation while closing the on-off valve.

  According to this configuration, when the pump is depressurized with the open / close valve opened, the liquid is sucked from the liquid supply channel via the connection channel and the connection port. Then, when the pump pressurizes with the open / close valve opened, the liquid is discharged to the second position of the liquid supply channel via the connection channel and the connection port. A one-way valve that restricts the passage of the liquid from the downstream side to the upstream side is provided at the first position upstream of the second position of the liquid supply channel. Therefore, the liquid ejected to the second position in the liquid supply channel is supplied to the liquid ejecting head side, and the liquid ejecting head is pressure-cleaned. Furthermore, when the pump is depressurized while the on-off valve is closed, the inflow of liquid from the liquid supply flow path is restricted, and therefore the pressure in the pump and the connection flow path connected to the pump is reduced. And the decompression state is maintained in the connection flow path even if the pump stops driving. Therefore, for example, even when the pump stops when the liquid in the connection channel is in contact with the gas, the pressure of the gas is low compared to the case where it is in contact with the high-pressure gas because the pressure of the gas is low. Gas penetration is suppressed. Therefore, it is possible to suppress the gas from being dissolved in the liquid and supply the liquid to the liquid ejecting head.

  In the liquid ejecting apparatus according to the aspect of the invention, the pump may include the end of the pressurization operation after the decompression operation with the on-off valve opened and the start of the decompression operation with the on-off valve closed. The liquid level of the liquid in the connection flow path is positioned closer to the pump than the on-off valve.

  According to this configuration, since the liquid level is located on the pump side with respect to the on-off valve, even when the liquid and the gas are in direct contact with each other, the gas is discharged to the liquid supply channel beyond the on-off valve. Can be suppressed.

  In the liquid ejecting apparatus according to the aspect of the invention, the pump may be provided with a connection portion connected to the connection flow path on one end side in the length direction, and an internal space with respect to the atmosphere on the other end side in the length direction. A tube provided with an opening to be opened and having at least an intermediate portion in the length direction having elasticity, and a pump frame having a support surface having an arcuate cross section capable of supporting the intermediate portion of the tube along the length direction; , A tube pump comprising a pressing member that can freely move around an axis that is an arc center of the support surface so as to close the inner space of the tube between the support surface and the tube pump, When the pressure member performs a pressure reducing operation by displacing in the direction approaching the opening in the length direction of the tube while crushing the intermediate portion of the tube. To operate under pressure by the pressing member is displaced in a direction approaching to the connection portion.

  According to this configuration, since the liquid can be pressurized with the movement of the pressing member, for example, as compared with the case where the gas in the tube is compressed and the pressure of the compressed gas is applied to the liquid to pressurize the liquid. Thus, the gas can be prevented from dissolving in the liquid.

  In the liquid ejecting apparatus according to the aspect of the invention, the pump may include a connection portion connected to the connection flow path on one end side in the length direction and a blocking portion on the other end side in the length direction. A tube having elasticity in at least an intermediate portion in the longitudinal direction, a pump frame having a support surface having an arcuate cross section capable of supporting the intermediate portion of the tube along its length direction, and the tube with respect to the support surface A pressing member that can freely move circularly about an axis that is an arc center of the support surface between a closed section that closes the internal space of the tube by pressing and a non-closed section different from the closed section In the tube pump, the pressing member circularly moves in one direction approaching the blocking portion in the length direction of the tube, and the tube pump is configured so that the pressing member moves the blocking section. While depressurization operation by circular motion to serial direction, the pressing member is operated pressurization by moving from the closed section by circular movement in the one direction to said non-block section.

  According to this configuration, the pressure reducing operation and the pressurizing operation of the tube pump can be performed by circularly moving the pressing member in one direction. That is, when the pressing member is positioned in the closed section and the tube is crushed in a single direction approaching the closed portion while being crushed, the volume in the internal space closer to the connecting portion than the crushed position in the tube Increases and the pressure is reduced. Therefore, when the on-off valve is opened, the liquid is sucked from the connection port, and the tube pump is depressurized. At this time, the volume of the internal space closer to the closing portion than the position crushed by the pressing member is reduced, and the gas in the internal space is compressed. Then, when the pressing member further moves to the non-occluding section by circular movement in one direction approaching the closing part, the liquid is pushed back to the connection port side by the pressure of the gas compressed in the internal space on the closing part side and discharged. Therefore, the tube pump is pressurized. Accordingly, since the pressure member can be circularly moved in one direction to perform the pressure reducing operation and the pressure applying operation, the tube pump is compared with the case where the pressure member is circularly moved in both directions to perform the pressure reducing operation and the pressure operating operation. The configuration can be simplified.

  In the liquid ejecting apparatus according to the aspect of the invention, the pump frame includes a cutout portion in which a part of the support surface is cut out in a circumferential direction centering on the axis, and the pressing member is located on the support surface. A closed section where the inner space of the tube is closed by pressing the tube and a non-closed section where the pressing member is not in the notch are positioned on a circular motion locus of the pressing member.

  According to this configuration, since the closed section and the non-closed section are positioned on the circular motion trajectory of the pressing member, the pressing member can be positioned in the closed section and the non-closed section with the circular motion. . When the pressing member is located in the non-blocking section, the blocking of the tube is released and the internal space communicates. Therefore, the pressure in the internal space of the tube can be easily adjusted by the amount of movement of the pressing member from the non-occluding section.

In the liquid ejecting apparatus according to the aspect of the invention, a filter may be provided on the connection port side with respect to the on-off valve in the connection channel.
According to this configuration, by providing the filter closer to the connection port than the on-off valve in the connection channel, the liquid that has passed through the filter can be discharged to the liquid supply channel. That is, even when the liquid in the decompressed internal space is degassed and bubbles are generated, the bubbles are separated by the filter when the pump is pressurized, so that the bubbles are discharged to the liquid supply channel. It is possible to reduce the risk of being done.

  In the liquid ejecting apparatus according to the aspect of the invention, the liquid ejecting head includes a reservoir that stores the supplied liquid and a plurality of nozzles that are respectively connected to the reservoir and can eject the liquid. And a decompression chamber provided adjacent to the reservoir via a permeation wall that is impermeable to liquid and permeable to gas, and a branch portion branched from a branch point of the connection flow path is the decompression chamber Connected to.

  According to this configuration, for example, even when bubbles are generated in the reservoir, the gas moves to the decompression chamber side through the transmission wall, so that bubbles generated in the reservoir can be reduced. Furthermore, by depressurizing the decompression chamber using a pump that supplies liquid to the liquid ejecting head, it is not necessary to provide a separate pump for decompressing the decompression chamber, and the liquid ejecting apparatus can be downsized.

  In the liquid ejecting apparatus according to the aspect of the invention, a filter is provided in the liquid supply flow path, and a position upstream of the filter is provided with a transmission wall that is impermeable to liquid and permeable to gas. A decompression chamber is provided adjacent to the liquid supply flow path, and a branch portion branched from a branch point of the connection flow path is connected to the decompression chamber.

  According to this configuration, since the bubbles separated when the liquid passes through the filter move to the decompression chamber through the transmission wall, the bubbles generated in the liquid supply channel can be reduced. Furthermore, by depressurizing the decompression chamber using a pump that supplies liquid to the liquid ejecting head, it is not necessary to provide a separate pump for decompressing the decompression chamber, and the liquid ejecting apparatus can be downsized.

FIG. 2 is a schematic diagram of a printer according to the first embodiment. FIG. 2 is a schematic diagram of an ink supply system. The schematic diagram of the maintenance pump at the time of suction drive. The schematic diagram of the maintenance pump at the time of suction drive. The schematic diagram of the maintenance pump at the time of discharge drive. The schematic diagram of the maintenance pump at the time of pressure reduction processing. The schematic diagram of the maintenance pump at the time of pressure reduction processing. The schematic diagram of the maintenance pump at the time of pressure reduction processing. The schematic diagram of the maintenance pump at the time of pressure reduction processing. The schematic diagram of the maintenance pump at the time of pressure reduction processing. The schematic diagram of the maintenance pump of 2nd Embodiment. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning. The schematic diagram of the maintenance pump of 3rd Embodiment. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning. Schematic diagram of maintenance pump during cleaning.

(First embodiment)
Hereinafter, a first embodiment in which a liquid ejecting apparatus of the invention is embodied in an ink jet printer will be described with reference to FIGS. In the following description, the terms “left-right direction” and “up-down direction” refer to the left-right direction indicated by arrows in FIG. Further, when referring to the “front-rear direction”, the direction orthogonal to the paper surface of FIG.

  As shown in FIG. 1, an ink jet printer (hereinafter referred to as “printer”) 11 as a liquid ejecting apparatus includes a transport unit 13 for transporting a sheet 12 as a target, and a printing for printing on the sheet 12. And a recording head unit 15.

  The transport unit 13 includes a rectangular plate-shaped platen 17 that is long in the left-right direction. A drive roller 18 extending in the front-rear direction is disposed on the right side of the platen 17 so as to be rotationally driven by a drive motor 19, while a driven roller 20 extending in the front-rear direction is disposed on the left side of the platen 17 so as to be rotatable. Further, a tension roller 21 extending in the front-rear direction is rotatably disposed below the platen 17.

  An endless transport belt 22 having a large number of through holes is wound around the drive roller 18, the driven roller 20, and the tension roller 21 so as to surround the platen 17. In this case, the tension roller 21 is urged downward by a spring member (not shown), and by applying tension to the conveyor belt 22, looseness of the conveyor belt 22 is suppressed.

  Then, when the driving roller 18 is rotationally driven in the clockwise direction when viewed from the front side, the conveying belt 22 is rotated in the clockwise direction when the outer side of the driving roller 18, the tension roller 21, and the driven roller 20 is viewed from the front side. It has become. Further, when the sheet 12 is at a position facing the upper surface of the platen 17, the sheet 12 is sucked to the platen 17 side through the conveying belt 22 by a suction unit (not shown), and is conveyed from the upstream left side to the downstream right side. It has come to be.

  A pair of upper and lower paper feed rollers 23 for feeding a plurality of unprinted paper sheets 12 one by one onto the transport belt 22 one by one is provided on the upper left side of the driven roller 20. On the other hand, on the diagonally upper right side of the driving roller 18, a pair of upper and lower paper discharge rollers 24 for discharging the printed paper 12 one by one from the transport belt 22 are provided.

  As shown in FIGS. 1 and 2, the recording head unit 15 includes a plurality of (four in the present embodiment) recording heads 26 to 29 extending in the front-rear direction and spaced in the left-right direction. Is provided. In addition, on the nozzle formation surfaces 26a to 29a that are the lower surfaces of the recording heads 26 to 29, a large number of nozzles 30 are regularly formed at predetermined intervals in the front-rear direction so as to form nozzle rows along the front-rear direction. It is open. The nozzles 30 thus configured are supplied with the same type of ink (liquid) for each of the recording heads 26 to 29 and ejected from the nozzles 30.

  That is, as shown in FIG. 2, the first recording head 26 receives black ink from an ink cartridge 31 serving as a liquid supply source containing black ink via an ink flow path 32 serving as a liquid supply flow path. Is connected to the ink supply device 33. Similarly, the second to fourth recording heads 27 to 29 are connected to an ink supply device 33 that supplies ink from ink cartridges 31 containing inks of cyan, magenta, and yellow, respectively.

  However, since the configuration of the ink supply device 33 that supplies ink from each ink cartridge 31 to each recording head 26 to 29 is the same, FIG. 2 shows one ink supply device that supplies ink to the first recording head 26. Only 33 is shown together with the first recording head 26 and the ink cartridge 31. In the following description, the first recording head 26 and the ink supply device 33 that supplies ink to the first recording head 26 shown in FIG. 2 will be described as an example.

  As shown in FIG. 2, a reservoir 36 communicating with the downstream side of the ink flow path 32 is formed in the first recording head 26 so as to extend in the front-rear direction along the nozzle row. A plurality of branch flow paths 35 individually corresponding to the nozzles 30 are branched from a plurality of positions in the extending direction. The branch channel 35 includes a cavity 37 that communicates with the nozzle 30, and a communication channel 38 that communicates the cavity 37 and the reservoir 36. Further, a piezoelectric element (not shown) is disposed at a position adjacent to the cavity 37 in the first recording head 26. The piezoelectric element contracts and expands to change the volume of the cavity 37, so that ink is ejected from the nozzle 30.

  As shown in FIGS. 2 and 3, the first position adjacent to the reservoir 36 is located above the reservoir 36 via a first transmission wall 39 that is impermeable to ink and permeable to gas. A decompression chamber 40 is provided. As shown in FIG. 2, the inner surface of the upper wall of the reservoir 36 is formed obliquely, and the central portion is formed so as to have a height in the vertical direction as compared with both end portions. The first decompression chamber 40 is provided so as to be adjacent to the reservoir 36 through the first transmission wall 39 constituting the wall surface of the central portion. Therefore, when air bubbles are generated in the reservoir 36, the air bubbles move to the central portion along the inner surface of the oblique upper wall and collect in the vicinity of the first transmission wall 39.

  Further, the position immediately before the connection point to the recording head 26 in the ink flow path 32 is a deaeration position PD, and the disk-shaped first filter 41 closes the ink flow path 32 at the deaeration position PD. Is provided. Note that the cross-sectional area of the ink flow path 32 in the portion where the first filter 41 is provided is larger than the cross-sectional area of other portions in the ink flow path 32, and the flow of ink when passing through the first filter 41 is larger. Road resistance has been relaxed. In the ink flow path 32, a position adjacent to the filter chamber 42 on the upstream side of the first filter 41 is passed through a second transmission wall 43 that is impermeable to ink and permeable to gas. Two decompression chambers 44 are provided.

  As shown in FIG. 2, the ink cartridge 31 includes a flexible ink pack 46 that stores ink, and a case 47 that stores the ink pack 46. In addition, a pressure pump 49 is connected to the case 47 via an air flow path 48, and an upstream end of the ink flow path 32 is connected to the ink pack 46. The pressure pump 49 supplies air into the case 47 via the air flow path 48 so that the ink pack 46 is crushed and the ink in the ink pack 46 is supplied to the ink flow path 32. It has become.

  In addition, the pressure adjustment position PT as the first position in the ink flow path 32 allows the ink to pass from the upstream side to the downstream side as the downstream pressure decreases, and adjusts the pressure in the ink flow path 32. A one-way valve 51 is provided. In other words, the one-way valve 51 includes a storage chamber 52 that primarily stores ink pressurized and supplied from the ink cartridge 31, and a pressure chamber 53 that is positioned downstream of the storage chamber 52. The storage chamber 52 and the pressure chamber 53 are separated by a partition wall portion 54, and a valve hole 54 a is formed through the partition wall portion 54. A valve body 56 that is urged in the valve closing direction by the spring 55 and contacts the partition wall portion 54 from the storage chamber 52 side is disposed in the valve hole 54 a, and the valve body 56 resists the urging force of the spring 55. Accordingly, the storage chamber 52 and the pressure chamber 53 communicate with each other by moving in the valve opening direction.

  That is, when ink is ejected from the nozzle 30 and consumed, the pressure chamber 53 is depressurized, and the film 57 is bent and deformed toward the pressure chamber 53 based on the pressure difference between the pressure chamber 53 and the atmosphere. When the bending force becomes larger than the urging force of the spring 55, the valve body 56 moves to the valve opening position away from the partition wall 54, and the pressurized ink in the storage chamber 52 flows into the pressure chamber 53 side. . When ink flows into the pressure chamber 53 and the chamber pressure is increased, the urging force of the spring 55 is overcome and the valve body 56 is moved again to the valve closing position where it abuts against the partition wall portion 54.

  As described above, the one-way valve 51 is opened by the pressure reduction on the downstream side of the valve body 56, whereas when the upstream side is pressurized, the valve body 56 receives a force in the closing direction, so that the valve is opened. Keep valve closed without valve. Similarly, when the downstream side is pressurized, the film 57 bends and deforms in the direction of increasing the volume of the pressure chamber 53, so that the valve body 56 closes without receiving a force in the valve opening direction from the film 57. Maintain valve status. Furthermore, since the upstream ink is pressurized by the pressurizing pump 49, the upstream side of the valve body 56 is not depressurized. That is, the one-way valve 51 is a valve that opens only when the downstream side is depressurized.

  A part of the pressure chamber 53 is constituted by a film 57 made of a flexible material (for example, synthetic resin or rubber). For example, a cantilever metal piece (for example, comb teeth) that can be displaced together with the film 57 is used. A piece of metal piece) is arranged at the contact point of the valve body 56.

  Further, a connection port 58 is provided at a transformation position PH as a second position downstream of the pressure adjusting position PT and upstream of the recording head 26, more specifically upstream of the deaeration position PD. Is formed. A cylindrical connection member 59 is connected to the connection port 58 so as to branch from the ink flow path 32 at the transformation position PH, and a maintenance pump 61 as a pump and a tube pump is connected to the tip of the connection member 59. Is connected.

  As shown in FIG. 3, the connection member 59 has a second filter 68 that closes the internal space (connection flow path) of the connection member 59 and a connection port 58 at a position near the connection port 58 on the proximal end side. A first on-off valve 69 that can be closed to restrict the flow of ink is provided. Further, a sensor 70 serving as a detection unit capable of detecting the presence or absence of ink sucked into the connection member 59 is provided at a position closer to the tip side (maintenance pump 61 side) than the first opening / closing valve 69 in the connection member 59. Is provided.

  Further, the connection member 59 has a branch portion 71 that branches from a branch point Pb closer to the maintenance pump 61 than the sensor 70 and is connected to the first decompression chamber 40. Note that the branching portion 71 is further connected to the second decompression chamber 44 by a branching portion 71 a further branched from the middle thereof. Furthermore, in the branch part 71, the 2nd on-off valve 72 which can block | close the internal space of the branch part 71 is provided in the position of the branch point Pb side rather than the part which the branch part 71a branched. The branching portion 71 is formed so that at least a part thereof is positioned above the branching point Pb in the gravity direction (that is, although not shown, the branching portion 71 is connected to the connecting member at the branching point Pb). A part of the flow path portion on the on-off valve 72 side from the end connected to 59 is formed so as to pass through a position above the branch point Pb). Therefore, even if the ink is sucked from the base end side to the tip end side beyond the branch point Pb, the ink enters the first decompression chamber 40 and the second decompression chamber 44 via the branch portion 71. Is suppressed.

  Then, the connection member 59 is inclined obliquely upward from the connection port 58 so that the base end side that is the connection port 58 side is positioned lower in the direction of gravity than the distal end side that is the maintenance pump 61 side. It is provided so that it may extend.

  The maintenance pump 61 is a pump capable of pressurizing the ink in the recording head 26 by sucking and discharging ink from the connection port 58 by changing the pressure in the connection member 59. That is, although the pressurizing pump 49 is provided separately from the maintenance pump 61, pressurization by the pressurizing pump 49 is blocked by the one-way valve 51, and the pressurizing force cannot be transmitted to the recording head 26. Therefore, in order to perform maintenance of the recording head 26, a maintenance pump 61 capable of pressurizing the ink in the recording head 26 is required in addition to the pressurizing pump 49.

  As shown in FIG. 3, the maintenance pump 61 is capable of pressing the tube 62, a cylindrical tube 62 having both ends opened in the length direction and having elasticity, a frame 63 as a pump frame that supports the tube 62, and the tube 62. And a pressing mechanism 64.

  The end of the tube 62 on the proximal end side is a connection portion 62a connected to the connection member 59, and the end of the tube 62 on the distal end side opens the internal space of the tube 62 to the atmosphere. The opening 62b is made. Furthermore, in the length direction of the tube 62, a position between the connecting portion 62a and the opening 62b is an intermediate portion 62c.

  The frame 63 includes a notch 63a in which a part of a ring-shaped plate member is notched, a tip support 63b that supports the tip of the tube 62 protruding from the notch 63a, and a C-shaped cross section. And an intermediate support portion 63c for supporting the intermediate portion 62c of the tube 62.

  In addition, the front-end | tip support part 63b of the frame 63 is formed in the cylinder shape so that the front-end | tip part of the tube 62 may be supported in the insertion state. Further, the intermediate support portion 63c in the frame 63 is a plate-like body that connects the tip support portion 63b and the connection member 59, and has a cross section so as to support the tube 62 from the outer peripheral side in a curved state. It is bent in an arc shape. That is, the intermediate portion 62c of the tube 62 is supported along the length direction on the support surface 63d that is an inner surface of the intermediate support portion 63c that is curved in an arcuate cross section.

  The tube 62 is provided so that the opening 62b on the distal end side is positioned above the connection port 58 in the direction of gravity. Further, the volume of the internal space of the intermediate portion 62 c is larger than the volume of the internal space between the first on-off valve 69 and the sensor 70 in the connection member 59.

  As shown in FIGS. 3 and 4, a pressing mechanism 64 is provided at the inner (inner peripheral side) position of the intermediate portion 62 c of the tube 62 supported in an arcuate shape by the intermediate support portion 63 c of the frame 63. Is arranged. The pressing mechanism 64 rotates on a rotating plate 76 that can rotate around a drive shaft 75 as an axis that is the center of the arc of the support surface 63d, and on the tip of a tongue piece 76a that protrudes radially outward of the rotating plate 76. A pressing roller 77 serving as a pressing member is provided. The pressing roller 77 is provided so as to be rotatable about a rotation shaft 78. And the press roller 77 is comprised so that the intermediate part 62c of the tube 62 may be pressed toward the intermediate support part 63c side of the frame 63 from the inner peripheral side at the time of the rotation. In other words, the pressing roller 77 is disposed so as to squeeze and squeeze the tube 62 with the support surface 63d of the intermediate support portion 63c.

  Therefore, in the intermediate portion 62 c of the tube 62, the internal space on the connecting member 59 side is connected to the connecting member 59 with the pressing point 62 d being a position crushed by the pressing roller 77 and the intermediate support portion 63 c of the frame body 63 as a boundary. Together with the internal space (connection flow path) of the ink chamber 79. In addition, the internal space on the tip end side that is closer to the opening 62b than the pressing point 62d is a gas chamber 80.

  Further, as shown in FIG. 3, on the circular motion locus of the pressing roller 77, the pressing roller 77 is a non-clamping area A as a non-blocking section with respect to the notch portion 63a, and the pressing roller 77 is blocked with respect to the intermediate support portion 63c. One clamping area B is provided as a section.

  That is, when the pressing roller 77 is located in the non-clamping region A by the cutout portion 63a, the clamping state of the tube 62 is released, and the ink chamber 79 and the gas chamber 80 are communicated (see FIG. 8). ). That is, the non-clamping region A is a position where the pressing roller 77 is not opposed to the intermediate support part 63c, and is a position where the intermediate part 62c of the tube 62 cannot be clamped between the intermediate support part 63c.

  The clamping region B is a position where the pressing roller 77 is opposed to the intermediate support part 63c via the intermediate part 62c of the tube 62, and is a position where the intermediate part 62c can be pressed against the intermediate support part 63c. . And in this embodiment, the area | region length in the circumferential direction centering on the drive shaft 75 is longer in the clamping area B than in the non-clamping area A.

  Now, when the drive shaft 75 rotates forward in accordance with forward rotation of the pressing motor 81 (see FIG. 2), the pressing roller 77 and the rotating plate 76 are in the direction indicated by the white arrow in FIG. In the following, it is called “positive direction”). That is, when the pressing roller 77 moves circularly in a direction approaching the opening 62b while maintaining the state where the tube 62 is crushed, the volume of the ink chamber 79 increases and the gas chamber 80 has a volume as shown in FIG. The pressing point 62d moves in the direction in which the volume decreases.

  Therefore, when the pressure roller 77 moves in the forward direction with the first opening / closing valve 69 opened, ink is sucked from the ink flow path 32 into the ink chamber 79 whose volume increases. That is, when the pressing motor 81 is driven to rotate forward, the maintenance pump 61 is driven to suck (a pressure reducing operation for reducing the pressure inside the ink chamber 79). At this time, the gas chamber 80 whose volume is reduced is in an atmospheric pressure state by discharging air from the opening 62b.

  When the drive shaft 75 rotates in the reverse direction as the pressing motor 81 rotates in the reverse direction, the pressing roller 77 and the rotating plate 76 rotate in the clockwise direction (the direction indicated by the white arrow in FIG. It is supposed to move in a circle. That is, when the pressing roller 77 moves circularly in a direction approaching the connecting portion 62a while maintaining the state where the tube 62 is crushed, the volume of the ink chamber 79 decreases and the volume of the gas chamber 80 increases. Point 62d moves.

  Therefore, when the pressing roller 77 performs a circular motion in the reverse direction with the first opening / closing valve 69 open, the ink in the ink chamber 79 whose volume is reduced is discharged to the ink flow path 32. That is, when the pressing motor 81 is driven in reverse, the maintenance pump 61 is driven to discharge (pressurizing operation for pressurizing the inside of the ink chamber 79). In addition, the gas chamber 80 whose volume increases at this time is in an atmospheric pressure state by sucking air from the opening 62b.

  Further, as shown in FIG. 2, the printer 11 is provided with a control unit 82 as a control unit that performs overall control of the operating state of the printer 11. Then, the control unit 82 drives and controls the piezoelectric elements (not shown), the pressure pump 49, the maintenance pump 61, and the pressing motor 81 provided in each of the recording heads 26 to 29, and performs printing and cleaning processing. ing. Note that the control of the maintenance pump 61 is the open / close control of the first and second open / close valves 69 and 72 based on the detection result of the sensor 70, as shown in FIG.

  Next, the operation of the printer 11 configured as described above will be described below. The maintenance pump 61 is assumed to perform initial filling after the ink cartridge 31 is mounted on the printer 11, and the recording head 26 and the ink flow path 32 are filled with ink. Further, in the drawing, the open valves of the first and second on-off valves 69 and 72 are shown in white, and the closed valves are shown in black.

  If the period during which printing is not performed and ink is not ejected from the nozzles 30 becomes long, the ink may evaporate from the nozzles 30 to increase the viscosity of the ink, or the meniscus position may increase. The rise in the meniscus position may occur not only in the evaporation of ink but also in other situations such as when the printer 11 receives an impact or when the end of the paper 12 contacts the nozzle 30.

  Therefore, the control unit 82 executes the cleaning process when, for example, a cleaning process execution command is received from a user (not shown) from the user or when it is determined that a predetermined time has passed since the previous cleaning process.

  As shown in FIG. 3, in performing the cleaning process, the maintenance pump 61 is configured such that the first on-off valve 69 is opened while the ink is sucked up to the sensor 70, and the second on-off valve 72 is It is assumed that the valve is closed. In addition, it is assumed that the pressing roller 77 is located at the suction start position P1 that is the proximal end of the sandwiching region B.

  From this state, the control unit 82 drives the pressing motor 81 to rotate forward to cause the pressing roller 77 to move in a counterclockwise direction. Then, as shown in FIG. 4, although ink is sucked from the connection port 58 into the ink chamber 79 that increases in volume and depressurizes, the intrusion of ink into the branch portion 71 is as described above. Since part of 71 is located above the branch point Pb, it is suppressed.

  Further, as shown in FIG. 5, when the pressing roller 77 moves to the suction end position P <b> 2 that is the end on the front end side of the clamping region B, the control unit 82 drives the pressing motor 81 in the reverse direction to move the pressing roller 77 in the reverse direction. Is moved to the suction start position P1 (see FIG. 3). Then, since the first opening / closing valve 69 is opened, the ink in the ink chamber 79 whose volume is reduced is discharged from the connection port 58 to the ink flow path 32.

  At this time, the ink is ejected through the second filter 68. Therefore, even when the ink is degassed in the ink chamber 79 and bubbles are generated in the ink, the bubbles are separated by the second filter 68, thereby suppressing the discharge of the bubbles to the ink flow path 32. Has been.

  By the way, in the ink flow path 32, the one-way valve 51 provided on the upstream side from the transformation position PH opens when the pressure is reduced from the downstream side, whereas when the pressure is applied from the downstream side. Keep the valve closed. Therefore, when the ink is discharged from the maintenance pump 61, the one-way valve 51 is closed, so that the ink is supplied to the recording head 26 side downstream from the pressure adjustment position PT, whereby the nozzle 30 is supplied. Then, the ink is discharged and the pressure cleaning of the recording head 26 is executed.

  In the present embodiment, the ink flow path 32 and the maintenance pump 61 are connected via the connection member 59. The maintenance pump 61 is driven to suck while ink is sucked up to the sensor 70, and then is driven to discharge. That is, at the end of the discharge drive (pressurization operation) after the maintenance pump 61 performs the suction drive (pressure reduction operation), the ink in the connection member 59 has a liquid level closer to the maintenance pump 61 than the first on-off valve 69. Therefore, the gas in the ink chamber 79 is suppressed from being discharged to the ink flow path 32. Therefore, even after the pressure cleaning is performed, that is, after the maintenance pump 61 is driven to discharge, the ink remains in the connection member 59, and the ink in the connection member 59 is in a state in which the gas is easily dissolved.

  For this reason, in order to suppress such gas dissolution into the ink, a decompression process for decompressing the inside of the ink chamber 79 is necessary after the pressure cleaning is performed. Specifically, from the state shown in FIG. 3, the controller 82 closes the first on-off valve 69, opens the second on-off valve 72, and drives the pressing motor 81 in the normal direction to press it. The roller 77 is circularly moved in the forward direction. That is, the suction drive (decompression operation) of the maintenance pump 61 is started in a state where the ink level is positioned closer to the maintenance pump 61 than the first on-off valve 69.

  Then, as shown in FIG. 6, since the first on-off valve 69 is closed and the inflow of ink from the ink flow path 32 is restricted, the volume increases due to the movement of the pressing roller 77 in the forward direction. The inside of the ink chamber 79 is depressurized. At this time, the second on-off valve 72 is opened and the first and second decompression chambers 40 and 44 communicate with the ink chamber 79 via the branch portions 71 and 71a. The decompression chambers 40 and 44 are also decompressed. On the other hand, the gas chamber 80 whose volume is reduced by the movement of the pressing roller 77 in the positive direction is maintained in an atmospheric pressure state by discharging air from the opening 62b.

  Then, as shown in FIG. 7, when the pressing roller 77 moves to the suction end position P2, the control unit 82 closes the second on-off valve 72 while maintaining the closed state of the first on-off valve 69. To do. Thereafter, the pressing motor 81 is further driven to rotate forward to rotate the pressing roller 77 in the forward direction, thereby positioning the pressing roller 77 in the non-clamping region A (see FIG. 8).

  That is, as shown in FIG. 8, when the pressure roller 77 is located in the non-clamping area A, the decompressed ink chamber 79 and the gas chamber 80 communicate with each other, air is sucked from the opening 62b, and the ink chamber 79 is primary. Atmospheric pressure state. On the other hand, the first and second decompression chambers 40 and 44 are maintained in a decompressed state because the second on-off valve 72 is closed.

  Subsequently, the control unit 82 drives the pressing motor 81 to rotate forward to cause the pressing roller 77 to circularly move in the forward direction, and opens the second opening / closing valve 72 in a state where the pressing roller 77 is positioned in the clamping region B. (See FIG. 9). Thereafter, the controller 82 stops driving the pressing motor 81 at the timing when the pressing roller 77 is positioned at the suction end position P2 (see FIG. 10).

  That is, since the first and second decompression chambers 40 and 44 are in a decompressed state, the second on-off valve 72 is opened, and the ink chamber 79 communicates with the first and second decompression chambers 40 and 44. Then, the pressure in the ink chamber 79 is reduced. Therefore, the inside of the ink chamber 79 can be depressurized as compared with the case where the pressing roller 77 is rotated once from the state where the first and second decompression chambers 40 and 44 are in the atmospheric pressure state.

  When the first and second decompression chambers 40 and 44 are in a decompressed state, bubbles generated in the reservoir 36 and the filter chamber 42 are collected through the first and second transmission walls 39 and 43, respectively. The Further, since the inside of the ink chamber 79 is also in a reduced pressure state, the gas dissolved in the ink in the ink chamber 79 is easily degassed.

  The pressure roller 77 is located at the suction end position P2 until the next cleaning process is executed, and the ink chamber 79 and the first and second decompression chambers 40 and 44 are maintained in a decompressed state.

According to the first embodiment, the following effects can be obtained.
(1) When the maintenance pump 61 is driven to suck while the first on-off valve 69 is opened, ink is sucked from the ink flow path 32 via the connection member 59 and the connection port 58. When the maintenance pump 61 is driven to discharge with the first on-off valve 69 opened, ink is discharged to the transformation position PH of the ink flow path 32 through the connection member 59 and the connection port 58. A one-way valve 51 that restricts the passage of ink from the downstream side to the upstream side is provided at the pressure adjustment position PT upstream of the transformation position PH of the ink flow path 32. Therefore, the ink ejected to the pressure adjusting position PT in the ink flow path 32 is supplied to the recording heads 26 to 29 and the recording heads 26 to 29 are cleaned. Further, when the maintenance pump 61 is driven by suction while the first on-off valve 69 is closed, the inflow of ink from the ink flow path 32 is restricted, and therefore the inside of the ink chamber 79 of the tube 62 is decompressed. And, even if the maintenance pump 61 stops driving, the reduced pressure state is maintained in the connection member 59. Therefore, for example, even when the pump is stopped when the ink in the ink chamber 79 is in contact with the air, the pressure of the air is low compared to the case where the pump is stopped because the pressure of the air is low. Air melting is suppressed. Further, when the maintenance pump 61 is driven to discharge while the first on-off valve 69 is open, the ink flow is allowed, so that the ink in which the dissolution of air is suppressed is discharged to the ink flow path 32. Therefore, it is possible to suppress the dissolution of air into the ink and supply the ink to the recording heads 26 to 29.

  (2) Even when the maintenance pump 61 is driven to discharge after the suction drive, the ink level in the connection member 59 is located closer to the maintenance pump 61 than the first on-off valve 69, so that the ink and air directly Even in the case of contact, air can be prevented from being discharged to the ink flow path 32 beyond the first on-off valve 69.

  (3) Since the ink can be pressurized in accordance with the movement of the pressing roller 77, for example, compared with a case where the gas in the tube 62 is compressed and the pressure of the compressed gas is applied to the ink to pressurize the ink. Gas dissolution into the ink can be suppressed.

  (4) Since the clamping region B and the non-clamping region A are positioned on the circular motion locus of the pressing roller 77, the pressing roller 77 is positioned in the clamping region B and the non-clamping region A along with the circular motion. be able to. When the pressing roller 77 is positioned in the non-clamping area A, the block of the tube 62 is released and the ink chamber 79 and the gas chamber 80 are communicated. Therefore, the pressure of the ink chamber 79 of the tube 62 can be easily adjusted by the amount of movement of the pressing roller 77 from the non-nip region A.

  (5) By providing the second filter 68 closer to the connection port 58 than the first opening / closing valve 69 in the connection member 59, the ink that has passed through the second filter 68 can be discharged to the ink flow path 32. . That is, even when the depressurized ink in the ink chamber 79 is degassed and bubbles are generated, the bubbles are separated by the second filter 68 when the maintenance pump 61 is driven to discharge. The possibility of being discharged to the ink flow path 32 can be reduced.

  (6) For example, even when bubbles are generated in the reservoir 36, the gas moves toward the first decompression chamber 40 via the first transmission wall 39. Can be reduced. Furthermore, it is not necessary to separately provide a pump for decompressing the first decompression chamber 40 by decompressing the first decompression chamber 40 using the maintenance pump 61 that supplies ink to the recording heads 26 to 29. The printer 11 can be downsized.

  (7) Since the bubbles separated when the ink passes through the first filter 41 move to the second decompression chamber 44 via the second transmission wall 43, the bubbles generated in the ink flow path 32 Can be reduced. Furthermore, by depressurizing the second decompression chamber 44 using the maintenance pump 61 that supplies ink to the recording heads 26 to 29, there is no need to provide a separate pump for decompressing the second decompression chamber 44, The printer 11 can be downsized.

  (8) Since the frame 63 has rigidity and the intermediate portion 62c is crushed by the pressing roller 77, for example, the gas barrier property is improved as compared with a diaphragm pump that displaces a flexible member such as a diaphragm by air pressure. be able to.

  (9) The first on-off valve 69 is opened and closed according to the control of the control unit 82, and the maintenance pump 61 is driven for suction and discharge. Therefore, the maintenance pump 61 can be easily stopped in a state in which the dissolution of air into the ink is suppressed.

  (10) In the connecting member 59, the branch portion 71 branches from the tip side of the sensor 70, and the ink level is located near the sensor 70 (that is, between the first on-off valve 69 and the branch point Pb). Thus, the first on-off valve 69 was closed and the second on-off valve 72 was opened to drive the maintenance pump 61 by suction. Therefore, for example, when the maintenance pump 61 is driven by suction when the ink level is located closer to the maintenance pump 61 than the branch point Pb, the gas in the branch portion 71 is easily dissolved in the ink as bubbles. End up. In this regard, in the present embodiment, the ink chamber 79 can be depressurized in a state where the ink level is located closer to the first on-off valve 69 than the branch point Pb and air is present at the branch point Pb. Therefore, the gas in the ink chamber 79 can be directly sucked at the branch point Pb. Therefore, the gas can be further prevented from being dissolved into the ink.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment only in that a tube with a closed end is used and the rotation direction of the pressing roller 77 is one direction. And since the other structure is common, the same code | symbol is attached | subjected about the same structure part, and the detailed duplication description is abbreviate | omitted.

  That is, as shown in FIG. 11, the tube 85 of the maintenance pump 84 serving as a pump and tube pump is connected to a connecting portion 85a on the base end side (one end side in the length direction of the tube 85) so that the internal space communicates. It is connected to the member 59. The tube 85 is closed at the distal end side (the other end side in the length direction of the tube 85) to form a closed portion 85b, and the intermediate portion 85c is supported by the intermediate support portion 63c.

  Further, as the pressing motor 81 is driven, the pressing roller 77 is positioned in the clamping region B (see FIG. 3) and presses the tube 85, and approaches the closing portion 85b in the length direction of the tube 85. Make a circular motion in the direction (counterclockwise direction indicated by the white arrow).

  That is, for example, when the pressing roller 77 positioned in the clamping region B is circularly moved in the counterclockwise direction with the first opening / closing valve 69 opened, the ink flow path is increased in the ink chamber 79 whose volume increases. Ink is sucked from 32. That is, the maintenance pump 84 performs a suction drive (a pressure reducing operation for reducing the pressure in the ink chamber 79) by moving the pressing roller 77 counterclockwise in the clamping region B as the pressing motor 81 is driven.

  Further, when the pressing roller 77 moves in the counterclockwise direction in the clamping region B, the volume of the gas chamber 80 decreases, so that the gas in the gas chamber 80 is compressed. Therefore, when the pressing roller 77 further rotates counterclockwise and moves to the non-nipping region A, the gas chamber 80 and the ink chamber 79 communicate with each other, and the pressure of the air compressed in the gas chamber 80 is applied to the ink chamber 79. In operation, ink is ejected from the connection port 58. Accordingly, the maintenance pump 84 rotates the pressure roller 77 in the counterclockwise direction indicated by the white arrow and moves it from the clamping area B to the non-nipping area A, thereby causing ejection driving (pressurization for pressurizing the inside of the ink chamber 79). Operate.

Next, the operation when cleaning is performed by the maintenance pump 84 configured as described above will be described below.
As shown in FIG. 11, in the maintenance pump 84 in the standby state, the first opening / closing valve 69 is closed while the ink level is positioned in the vicinity of the sensor 70, whereas the second opening / closing is performed. The valve 72 is opened. Furthermore, it is assumed that the pressure roller 77 is positioned at the suction end position P2 and the ink chamber 79 is depressurized while the gas in the gas chamber 80 is compressed.

  From the state shown in FIG. 11, the controller 82 first closes the second on-off valve 72 and then opens the first on-off valve 69 as shown in FIG. Then, the ink is sucked from the ink flow path 32 through the connection port 58 into the decompressed ink chamber 79. Thereafter, the control unit 82 drives the pressing motor 81 to circularly move the pressing roller 77 in the counterclockwise direction indicated by the white arrow to be positioned in the non-clamping region A.

  Then, as shown in FIG. 13, since the gas chamber 80 and the ink chamber 79 communicate with each other, the pressure of the gas compressed in the gas chamber 80 acts on the ink in the ink chamber 79, and the ink is connected to the connection port 58. From the ink to the ink flow path 32.

  Further, after the pressing roller 77 moves to the non-clamping area A, the control unit 82 closes the first on-off valve 69 when the valve opening time corresponding to the amount of ink to be ejected has elapsed. That is, for example, when there are a large number of poorly ejected nozzles 30 and strong cleaning is performed, the amount of ink ejected is large. Therefore, the valve opening time becomes longer than when weak cleaning is performed with a small amount of ejected ink. Further, since the tube 85 has a smaller sectional area in the vicinity of the opening / closing valve 69 than the sectional area of the other portion in the length direction, the flow rate when ink is ejected is limited, and the adjustment of the ejected ink amount becomes easy. ing.

  Thereafter, the control unit 82 further drives the pressing motor 81 to rotate forward to cause the pressing roller 77 to circularly move in the direction indicated by the white arrow (counterclockwise direction), and the pressing roller 77 is positioned in the clamping region B. Then, the second on-off valve 72 is opened (see FIG. 14). Further, the control unit 82 stops driving the pressing motor 81 so that the pressing roller 77 is positioned at the suction end position P2 (see FIG. 11). Then, as shown in FIG. 11, the ink chamber 79 whose volume increases and the first and second decompression chambers 40 and 44 communicating with the ink chamber 79 are decompressed and the gas in the gas chamber 80 whose volume decreases. Is pressurized. The pressure roller 77 is positioned at the suction end position P2 until the next cleaning process is executed, and the ink chamber 79 and the first and second decompression chambers 40 and 44 are maintained in a decompressed state.

According to the said 2nd Embodiment, in addition to the effect of (1)-(10) in 1st Embodiment, the following effects can be acquired further.
(11) By causing the pressing roller 77 to circularly move in one direction, the suction drive and the discharge drive of the maintenance pump 84 can be performed. That is, when the pressing roller 77 is positioned in the clamping region B and the tube 85 is crushed in a one-way direction close to the closing portion 85b, the tube 85 is connected more than the position crushed by the pressing roller 77. The volume of the ink chamber 79 on the side of the opening 58 is increased and the pressure is reduced. Therefore, when the first on-off valve 69 is opened, ink is sucked from the connection port 58 and the maintenance pump 84 is driven to suck. At this time, the volume of the gas chamber 80 closer to the closing portion 85b than the position crushed by the pressing roller 77 is reduced, and the air in the gas chamber 80 is compressed. Then, when the pressing roller 77 further moves in the one direction approaching the closed portion 85b and is displaced to the non-clamping region A, the ink is connected to the connection port 58 by the pressure of the air compressed in the gas chamber 80 on the closed portion 85b side. The maintenance pump 84 is driven to discharge because it is pushed back to the side and discharged. Accordingly, since the suction roller and the discharge drive can be performed by circularly moving the pressing roller 77 in one direction, the maintenance pump 84 is compared with the case of performing the suction driving and the discharge driving by circularly moving the pressing roller 77 in both directions. The configuration can be simplified.

(9) Since the maintenance pump 84 can eject ink vigorously with the ejection driving, it can perform pressure cleaning with a small amount of ink.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment differs from the second embodiment only in that an intermediate opening is formed in the connection member 59 and the moving direction of the pressing roller 77 that moves circularly in one direction is changed. . And since the other structure is common, the same code | symbol is attached | subjected about the same structure part, and the detailed duplication description is abbreviate | omitted.

  That is, as shown in FIG. 15, a cylindrical portion 90 extending upward in the gravity direction is formed on the maintenance pump 84 side of the sensor 70 of the connecting member 59. The cylinder portion 90 is provided with an intermediate opening 90a that opens the internal space of the connection member 59 to the atmosphere, and an air release valve 91 that can close the intermediate opening 90a.

  Further, the pressing roller 77 is moved in one direction away from the closing portion 85b in the length direction of the tube 85 while keeping the intermediate portion 85c pressed in accordance with the driving of the pressing motor 81 (a clock indicated by a white arrow in FIG. 15). Circular movement in the rotation direction).

  Therefore, for example, when the pressing roller 77 positioned in the clamping region B is rotated in the clockwise direction indicated by the white arrow while the first opening / closing valve 69 is opened, the ink in the ink chamber 79 whose volume decreases is obtained. The ink is discharged from the connection port 58 to the ink flow path 32. That is, the maintenance pump 84 drives the pressure motor 81 to move the pressure roller 77 in the clamping region B, thereby performing ejection driving (pressure operation for pressurizing the inside of the ink chamber 79) (see FIG. 18).

  Further, when the pressing roller 77 moves in the clamping region B, the inside of the gas chamber 80 whose volume increases is depressurized. Therefore, when the pressing roller 77 further rotates in the clockwise direction indicated by the white arrow and moves to the non-nipping region A, the gas chamber 80 and the ink chamber 79 communicate with each other, and ink is sucked from the connection port 58. Accordingly, the maintenance pump 84 rotates the pressure roller 77 in the clockwise direction indicated by the white arrow, and moves from the sandwiching area B to the non-nipping area A, thereby performing suction driving (decompression operation for decompressing the ink chamber 79). (See FIG. 17).

Next, the operation when cleaning is performed by the maintenance pump 84 configured as described above will be described below.
As shown in FIG. 15, in the maintenance pump 84, the first and second on-off valves 69 and 72 are closed while ink is sucked up to the sensor 70, whereas the air release valve 91 is It is assumed that the valve is opened and the pressing roller 77 is located at the suction end position P2.

  When cleaning is performed, first, as shown in FIG. 15, the control unit 82 drives the pressing motor 81 to cause the pressing roller 77 to circularly move in the clockwise direction indicated by the white arrow. Then, in the ink chamber 79 whose volume is reduced, air is discharged from the intermediate opening 90a to be in an atmospheric pressure state. On the other hand, the volume of the gas chamber 80 is increased and the pressure is reduced.

  Further, as shown in FIG. 16, when the pressing roller 77 moves to the suction start position P1, the control unit 82 closes the atmosphere release valve 91 and then opens the first on-off valve 69. Then, when the controller 82 further drives the pressing motor 81 and moves the pressing roller 77 to the non-clamping area A as shown in FIG. 17, the ink chamber 79 and the gas chamber 80 communicate with each other. Accordingly, the reduced pressure in the gas chamber 80 is transmitted to the ink chamber 79 and ink is sucked from the ink flow path 32.

  Then, as shown in FIG. 18, when the pressing roller 77 further moves circularly, the pressing roller 77 moves to the clamping region B and moves while crushing the tube 85. Then, since the volume of the ink chamber 79 is reduced, ink is discharged from the connection port 58 to the ink flow path 32. On the other hand, the gas chamber 80 whose volume increases is decompressed.

  Then, as shown in FIG. 19, when the pressing roller 77 moves to the suction start position P1, the control unit 82 closes the first on-off valve 69, and then further presses the pressing roller 77 as shown in FIG. Is moved to the non-clamping area A. Then, the ink chamber 79 and the gas chamber 80 communicate with each other, and the reduced pressure in the gas chamber 80 is transmitted to the ink chamber 79 to reduce the pressure in the ink chamber 79, but the first on-off valve 69 is closed. Since the inflow of ink is restricted, the inside of the ink chamber 79 is maintained in a reduced pressure state.

  In addition, as shown in FIG. 20, the controller 82 opens the second on-off valve 72 after closing the air release valve 91. Then, the decompressed ink chamber 79 and the first and second decompression chambers 40 and 44 communicate with each other via the branch portions 71 and 71a, so that the interiors of the first and second decompression chambers 40 and 44 are decompressed. The Accordingly, bubbles generated in the reservoir 36 and the filter chamber 42 are transmitted through the first and second transmission walls 39 and 43 and collected in the first and second decompression chambers 40 and 44.

  The pressure roller 77 is positioned at the suction end position P2 until the next cleaning process is executed, and the ink chamber 79 and the first and second decompression chambers 40 and 44 are maintained in a decompressed state.

According to the said 3rd Embodiment, in addition to the effect of (1)-(9) in 1st, 2nd embodiment, the following effects can be acquired further.
(10) When the bubbles generated in the reservoir 36 or the filter chamber 42 are collected in the first and second decompression chambers 40 and 44, the first and second decompression chambers 40 and 44 and the first and second decompression chambers The pressure in the ink chamber 79 communicating with the decompression chambers 40 and 44 increases. However, since the ink chamber 79 can be opened to the atmosphere by opening the atmosphere release valve 91, pressure fluctuation when the ink chamber 79 and the first and second decompression chambers 40 and 44 are decompressed is suppressed. be able to.

The above embodiment may be changed to another embodiment as described below.
In the above embodiments, the first and second decompression chambers 40 and 44 and the first and second transmission walls 39 and 43 may be omitted. In the case where the decompression chambers 40 and 44 are not provided, the branch portion 71 may not be provided. Further, only one of them may be provided. Further, maintenance pumps 61 and 84 may be provided for the respective decompression chambers 40 and 44.

  In each of the above embodiments, the branch portion 71 branched at the branch point Pb may be connected to the ink flow path 32 of the ink supply device 33 that supplies different ink. In addition, by providing an opening / closing valve in each branch portion, a single maintenance pump 61 can degas a plurality of types of ink. Further, the branching section is provided with a first decompression chamber 40 adjacent to the reservoir provided in each of the recording heads 26 to 29 so as to correspond to each ink, and a second decompression adjacent to the ink flow path corresponding to each ink. It may be connected to the chamber 44.

  In each of the above embodiments, the second filter 68 may not be provided. For example, the connection member 59 may be lengthened to prevent bubbles from being discharged into the ink flow path 32.

  -In the said 1st Embodiment, the maintenance pump 61 may use the piston pump which carries out suction drive and discharge drive by reciprocatingly moving a piston in a cylinder. The piston pump is driven to discharge by moving the piston in a direction to increase the volume of the ink chamber surrounded by the cylinder and the piston, and is moved by moving the piston in a direction to decrease the volume of the ink chamber. Drive by suction.

  -In the said 1st, 2nd embodiment, you may form the intermediate | middle opening part provided with the air release valve in the tubes 62 and 85 like 3rd Embodiment. In this case, the pressure applied to the ink can be adjusted by opening control of the air release valve.

  -In the said 1st Embodiment, it is good also as a structure which does not provide the non-clamping area | region A. FIG. In other words, the tube 62 may be provided in a state where it is rotated at least once, and the pressing roller 77 may block the intermediate portion 62c regardless of the position of the pressing roller 77 in the circular motion locus. In this case, the pressing roller 77 may be driven for suction or discharge by circularly moving the pressing roller 77 one or more times.

  In each of the above embodiments, the tubes 62 and 85 may be connected to the ink flow path 32, and the connection portions 62 a and 85 a on the proximal end side of the tubes 62 and 85 may be connected to the connection port 58 of the ink flow path 32. Further, the ends of the tubes 62 and 85 on the distal end side may be connected to another member, and an opening or a closed portion may be formed in the separate member.

  -In each above-mentioned embodiment, if opening 62b and blockade part 85b are formed in the tip side in the length direction of tubes 62 and 85 rather than middle parts 62c and 85c of tubes 62 and 85, they are not ends. May be.

  In the first and third embodiments, the maintenance pumps 61 and 84 can continuously perform the suction drive without performing the discharge drive. Therefore, the pressure pump 49 and the air flow path 48 may be omitted, and the ink may be sucked from the ink cartridge 31 by the maintenance pumps 61 and 84.

  In the third embodiment, when the maintenance pump 84 performs suction driving, when the sensor 70 detects ink, the control unit 82 opens the atmosphere release valve 91 to limit ink suction. Also good.

  In each of the above embodiments, the sensor 70 may not be provided, and the leakage of ink from the opening 62b and the intermediate opening 90a may be suppressed by limiting the movement range of the pressing roller 77, for example.

  In each of the above embodiments, the opening 62b and the closing portion 85b may be positioned below the connection port 58 in the gravity direction. That is, for example, the gas may be kept at the tip side depending on the thickness of the tubes 62 and 85, the viscosity of the ink, and the surface tension.

  In each of the above embodiments, for example, an endless chain or belt may be fixed to the pressing roller 77, and the pressing roller 77 may be rotated or reciprocated by rotating the chain or belt. That is, it is not necessary for the pressing roller 77 to perform a circular motion, and if the pressing point 62d of the tube 62 can be moved along with the movement, the movement locus can be arbitrarily set. Therefore, the tube 62 should just be arrange | positioned along at least one part of the movement locus | trajectory of the press roller 77, for example, and may be provided in linear form, for example.

In each of the above embodiments, the intermediate support part 63c of the frame 63 may not be provided, and the frame 63 may be sandwiched by, for example, a pair of rollers.
In each of the above embodiments, the connection member 59 may be formed integrally with a member that forms the ink flow path 32, and the connection flow path may be branched from the ink flow path 32.

  In each of the above embodiments, the maintenance pumps 61 and 84 may be connected to the reservoir 36 so that ink in the reservoir 36 is sucked and discharged. That is, when the maintenance pump 61 is connected to the reservoir 36, the reservoir 36 functions as a liquid supply channel that supplies ink to the nozzles 30.

  In each of the above embodiments, the pressing roller 77 is movable in the radial direction around the drive shaft 75, and a closed section in which the inner spaces of the tubes 62 and 85 can be closed, and the drive shaft 75 side of the closed section. It may be displaced between the non-blocking sections.

  In each of the above embodiments, the control unit 82 is not provided, and the user manually controls the drive of the first and second on-off valves 69 and 72, the air release valve 91, and the maintenance pumps 61 and 84. It may be.

  In each of the above embodiments, the liquid ejecting apparatus is embodied in the ink jet printer 11, but a liquid ejecting apparatus that ejects or discharges liquid other than ink may be employed. The present invention can be used for 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 a state in which the substance is in a liquid phase, such as a liquid 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 a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid as a sample used as a precision pipette, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant 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 an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

Next, the technical idea that can be grasped from each of the above embodiments will be added below.
The liquid ejecting apparatus according to claim 1, further comprising control means for controlling the on-off valve and the pump.

  According to this configuration, the on-off valve is opened and closed according to the control of the control means, and the pump is driven to perform suction and discharge. Therefore, the pump can be easily stopped in a state where the gas is prevented from being dissolved in the liquid.

  DESCRIPTION OF SYMBOLS 11 ... Printer (liquid ejecting apparatus), 12 ... Paper (target), 26-29 ... Recording head (liquid ejecting head), 30 ... Nozzle, 31 ... Ink cartridge (liquid supply source), 32 ... Ink flow path (liquid supply) Flow path), 36 ... reservoir, 39 ... first transmission wall, 40 ... first decompression chamber, 41 ... first filter, 43 ... second transmission wall, 44 ... second decompression chamber, 51 ... one Direction valve, 58 ... Connection port, 61, 84 ... Maintenance pump (pump, tube pump), 62, 85 ... Tube, 62a, 85a ... Connection, 62b ... Opening, 62c, 85c ... Intermediate part, 63 ... Frame (Pump frame), 63a ... notch, 63d ... support surface, 68 ... second filter, 69 ... first on-off valve, 71, 71a ... branching portion, 75 ... drive shaft (axis) 77 ... pressure roller ( Press member 79 ... Ink chamber (internal space, connection flow path), 80 ... Gas chamber (internal space), 82 ... Control unit (control means), 85b ... Closed part, A ... Non-clamping region (non-closed section), B ... Nipping region (blocking section), Pb ... branch point, PH ... transforming position (second position), PT ... pressure adjusting position (first position).

Claims (8)

A liquid ejecting head that ejects liquid onto a target;
A liquid supply channel capable of supplying liquid from an upstream side which is a liquid supply source side to a downstream side which is the liquid jet head side;
A one-way valve which is provided at a first position in the liquid supply flow path and allows passage of the liquid from the upstream side to the downstream side;
A connection port provided at a second position downstream of the first position in the liquid supply channel;
A pump connected to a connection flow path extending from the connection port and performing a pressure reduction operation and a pressure operation;
An on-off valve arranged between the pump and the connection port and capable of closing the connection flow path,
The pump performs a pressure reducing operation with the on-off valve opened, sucks the liquid from the connection port, and then pressurizes to discharge the liquid from the connection port, and then closes the on-off valve. A liquid ejecting apparatus characterized in that after the pressure reducing operation is performed in the state, the driving is stopped and the pressure reducing state when the driving is stopped is maintained. The pump has the liquid in the connection channel at the end of the pressurizing operation after the decompression operation with the on-off valve opened and at the start of the decompression operation with the on-off valve closed. 2. The liquid ejecting apparatus according to claim 1, wherein the liquid level is positioned closer to the pump than the on-off valve. The pump is
A connection portion connected to the connection flow path is provided at one end side in the length direction, and an opening for opening the internal space to the atmosphere is provided at the other end side in the length direction. A tube having at least an intermediate portion having elasticity; and
A pump frame having an arcuate cross-sectional support surface capable of supporting the intermediate portion of the tube along its length;
A tube pump comprising: a pressing member that is capable of circular movement about an axis that is a center of an arc of the support surface so as to close the internal space of the tube between the support surface and
The tube pump performs a pressure reducing operation by displacing the pressing member in a direction approaching the opening in the length direction of the tube while crushing the intermediate portion of the tube, and the pressing member is connected to the connecting portion. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus performs a pressurizing operation by being displaced in a direction approaching. The pump is
A connecting portion connected to the connection flow path is provided on one end side in the length direction, and a blocking portion is provided on the other end side in the length direction, and at least an intermediate portion in the length direction has elasticity. ,
A pump frame having an arcuate cross-sectional support surface capable of supporting the intermediate portion of the tube along its length;
A circle between the closed section that closes the inner space of the tube by pressing the tube against the support surface and a non-closed section that is different from the closed section is centered on an axis that is the arc center of the support surface. A tube pump comprising a movable pressing member,
The pressing member circularly moves in one direction approaching the blocking portion in the length direction of the tube,
The tube pump performs a pressure reducing operation by the pressing member circularly moving in the one direction in the closed section, and the pressing member circularly moves in the one direction and moves from the closed section to the non-closed section. The liquid ejecting apparatus according to claim 1, wherein a pressure operation is performed. The pump frame has a cutout portion in which a part of the support surface is cut out in a circumferential direction around the axis.
When the pressing member presses the tube against the support surface, a closed section in which the inner space of the tube is closed and a non-closed section in which the pressing member is not in the notch portion are on the circular motion locus of the pressing member. The liquid ejecting apparatus according to claim 3, wherein the liquid ejecting apparatus is located. The liquid ejecting apparatus according to claim 1, wherein a filter is provided closer to the connection port than the on-off valve in the connection flow path. The liquid jet head includes:
A reservoir that is connected to the liquid supply channel and stores the supplied liquid;
A plurality of nozzles each connected to the reservoir and capable of ejecting liquid;
A pressure reducing chamber provided adjacent to the reservoir through a permeable wall that is impermeable to liquid and permeable to gas, and
The liquid ejecting apparatus according to claim 1, wherein a branch portion branched from a branch point of the connection flow path is connected to the decompression chamber. A filter is provided in the liquid supply flow path, and the liquid supply flow path is adjacent to the liquid supply flow path through a permeable wall that is impermeable to liquid and permeable to gas at a position upstream of the filter. To provide a decompression chamber,
The liquid ejecting apparatus according to claim 1, wherein a branch portion branched from a branch point of the connection flow path is connected to the decompression chamber.

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