JP6254211B2 - Liquid supply system and ink jet recording apparatus provided with the same - Google Patents

Description

  The present invention relates to a liquid supply system that supplies liquid from a liquid supply source to an ejection head, and an ink jet recording apparatus that includes the liquid supply system.

  In recent years, printing of relatively large printed materials such as signs and posters with an ink jet recording apparatus has been increasing. In such a recording apparatus, the amount of ink consumed is larger than that of a home printer. Therefore, a so-called off-carriage method is adopted in which a large-capacity ink cartridge is arranged away from the carriage on which the ink head is mounted. In an off-carriage type recording apparatus, an ink supply path (typically a flexible tube) between an ink cartridge and an ink head becomes longer as the size increases. Then, the pressure fluctuation in the ink supply path becomes large. As a result, ink is not stably supplied to the ink head, and the print image quality may deteriorate.

  Therefore, for example, Patent Document 1 discloses an ink jet printer having a configuration in which a damper and a tube pump are arranged in an ink supply path. According to this configuration, the pressure fluctuation can be reduced by the damper, and ink can be stably supplied to the ink head.

JP 2010-194915 A

One liquid supply system according to the present invention includes a liquid supply source for storing a liquid, a discharge head having a nozzle for discharging the liquid, and a storage chamber that communicates with the discharge head and temporarily stores the liquid. A liquid supply path that is provided in the liquid supply path that is provided in the liquid supply path, and a liquid supply path that has one end communicating with the liquid supply source and the other end communicated with the damper, and that supplies liquid from the liquid supply source toward the damper And a pressure control valve provided between the liquid supply source in the liquid supply path and the liquid supply device . The liquid supply source communicates with the first liquid path that communicates with the liquid supply path, the first liquid tank that communicates with the first liquid path and stores liquid, and the first liquid path. A liquid circulation path, a second liquid tank communicating with the liquid circulation path and storing the same liquid as the first liquid tank, a liquid circulation pump provided in the liquid circulation path, and the liquid circulation path And a differential pressure valve provided in the. The second liquid tank is disposed below the nozzle of the ejection head in the gravity direction.
One liquid supply system according to the present invention includes a liquid supply source for storing a liquid, a discharge head having a nozzle for discharging the liquid, and a storage chamber that communicates with the discharge head and temporarily stores the liquid. A liquid supply path that is provided in the liquid supply path that is provided in the liquid supply path, and a liquid supply path that has one end communicating with the liquid supply source and the other end communicated with the damper, and that supplies liquid from the liquid supply source toward the damper An apparatus, and a control device that controls operation and stop of the liquid supply device. The liquid supply source communicates with the first liquid path that communicates with the liquid supply path, the first liquid tank that communicates with the first liquid path and stores liquid, and the first liquid path. A liquid circulation path, a second liquid tank communicating with the liquid circulation path and storing the same liquid as the first liquid tank, a liquid circulation pump provided in the liquid circulation path, and the liquid circulation path And a differential pressure valve provided in the. The first liquid tank is disposed above the nozzle of the ejection head in the gravity direction. The second liquid tank is disposed below the nozzle of the ejection head in the gravity direction.

1 is a front view of an ink jet printer according to a first embodiment. FIG. 2 is a partial perspective view of the ink jet printer shown in FIG. 1. FIG. 3 is a block diagram showing a structure for supplying ink from an ink cartridge to an ink head in the ink jet printer shown in FIG. 2. It is a longitudinal cross-sectional view which shows the structure of a damper. It is a longitudinal cross-sectional view which shows the structure of a supply pump. It is a longitudinal cross-sectional view which shows the structure of a pressure control valve. It is a block diagram which shows the structure which supplies ink to the ink head from the ink cartridge which concerns on 2nd Embodiment. FIG. 10 is a block diagram illustrating a structure for supplying ink from an ink cartridge according to a third embodiment to an ink head. It is a block diagram which shows the structure which supplies an ink from the ink cartridge which concerns on 4th Embodiment to an ink head. FIG. 10 is a block diagram illustrating a structure for supplying ink from an ink cartridge according to a fifth embodiment to an ink head. It is a block diagram which shows the structure which supplies an ink from the ink cartridge which concerns on the modification of 5th Embodiment to an ink head. It is a block diagram which shows the structure which supplies ink to the ink head from the ink cartridge which concerns on 6th Embodiment. It is a block diagram which shows the structure which supplies an ink from the ink cartridge which concerns on the modification of 6th Embodiment to an ink head.

  Hereinafter, embodiments of a liquid supply system and an ink jet recording apparatus according to the present invention will be described with reference to the drawings. The embodiments described herein are, of course, not intended to limit the present invention in particular. Further, members / parts having the same action are denoted by the same reference numerals, and redundant description is omitted or simplified. In the following description, “height” refers to the length in the gravitational direction (vertical direction) when the ink supply system is normally arranged at a predetermined position in a predetermined posture. Further, terms such as “upper side”, “lower side”, and “lower side” are based on the direction of gravity when the ink supply system is normally arranged at a predetermined position in a predetermined posture. Further, the “stop” of the liquid supply device means a general state where the liquid supply device is not driven, and includes not only a state where the power supply is shut off but also a standby state where the power is supplied.

<First Embodiment>
FIG. 1 is a front view of an ink jet printer (hereinafter referred to as a printer) 10 according to a first embodiment of the present invention. The printer 10 is an example of an ink jet recording apparatus. In FIG. 1 and FIG. 2, symbols L and R indicate left and right, respectively. However, this is only a direction for convenience of description, and does not limit the installation mode of the printer 10 at all. The printer 10 is for printing on the recording paper 5 which is a recording medium. The recording media include not only paper such as plain paper, but also recording media made of various materials such as resin materials such as polyvinyl chloride (PVC) and polyester, aluminum, iron, and wood. It is.

  The printer 10 includes a printer main body 2 and a guide rail 3 fixed to the printer main body 2. The guide rail 3 extends in the left-right direction. The carriage 1 is engaged with the guide rail 3. Rollers (not shown) are respectively provided on the left end side and the right end side of the guide rail 3. A carriage motor (not shown) is connected to one of these rollers. This one roller is rotationally driven by a carriage motor. An endless belt 6 is wound around both rollers. The carriage 1 is fixed to the belt 6. When the roller rotates and the belt 6 travels, the carriage 1 moves in the left-right direction. Thus, the carriage 1 is configured to be movable in the left-right direction along the guide rail 3.

  The printer main body 2 is provided with a platen 4 that supports the recording paper 5. The platen 4 is provided with a pair of upper and lower grid rollers and a pinch roller (not shown). The grid roller is connected to a feed motor (not shown). The grid roller is driven to rotate by a feed motor. When the grid roller rotates while the recording paper 5 is sandwiched between the grid roller and the pinch roller, the recording paper 5 is conveyed in the front-rear direction.

  The printer main body 2 includes a plurality of so-called ink cartridges 11. The ink cartridge 11 is a tank (ink supply source) that stores ink. The ink cartridge 11 is an example of a liquid supply source. Specifically, a plurality of ink cartridges 11C, 11M, 11Y, 11K, and 11W are detachably attached to the printer main body 2. Cyan ink is stored in the ink cartridge 11C. Magenta ink is stored in the ink cartridge 11M. Yellow ink is stored in the ink cartridge 11Y. Black ink is stored in the ink cartridge 11K. White ink is stored in the ink cartridge 11W. Each ink cartridge 11 is provided with an ink outlet (not shown).

  The printer 10 has an ink supply system for each color of ink. In addition to the ink cartridge 11, the ink supply system includes an ink head 15, a damper 14, an ink supply path 16, a supply pump 13, a pressure control valve 12, and a control device 18. The ink head 15 and the damper 14 are mounted on the carriage 1 and reciprocate in the left-right direction. On the other hand, the ink cartridge 11 is not mounted on the carriage 1 and does not reciprocate in the left-right direction. For this reason, most of the ink supply path 16 (at least half of the total length) is arranged extending in the left-right direction so that the ink supply path 16 is not damaged even if the carriage 1 moves in the left-right direction. In this embodiment, since five types of ink are used, a total of five ink supply paths 16 are provided. These ink supply paths 16 are covered with a cable protection guide device 7. The cable protection guide device 7 is, for example, a cable bear (registered trademark).

  Hereinafter, as an example, the ink head 15, the damper 14, the ink supply path 16, the supply pump 13, and the pressure control valve 12 provided in the ink cartridge 11C that stores cyan ink will be described. FIG. 2 is a partial perspective view of the printer 10. FIG. 3 is a schematic diagram illustrating a structure for supplying ink from the ink cartridge 11 </ b> C to the ink head 15. Here, the direction of ink flow during printing is indicated by arrows. In FIG. 2, symbols F and Rr indicate front and rear, respectively. Moreover, in FIG. 3 etc., the codes | symbols U and D have each shown the upper direction and the downward direction of the gravitational direction.

The ink head 15 ejects ink. The ink head 15 is an example of an ejection head. A plurality of nozzles 15 b that eject ink are formed on the lower surface 15 a of the ink head 15. The lower surface (surface on the nozzle 15b side) 15a of the ink head 15 is maintained at a pressure equal to or lower than atmospheric pressure (negative pressure), for example, about −50 mmH ₂ O so that ink does not leak. However, the pressure is only an example and can be changed as appropriate. An actuator (not shown) made of a piezoelectric element or the like is provided inside the ink head 15. When this actuator is driven, ink is ejected from the nozzle 15b. As shown in FIG. 3, in the present embodiment, the ink head 15 is disposed at a position lower than the ink cartridge 11C. In other words, the ink cartridge 11C is disposed above the nozzle 15b of the ink head 15. With such a configuration, the water head of the ink cartridge 11 </ b> C is higher than the water head of the ink head 15. For this reason, ink leakage from the nozzles 15b of the ink head 15 is likely to occur other than during printing (for example, when the printer is stopped). Therefore, the present invention has a high effect. However, the ink head 15 may be disposed at the same height as the ink cartridge 11C. The ink head 15 may be disposed at a position higher than the ink cartridge 11C. The ink head 15 may be arbitrarily movable in the height direction.

  The damper 14 communicates with the ink head 15 and plays a role of supplying ink to the ink head 15. The damper 14 also plays a role of mitigating ink pressure fluctuations. The ink discharge operation of the ink head 15 is stabilized by the damper 14. FIG. 4 is a longitudinal sectional view of the damper 14. As shown in FIG. 4, the damper 14 of this embodiment does not have what is called a valve structure. The damper 14 includes a damper main body 21 having a concave cross section and a damper film 22 attached so as to cover the concave portion of the damper main body 21. A region surrounded by the damper main body 21 and the damper film 22 is an ink storage chamber 23. An ink introduction port 24 is formed on the upper surface on the front side of the damper main body 21. An ink outlet 25 is formed on the lower surface of the damper main body 21 on the back side. One end of the ink supply path 16 is connected to the ink introduction port 24. The ink head 15 is connected to the ink outlet 25.

  The damper main body 21 is typically made of resin. The damper film 22 is typically composed of a flexible resin film. The damper film 22 is affixed to the edge of the damper main body 21 with a tension that can bend to the inside and the outside of the ink storage chamber 23. The ink storage chamber 23 temporarily stores ink. A concave cover body 28 is provided outside the damper film 22.

  One end of a coil spring 26 is attached to the damper main body 21. A pressing body 27 is supported on the other end of the coil spring 26. The coil spring 26 is an example of an elastic body that presses the pressing body 27 toward the damper film 22. Although the structure of the press body 27 is not specifically limited, In this embodiment, the press body 27 is a flat plate member made of stainless steel. The pressing body 27 is formed so that the damper film 22 can be pressed uniformly. The coil spring 26 is maintained in a compressed state. Therefore, the damper film 22 is always pressed toward the outside of the ink storage chamber 23 (the right side in FIG. 4). The volume of the ink storage chamber 23 can be changed by the coil spring 26 expanding and contracting and the damper film 22 being bent.

  In a preferred aspect, the damper 14 includes an ink storage amount detection device that detects the ink storage amount in the ink storage chamber 23. The ink storage amount detection device detects, for example, whether or not the ink amount in the ink storage chamber 23 is a predetermined capacity or less. The configuration of the ink storage amount detection device is not particularly limited. In the present embodiment, a photo sensor 28 a is installed on the cover body 28 outside the damper film 22, and the ink storage amount is detected from the position change of the damper film 22. When the ink stored in the ink storage chamber 23 decreases, the damper film 22 bends to the inside of the ink storage chamber 23. Then, the bending of the damper film 22 is optically detected by the photo sensor 28a. Thereby, it can be seen that the ink in the ink storage chamber 23 has a predetermined capacity or less. Further, instead of the combination of the photosensor 28a and the detection piece, for example, a pressure gauge may be installed inside the ink storage chamber 23. Thereby, it may be determined from the pressure change in the ink storage chamber 23 whether the ink storage amount is a predetermined capacity or less.

  The ink cartridge 11 </ b> C and the damper 14 communicate with each other through an ink supply path 16. One end of the ink supply path 16 communicates with the ink outlet of the ink cartridge 11C. The other end of the ink supply path 16 communicates with the ink introduction port 24 of the damper 14. The ink supply path 16 forms a flow path that guides ink from the ink cartridge 11 </ b> C to the damper 14 and eventually the ink head 15. The ink supply path 16 has flexibility and flexibility and is configured to be elastically deformable. The ink supply path 16 is an example of a liquid supply path. The configuration of the ink supply path 16 is not particularly limited, but in the present embodiment, it is a resin-made easily deformable tube. However, it may be made of a material other than the tube. A part of the ink supply path 16 may be constituted by a tube.

  In the present embodiment, the ink supply path 16 is configured by tubes 16a, 16b, 16c, and 16d. The tube 16a allows the ink cartridge 11C and the pressure control valve 12 to communicate with each other. The tube 16 b communicates the pressure control valve 12 and the supply pump 13. The tube 16 c is an ink supply path in the supply pump 13. The tube 16d allows the supply pump 13 and the damper 14 to communicate with each other. The damper 14 is connected to the ink head 15. Ink is supplied from the ink cartridge 11C to the ink head 15 through such a path.

  The supply pump 13 is provided in the ink supply path 16. The supply pump 13 is a device that supplies ink from the ink cartridge 11 </ b> C toward the damper 14. The supply pump 13 is an example of a liquid supply device. FIG. 5 is a longitudinal sectional view showing the configuration of the supply pump 13. In this embodiment, the supply pump 13 is a so-called tube pump of the trochoid pump type. The tube pump has both a liquid feeding part and a pressing part. The liquid feeding unit feeds ink toward the damper 14. The pressing portion switches between a pressing state in which the tube 16c is deformed by applying a pressing force and an open state in which the tube 16c is not deformed. By using a tube pump having both a liquid part and a pressing part, the number of parts can be reduced and the configuration can be simplified. Here, “pressing” refers to applying pressure to such an extent that the cross section of the tube 16c is recessed (deforms). Therefore, it is not always necessary to crush until the cross section of the tube 16c is completely closed.

  The supply pump 13 of this embodiment includes a frame 31, a tube 16 c that is disposed in a substantially U shape in the frame 31, and a wheel 32 that is rotatably disposed in the frame 31. One end of the tube 16 c is connected to the pressure control valve 12 via the tube 16 b of the ink supply path 16. The other end of the tube 16c is connected to the damper 14 via the tube 16d. A drive shaft 33 is provided at the center of the wheel 32. The drive shaft 33 is connected to the motor 34. The motor 34 is connected to the control device 18 and controlled by the control device 18. The wheel 32 is provided with two cylindrical pressing rollers 35. The two pressing rollers 35 are opposed to each other with the drive shaft 33 interposed therebetween.

  When the supply pump 13 is stopped, the two pressing rollers 35 are accommodated in a predetermined standby position that does not come into contact with the tube 16c. That is, when the supply pump 13 is stopped, the two pressing rollers 35 move inward in the radial direction of the drive shaft 33. Thereby, the pressing part of the tube 16c is maintained in an open state. On the other hand, when the supply pump 13 is driven by the control device 18, the two pressing rollers 35 move outward in the radial direction of the drive shaft 33. When the motor 34 is driven in this state, the drive shaft 33 rotates. When the drive shaft 33 rotates, the wheel 32 rotates. The pressing roller 35 turns around the drive shaft 33 according to the rotation of the wheel 32. At this time, the pressing roller 35 changes its position while partially pressing the tube 16c sequentially. As a result, pressure is generated in the tube 16c, and the ink in the tube 16c is sent out in the direction in which the pressing roller 35 moves (here, the direction A). That is, when the supply pump 13 is operating, the tube 16 c is pressed by the pressing roller 35. In the present embodiment, the pressing portion is configured by the pressing roller 35, and the liquid feeding unit is configured by the drive shaft 33, the wheel 32, and the pressing roller 35.

  In the above-described embodiment, the supply pump 13 is a tube pump, but the type of the supply pump 13 is not particularly limited. For example, the liquid supply device may be configured by a combination of a liquid feeding specialized device that sends liquid from the ink cartridge 11C toward the damper 14 and a pressing member that can switch the tube 16c between a pressed state and an open state. As an example, a combination of a diaphragm pump (membrane pump) and a pressing roller member is illustrated. In addition, the order which connects a liquid feeding apparatus and a press member is not specifically limited, Which may be arrange | positioned at the damper 14 side. When the liquid feeding device and the pressing member are separated, the liquid feeding device and the pressing member are connected to the control device, respectively. The pressing member is also connected to the motor. The control device controls the operation and stop of the liquid feeding device, and the pressed state and open state of the pressing member. When the motor is driven by the control device, the pressing member brings a predetermined portion of the tube into a pressed state. When the motor is stopped, the pressed portion of the tube is released. In one example, the liquid feeding device is operated while repeating the pressed state and the released state at predetermined time intervals. Accordingly, ink is sent toward the damper as in the case where the tube pump is used.

  The pressure control valve 12 controls the nozzle 15b of the ink head 15 to a negative pressure when the supply pump 13 is stopped, and plays a role of preventing ink leakage. The pressure control valve 12 is provided in the ink supply path 16. In the present embodiment, the pressure control valve 12 is provided between the ink cartridge 11 </ b> C and the supply pump 13.

  In the present embodiment, the pressure control valve 12 is fixed to a predetermined stationary table (for example, the printer main body 2) so that the lower surface is substantially perpendicular to the direction of gravity. According to this aspect, the ink supply amount can be adjusted with higher accuracy than when the pressure control valve 12 is mounted on the carriage 1 together with the ink head 15, for example. That is, the pressure control valve 12 is configured such that the valve member opens and closes based on the bending deformation of the pressure sensitive film 42. Therefore, the operation accuracy of the valve structure can be improved by fixing the pressure control valve 12 to a stable location without mounting it on the carriage 1. As a result, the ink supply amount can be adjusted more stably. Further, the lower surface of the pressure control valve 12 is disposed at a position lower than the lower surface of the ink cartridge 11C. The lower surface of the pressure control valve 12 is arranged at a position higher than the surface (lower surface) 15a of the ink head 15 on the nozzle 15b side. According to the above aspect, the ink smoothly moves toward the ink head 15 by its own weight. For this reason, ink can be supplied to the head more stably.

  FIG. 6 is a longitudinal sectional view showing the configuration of the pressure control valve 12. As shown in FIG. 6, the pressure control valve 12 includes a case body 41 having a hollow structure and a pressure-sensitive film 42 that can be bent and deformed in the film thickness direction by a load of pressure. That is, the pressure control valve 12 of this embodiment is a diaphragm type. The case body 41 is typically made of resin. The case body 41 is partitioned into two space areas in the vertical direction. In other words, the partition wall 47 a that divides the height direction into two space regions is disposed inside the case body 41. The upper space area surrounded by the case body 41 is the first pressure chamber 43. An ink inlet 44 through which ink flows is formed in the left wall of the first pressure chamber 43. The ink inlet 44 communicates with the ink cartridge 11 through the tube 16 a of the ink supply path 16.

  The lower surface of the case body 41 is open, and a pressure sensitive film 42 is attached so as to cover the opening. The pressure sensitive film 42 is substantially perpendicular to the direction of gravity. A lower space region surrounded by the case body 41 and the pressure-sensitive film 42 is a second pressure chamber 45. The pressure-sensitive film 42 is typically made of a resin film having flexibility. The pressure-sensitive film 42 is attached to the edge of the lower surface of the case main body 41 with a tension that can bend to the inside of the second pressure chamber 45. An ink outlet 46 through which ink flows out is formed on the left wall of the second pressure chamber 45. The damper 14 is connected to the ink outlet 46 via the tube 16 b of the ink supply path 16. In addition, the arrow of FIG. 6 has shown the inflow / outflow direction of the ink.

  A part of the partition wall 47 a is provided with a communication port 47 b that allows the first pressure chamber 43 and the second pressure chamber 45 to communicate with each other. A valve rod (valve member) 48 having a T-shaped longitudinal section is disposed in the communication port 47b. The valve rod 48 extends from the first pressure chamber 43 toward the second pressure chamber 45 (downward in FIG. 6) so as to penetrate the partition wall 47a. The extending direction of the valve rod 48 is substantially parallel to gravity. The end of the valve rod 48 is connected to the pressure sensitive film 42. The valve rod 48 moves in the major axis direction (vertical direction) in conjunction with the displacement (deflection) of the pressure sensitive film 42. Thereby, the communication port 47b is opened and closed. Inside the first pressure chamber 43, the valve rod 48 includes a seal member 48a. The seal member 48a is an elastic body (for example, made of rubber).

  The valve rod 48 may be made of a material having excellent corrosion resistance against ink. The valve rod 48 is typically made of metal, for example, brass, copper, silver, platinum, gold, stainless steel, or the like. Especially, it is preferable that it is a product made from brass with large specific gravity. This increases the weight (self-weight) of the valve rod 48 itself. Therefore, when the pressure sensitive film 42 is not bent and deformed, the buoyancy of the valve rod 48 is suppressed, and the valve rod 48 is pressed in the direction of gravity by its own weight. Thereby, the closed state of the communication port 47b is suitably maintained. Note that a general pressure control valve requires a biasing member (for example, a seal spring) for pressing the valve rod against the partition wall and biasing the valve rod to the closed position. However, according to the above configuration, the communication port 47b can be stably maintained in a closed state without using an urging member.

  A pressure receiving body 49a is in contact with the end of the valve rod 48 on the second pressure chamber 45 side substantially vertically. The pressure receiving body 49 a is placed on the surface of the pressure sensitive film 42. By including the pressure receiving body 49 a, the displacement based on the bending deformation of the pressure sensitive film 42 can be stably transmitted to the valve rod 48. Although the structure of the pressure receiving body 49a is not specifically limited, In this embodiment, it is a resin-made disk-shaped member.

One end of a cylindrical coil spring 49b is fixed to the surface of the pressure receiving body 49a on the valve rod 48 side. The coil spring 49 b has a winding diameter that is slightly larger than the end of the valve rod 48. The coil spring 49b is formed so that the end of the valve rod 48 can be inserted. The coil spring 49b prevents the pressure sensitive film 42 from being bent to the outside of the second pressure chamber 45 (downward in FIG. 6). Thereby, the inside of the pressure control valve 12 is maintained at a negative pressure. That is, the coil spring 49b is a negative pressure holding member. In the present embodiment, the second pressure chamber 45 is maintained at a negative pressure of about −100 mmH ₂ O. Further, the pressure control valve 12 (the center in the height direction in design) and the lower surface 15a of the ink head 15 are maintained at a pressure difference of about 50 mmH ₂ O. As a result, the effect of the present invention of preventing ink leakage from the ink head is more effectively exhibited. However, the pressure is only an example and can be changed as appropriate.

  When it is not during printing, that is, when the supply pump 13 is stopped, the second pressure chamber 45 stores a predetermined amount or more of ink. Therefore, the valve rod 48 is pressed against the partition wall 47a by its own weight. Thereby, the communication port 47b is kept closed. In other words, the communication port 47b is not opened unless the amount of ink in the second pressure chamber 45 is reduced. As a result, the lower surface 15a of the ink head 15 is maintained in a negative pressure state by the atmospheric pressure. As a result, ink leakage from the ink head 15 can be accurately prevented. Moreover, according to the said structure, it is not necessary to maintain the ink supply path 16 in a press state. For this reason, deterioration of a tube can be prevented beforehand.

  On the other hand, during printing, when the supply pump 13 is driven, ink in the second pressure chamber 45 is sucked out and sent to the damper 14. Then, the amount of ink stored in the second pressure chamber 45 is reduced, and the inside of the second pressure chamber 45 becomes negative pressure. As a result, the pressure-sensitive film 42 is pushed to the atmospheric pressure and is bent inside the second pressure chamber 45 (upward in FIG. 6). By the movement of the pressure-sensitive film 42, the valve rod 48 is pushed up in the major axis direction against its own weight (self-weight). As a result, the valve rod 48 is separated from the partition wall 47a, and the communication port 47b is opened. Then, ink flows from the first pressure chamber 43 to the second pressure chamber 45.

  As the ink flows into the second pressure chamber 45, the pressure difference between the second pressure chamber 45 and the outside of the pressure sensitive film 42 becomes smaller. Accordingly, the bending of the pressure sensitive film 42 is alleviated. As a result, the valve rod 48 is returned downward in the major axis direction by its own weight. When the valve rod 48 contacts the partition wall 47a, the communication port 47b is closed. By utilizing its own weight, the valve rod 48 moves relatively slowly. For this reason, the pressure fluctuation (pulsation) of the ink accompanying opening / closing of the communication port 47b can be suppressed small. Further, according to the above configuration, the communication port 47 b opens and closes in conjunction with the bending deformation of the pressure sensitive film 42. For this reason, it is not necessary to control the pressure control valve 12 electrically, and it is simple.

  The control device 18 controls the operation and stop of the supply pump 13. Accordingly, the control device 18 controls the supply of ink from the ink cartridge 11C to the ink head 15. The control device 18 is typically a so-called computer. The control device 18 may include a central processing unit (CPU) and a ROM or RAM that stores programs executed by the CPU.

  When printing is started, the supply pump 13 is driven by the control device 18. At the same time, ink is ejected from the nozzle 15 b of the ink head 15 toward the recording paper 5. When ink is ejected, the ink stored in the damper 14 is supplied to the ink head 15. When the amount of ink stored in the damper 14 decreases, the control device 18 drives the supply pump 13. As a result, the ink in the second pressure chamber 45 of the pressure control valve 12 is sent to the damper 14. When the amount of ink in the second pressure chamber 45 decreases, the valve rod 48 opens as described above, and ink flows from the first pressure chamber 43 toward the second pressure chamber 45. The first pressure chamber 43 of the pressure control valve 12 communicates with the ink cartridge 11C. Therefore, the reduced ink amount is replenished from the ink cartridge 11C to the first pressure chamber 43. As described above, ink is stably supplied from the ink cartridge 11C to the ink head 15 during printing.

  In a preferred embodiment, the control device 18 controls the operation and stop of the supply pump 13 based on the detection result of the ink storage amount detection device provided in the damper 14. That is, when the amount of ink stored in the ink storage chamber 23 of the damper 14 is reduced to a predetermined value or less, a signal is output to the control device 18. The control device 18 drives the supply pump 13 when receiving this signal. Then, the supply pump 13 is operated for a certain time. When the ink storage amount in the ink storage chamber 23 reaches a predetermined maximum value, a signal is output to the control device 18. The control device 18 stops the supply pump 13 when receiving this signal. According to the above configuration, the liquid supply device can be operated according to the amount of liquid stored in the damper 14. Thereby, an appropriate amount of liquid can be sent to the damper 14 in a timely manner, and the liquid can be supplied more stably.

  In another preferred embodiment, the control device 18 controls the supply pump 13 to be driven at a constant rotation speed from the operation to the stop of the liquid supply device. That is, the controller 18 does not need to change the rotation speed of the supply pump 13 according to, for example, ink pressure. In this embodiment, ink pressure fluctuations are suppressed by the action of the damper 14. For this reason, it is not necessary to perform complicated control, and it is simple.

Second Embodiment
Next, a printer according to the second embodiment will be described. FIG. 7 is a block diagram showing a structure for supplying ink from the ink cartridge 11C to the ink head 15 according to the second embodiment. In the second embodiment, the ink supply system includes a cap 19 and a suction pump 20. Configurations other than the cap 19 and the suction pump 20 are the same as those in the first embodiment. The cap 19 is attached to the ink head 15 so as to cover the nozzle 15b on the lower surface 15a of the ink head 15 except during printing. Thereby, drying of the ink adhering to the ink head 15 is suppressed, and clogging of the nozzle 15b is prevented. The suction pump 20 sucks the inside of the cap 19. The suction pump 20 is connected to the cap 19. The suction pump 20 is connected to a motor (not shown). The motor is connected to the control device 18 and controlled by the control device 18. When the motor is driven with the cap 19 attached to the ink head, the suction pump 20 operates to suck the inside of the cap 19. For example, when the printer is not used for a long time, the dried and solidified ink may be clogged in the nozzle 15b. According to the said structure, the dried and solidified ink can be removed suitably. Thereby, stable printing can be performed.

  The above-described configuration can be suitably used when the ink supply path 16 is filled with a liquid (for example, ink or cleaning liquid), for example, during printer maintenance or flushing. In a preferred embodiment, first, the cap 19 is attached to the nozzle 15 b of the ink head 15. Next, the motor is driven by the control device 18 to operate the suction pump 20. At this time, the pressing portion of the supply pump 13 is opened by the control device. Typically, the supply pump 13 is stopped by the control device 18. According to the above configuration, the liquid flows from the liquid supply unit to the ink head 15 at a stretch. Therefore, for example, when the ink cartridge 11C is replaced, the liquid can flow into the ink supply path 16 in a relatively short time.

  In another preferred embodiment, first, the cap 19 is attached to the nozzle 15 b of the ink head 15. Next, the pressing unit of the supply pump 13 is brought into a pressed state by the control device 18. In this state, the motor is driven by the control device 18 to operate the suction pump 20. Then, after operating the suction pump 20 for a predetermined time, the control device 18 opens the pressing portion of the supply pump 13. As described above, when the suction pump 20 is operated with the pressing portion in the pressed state, a large pressure difference is generated between the pressure control valve 12 and the suction pump 20. For this reason, when the pressing portion is thereafter opened, the liquid flows toward the suction pump 20 at a stretch. Accordingly, it is possible to allow the liquid to suitably flow into the ink supply path 16 while preventing bubbles from remaining in the ink supply path 16.

<Third Embodiment>
Next, a printer according to a third embodiment will be described. FIG. 8 is a block diagram showing a structure for supplying ink from the ink supply source 50 to the ink head 15 according to the third embodiment. In the third embodiment, the ink supply source 50 includes a circulation mechanism. The configuration other than the ink supply source 50 is the same as that in the first embodiment. This circulation mechanism agitates the ink stored in the ink supply source. This circulation mechanism is particularly effective for an ink (for example, white ink) in which a color material easily precipitates. By providing a circulation mechanism in the ink supply source, it is possible to prevent the color material from being separated or precipitated, and to maintain the ink in a homogeneous state.

  In FIG. 8, the ink supply source 50 includes a first ink tank 51, a second ink tank 52, two ink paths 53 and 54, and a circulation pump 55. The first ink tank 51 and the second ink tank 52 store the same color ink. The two ink tanks 51 and 52 may have the same shape or capacity, or may be different. In one example, the first ink tank 51 is a normal ink cartridge, and the second ink tank 52 is a large-capacity ink cartridge. The capacity of the second ink tank 52 is larger than the capacity of the first ink tank 51. The arrangement of the two ink tanks 51 and 52 in the height direction can be arbitrarily determined. For example, the first ink tank 51 may be disposed above the second ink tank 52, the second ink tank 52 may be disposed above the first ink tank 51, or 2 The two ink tanks 51 and 52 may be arranged at the same height.

  The two ink paths 53 and 54 communicate the first ink tank 51 and the second ink tank 52. At least one of the two ink paths 53 and 54 is provided with a circulation pump 55. In the present embodiment, a circulation pump 55 is provided in the ink path 53. The circulation pump 55 is not particularly limited, but is, for example, a diaphragm pump. The circulation pump 55 is provided with a one-way valve as required. The one-way valve allows ink flow toward one side and blocks ink flow in the opposite direction. Circulation pump 55 is connected to a motor (not shown). The motor is connected to the control device 18 and controlled by the control device 18.

  At the time of ink circulation, the motor is driven by the control device 18 and the circulation pump 55 is operated. Then, the ink flows through the ink path 53 from the first ink tank 51 toward the second ink tank 52. Ink flows from the second ink tank 52 toward the first ink tank 51 in the ink path 54. The arrows in FIG. 8 indicate the flow of ink during ink circulation. In this way, ink can be circulated between the first ink tank 51 and the second ink tank 52. For example, it is possible to constantly circulate ink between the first ink tank 51 and the second ink tank 52 and to feed a part of the ink toward the ink supply path 16. Therefore, separation and precipitation of solid content in the liquid can be prevented at a higher level.

  On the other hand, at the time of printing, ink is sent from the first ink tank 51 or the second ink tank 52 toward the tube 16a according to the arrangement of the ink tanks 51 and 52, the remaining amount of ink, and the like. The ink flow from the tube 16a to the ink head 15 is the same as in the first embodiment. Further, the pressure fluctuation caused by the circulation pump 55 is absorbed by the pressure control valve 12. For this reason, the ink supply path 16 after the pressure control valve 12 is not affected by the ink circulation. Accordingly, ink does not leak from the nozzle 15b of the ink head 15. Therefore, it is not always necessary to provide a valve inside the ink supply source 50 (for example, a portion where the ink path 54 communicates with the tube 16a).

  In a preferred embodiment, the first ink tank 51 includes an ink remaining amount sensor 51a. The configuration of the remaining ink sensor 51a may be the same as that conventionally known. The ink remaining amount sensor 51 a is connected to the control device 18. Information on the remaining ink amount is transmitted to the control device 18. The control device 18 displays the remaining amount of ink in the ink supply source 50, that is, the two ink tanks 51 and 52, on a display unit (not shown) of the printer main body 2. For example, the ink end lamp is turned on when the ink in the ink supply source 50 becomes empty. The user can grasp the ink remaining amount of the ink supply source 50 via the display unit of the printer main body 2.

<Fourth embodiment>
Next, a printer according to a fourth embodiment will be described. FIG. 9 is a block diagram illustrating a structure for supplying ink from the ink supply source 50 to the ink head 15 according to the fourth embodiment. In the fourth embodiment, the ink supply source 50 includes a circulation mechanism different from that of the third embodiment.

  In FIG. 9, the ink supply source 50 includes a first ink tank 51, a second ink tank 52, ink paths 53 a and 54, a circulation pump 55, and a differential pressure valve 56. Detailed description of the same components as those in the third embodiment will be omitted. The first ink tank 51 is disposed above the pressure control valve 12. Further, the second ink tank 52 is disposed below the lower surface 15 a of the ink head 15. Both ends of the ink path 53 a communicate with the ink path 54. In the ink path 54, a communication portion closer to the second ink tank 52 is a first communication portion 541, and a communication portion farther from the ink path 54 is a second communication portion 542. The ink path 54 includes ink paths 54a, 54b, and 54c. The ink path 54 a communicates the second ink tank 52 and the first communication portion 541. The ink path 54 b communicates the first communication part 541 and the second communication part 542. The ink path 54c communicates the second communication portion 542 and the tube 16a.

  In the present embodiment, a circulation pump 55 is provided in the ink path 53a. A differential pressure valve 56 is provided in the ink path 54b. In the differential pressure valve 56, when there is a difference between the upstream pressure and the downstream pressure, the valve body is opened to open the flow path. As a result, the pressure on the upstream side and the downstream side of the differential pressure valve 56 is maintained constant. The configuration of the differential pressure valve 56 is not particularly limited. For example, the opening and closing of the valve body is controlled using the spring force of an elastic body (for example, a spring) engaged with the valve body.

At the time of ink circulation, the motor is driven by the control device 18 and the circulation pump 55 is operated. Then, the ink discharged from the circulation pump 55 reaches the differential pressure valve 56 through the second communication portion 542 and the ink path 54b. The differential pressure valve 56 is configured such that the valve body is opened when the pressure difference between the upstream side and the downstream side of the ink path 54b reaches a predetermined opening pressure.
When the valve body of the differential pressure valve 56 is released, ink flows toward the first communication portion 541. This reduces the pressure difference between the upstream side and the downstream side of the ink path 54b. When the pressure difference between the upstream side and the downstream side becomes equal, the valve body of the differential pressure valve 56 is closed. The ink that has passed through the differential pressure valve 56 returns to the circulation pump 55 via the ink path 53a. The arrows in FIG. 9 indicate the flow of ink during ink circulation. In this way, ink can be circulated between the ink paths 53a and 54b. On the other hand, at the time of printing, ink flows from the first ink tank 51 or the second ink tank 52 to the ink head 15 as in the third embodiment. When part of the ink in the ink paths 53a and 54b is supplied toward the ink head 15, ink is supplied from the second ink tank 52 to the ink paths 53a and 54b.

  According to the configuration of the fourth embodiment, the second ink tank 52 can be disposed below the lower surface 15 a of the ink head 15. Such a configuration is particularly preferable when, for example, the second ink tank 52 has a large size and / or a large capacity. That is, the second ink tank 52 is usually disposed above the lower surface 15a of the ink head 15 so that the ink can easily move to the ink head 15 due to its own weight (see the third embodiment, FIG. 8, etc.). . However, when the second ink tank 52 has a large size and / or a large capacity, it is difficult to move upward in the direction of gravity. For this reason, lifting the second ink tank 52 upward in the direction of gravity when replacing the second ink tank 52 poses a heavy burden on the user. According to the present embodiment, the second ink tank 52 can be installed below the lower surface 15a of the ink head 15 (for example, the ground). That is, it is not necessary to lift the second ink tank 52 and install it. For this reason, the burden on the user accompanying the replacement of the second ink tank 52 can be greatly reduced.

<Fifth Embodiment>
Next, a printer according to a fifth embodiment will be described. FIG. 10 is a block diagram illustrating a structure for supplying ink from the ink cartridge 11C to the ink head 15 according to the fifth embodiment. In the fifth embodiment, the ink supply system includes an ink recovery path 61. Other configurations are the same as those in the first embodiment.

  In FIG. 10, the ink recovery path 61 is a path for returning ink from the damper 14 to the tube 16a. One end of the ink recovery path 61 is connected to the damper 14. The other end of the ink recovery path 61 is connected between the ink cartridge 11C of the ink supply path 16 and the pressure control valve 12, that is, to the tube 16a. The ink recovery path 61 is made of the same material as that of the ink supply path 16, for example.

  A three-way valve 62 is disposed at a portion where the ink recovery path 61 and the tube 16a communicate with each other. The three-way valve 62 includes a first connection port 621 that communicates with the ink cartridge 11 </ b> C, a second connection port 622 that communicates with the tube 16 a of the ink supply path 16, and a third connection port 623 that communicates with the ink recovery path 61. . The three-way valve 62 is not particularly limited, but is, for example, an electromagnetic valve. The three-way valve 62 is connected to the control device 18. Switching of the communication state of the three connection ports 621, 622, 623 is controlled by the control device 18.

  At the time of ink circulation, first, the cap 19 is attached to the lower surface (surface on the nozzle 15b side) 15a of the ink head 15. Next, the control device 18 opens the second connection port 622 and the third connection port 623 of the three-way valve 62 and closes the first connection port 621. That is, the three-way valve 62 is switched to a state where the second connection port 622 and the third connection port 623 are connected. In this state, the motor is driven to operate the supply pump 13. Then, the ink flows from the damper 14 toward the three-way valve 62 in the ink recovery path 61. The ink that has passed through the ink recovery path 61 flows again toward the damper 14 through the ink supply path 16. The arrows in FIG. 10 indicate the flow of ink during ink circulation. In this way, ink can be circulated in the system. This allows the ink in the system to be kept homogeneous. As a result, it is possible to prevent the solid content (for example, coloring material) in the ink from being separated or precipitated. Also, waste of ink can be reduced.

  On the other hand, at the time of printing, the control device 18 opens the first connection port 621 and the second connection port 622 of the three-way valve 62 and closes the third connection port 623. The three-way valve 62 is switched to a state where the first connection port 621 and the second connection port 622 are connected. Then, ink is sent from the ink cartridge 11C toward the tube 16a. The ink flow from the tube 16a to the ink head 15 is the same as in the first embodiment.

  In the modification shown in FIG. 11, two choke valves 63 and 64 are used in place of the three-way valve 62 in the communication portion 611 where the ink recovery path 61 and the tube 16a communicate. The choke valves 63 and 64 are an example of a first valve and a second valve. The choke valve 63 is provided in the ink recovery path 61. The choke valve 63 opens and closes a portion between the damper 14 and the communication portion 611. The choke valve 64 is provided on the tube 16a. The choke valve 64 opens and closes a portion between the ink cartridge 11C and the communication portion 611. The choke valves 63 and 64 are connected to the control device 18. Opening and closing of the choke valves 63 and 64 is controlled by the control device 18.

  At the time of ink circulation, first, the cap 19 is attached to the lower surface (surface on the nozzle 15b side) 15a of the ink head 15. Next, the control device 18 opens the choke valve 63 and closes the choke valve 64. In this state, the motor is driven to operate the supply pump 13. Then, the ink flows from the damper 14 toward the choke valve 63 in the ink collection path 61. The ink that has passed through the ink recovery path 61 flows again toward the damper 14 through the ink supply path 16. The arrows in FIG. 11 indicate the flow of ink during ink circulation. In this way, ink can be circulated in the system as in FIG.

  On the other hand, at the time of printing, the control device 18 opens the choke valve 64 and closes the choke valve 63. Then, ink is sent from the ink cartridge 11C toward the tube 16a. The ink flow from the tube 16a to the ink head 15 is the same as in the first embodiment.

<Sixth Embodiment>
Next, a printer according to a sixth embodiment will be described. FIG. 12 is a block diagram showing a structure for supplying ink from the ink supply source 70 to the ink head 15 according to the sixth embodiment. In the sixth embodiment, the ink supply source 70 includes a plurality of ink tanks. The ink supply system includes an ink recovery path. Other configurations are the same as those in the first embodiment.

  In FIG. 12, the ink supply source 70 includes a first ink tank 51, a second ink tank 52, a first ink path 71, a second ink path 72, and a three-way valve 73. .

  The two ink tanks 51 and 52 and the remaining ink sensor 51a are the same as in the third embodiment. The first ink path 71 communicates with the first ink tank 51. The second ink path 72 communicates with the second ink tank 52. The three-way valve 73 is disposed at a portion where the first ink path 71, the second ink path 72, and the tube 16 a of the ink supply path 16 communicate with each other. The three-way valve 73 includes a first connection port 731 that communicates with the first ink path 71, a second connection port 732 that communicates with the second ink path 72, and a third connection that communicates with the tube 16 a of the ink supply path 16. And a mouth 733. The three-way valve 73 is not particularly limited, but is, for example, an electromagnetic valve. The three-way valve 73 is connected to the control device 18. Switching of the communication state of the three connection ports 731, 732, and 733 is controlled by the control device 18.

  The ink recovery path 74 is a path for returning ink from the damper 14 to the first ink tank 51. One end of the ink recovery path 74 is connected to the ink tank 51. The other end of the ink recovery path 74 is connected to the damper 14. The ink recovery path 74 is made of the same material as the ink supply path 16.

  At the time of ink circulation, first, the cap 19 is attached to the lower surface (surface on the nozzle 15b side) 15a of the ink head 15. Next, the control device 18 opens the first connection port 731 and the third connection port 733 of the three-way valve 73 and closes the second connection port 732. The three-way valve 73 is switched to a state where the first connection port 731 and the third connection port 733 are connected. In this state, the motor is driven to operate the supply pump 13. Then, the ink flows from the damper 14 toward the first ink tank 51 through the ink collection path 74. The ink that has passed through the ink recovery path 74 flows again toward the damper 14 through the ink supply path 16. The arrows in FIG. 12 indicate the flow of ink during ink circulation. In this manner, even when the ink supply source 70 includes a plurality of ink tanks 51 and 52, ink can be circulated in the system.

  On the other hand, at the time of printing, the control device 18 opens the second connection port 732 and the third connection port 733 of the three-way valve 73 and closes the first connection port 731. The three-way valve 73 is switched to a state in which the second connection port 732 and the third connection port 733 are connected. In this state, the motor is driven to operate the supply pump 13. Then, ink is sent from the second ink tank 52 toward the tube 16a. The ink flow from the tube 16a to the ink head 15 is the same as in the first embodiment.

  In a preferred embodiment, the ink collection path 74 is provided with a one-way valve 74a. The one-way valve allows the ink flow in the direction from the damper 14 toward the first ink tank 51, but prevents the ink flow in the opposite direction (the direction from the first ink tank 51 toward the damper 14). Is. According to the study by the present inventors, the water head difference between the first ink tank 51 and the ink head 15 becomes excessively large depending on the arrangement of the first ink tank 51 and the like. Ink may flow backward toward the nozzle 14. For example, when the first ink tank 51 is disposed above the nozzle 15 b of the ink head 15, the pressure may be applied to the nozzle 15 b through the ink recovery path 74. However, according to the above configuration, the water head applied to the ink head 15 can be accurately supplemented. Therefore, ink can be circulated stably in the system.

  In the embodiment having the one-way valve 74a, at the time of ink circulation, the ink can be circulated in the system as in the case where the one-way valve is not provided. Further, in the aspect having the one-way valve 74a, at the time of printing, the same control as in the case without the one-way valve described above can be performed. Alternatively, all the connection ports 731, 732, and 733 of the three-way valve 73 can be opened by the control device 18. When the one-way valve 74 a is provided between the first ink tank 51 and the damper 14, ink does not flow from the first ink tank 51 into the damper 14 even if all the three-way valves 73 are opened. For this reason, the motor is driven with all the connection ports 731, 732, 733 of the three-way valve 73 opened, and the supply pump 13 is operated. Then, ink is sent from the second ink tank 52 toward the tube 16a as in the case where there is no one-way valve. Further, when the first ink tank 51 is not full, ink is also sent from the second ink tank 52 to the first ink tank 51. When the second ink tank 52 becomes empty, ink is sent from the first ink tank 51 toward the tube 16a. The first ink tank 51 includes an ink remaining amount sensor 51a. For this reason, the user can know whether or not the second ink tank 52 is empty, and the ink remaining amount and the ink end of the first ink tank 51 by the ink remaining amount sensor 51a.

  In the modification shown in FIG. 13, two choke valves 75 and 76 are used in place of the three-way valve 73 in the communication portion 711 where the first ink path 71 and the tube 16 a communicate. The choke valves 75 and 76 are an example of a first valve and a second valve. The choke valve 75 is provided in the second ink path 72. The choke valve 75 opens and closes a portion between the second ink tank 52 and the communication portion 711. The choke valve 76 is provided in the first ink path 71. The choke valve 76 opens and closes a portion between the first ink tank 51 and the communication portion 711. The choke valve 76 is opened and closed when, for example, the ink supply path 16 is filled with ink. The choke valves 75 and 76 are connected to the control device 18. The opening and closing of the choke valves 75 and 76 is controlled by the control device 18.

  At the time of ink circulation, first, the cap 19 is attached to the lower surface (surface on the nozzle 15b side) 15a of the ink head 15. Next, in a state where the ink head 15 is covered with the cap 19, the control device 18 opens the choke valve 76 and closes the choke valve 75. In this state, the motor is driven to operate the supply pump 13. Then, ink flows from the damper 14 toward the choke valve 75 to the ink recovery path 74. The ink that has passed through the ink recovery path 74 flows again toward the damper 14 through the ink supply path 16. The arrows in FIG. 13 indicate the flow of ink during ink circulation. In this way, ink can be circulated in the system, similar to FIG.

  On the other hand, at the time of printing, the choke valves 75 and 76 are opened by the control device 18 with the nozzle 15b of the ink head 15 being opened. Then, first, ink is sent from the second ink tank 52 located higher than the first ink tank 51 toward the tube 16a. The ink flow from the tube 16a to the ink head 15 is the same as in the first embodiment. The ink of the ink head 15 is ejected from the nozzle 15b. When the second ink tank 52 becomes empty, ink is sent from the first ink tank 51 toward the tube 16a. The first ink tank 51 includes an ink remaining amount sensor 51a. For this reason, when the first ink tank 51 becomes empty, the ink end is detected.

  The preferred embodiments of the present invention have been described above. However, the above-described embodiment is merely an example, and the present invention can be implemented in various other forms. For example, in each of the above embodiments, the ink supply system is mounted on the ink jet recording apparatus (specifically, the ink jet printer 10), but the present invention is not limited to this. For example, the present invention can also be applied to various manufacturing apparatuses that employ an inkjet method, measuring instruments such as micropipettes, and the like. The ink jet recording apparatus may be any apparatus that can record an image. In each of the above embodiments, the liquid stored in the liquid supply source (specifically, the ink cartridge 11C or the like) is ink, but the present invention is not limited to this. The liquid may be, for example, a cleaning liquid used for maintenance of the recording apparatus.

<Other inventions>
In an off-carriage type recording apparatus, the ink cartridge may be arranged at a position higher than the ink head. In such a case, the water head of the ink cartridge becomes larger than the ink head. Therefore, there is a possibility that ink leaks from the ink head at times other than printing. In the configuration of Patent Document 1, since the tube pump is stopped at times other than printing, the ink supply path (tube) in the tube pump is closed by being pressed, and ink is prevented from leaking from the ink head. It is thought that.

However, in the above configuration, for example, when the printer is not used for a long time, the same portion of the tube is continuously pressed, so the same portion of the tube remains crushed. For this reason, the tube of the said press location may harden | cure and elasticity may fall. As a result, the ink flow path may be blocked or damaged, and it may be difficult to stably supply ink during printing.

Accordingly, another object of the present invention is to provide a liquid supply system in which liquid is stably supplied to the ejection head when the system is used, and liquid leakage from the ejection head is accurately prevented when the system is not used. It is another object of the present invention to provide an ink jet recording apparatus provided with the liquid supply system.

In a first other aspect, an ink supply system is provided. The ink supply system includes a liquid supply source for storing liquid, an ejection head having a nozzle for ejecting liquid, a damper having a storage chamber that communicates with the ejection head and temporarily stores the liquid, and has one end A liquid supply path that communicates with the liquid supply source and the other end communicates with the damper; a liquid supply apparatus that is provided in the liquid supply path and that supplies liquid from the liquid supply source toward the damper; and the liquid A pressure control valve provided between the liquid supply source and the liquid supply device in the supply path; and a control device for controlling operation and stop of the liquid supply device. The pressure control valve is configured to close the liquid supply path when the liquid supply device is stopped.

In the above configuration, when the liquid supply device is stopped, the liquid supply path is closed by the pressure control valve. Thereby, the nozzle of the ejection head can be maintained in a negative pressure state. Therefore, when the liquid supply system is not used, it is possible to accurately prevent liquid (for example, ink) leakage from the ejection head. Further, the liquid supply source can be arranged at a position higher than the ejection head, and the degree of freedom in design (layout) in the height direction can be increased. Furthermore, in the above configuration, it is not necessary to continue crushing a part of the liquid supply path when the system is not used. For this reason, the trouble as described above can be prevented. Therefore, when using the liquid supply system, the liquid can be stably supplied to the ejection head.

According to a preferred aspect of the first other invention, the liquid supply source is disposed above the nozzle of the ejection head in the direction of gravity.

In the said aspect, the position head of a liquid supply source becomes higher than a head. For this reason, liquid leakage from the head is likely to occur. Therefore, the present invention has a high effect.

According to another preferred aspect of the first other invention, the pressure control valve is disposed above the nozzle of the head in the direction of gravity.

According to the above aspect, the liquid smoothly moves from the pressure control valve toward the head by its own weight. For this reason, the liquid can be supplied to the head more stably.

According to another preferred aspect of the first other invention, the liquid supply source is disposed above the pressure control valve in the direction of gravity.

According to the above aspect, the liquid smoothly moves from the liquid supply source toward the liquid supply path by its own weight. For this reason, the liquid can be supplied to the head more stably.

According to another preferable aspect of the first other invention, the damper includes a detection device that detects the amount of liquid stored in the storage chamber. Based on the detection result of the detection device, the control device operates the liquid supply device when the liquid storage amount of the damper becomes a predetermined value or less, and when the liquid storage amount of the damper reaches a predetermined maximum value. The liquid supply device is configured to stop.

According to the said aspect, a liquid supply apparatus can be operated according to the liquid storage amount in a damper. Thus, an appropriate amount of liquid can be sent to the damper in a timely manner. Therefore, the liquid can be supplied more stably.

According to another preferable aspect of the first other invention, the control device controls the liquid supply device to be driven at a constant rotational speed during the period from the operation to the stop of the liquid supply device. .

According to the said aspect, the pressure fluctuation of a liquid can be suppressed by the effect | action of a damper. For this reason, when the head is discharging liquid, the liquid supply device can be driven at a constant rotational speed. Therefore, it is not necessary to perform complicated control and it is simple.

According to another preferable aspect of the first other invention, the pressure control valve includes a first pressure chamber into which liquid flows, a second pressure chamber from which liquid flows out, the first pressure chamber, and the first pressure chamber. A communication port that connects the two pressure chambers, and a valve member that opens and closes the communication port. A part of the wall surface of the second pressure chamber is formed of a pressure-sensitive film that can be bent and deformed. The valve member is connected to the pressure-sensitive film, and is configured to open and close the communication port with a pressing force by which the pressure-sensitive film is bent and deformed in the film thickness direction.

According to the above aspect, the communication port opens and closes in conjunction with the bending deformation of the pressure sensitive film. For this reason, there is no need to electrically control the pressure control valve, which is simple.

According to another preferable aspect of the first other invention, a cap mounted on the head so as to cover the nozzle and a suction pump for sucking the inside of the cap are provided.

According to the said aspect, a liquid can be suitably filled with a liquid supply path at the time of a maintenance or flushing, for example. As a result, bubbles can be prevented from flowing into the liquid supply path, and problems such as printing defects can be prevented. For example, when the dried and solidified component is clogged in the nozzle, it can be suitably removed.

According to another preferable aspect of the first other aspect of the invention, the liquid supply path has an elastically deformable tube. The liquid supply device includes a pressing portion that can be switched between a pressing state in which the tube is deformed by applying a pressing force to the tube and an open state in which the tube is not deformed. The control device operates the suction pump with the pressing portion of the liquid supply device in an open state.

According to the above aspect, the liquid flows from the liquid supply source to the head all at once. Therefore, for example, during maintenance or flushing, the liquid supply path can be filled with the liquid in a relatively short time.

According to another preferable aspect of the first other invention, the liquid supply device can be switched between a pressed state in which the tube is deformed by applying a pressing force to the tube and an open state in which the tube is not deformed. It has a pressing part. The said control apparatus makes the said press part of the said liquid supply apparatus into an open state, after operating the said suction pump for a predetermined time by making the said press part of the said liquid supply apparatus into a press state.

According to the above aspect, a large pressure difference is generated between the liquid supply device and the suction pump, and a strong negative pressure region can be created. For this reason, it is possible to suitably allow the liquid to flow in while preventing bubbles from remaining in the liquid supply path.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. A first liquid path connected to the first liquid tank and the second liquid tank; a second liquid path connected to the first liquid tank and the second liquid tank; A liquid circulation pump provided in at least one of the first liquid path and the second liquid path.

According to the above aspect, the stored liquid can be agitated inside the liquid supply source. For example, ink is a mixture of color materials and solvents. By appropriately stirring the liquid, it is possible to prevent the solid content (for example, the coloring material) in the liquid from being separated or precipitated. For this reason, the stored liquid can be maintained in a homogeneous state.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. And a liquid circulation path for circulating the liquid stored in the second liquid tank, a liquid circulation pump provided in the liquid circulation path, and a differential pressure valve provided in the liquid circulation path.

According to the above aspect, the liquid stored in the second liquid tank can be stirred. And the said liquid can be maintained in a homogeneous state.

According to another preferable aspect of the first other invention, the second liquid tank is disposed below the nozzle of the ejection head in the direction of gravity.

According to the above aspect, there is no need to lift the liquid tank upward when replacing the liquid tank. Therefore, especially when the second liquid tank is large and / or heavy, the burden on the user can be reduced.

According to another preferable aspect of the first other invention, one end communicates between the liquid supply source in the liquid supply path and the pressure control valve, and the other end communicates with the damper. A recovery path, and a three-way valve provided at a portion where the liquid supply path and the liquid recovery path communicate with each other.

According to another preferable aspect of the first other invention, one end communicates between the liquid supply source in the liquid supply path and the pressure control valve, and the other end communicates with the damper. A recovery path; a communication portion in which the liquid supply path and the liquid recovery path communicate; a first valve provided in the liquid recovery path; and the liquid supply source and the communication section in the liquid supply path. And a second valve provided between the two.

According to an aspect in which a three-way valve or two valves are provided in a portion where the liquid supply path and the liquid recovery path communicate with each other, the liquid can be circulated in the system. Thereby, it can prevent highly that solid content (for example, coloring material) in a liquid isolate | separates or precipitates.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. A first liquid path communicating with the first liquid tank, a second liquid path communicating with the second liquid tank, the first liquid path, the second liquid path, and the A three-way valve connected to the liquid supply path, one end communicating with the first liquid tank, and the other end communicating with the damper, the liquid recovery path including the first liquid tank A one-way valve for preventing the flow of liquid from the liquid tank toward the damper is provided, and the control device controls switching of the three-way valve.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. A first liquid path communicating with the first liquid tank, a second liquid path communicating with the second liquid tank, the first liquid path, the second liquid path, and the liquid A communication portion that communicates with the supply path, a first valve provided in the first liquid path, and a second valve provided in the second liquid path, one end of which is the first valve A liquid recovery path that communicates with the liquid tank and the other end communicates with the damper, and the liquid recovery path includes a one-way valve that prevents a flow of liquid from the first liquid tank toward the damper, The control device is configured to turn off the first valve and the second valve. To control.

According to the aspect including the one-way valve, ink does not flow backward from the first liquid tank toward the damper even when the water head difference between the liquid tank and the head is particularly large. Therefore, the liquid can be circulated stably in the system.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. A first liquid path communicating with the first liquid tank, a second liquid path communicating with the second liquid tank, the first liquid path, the second liquid path, and the A three-way valve connected to the liquid supply path. The liquid supply system includes a liquid recovery path having one end communicating with the first liquid tank and the other end communicating with the damper. The control device controls switching of the three-way valve.

According to another preferable aspect of the first other invention, the liquid supply source includes a first liquid tank that stores a liquid and a second liquid tank that stores the same liquid as the first liquid tank. A first liquid path communicating with the first liquid tank, a second liquid path communicating with the second liquid tank, the first liquid path, the second liquid path, and the liquid A communication portion that communicates with the supply path, a first valve provided in the first liquid path, and a second valve provided in the second liquid path, one end of which is the first valve And a liquid recovery path that communicates with the damper at the other end, and the control device controls switching between the first valve and the second valve.

According to the above aspect, even when a plurality of liquid tanks are provided, the liquid can be circulated in the system. Thereby, it can prevent highly that solid content (for example, coloring material) in a liquid isolate | separates or precipitates.

In another aspect of the invention, an ink jet recording apparatus including the liquid supply system is provided.

According to the first other aspect of the invention, the liquid can be stably supplied to the head when the liquid supply system is used. In addition, when the liquid supply system is not used, liquid leakage from the head can be accurately prevented.

DESCRIPTION OF SYMBOLS 1 Carriage 2 Printer main body 3 Guide rail 7 Cable protection guide apparatus 10 Inkjet printer (inkjet recording apparatus)
11, 11C, 11M, 11Y, 11K, 11W Ink cartridge (liquid supply source)
12 Pressure control valve 13 Supply pump (liquid supply device)
14 Damper 15 Ink head (ejection head)
16, 16a, 16b, 16c, 16d Ink supply path (liquid supply path)
18 Control device

Claims (14)

A liquid supply source for storing liquid;
An ejection head having a nozzle for ejecting liquid;
A damper that communicates with the ejection head and has a storage chamber in which liquid is temporarily stored;
A liquid supply path having one end communicating with the liquid supply source and the other end communicating with the damper;
A liquid supply device that is provided in the liquid supply path and supplies liquid from the liquid supply source toward the damper;
A control device for controlling the operation and stop of the liquid supply device;
A pressure control valve provided between the liquid supply source and the liquid supply device in the liquid supply path;
With
The liquid source is
A first liquid path communicating with the liquid supply path;
A first liquid tank communicating with the first liquid path and storing liquid;
A liquid circulation path communicating with the first liquid path;
A second liquid tank communicating with the liquid circulation path and storing the same liquid as the first liquid tank;
A liquid circulation pump provided in the liquid circulation path;
A differential pressure valve provided in the liquid circulation path;
With
The liquid supply system, wherein the second liquid tank is disposed below the nozzle of the ejection head in the direction of gravity. A liquid supply source for storing liquid;
An ejection head having a nozzle for ejecting liquid;
A damper that communicates with the ejection head and has a storage chamber in which liquid is temporarily stored;
A liquid supply path having one end communicating with the liquid supply source and the other end communicating with the damper;
A liquid supply device that is provided in the liquid supply path and supplies liquid from the liquid supply source toward the damper;
A control device for controlling the operation and stop of the liquid supply device;
With
The liquid source is
A first liquid path communicating with the liquid supply path;
A first liquid tank communicating with the first liquid path and storing liquid;
A liquid circulation path communicating with the first liquid path;
A second liquid tank communicating with the liquid circulation path and storing the same liquid as the first liquid tank;
A liquid circulation pump provided in the liquid circulation path;
A differential pressure valve provided in the liquid circulation path;
With
The second liquid tank is disposed below the nozzle of the ejection head in the gravity direction ,
The liquid supply system, wherein the first liquid tank is disposed above the nozzles of the ejection head in a gravitational direction . The liquid supply system according to claim 1 or 2 , wherein the second liquid tank is larger in size than the first liquid tank. 4. The liquid supply system according to claim 1, wherein the second liquid tank is heavier than the first liquid tank. 5. Before SL pressure control valve, the which the liquid in the nozzles of the discharge head is configured to maintain a negative pressure state, when the liquid supply device is stopped to close the liquid supply passage is configured, the liquid supply system described in claim 1. A pressure control valve provided between the liquid supply source in the liquid supply path and the liquid supply device, and maintaining the liquid in the nozzle of the discharge head in a negative pressure state;
  The liquid supply system according to claim 2, wherein the pressure control valve is configured to close the liquid supply path when the liquid supply device is stopped. Said pressure control valve, the discharge head of the disposed above the gravitational direction than the nozzle, the liquid supply system described in any one of claims 1,5,6. The damper includes a detection device that detects the amount of liquid stored in the storage chamber,
The control device operates the liquid supply device when the liquid storage amount of the damper becomes a predetermined value or less based on the detection result of the detection device, and when the liquid storage amount of the damper reaches a predetermined maximum value. wherein the liquid supply device is configured to stop the liquid supply system described in any one of claims 1 to 7. The control device according to any one of claims 1 to 8 , wherein the liquid supply device is controlled to be driven at a constant rotation speed during a period from the operation to the stop of the liquid supply device. Liquid supply system. The pressure control valve is
A first pressure chamber into which liquid flows,
A second pressure chamber through which the liquid flows out;
A communication port connecting the first pressure chamber and the second pressure chamber;
A valve member for opening and closing the communication port;
With
A part of the wall surface of the second pressure chamber is composed of a pressure-sensitive film that can be bent and deformed,
The valve member is coupled to the sense of the pressure membrane, the sensitive pressure membrane is arranged to open and close the communication opening by pressing force resiliently deformed in the thickness direction, of claim 1, 5, 6, 7 The liquid supply system described in any one. A cap attached to the discharge head so as to cover the nozzle;
And a suction pump for sucking in the cap, a liquid supply system according to any one of claims 1 to 10. The liquid supply path has an elastically deformable tube,
The liquid supply device has a pressing portion that can be switched between a pressing state in which the tube is deformed by applying a pressing force to the tube and an open state in which the tube is not deformed,
The liquid supply system according to claim 11 , wherein the control device operates the suction pump with the pressing portion of the liquid supply device in an open state. The liquid supply device has a pressing portion that can be switched between a pressing state in which the tube is deformed by applying a pressing force to the tube and an open state in which the tube is not deformed,
The control device, after the allowed suction pump is operated for a predetermined period of time the pressing portion of the liquid supply device as a pressing state, the pressing portion to an open state of the liquid supply device, according to claim 11 Liquid supply system. An ink jet recording apparatus comprising the liquid supply system according to any one of claims 1 to 13 .

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