JP2010030097A - Liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting apparatus which keeps controlling of valves simple in the case when a plurality of recording heads are provided. <P>SOLUTION: The liquid jetting apparatus is equipped with cartridges 20 filled with liquid, a plurality of jetting heads 2 for jetting the liquid fed from the cartridges 20, sub-tanks 21 provided between the cartridges 20 and a plurality of the jetting heads 2 and feeding the liquid from the cartridges to respective jetting heads by water head differences, and valve groups 24-27 provided in liquid feeding flow paths between the sub-tanks 21 and a plurality of the jetting heads 2. A plurality of head groups G1 and G2 containing at least two jetting heads 2 are constituted, and the valve groups 24-27 are composed of the same number of the valves 24a, 24b-27a and 27b as those of the head groups G1 and G2, and respective valves 24a, 24b-27a and 27b are respectively connected with the head groups G1 and G2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus.

  As a liquid ejecting apparatus that ejects a liquid, for example, an ink jet recording apparatus is known. An ink jet recording apparatus is an apparatus that records characters, images, and the like on a recording medium, and is configured such that ink is ejected onto a recording medium from nozzles provided on a recording head (ejection head). In particular, a so-called off-carriage type printer is known in which a large-capacity ink cartridge is arranged at a position away from the ejection head and ink is supplied from the ink cartridge to the ejection head via a supply pipe.

Such an off-carriage type printer performs a choke suction operation by using a valve provided between the ink cartridge and the recording head during the cleaning process (see, for example, Patent Document 1). The choke suction operation is an operation for increasing the negative pressure on the downstream side of the valve by performing the suction operation with the valve closed. When the valve is opened from the state in which the negative pressure is increased by the choke suction operation, the cleaning process can be efficiently performed while discharging the air contained in the ink flow path to the outside.
JP 2006-7493 A

  However, in the above prior art, since a valve is provided for each ink cartridge that supplies ink to each nozzle of the recording head, for example, when applied to a printer equipped with a plurality of recording heads, the number of valves increases. It becomes difficult to control.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting apparatus capable of simplifying control of a valve even when a plurality of recording heads are provided. .

  In order to solve the above-described problems, a liquid ejecting apparatus according to the invention includes a supply path that supplies the liquid to a plurality of ejection heads that eject the liquid from a liquid storage section in which the liquid is stored, and a middle of the supply path. A sub-tank that is capable of supplying the liquid supplied from the liquid storage unit to each of the ejection heads by a water head difference, and a valve group that is provided midway between the sub-tank and the plurality of ejection heads in the supply path. A plurality of head groups including at least two of the ejection heads, and the valve group includes the same number of valves as the head group, and each of the valves is connected to each of the head groups via the supply path. Connected.

  According to the liquid ejecting apparatus of the present invention, since one valve is provided for the head group including a plurality of ejecting heads, for example, choke suction is performed on the plurality of ejecting heads by closing one valve. It is possible to simplify the control of the valve. Further, in this configuration, since the sub tank supplies the liquid using the water head difference, for example, the liquid can be satisfactorily supplied to the plurality of jet heads by arranging the sub tank near the jet head.

Moreover, in the said liquid injection apparatus, it is preferable to provide the check valve provided in the middle of the said liquid storage part and the said sub tank in the said supply path.
According to this configuration, it is possible to prevent the liquid from leaking when the liquid storage unit is replaced by the check valve.

In the liquid ejecting apparatus, it is preferable that the liquid selected from any one of a plurality of the liquid storage units in which the same kind of the liquid is stored is supplied to the sub tank. Here, the same type of liquid means, for example, a liquid having the same color and characteristics, and means a liquid that can be replaced with one liquid.
According to this configuration, a large amount of liquid can be ejected continuously by switching between a plurality of liquid storage units filled with the same liquid. Therefore, continuous printing is possible.

In the liquid ejecting apparatus, it is preferable that an adjustment mechanism that can adjust a height of the sub tank with respect to the liquid storage portion is provided.
According to this configuration, for example, by holding the height of the sub tank above or the same as that of the liquid storage portion by the adjustment mechanism, air can be prevented from entering the sub tank when the liquid storage portion is attached or detached. Further, for example, by maintaining the height of the sub tank below or the same as that of the liquid storage portion by the adjusting mechanism, the speed of supplying the liquid from the liquid storage portion side to the sub tank side can be improved.

In the liquid ejecting apparatus, it is preferable that the head group is configured based on at least one of a usage frequency of each ejecting head and a relative position with respect to another ejecting head.
According to this configuration, since the head group is configured based on the frequency of use of the head and the relative positional relationship of the head, choke suction is performed on each ejection head by selectively closing the valve. It can be done well.

In the liquid ejecting apparatus, it is preferable that at least one of the head groups is different in at least one of a supply path length and a supply path diameter from the valve to each of the ejection heads.
According to this configuration, since at least one of the supply path length and the supply path diameter can be set in various ways, predetermined processing (for example, choke cleaning) is positively performed on a desired ejection head constituting the head group. Is possible.

  Hereinafter, with reference to the drawings, embodiments of the liquid ejecting apparatus of the invention will be described. In the present embodiment, as an example of the liquid ejecting apparatus according to the present invention, an ink jet printer (hereinafter referred to as printer 1) is illustrated.

FIG. 1 is a diagram illustrating a schematic configuration of a printer 1 according to the present embodiment. FIG. 2 is a diagram illustrating a configuration of an ink supply path from the ink cartridge (liquid storage unit) 20 to the head unit 10 of the printer 1 according to the present embodiment.
As shown in FIG. 1, the printer 1 includes a head unit 10 that ejects ink, a recording sheet conveyance mechanism 11 that conveys a recording sheet 100 as a medium that ejects ink from the head unit 10, and a head unit 10. And a cap unit 30 for performing maintenance. The recording paper transport mechanism 11 includes transport roller pairs 12 and 13 for transporting the recording paper 100, and a platen 14 for placing the recording paper 100.

  The printer 1 has a plurality (five in the present embodiment) of ink cartridges 20 (20C, 20M, 20Y, 20B1, and 20B2) for supplying ink to the head unit 10.

  The ink cartridge 20C is filled with C (cyan) ink, the ink cartridge 20M is filled with M (magenta) ink, and the ink cartridge 20Y is filled with Y (yellow) ink. The ink cartridge 20B1 is filled with B (black) ink. The ink cartridge 20B2 is filled with the same type of B (black) ink as the ink cartridge 20B1. Here, the same type of ink means, for example, inks having the same color and characteristics, and can be replaced with one ink. These ink cartridges 20 (20C, 20M, 20Y, 20B1, 20B2) are connected to sub tanks 21 provided on the head unit 10 side through tubes (supply paths) T1 to T4 as ink flow paths. It has become.

  Here, tubes (supply paths) T5 and T6 connected to the ink cartridges 20B1 and 20B2, respectively, are connected to the tube (supply path) T4 via the selection valve B1. That is, by switching the selection valve B1, one of the ink cartridges 20B1 and 20B2 B (black) can be supplied to the head unit 10 side. According to this configuration, when one of the ink cartridges 20B1 and 20B2 runs out of black ink, which is frequently used in normal printing such as document printing, the ink is continuously switched to the other. Can be printed in large quantities.

  A pressure pump 23 is connected to each ink cartridge 20 via a tube T11. Specifically, one end side of the tube T11 is branched into five, and each of these branch portions is connected to each ink cartridge 20. The pressurizing pump 23 is connected to a drive motor (not shown) to generate pressurized air, and sends it to each ink cartridge 20 to supply ink filled in the cartridge to the head unit 10 (sub tank 21). It is designed to be pumped to the side.

  The head unit 10 is configured by mounting a plurality (six in this embodiment) of recording heads (jet heads) 2 on a carriage (not shown). Each recording head 2 has four nozzle rows including a plurality of nozzles, and ink of four colors is supplied from the ink cartridge 20 to each nozzle row. That is, each recording head 2 can eject four colors of ink.

  Moreover, the head unit 10 is comprised by the 1st head group G1 and the 2nd head group G2, as FIG. 2 shows. The first head group G1 includes the recording heads 2A to 2C. The second head group G2 includes the recording heads 2D to 2F.

  Further, the printer 1 includes a plurality of sub tanks 21 that are connected to the ink cartridge 20 via the tubes T1 to T4 and supply ink to each recording head 2 from the ink cartridge 20 side. The sub tank 21 is disposed vertically above the head unit 10 (see FIG. 1). Thereby, the sub tank 21 can temporarily store the ink supplied from the ink cartridge 20 and supply the ink to each recording head 2 by utilizing the water head difference. That is, in the printer 1 according to the present embodiment, ink is supplied to each recording head 2 by using the pressurized air and the water head difference of the pressure pump 23. Therefore, it is not necessary to operate the pressure pump 23 continuously, and the power consumption in the printer 1 can be suppressed. The sub tank 21 is preferably arranged in the vicinity of the head unit 10 (for example, within 50 cm). In this way, it is possible to satisfactorily supply ink to a large number (six in this embodiment) of the recording heads 2 by suppressing the resistance in the ink flow path.

  As shown in FIG. 2, the printer 1 includes valve groups 24 and 25 provided in ink supply paths (supply paths) T12, T13, T14, and T15 between the sub tank 21 and the head unit 10 (a plurality of recording heads 2), respectively. , 26, 27. Each valve group 24 to 27 is composed of two choke valves (valves). For example, the valve group 24 includes choke valves 24a and 24b, the valve group 25 includes choke valves 25a and 25b, the valve group 26 includes choke valves 26a and 26b, and the valve group 27 includes choke valves 27a and 27b. It is composed of

  Each of the choke valves constituting each of the valve groups 24 to 27 is connected to the recording head 2 constituting the first and second head groups G1 and G2.

  Specifically, the choke valve 24a is connected to the respective recording heads 2A, 2B, and 2C constituting the first head group G1 through the tube T12. The choke valve 24b is connected to the recording heads 2D, 2E, and 2F that configure the second head group G2 via the tube T12. The choke valves 25a and 25b are also connected to the first and second head groups G1 and G2 (recording head 2) via the tube T13, respectively. The choke valves 26a and 26b are also connected to the first and second head groups G1 and G2 (recording head 2) through the tube T14. The choke valves 27a and 27b are also connected to the first and second head groups G1 and G2 (recording head 2) via the tube T15, respectively. The tubes T12 to T15 are connected to the back pressure adjusting unit 6 in each recording head 2, and the ink in the ink cartridge 20 is introduced into the ink flow path in the head via the back pressure adjusting unit 6. It has become so. Based on such a configuration, ink of four colors (C, M, Y, B) is supplied from the ink cartridge 20 to each recording head 2 so that each head can perform full color printing. It has become.

  In addition, the printer 1 includes a check valve 40 between the ink cartridge 20 and the sub tank 21. Specifically, it is provided at a connection portion with each ink cartridge 20 of tubes T1, T2, T3, T5, and T6 that supply ink to the head unit 10 side. This prevents the ink from leaking out from the head unit 10 side when the ink cartridge 20 is attached or detached.

  FIG. 3 is a diagram showing in detail the configuration of the ink flow path from the ink cartridge 20 to the head unit 10 and the cap unit 30 used for maintenance of the head unit 10. In FIG. 3, the ink cartridge 20C is shown as an example, but the other ink cartridges 20M, 20Y, 20B1, and 20B2 have the same configuration.

  As shown in FIG. 3, the ink cartridge 20 </ b> C (20) includes a case member 51 and an ink pack 52 housed in the case member 51 and formed of a plastic material. Ink pack 52 stores ink L (cyan; C) supplied to recording head 2. Further, in the ink cartridge 20C, when pressurized air is sent from the pressure pump 23 into the case member 51 via the tube T11, the ink pack 52 is pressed, and the ink L is supplied to the head unit 10 side.

  The sub tank 21 is formed by molding a resin material such as polypropylene. The sub tank 21 is formed with a recess to be the ink chamber 57, and the ink chamber 57 is partitioned by sticking a transparent elastic sheet to the opening surface of the recess. Based on such a configuration, the sub tank 21 absorbs the pressure fluctuation of the ink L, and the ink L is supplied to the recording head 2 side in a state where the pressure fluctuation is absorbed in the sub tank 21. Thus, the sub tank 21 functions as a pressure damper.

  As shown in FIG. 3, the tube T12 is branched into two from the sub tank 21 toward the head unit 10, and choke valves 24a and 24b are connected to each. The tube T12 is connected to each of the recording heads 2A to 2C constituting the first head group G1 on the downstream side (recording head 2 side) of the choke valve 24a. Further, the tube T12 is connected to each of the recording heads 2D to 2E constituting the above-described second head group G2 on the downstream side (recording head 2 side) of the choke valve 24b.

In the present embodiment, the head groups G1 and G2 have different ink flow path lengths and ink flow path diameters (supply path diameters) from the choke valves 24a and 24b to the recording heads 2, as shown in FIG. Specifically, as shown in FIG. 1, the recording heads 2C and 2D arranged at the center of the head unit 10, the recording heads 2B and 2E arranged outside thereof, and the recording heads 2A and 2F arranged further outside are arranged in this order. The ink flow path length (supply path length) to the corresponding choke valves 24a and 24b was set longer, and the ink flow path diameter to the corresponding choke valves 24a and 24b was set smaller. Note that at least one of the ink flow path length and the ink flow path diameter may be different.
Furthermore, in addition to adjusting the ink flow path length and the ink flow path diameter, for example, by adjusting the bending condition of the tube T12 constituting the ink flow path, the ink flow condition is adjusted by changing the internal resistance in the tube. You may make it do.
Thereby, in choke cleaning as will be described later, the ink flows most positively into the recording heads 2C and 2D. Similarly, the ink flow path is also provided between the choke valves 25a, 25b to 27a, 27b corresponding to the sub tanks 21 connected to the other ink cartridges 20 (20Y, 20M, 20B1, 20B2) and the recording heads 2. The lengths are different, and the ink flows most positively into the recording heads 2C and 2D. That is, the choke cleaning described later can be positively performed on the recording head 2 arranged in the center of the head unit that is frequently used.

  The printer 1 also includes an adjustment mechanism 53 that enables the height of the sub tank 21 relative to the ink cartridge 20 to be adjusted. Specifically, the adjustment mechanism 53 is attached to the sub tank 21. The adjustment mechanism 53 can adjust the height of the sub tank 21 according to the status of the printer 1. For example, the adjustment mechanism 53 places the sub tank 21 above or at the same height as the ink cartridge 20 when the ink cartridge 20 is attached or detached. This prevents air bubbles from entering the sub tank 21 when the ink cartridge 20 is detached. At this time, the check valve 40 prevents the ink from overflowing.

The adjustment mechanism 53 arranges the sub tank 21 below or at the same height as the ink cartridge 20 during normal operation (ink ejection). Thereby, the ink supply speed from the ink cartridge 20 side to the sub tank 21 side can be improved by utilizing the water head difference.
The adjustment mechanism 53 may be attached to each of the sub tanks 21 or may be provided in common for the plurality of sub tanks 21.

  Even if the ink in the ink cartridge 20 becomes empty, the printer 1 can continuously perform the printing process by using the ink in the sub tank 21. That is, since the printing process can be performed while replacing the ink cartridge 20, the printing process can be continuously performed.

  Each recording head 2 has a nozzle substrate 15 on which a plurality of nozzles 16 for ejecting ink are formed. Note that the surface of the nozzle substrate 15 constitutes an ejection surface 15a.

  The cap unit 30 is formed between the cap member 85 that is in contact with the ejection surface 15a of each recording head 2, the ink absorber 87 disposed in the cap member 85, and the cap member 85 and the ejection surface 15a. A suction pump 83 is provided to place the space to be in a negative pressure state.

  The cap member 85 is constituted by a member obtained by molding an elastic material such as rubber into a tray shape, and a frame-shaped seal member 82 is provided on the upper surface thereof. The cap member 85 can be satisfactorily adhered to the ejection surface 15 a of the recording head 2 via the seal member 82. The ink absorber 87 is formed of a sponge-like member capable of holding (absorbing) ink, a porous member, or the like, and in this embodiment is formed of a nonwoven fabric such as felt. A tube T80 that communicates with the inside of the cap member 85 is connected to the bottom of the cap member 85, and the ink collected by the ink absorber 87 is sucked by the suction pump 83 via the tube T80, and downstream. It is collected in a waste ink tank 88 provided.

  Further, the cap member 85 is provided with a moving mechanism (not shown) so that the cap member 85 can come into contact with the ejection surface 15a. The moving mechanism may be provided for each cap member 85, or may be provided for each cap member 85 corresponding to the recording heads 2 constituting each head group G1, G2. Further, the recording head 2 may be moved (for example, lowered) to bring the seal member 82 of the cap member 85 and the ejection surface 15a into close contact with each other.

  The cap unit 30 is used for maintenance processing in the printer 1 described later. The maintenance process is a suction operation for discharging ink from the recording head 2. Here, the suction operation includes a normal suction operation and a choke suction operation.

  In the normal suction operation, the cap member 85 is brought into close contact with the injection surface 15a without closing the choke valves 24a and 24b, and the internal space formed between the injection surface 15a and the cap member 85 is decompressed by the suction pump 83. In this operation, ink is sucked from the nozzles 16 on the ejection surface 15a. As a result, the ink that has clogged the nozzle 16 can be forcibly discharged, and the ejection characteristics of the recording head 2 can be maintained or recovered.

  In contrast, in the choke suction operation, the suction pump 83 is operated by bringing the cap member 85 into close contact with the ejection surface 15a while the choke valves 24a and 24b are closed. As a result, the inside of the recording head 2 is brought into a large negative pressure state via the nozzle 16. Then, ink is poured into the recording head 2 at once by opening the choke valve. By such a choke suction operation, it is possible to perform choke cleaning that discharges bubbles remaining in the ink flow path in the recording head 2 and thickened ink fixed in the nozzle to the outside.

  Next, the configuration of each recording head 2 constituting the head unit 10 will be described with reference to the drawings.

  FIG. 4 is a cross-sectional view showing the configuration of the head main body 68 and the flow path forming unit 72 of the recording head 2. As shown in the figure, the flow path forming unit 72 is joined to the bottom of the head main body 68.

  The head main body 68 is a box-shaped member made of synthetic resin, and includes a storage space 73 for storing the drive unit 74 and an internal flow path 78 for guiding the ink supplied from the outside to the flow path forming unit 72. Has been.

  The drive unit 74 disposed in the accommodation space 73 includes a plurality of piezoelectric vibrators 75, a fixing member 76 that supports upper ends of the plurality of piezoelectric vibrators 75, and a flexible cable that supplies a drive signal to the piezoelectric vibrators 75. 77. The piezoelectric vibrator 75 is provided corresponding to each of the plurality of nozzles 16. The internal flow path 78 is formed so as to penetrate the head main body 68 in the vertical direction in FIG. 4, circulates ink supplied from the upper side in the figure, and supplies it to the flow path forming unit 72 through the opening end on the lower side in the figure. To do.

  The flow path forming unit 72 is obtained by laminating the diaphragm 69, the flow path substrate 70, and the nozzle substrate 15, and joining and integrating them with an adhesive or the like. The flow path forming unit 72 includes a common ink chamber 79 connected to the internal flow path 78 of the head main body 68, an ink supply port 80 connected to the common ink chamber 79, and a pressure chamber connected to the ink supply port 80. 81 is formed. The pressure chamber 81 is provided corresponding to each nozzle 16, and each is connected to the nozzle 16 at the end opposite to the common ink chamber 79.

  The diaphragm 69 is obtained by laminating an elastic film on a metal support plate such as stainless steel. An island portion 84 joined to the lower end of the piezoelectric vibrator 75 is formed in a portion corresponding to the pressure chamber 81 of the vibration plate 69 by removing the support plate in an annular shape by etching or the like, and functions as a diaphragm portion. . That is, in the diaphragm 69, the elastic film portion around the island portion 84 is elastically deformed in accordance with the driving of the piezoelectric vibrator 75 on the pressure chamber 81, and the island portion 84 moves up and down. Further, a portion in which a part of the support plate is removed to form only an elastic film is provided between the vibration plate 69 and the vicinity of the lower end of the internal flow path 78, and this portion is a pressure in the common ink chamber 79. The compliance unit 86 absorbs fluctuations.

  The flow path substrate 70 has recesses for forming spaces for the common ink chamber 79, the ink supply port 80, and the pressure chamber 81 that connect the lower end of the internal flow path 78 and the nozzle 16. These recesses are formed by anisotropically etching a silicon single crystal substrate that is a base material of the flow path substrate 70.

  The nozzle substrate 15 has a plurality of nozzles 16 formed at a predetermined interval (pitch) in a predetermined direction. The nozzle substrate 15 of the present embodiment is a plate-like member made of a metal such as stainless steel, and the outer surface thereof is an ejection surface 15a.

  Next, a maintenance method using the cap unit 30 will be described as an operation of the printer 1. In the following description, the process of performing chalk cleaning will be mainly described. In this description, reference is made to FIG.

  First, the seal member 82 of the cap member 85 is brought into contact with the recording heads 2 of the head groups G1 and G2 that perform chalk cleaning. In this description, a case where the chalk cleaning is performed for the first head group G1 will be described.

  For example, in this description, the cap member 85 (seal member 82) is brought into contact with the recording heads 2A, 2B, and 2C constituting the first head group G1. Subsequently, the choke valves 24a to 27a are closed. In this state, the suction pump 83 connected to the cap member 85 that contacts the recording heads 2A, 2B, and 2C is driven.

  Then, since the ink supply paths (tubes T12 to T15) are closed between the first head group G1 and the sub tank 21 by the choke valves 24a to 27a, the recording heads 2A, 2B, The inside of 2C becomes a large negative pressure state. Then, by opening the choke valves 24a to 27a, ink is poured into the recording heads 2A, 2B, and 2C at once due to the accumulated negative pressure. At this time, bubbles staying in the ink supply paths in the recording heads 2A, 2B, and 2C and the thickened ink fixed in the nozzles are discharged to the outside.

  Here, in the printer 1 according to the present embodiment, the ink flow path length is made different between the choke valves 24a to 27a and the respective recording heads 2 as described above, and is arranged at the center of the frequently used head unit 10. Strong choke cleaning can be performed by positively pouring ink into the recording head 2.

  As described above, according to this embodiment, after the ink flow path downstream of each of the choke valves 24a to 27a is branched, it is connected to the head group G1 including the plurality of recording heads 2A, 2B, and 2C. By closing these choke valves 24a to 27a, the ink can flow into the plurality of recording heads 2A, 2B, and 2C to perform choke cleaning. Therefore, the control of the choke valve can be simplified as compared with the conventional configuration in which a valve is provided for each nozzle row of the head.

  When performing normal suction operation, the choke valves 24a and 24b are not used, the cap member 85 is brought into close contact with the ejection surface 15a, and the internal space formed between the ejection surface 15a and the cap member 85 by the suction pump 83. And the ink is sucked from the nozzles 16 on the ejection surface 15a. Thereby, for example, the ejection characteristics of the recording head 2 can be maintained or recovered by discharging the thickened ink in the nozzles 16.

  The preferred embodiments according to the present invention have been described above with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to such examples, and the above embodiments may be combined. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above embodiment, the head unit 10 including the six recording heads 2 includes the two head groups G1 and G2. However, the present invention is not limited to this. For example, the number of recording heads constituting the head unit 10 may be six or more. In this case, the number of head groups may be set to 3 or more. Here, it is desirable to set the number of recording heads 2 constituting each head group to three or four. This is because the choke suction can be satisfactorily performed with respect to the recording head of each head group by one choke valve.

  In the above embodiment, the number of recording heads 2 constituting each head group is the same number (three), but may be different. In this case, it is preferable to configure the head group based on at least one of the usage frequency of each recording head 2 and the relative position with respect to the other recording heads 2.

  Here, since the recording heads 2B, 2C, 2D, and 2E inside the head unit 10 are arranged adjacent to each other, they are used at substantially the same timing in a predetermined printing process. Therefore, choke cleaning is required at substantially the same timing. On the other hand, the recording heads 2A and 2F outside the head unit 10 are used in the same process because they are used when the width of the recording paper 100 becomes larger than a predetermined value. Therefore, choke cleaning is required at the same timing.

  In such a case, the head group is configured based on the relative position with respect to the other recording heads 2. Specifically, the recording heads 2B, 2C, 2D, and 2E arranged inside the head unit 10 are set as one head group, and the recording heads 2A and 2F arranged outside the head unit 10 are set as other heads. Group.

  In this way, choke cleaning can be performed on the recording head 2 that needs to be cleaned at the same timing by selectively closing the choke valve. Therefore, it is possible to prevent a problem that the ink is wastedly discharged by performing chalk cleaning on the recording head 2 that does not require cleaning.

  Further, when a head group is configured based on the usage frequency of each recording head 2, for example, the recording head 2 that frequently ejects ink is set as one head group (a head group that is frequently used), and ink ejection is performed at predetermined time intervals. The recording head 2 that performs the recording is set as another head group (a head group that is used less frequently).

  In this case, the recording heads 2 of the head group having a high usage frequency are more frequently subjected to choke cleaning than the recording heads 2 having a low usage frequency. Therefore, by selectively closing the choke valve, it is possible to frequently perform choke cleaning on the desired recording head 2 and prevent waste of ink.

  In the above-described embodiment, the ink flow path length and the ink flow path diameter from the choke valve to each recording head are different in both the head groups G1 and G2. However, when a head group different from the present embodiment is configured as described above, the ink flow path length and the ink flow path diameter may be varied only in at least one of the head groups.

  In the above embodiment, an ink jet printer and an ink cartridge are employed. However, a liquid ejecting apparatus that ejects or discharges liquid other than ink and a liquid container containing the liquid are employed. Also good. 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 a material that can be ejected by the liquid ejecting apparatus. For example, it may be in the state when the substance is in a liquid phase, and may be in a liquid state with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts) ) And a liquid as one state of the substance, as well as particles in which functional material particles made of solid materials such as pigments and metal particles are dissolved, dispersed or mixed in a solvent. In addition, typical examples of the liquid include ink and liquid crystal as described in the above embodiments. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot-melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a coloring 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 ejecting apparatuses and liquid containers.

FIG. 2 is a diagram illustrating a schematic configuration of a printer. FIG. 4 is a diagram illustrating an ink supply path from an ink cartridge to a head unit. The figure which shows the structure of an ink flow path and a cap unit. Sectional drawing which shows the structure of a head main body and a flow-path formation unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer (liquid ejecting apparatus), 2 ... Recording head (ejection head), 20 ... Ink cartridge (liquid storage part), 21 ... Sub tank, 24, 25, 26, 27 ... Valve group, 24a, 24B, 25A, 25b , 26a, 26b, 27a, 27b ... choke valve (valve), 40 ... check valve, 53 ... adjustment mechanism, G1, G2 ... head group, L ... ink (liquid), T1-T6, T12-T15 ... tube ( Supply channel)

Claims (6)

A supply path for supplying the liquid to a plurality of ejection heads for ejecting the liquid from a liquid storage section in which the liquid is stored;
A sub-tank that is provided in the middle of the supply path and that can supply the liquid supplied from the liquid reservoir to each of the ejection heads by a water head difference;
A valve group provided midway between the sub tank and the plurality of ejection heads in the supply path;
A plurality of head groups including at least two of the ejection heads are configured, and the valve group includes the same number of valves as the head group, and each of the valves is connected to each of the head groups via the supply path. A liquid ejecting apparatus that is connected.   The liquid ejecting apparatus according to claim 1, further comprising a check valve provided in the supply path in the middle of the liquid storage unit and the sub tank.   3. The liquid ejecting apparatus according to claim 1, wherein the liquid selected from any one of a plurality of the liquid storage units storing the same type of liquid is supplied to the sub tank. 4. .   The liquid ejecting apparatus according to claim 1, further comprising an adjustment mechanism that enables adjustment of a height of the sub tank with respect to the liquid storage unit.   5. The liquid jet according to claim 1, wherein the head group is configured based on at least one of a use frequency in each of the jet heads and a relative position with respect to another jet head. apparatus.   The liquid ejecting apparatus according to claim 1, wherein at least one of the head groups is different in at least one of a supply path length and a supply path diameter from the valve to each of the ejection heads. .

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