JP4882242B2 - Droplet ejector - Google Patents

Description

  The present invention relates to a droplet ejecting apparatus that ejects liquid supplied from a main tank and temporarily stored in a sub tank from an ejecting head.

  Conventionally, in this type of droplet ejecting apparatus, bubbles or foreign substances are clogged in the nozzle of the ejecting head, or the liquid in the nozzle dries due to the fact that it has not been used for a long time, so that the components are solid or slurry. There is a case where normal injection cannot be performed due to adhesion inside.

  As a specific example of a droplet ejecting apparatus in which such a problem occurs, an image or the like is recorded on a recording medium by ejecting ink once stored in a sub tank from a recording head (corresponding to the above ejecting head). An ink jet recording apparatus is mentioned. If the nozzles are clogged with foreign matter or the like or the ink in the nozzles dries in the ink jet recording apparatus, the ink may not be ejected normally and a good image (recording result) may not be obtained.

  For this reason, an ink jet recording apparatus is generally provided with a recovery function for recovering a state in which ink is normally ejected by removing ink, foreign matter, and the like in the nozzles at regular time intervals, for example.

  As a specific method for realizing the recovery function, a negative pressure suction method is known in which a cap is placed on a nozzle of a recording head and ink, foreign matter, or the like is sucked from the nozzle in this state. However, this method has a problem that a large amount of ink is consumed every time the recovery operation is performed because a large amount of ink is sucked.

Therefore, a positive pressure purge method has been proposed in which pressure (positive pressure) is applied to ink from the upstream side of the ink supply path with respect to the recording head to eject ink and the like from the nozzles. As a specific example of the positive pressure purge method, the air inside the sub tank is compressed by compressing the air inside the sub tank using an air pressurizing pump, and the ink is pushed downstream from the recording head by that pressure, and the ink from the recording head Is known (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 5-92578 (FIG. 1)

  However, if the nozzle is recovered by compressing the air in the sub tank as in the method described in Patent Document 1, the air is first compressed, and the pressure is transmitted to the ink level stored in the sub tank. As pressure is applied to the ink, the pressure loss is large and the efficiency is poor. Moreover, since the ink flows back not only to the recording head side but also to the supply source side due to compression, the efficiency may be further deteriorated. Therefore, it is essential to install a check valve to prevent the backflow.

  Furthermore, in order to restore the nozzle to a normal state, it is necessary to eject ink from the nozzle at a somewhat high flow rate. In the case of positive pressure purge by air compression, the ink flow rate is due to a large pressure loss, etc. Rises relatively slowly. For this reason, ink flows out steadily until the flow velocity required for the recovery operation rises, and the ink is wasted.

  On the other hand, as one of the methods for eliminating the drawbacks of the positive pressure purge method by air compression, the subtank formed of a flexible material is filled with ink, and the subtank is deformed. A positive pressure purge method is also considered in which ink is ejected by directly applying pressure to ink by changing (decreasing).

  However, the method of ejecting at the pressure generated by the volume change as described above rapidly rises to the flow velocity necessary for the recovery operation, so that wasteful ink consumption during the recovery operation is reduced, but the ink is discharged at the pressure at the time of the volume change. There is a risk that the efficiency may be reduced by flowing back to the supplier side. Therefore, it is essential to install a check valve.

  In addition, after the recovery operation is performed by changing the volume, when restoring the volume (returning the sub tank to the original shape), the negative pressure generated in the nozzle due to the restoration causes the ink to flow backward from the nozzle, and the negative pressure Depending on the size, the meniscus of the nozzle may not be maintained.

  Such a problem is not limited to the ink jet recording apparatus, and is a common problem that may occur in various droplet ejecting apparatuses configured to eject the liquid once stored in the sub tank from the nozzles of the ejecting head.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a droplet ejecting apparatus capable of performing a nozzle recovery operation by a positive pressure purge method efficiently and reliably with a simple configuration and suppressing liquid consumption. The purpose is to provide.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to an ejection head having a nozzle capable of ejecting liquid droplets, a main tank containing liquid, and a liquid supply from the main tank to the nozzle of the ejection head. And a subtank provided in a path. The sub-tank has an inflow port for allowing the liquid supplied from the main tank to flow inside, temporarily stores the liquid flowing in from the inflow port, and sends the stored liquid to the ejection head.

The sub-tank of the present invention is a plate-like member provided so as to block the internal liquid supply path on the downstream side of the liquid supply path from the inlet, and is formed so as to penetrate the member. At least one liquid passage through which liquid can pass is formed between the upstream side and the downstream side of the member in the supply path, and the downstream side liquid is directly pressurized by being moved downstream. A possible press member, and one end is connected to the upstream surface of the press member and the other end protrudes to the outside of the sub tank, and external force is applied to the other end by an operation from the outside of the sub tank. And a connecting member for pressing and moving the pressing member to the downstream side. The plurality of liquid flow paths are formed in a press member other than a portion where one end of the connection member is connected, so that the liquid flows between the upstream and downstream sides of the press member via each liquid flow path. It is configured to pass. In addition, a pressing drive means is provided outside the sub tank and moves the pressing member to the downstream side at a predetermined moving speed by operating the connecting member. The moving speed is such that the pressing member moves downstream at the moving speed, so that the liquid on the downstream side pressurizes the liquid on the downstream side while flowing in the upstream side via the liquid flow path, and the liquid is discharged from the nozzle. This is the speed at which droplets can be forcibly ejected.

In the droplet ejecting apparatus configured as described above, when the pressing member is moved to the downstream side at a predetermined moving speed , the liquid downstream of the pressing member passes through the liquid flow path formed in the pressing member. However, it is pressurized by the channel resistance of the liquid channel. Therefore, this pressurization forcibly discharges droplets, foreign matters, and the like from the nozzles of the ejection head, thereby realizing a recovery function (positive pressure purge).

That is, the press member is provided so as to shut off the liquid supply path in the sub tank, but it is not completely shut off, and the liquid is supplied from the supply source to the nozzle side by providing the liquid flow path. The state that is to be held. In addition, when the press member is moved downstream at a predetermined moving speed while directly pressing the liquid, the downstream side is pressurized by the flow path resistance of the liquid flow path, and positive pressure purge is performed. It is composed.

Moving speed, when brought into pressing (move) the press member, the downstream side region of the press member, a rate such that the required pressure is applied to eject a droplet from the ejection head, it is formed on the press member In consideration of the number of liquid channels, the cross-sectional area (inner diameter), the position, and the like, it may be determined as appropriate so that a recovery function is realized by discharging droplets from the nozzle when pressed.

  The press member is provided so that no inflow port exists on the downstream side of the liquid supply path, that is, on the downstream side of the press member. For this reason, even if the press member moves downstream and the downstream side is pressurized, the upstream side (that is, the inlet side) is not pressurized. Therefore, when the positive pressure purge is performed, the liquid is upstream (main tank side). There is no risk of backflow.

Therefore, according to the droplet ejecting apparatus having the above configuration, the recovery operation by directly pressurizing the liquid in the sub tank can be realized with a simple configuration in which the press member is moved downstream via the connecting member. Pressure loss and liquid consumption during the recovery operation are suppressed, and droplets can be ejected efficiently and reliably. In addition, since the liquid channel is formed in the press member, the liquid can always be supplied to the ejection head side through the liquid channel even during the normal droplet ejection operation. In addition, even if the pressing member is returned to the original position (upstream side) after the recovery operation, the liquid flows downstream through the liquid flow path, so that the back flow of the liquid from the nozzle can be prevented.
Further, since the pressing drive means is configured to operate the connecting member, the pressing member moves downstream (pressurization of the downstream liquid) and returns to the original position without bothering the user. Can be performed automatically.

Note that the press member and the connecting member do not necessarily have to be connected by mechanical parts or the like, for example, they are in a state of being bonded by an adhesive, or both are integrally formed. As long as the press member can be moved to the downstream side by operating the connecting member from the outside of the subtank (of course, at a speed at which the recovery operation can be performed), there are various specific modes of connection. The embodiment can be adopted. Moreover, both connection may be direct connection or indirect connection.
Further, the operation of the connecting member by the pressing drive means (pressing of the pressing member) may be such that the pressing drive means directly operates (presses etc.) the connecting member. In the case where the elastic support means is provided as described above, the connecting member may be operated indirectly by pressing / deforming the elastic support means.

  In the present invention, “ejection” means that droplets are ejected from the nozzle by the operation of the ejection head itself, and “discharge” means that liquid is ejected by an operation upstream of the ejection head. It means that droplets are forcibly ejected from the nozzle by being fed into the head.

By the way, after the press member is moved downstream and the positive pressure purge is performed, it is necessary to return the press member to the original position so that the positive pressure purge can be performed again .

Therefore, after the pressing member is moved downstream and the recovery operation is performed, the sub-tank is provided with an elastic support means, for example, as described in claim 2, so that it returns to the original position naturally. Good. The elastic support means is configured such that when the connecting member is not operated, the pressing member is made stationary in the sub-tank, and the connecting member is operated by the pressing drive means so that the pressing member is moved downstream from the stationary position. During the movement, the pressing member or the connecting member is urged so that the pressing member returns to the original stationary position.

  The relationship between the elastic support means and the connecting member or the press member is, for example, a configuration that receives an urging force from the elastic support means when the press member is moved by directly operating (pressing, etc.) the connecting member from the outside of the sub tank. Alternatively, for example, the elastic support means supports the connection member outside the sub tank, and the elastic support means is elastically deformed so that the connection member is pressed and the press member moves. Alternatively, various configurations can be adopted as long as the moved pressing member can return to the original stationary position by the biasing force.

  According to the droplet ejecting apparatus of the second aspect configured as described above, the stationary member is stationary at a fixed position (a position where the liquid is immersed in the liquid in the sub tank) in the normal state, and the pressing member is moved when the recovery operation is performed. In this case, after the recovery operation is completed, the pressing member is returned to its original position and stopped by the urging force of the elastic support means. Can be restored.

  Here, the stronger the biasing force by the elastic support means, the faster the return speed (moving speed) when the press member returns to the stationary position by the biasing force after moving the press member downstream. Depending on the return speed, the negative pressure generated on the downstream side of the press member increases (that is, the difference from the atmospheric pressure increases), the meniscus formed on the nozzle is not maintained, and the liquid flows backward from the nozzle. There is a risk that. In such a case, droplets are not normally ejected during a normal operation in which droplets are actually ejected from the nozzle, which adversely affects the ejection result.

Therefore, for example, as described in claim 3, the elastic support means, when the connection in a state where the pressing member is moved from the position at rest member is released from the operation by pressing the drive means by the pressing drive means, The press member may be configured to be biased so that the meniscus in the nozzle is maintained even if a negative pressure is generated on the downstream side of the press member by returning to the stationary state.

  According to the droplet ejecting apparatus configured as described above, after the pressing member is moved and the recovery operation is performed, the elastic support means urges the pressing member so that the meniscus of the nozzle is maintained (original) Therefore, the subsequent normal droplet ejection is not adversely affected.

The specific configuration of the press member may be various depending on the shape of the entire press member (outer peripheral shape), the cross-sectional area (inner diameter) of the liquid flow path, the number, the shape, the formation position, and the like. As described in FIG. 4, a plurality of liquid channels having the same cross-sectional area can be formed. By doing so, since the flow resistance of each liquid flow path becomes uniform, the downstream side can be pressurized with good balance when the press member is moved downstream.

Further, in this case, not only a plurality of liquid channels having the same cross-sectional area are formed, but also, for example, as in claim 5 , the positional relationship is symmetrical with respect to the center of the press member. It is preferable that a plurality of sets of two liquid flow paths having the same cross-sectional area are formed. That is, the plurality of liquid flow paths are not irregularly formed in the press member, but are formed so as to have a symmetrical positional relationship with respect to the center (center of gravity) of the press member.

  By configuring the press member in this way, the flow resistance of each liquid flow channel becomes uniform, and when the press member is moved downstream, the entire downstream liquid can be evenly pressurized. Thus, it is possible to pressurize in a more balanced manner, and to perform a more efficient recovery operation.

Further, for example, as in claim 6, wherein a plurality of liquid flow paths may be configured to be formed in a mesh shape. With such a configuration, the liquid flow paths having the same shape and cross-sectional area are inevitably formed in a regular array over the entire surface of the press member. Therefore, for moving the pressing member to the downstream side over the entire surface of the press member uniform flow resistance occurs, the downstream side entire surface is pressed more evenly pressurized, further efficiency compared to the arrangement according to claim 5, Recovery operation can be performed.

Various relations of the outer peripheral shape of the press member with respect to the inner wall shape of the sub tank are also conceivable. For example, a gap may be provided between the inner wall of the sub tank and the outer periphery of the press member so that the gap functions as a liquid flow path. However, as described in claim 7 , for example, the cross section of the inner wall of the sub-tank is formed so that the outer periphery thereof has a curved shape or a shape in which the curved line and the straight line are continuously connected, and the press member has an outer peripheral shape thereof. However, they may all be formed in the same shape as the cross-sectional shape of the inner wall so as to be in contact with the inner wall of the sub tank.

  That is, a gap (liquid flow path) is not formed between the outer periphery of the press member and the inner wall of the sub tank, and the liquid flow path is formed inside the press member. With this configuration, it is possible to suppress variation in flow resistance when the liquid passes through the liquid flow channel of the press member to the upstream side when the press member is pressed. The variation in the liquid discharge amount can be suppressed. As a result, in addition to stabilizing the recovery performance, the running cost of the droplet ejecting apparatus can be reduced.

Preferred embodiments of the present invention will be described below with reference to the drawings.
In this embodiment, the present invention is applied to an ink jet recording apparatus that constitutes a so-called multi-function apparatus having a printer function, a scanner function, a copy function, a facsimile function, and the like.

<Overall configuration of multi-function device 1>
As shown in FIGS. 1 and 2, the multi-function device 1 of the present embodiment is provided with a scanner 2 at the top of a case 1 a, and on the lower part (upper part in the case 1 a), to the recording paper 20 with the above various functions. An ink jet recording apparatus 7 for recording (image formation) is provided. A paper feeding device 30 is provided in the lower part of the case 1a.

  Further, a box-shaped metal frame 5 is disposed behind the case 1 a and above the paper feeding device 30. The frame 5 has a substantially rectangular parallelepiped shape that is long in the left-right direction, and is fixed inside the case 1a in an extended state.

  An ink jet recording apparatus 7 is disposed in the upper part of the frame 5, and a conveyance path 5 a for guiding the recording paper 20 from the rear of the paper feeding apparatus 30 to the ink jet recording apparatus 7 is formed behind the frame 5. The ink jet recording apparatus 7 has a conveyance roller 7a at a location adjacent to the exit of the conveyance path 5a, and a discharge roller 7b at a location where the recording paper 20 on which an image is recorded is discharged. The transport roller 7a rotates by receiving the rotational driving force of a paper transport motor 123 (not shown in FIG. 2, see FIG. 7). The specific configuration of the ink jet recording apparatus 7 is as shown in FIG. 3, and details thereof will be described later.

  The paper feeding device 30 includes a paper feeding cassette 3 that is inserted and set from the opening 1b of the case 1a. The paper feed cassette 3 is provided with a paper storage unit 3a for storing the stacked recording papers 20. When the paper feed cassette 3 is inserted into the case 1a, the recording paper 20 in the paper storage unit 3a is stored in the case 1a. It is arranged in the back.

  Then, the recording paper 20 stacked on the uppermost layer of the paper storage unit 3a is sent to the ink jet recording apparatus 7 through the conveyance path 5a as the paper feed roller 8 rotates. The paper feed roller 8 is rotatably held at the tip of a long arm 10 that is pivotally supported by the drive shaft 9, and the drive shaft 9 is fed by a paper feed motor 122 (not shown in FIG. 2). (See FIG. 7), the rotation is transmitted and rotated by receiving the rotational driving force of FIG.

  An operation panel 6 including various operation buttons and a liquid crystal panel is provided on the upper front surface of the multi-function device 1. With this operation panel 6, the user can set various setting items for various functions of the multi-function device 1, enter necessary items such as a facsimile number, and check the operation status, communication history, and the like. it can.

<Configuration of Inkjet Recording Device 7>
Next, a specific configuration of the inkjet recording device 7 mounted in the multi-function device 1 will be described with reference to FIG. This ink jet recording apparatus 7 corresponds to the liquid droplet ejecting apparatus of the present invention.

  As shown in FIG. 3, in this ink jet recording apparatus 7, the guide bar 24 is installed in the width direction of the recording paper 20 conveyed by the conveying roller 7 a and the head unit 11 is mounted on the guide bar 24. The carriage 4 is inserted. The head unit 11 uses four colors of ink supplied from the ink cartridge 71 (see FIG. 4B) as droplets from the nozzles 37, 47, 57, and 67 (see FIG. 4A) of the recording head 69. The recording is performed on the recording paper 20, and a specific configuration thereof will be described later.

  The carriage 4 is connected to an endless belt 25 provided along the guide bar 24, and the endless belt 25 includes a pulley 26 of a carriage motor 28 installed on one end side of the guide bar 24 and the other end of the guide bar 24. It is hooked between an idle pulley 27 installed on the side.

  That is, the carriage 4 is configured to reciprocate in the width direction of the recording paper 20 along the guide bar 24 by the driving force of the carriage motor 28 transmitted via the endless belt 25.

Further, in the vicinity of the guide bar 24, a timing slit 29 in which slits having a constant width are formed at regular intervals is provided along the guide bar 24.
A detection unit (not shown) made of a photo interrupter is provided below the carriage 4 so that the light emitting element and the light receiving element face each other with the timing slit 29 interposed therebetween. In addition, a linear encoder (carriage feed encoder) 118 (see FIG. 7) is configured. The carriage feed encoder 118 detects the amount of movement (position) of the carriage 4 (head unit 11).

  Here, the area in which the carriage 4 reciprocates along the guide bar 24 includes a recording area in which recording on the recording paper 20 is performed, a standby area and a gap adjustment area in which recording is not performed, as shown in the figure. These are divided into three areas.

  Among these, the standby area is set near the pulley 26 side end of the guide bar 24, and includes a home position (right end position in FIG. 3) where the carriage 4 waits during a period when recording or maintenance is not performed. Wiping of the opening surface of each nozzle 37, 47, 57, 67 (hereinafter also referred to as “wiping”), and removing the dried ink and mixed foreign matters in each nozzle, normal ink ejection is performed. This is a region where a recovery operation (positive pressure purge) is performed.

  The gap adjustment area is an area in which a gap adjustment device (not shown) can be operated. By operating this gap adjustment device, the nozzles 37, 47, 57, and 67 (see FIG. 4) of the recording head 69 can be used. The gap (gap) with the recording paper 20 can be adjusted.

  In the standby area, a cap 21 is provided at a position facing the recording head 69 when the carriage 4 is stopped at the home position. The cap 21 is for capping to cover all the nozzles 37, 47, 57, 67 of the recording head 69 and prevent the ink from drying, and is driven by the cap driving unit 22.

  That is, while the carriage 4 is stopped at the home position, the cap 21 is raised and the recording head 69 below the head unit 11 is covered, and the carriage 4 is moved during recording operation and maintenance. In this case, the cap 21 that is being capped is lowered to expose the nozzles 37, 47, 57, and 67, and the carriage 4 is movable.

  Further, a waste ink tray 16 for receiving ink ejected from the nozzles 37, 47, 57, and 67 during the recovery operation, and the nozzles 37, A wiper blade 18 is provided for wiping off ink adhering to the opening surfaces of 47, 57 and 67. The wiper blade 18 is configured to be moved in the vertical direction of FIG. 3 by the wiper drive unit 19 and is normally lowered to the wiper drive unit 19 side. Wiping of the nozzles 37, 47, 57, and 67 is performed.

  That is, as will be described in detail later, during the recovery operation, when each nozzle 37, 47, 57, 67 has moved to a position facing the waste ink receiving tray 16, ink is ejected from the corresponding nozzle, and the recovery operation Ink or the like adhering to the opening surface of each nozzle is wiped off by the wiper blade 18.

  Furthermore, a pressing roller driving device 12 is provided in the standby area above the head unit 11 (on the side opposite to the recording head 69). The pressing roller driving device 12 is configured such that the roller shaft driving unit 13 drives a roller shaft 13a, which has a pressing roller 14 rotatably attached to the tip side, in the vertical direction. During normal times when the recovery operation is not performed, the position of the pressure roller 14 is adjusted so that the pressure roller 14 does not come into contact with the head unit 11. The roller shaft 13a is lowered (that is, the pressing roller 14 is lowered) so that the roller 14 comes into contact with each elastic support member 35, 45, 55, 65 (see FIG. 4) provided on the upper portion of the head unit 11.

  In the inkjet recording apparatus 7 configured as described above, when the recording operation or the maintenance operation is started, the carriage 4 stopped at the home position starts the recording after the cap 21 covering the recording head 69 is removed. Start moving towards the area.

  At this time, in the case of a maintenance operation or a recording operation that needs to be performed before that (for example, when a certain period or more has elapsed since the previous recording operation), the pressing roller driving device 12 The pressing roller 14 is lowered, and the elastic support members 35, 45, 55, 65 on the head unit 11 are pressed by the pressing roller 14 with the movement of the carriage 4, and the recovery operation is performed. In the meantime, the ink discharged from the nozzles 37, 47, 57, and 67 is stored in the waste ink tray 16 as described above.

  After the recovery operation is completed, the carriage 4 further moves toward the recording area, and ink or the like adhering to the opening surfaces of the nozzles 37, 47, 57, 67 is wiped off by the wiper blade 18. After wiping, the entire opening surface of each nozzle 37, 47, 57, 67 is in a state where all the inks of each color are mixed, and if left as it is, the color corresponding to the nozzle from the opening surface of each nozzle. Ink of other colors other than the color enters and color mixing occurs. Therefore, after wiping, the carriage 4 is once returned to the position facing the waste ink tray 16 and the recording head 69 is driven in the same manner as when actually recording on the recording paper 20, and the nozzles 37, 47, 57, and 67 are driven. Ink is ejected. This is so-called preliminary injection (also called preliminary discharge) or flushing.

  When the flushing is completed, the head is returned to the home position again in the case of only the maintenance operation, and the recording head 69 is capped by the cap 21, but in the recording operation, the carriage 4 moves toward the recording area and the recording operation is performed. Be started. However, at the start of the recording operation, the carriage 4 is moved to the gap adjustment region and brought into contact with the end portion (left end in FIG. 3), and then moved to the recording region side by a predetermined distance (returned) and temporarily stopped. By doing so, the initial position of the recording start is set.

<Configuration of head unit 11>
Next, a specific configuration of the head unit 11 will be described with reference to FIG. It is a figure which shows the detailed structure of a head unit, (a) is sectional drawing at the time of seeing from a front direction, (b) is AA sectional drawing of (a).

  As shown in FIG. 4A, the head unit 11 includes a recording head 69 at the lower part, and the upper part of the recording head 69 stores sub-tanks 31, 41, 51, 61 is provided. Specifically, in order from the left in FIG. 4A, black ink 36 is stored in the sub tank 31, cyan ink 46 is stored in the adjacent sub tank 41, and yellow ink is stored in the adjacent sub tank 51. Ink 56 is stored, and magenta ink 66 is stored in the subtank 61 next to the ink 56 (the rightmost side in the figure).

  In the recording head 69, nozzles 37, 47, 57, 67 for ejecting the ink in the corresponding sub tanks onto the recording paper 20 are formed below the sub tanks 31, 41, 51, 61. Since the recording head 69 is of a known piezo type that ejects ink droplets from each nozzle as the piezoelectric element expands and contracts, the description of the detailed configuration is omitted.

  Next, the internal configuration of each of the subtanks 31, 41, 51, 61 will be described in more detail. The configuration of each of the subtanks 31, 41, 51, 61 is basically completely different except that the color of the ink to be stored is different. The same. Therefore, in the following description, the sub tank 31 (the leftmost side in FIG. 4) in which the black ink 36 is stored will be mainly described, and the detailed description of the other three sub tanks 41, 51, 61 will be omitted.

  As shown in FIGS. 4A and 4B, the sub tank 31 in which the black ink 36 is stored has an ink outlet 31b formed in the lower part and an ink inlet 31a formed in the upper part of the side surface. Yes. The ink inlet 31 a is connected to a flexible ink supply tube 72 by a joint 73, and the ink supply tube 72 is connected to an ink cartridge 71 that stores black ink 36.

  With this configuration, the ink (black) in the ink cartridge 71 is supplied via the ink supply tube 72 and flows into the sub tank 31 from the ink inlet 31a. The ink 36 that has flowed in is temporarily stored in the sub-tank 31, and is supplied from the lower ink outlet 31b to the recording head 69 side when the ink 36 is ejected and ejected from the nozzle 37 during recording or recovery operation. 37 is ejected and discharged.

  As shown in the drawing, the sub-tank 31 normally stores the ink 36 to a depth slightly higher than the ink inlet 31a. Each time ink is ejected or ejected from the nozzle 37, the amount of ejected or ejected ink is stored. Ink is supplied from the ink cartridge 71 through the ink supply tube 72.

  In the present embodiment, the sub tank 31 is provided with a positive pressure application portion 39 for performing a recovery operation, and an elastic support member 35 that supports the positive pressure application portion 39 (strictly, supports the end of the connecting shaft 34). Is provided.

  The positive pressure imparting portion 39 includes a plate-like mesh press member 32 and a connecting member 38 that connects the mesh press member 32 and the elastic support member 35. The connecting member 38 further includes a support plate 33 bonded to the mesh press member 32 and a connecting shaft 34 having one end connected to the support plate 33 and the other end connected to the elastic support member 35.

  FIG. 5 shows a more detailed configuration of the mesh press member 32 and the connecting member 38 constituting the positive pressure applying unit 39. First, FIG. 5A is a plan view and a front view of the mesh press member 32. As shown in the drawing, the mesh press member 32 is a plate member having an elliptical shape as a whole, and a plurality of ink flow paths 32a (rectangular holes) having the same cross-sectional area are formed in a mesh shape over the entire plate surface. Yes.

  FIG. 5B is a plan view and a front view of the connecting member 38. As shown in the figure, the connecting member 38 has a shape in which a connecting shaft 34 is erected vertically at the center of a support plate 33 that is formed in the same size and shape as the mesh press member 32 on the entire outer periphery. The support plate 33 is formed with four through holes 33a, 33b, 33c, and 33d. Each of the through holes 33a to 33d has the same shape.

  The positive pressure application unit 39 configured as described above is supported by the elastic support member 35 so as to be disposed downstream of the ink inlet 31a in the sub tank and the ink supply path (the liquid supply path of the present invention). ing. That is, when the mesh press member 32 is stationary, the ink inlet 31a does not exist on the downstream side of the ink supply path from the mesh press member 32, and the downstream side is filled with ink. It is arranged at such a position.

  As shown in FIG. 5, the mesh press member 32 has an elliptical outer periphery, but this shape and size are almost the same as the cross-sectional shape of the inner wall of the sub tank 31. That is, the mesh press member 32 is formed and arranged so that the entire outer periphery thereof is in contact with the inner wall of the sub tank 31, in other words, so as to block the ink supply path in the sub tank 31. However, since a plurality of ink flow paths 32a are formed in a mesh shape over the entire surface of the mesh press member 32, the ink is not completely blocked upstream and downstream of the mesh press member 32. Instead, the ink can pass through the plurality of ink flow paths 32a.

  On the other hand, the elastic support member 35 connected to the other end of the connecting shaft 34 is formed in a spherical shape by a non-breathable elastic body such as butyl rubber or fluoro rubber, and its outer periphery is bonded to the sub tank 31. At the same time, the tip of the connecting shaft 34 protruding from the hole in the upper part of the sub tank 31 is connected to the center of the surface facing the sub tank 31 with an adhesive or the like. Since the tip end (the other end) of the connecting shaft 34 is connected to the elastic support member 35 in this way, the positive pressure applying portion 39 is stationary in the sub-tank 31 in a state as shown in FIG. Is done. When the elastic support member 35 receives a load downward from its upper part, the elastic support member 35 is recessed downward (in the upper surface direction of the sub tank 31), whereby the connecting shaft 34 is also pushed downward, and the mesh press member 32 is pressed and moves downward (downstream of the ink supply path). The normal time when the elastic support member 35 does not receive any external load and simply supports the connecting shaft 34 corresponds to the non-operation time of the present invention.

  When the load on the elastic support member 35 disappears and the free state is reached, the elastic support member 35 that has been recessed until then is restored to its original shape by its elastic force. As a result, the mesh press member 32 that has been moved to the downstream side also moves to the upstream side again and returns to the original stationary position.

<Recovery operation flow>
The flow of the recovery operation (positive pressure purge) in the ink jet recording apparatus 7 configured as described above will be described with reference to FIG. As shown in FIG. 6, in the first STEP before the recovery operation is started, the pressure roller 14 in the pressure roller driving device 12 is at a retracted position higher than the top of the elastic support member 35, and the mesh press member 32 is stationary. It is in the state position. The position in the stationary state is the same as the position shown in FIG.

  In the second STEP in which the recovery operation is started, the roller shaft driving unit 13 extends the roller shaft 13a downward, so that the pressing roller 14 approaches and is fixed to the sub tank 31. Thereafter, in the third STEP, the carriage 4 moves in the direction of the recording area, so that the elastic support member 35 provided on the upper part of the sub tank 31 approaches the pressing roller 14 and finally comes into contact. Then, as the carriage 4 advances (that is, as the sub tank 31 advances in the left direction in FIG. 6), the elastic support member 35 is elastically deformed so as to be recessed downward under the load from the pressing roller 14, and the connecting shaft 34 is pressed down. Then, the mesh press member 32 is pressed and moved downstream.

  At this time, the moving speed of the mesh press member 32 depends on the moving speed of the carriage 4. However, in this embodiment, when the mesh press member 32 moves downstream, the mesh press member 32 moves to the downstream area of the mesh press member 32. The moving speed of the carriage 4 is determined so that the pressure necessary to eject the ink 36 from the nozzles 37 of the recording head 69 is applied. Specifically, based on the number of ink flow paths 32a formed in the mesh press member 32, the cross-sectional area, etc., at what speed the mesh press member 32 is moved to the downstream side, each ink flow path 32a The moving speed of the carriage 4 may be determined in consideration of whether sufficient flow path resistance is generated and the downstream side is sufficiently pressurized.

Therefore, when the mesh press member 32 moves downstream while directly pressing the ink by the movement of the carriage 4, the ink flows upstream through the plurality of ink flow paths 32a formed in the mesh press member 32. At this time, the downstream side of the mesh press member 32 is pressurized by the flow path resistance of the ink flow path 32a. For this reason, this pressurization forcibly ejects ink, foreign matter, and the like from the nozzles 37 of the recording head 69, thereby realizing a recovery function (positive pressure purge) .

  In the fourth STEP in which the carriage 4 has further moved after the recovery operation is performed, the pressure roller 14 is separated from the elastic support member 35, and the pressure roller 14 itself returns to the original retracted position (position of the first STEP) again. . Therefore, the elastic support member 35 that has been recessed by receiving the load from the pressure roller 14 is released from the load and becomes free, and tries to return to the original shape (the shape of the first STEP) again. The restoring force at this time becomes an urging force for pulling the connecting shaft 34 upward to return the mesh press member 32 to the original stationary position, and the mesh press member 32 as the elastic support member 35 returns to the original shape. Will return to the original resting position.

  At this time, if the mesh press member 32 rapidly rises, depending on the speed, the negative pressure on the downstream side of the mesh press member 32 may increase, and the ink meniscus at the nozzle 37 may not be maintained. Therefore, in the present embodiment, the material and shape of the elastic support member 35 are selected so that the mesh press member 32 moves up at a speed within a range where the meniscus in the nozzle 37 is maintained. That is, the elastic support member 35 urges the connecting shaft 34 (and extends the mesh press member 32 so that the meniscus in the nozzle 37 is maintained even if a negative pressure is generated on the downstream side due to the rise of the mesh press member 32. Energize).

  The configuration and recovery operation of the sub-tank 31 in which the black ink 36 is stored have been described with reference to FIGS. 4 to 6. However, the configuration and recovery operation of the other three sub-tanks 41, 51, and 61 are also described. The flow is exactly the same as the sub-tank 31 described above, except that the color of the stored ink is different.

  Specifically, as shown in FIG. 4A, the sub-tank 41 in which the cyan ink 46 is stored includes a mesh press member 42, a connecting member including a connecting shaft 44 and a support plate 43, and a connecting shaft 44. An elastic support member 45 connected to the tip is provided. The sub tank 51 in which the yellow ink 56 is stored includes a mesh press member 52, a connecting member including a connecting shaft 54 and a support plate 53, and an elastic support member 55 connected to the tip of the connecting shaft 54. It has been. The sub-tank 61 in which the magenta ink 66 is stored includes a mesh press member 62, a connecting member including a connecting shaft 64 and a support plate 63, and an elastic support member 65 connected to the tip of the connecting shaft 64. It has been.

  Each of the sub tanks 41, 51, 61 is also connected to an ink cartridge containing ink of a corresponding color via an ink supply tube, although not shown, from the ink cartridge to the corresponding sub tank. Ink is supplied.

<Recovery processing>
Here, the electrical configuration of the inkjet recording apparatus 7 will be described with reference to the block diagram of FIG. As shown in FIG. 7, the ink jet recording apparatus 7 includes a control device 110 having a CPU 111, a ROM 112, a RAM 113, and an EEPROM 114.

  This control device 110 conveys the recording paper 20, various sensor groups 116 including well-known media sensors and registration sensors that can detect the presence / absence of the recording paper 20, its leading edge, rear edge, and edge in the width direction. It is electrically connected to a paper transport encoder 117 that detects the amount (position), the operation panel 6, a carriage feed encoder 118, and the like.

  Further, the control device 110 further includes a paper feed motor drive circuit 120a for driving the paper feed motor 122, a transport motor drive circuit 120b for driving the paper transport motor 123, and a carriage motor drive for driving the carriage motor 28. A circuit 120c, a recording head driving circuit 120d for driving the recording head 69 (jetting ink), a roller shaft driving circuit 120e for driving the roller shaft driving unit 13, and a cap driving circuit for driving the cap driving unit 22. 120f and a wiper drive circuit 120g for driving the wiper drive unit 19 are electrically connected to each other.

  Then, the CPU 111 controls each of the drive circuits 120a to 120g according to various programs stored in the ROM 112 and the EEPROM 114, so that each drive target is driven and controlled. As described above, the paper feed roller 8 is driven by the rotation of the paper feed motor 122, and the transport roller 7 a is driven by the rotation of the paper transport motor 123.

  In the present embodiment, the control device 110 is communicably connected to a personal computer (hereinafter abbreviated as “PC”) 125, and in accordance with a recording instruction from the PC 125, image data sent together with the recording instruction is sent. A known recording process for recording the image to be represented on the recording paper 20 is performed. In the recording process, the above-described recovery operation is executed as necessary.

  Hereinafter, this recording process will be described. FIG. 8 is a flowchart showing a recording process executed by the CPU 111. In the multi-function device 1, when the recording instruction is received from the PC 125, facsimile data is received, or when a recording operation is performed in the copy function, the CPU 111 causes the ROM 112 to record the image on the recording paper 20. The recording processing program is read out from, and processing is executed according to this program. This recording process is performed at every timing of image recording.

  When this process is started, first, in step (hereinafter abbreviated as “S”) 110, the cap 21 is driven by the cap driving unit 22 and is removed from the recording head 69. In S120, it is determined whether or not it is the recovery operation execution timing. This determination can be made based on, for example, whether or not a predetermined time has elapsed since the previous recording process. If the recovery operation execution timing has not been reached, the process proceeds to S200 and image recording is performed. That is, image recording is started without performing a recovery operation.

  On the other hand, if it is the recovery operation execution timing, the process proceeds to S130, and the pressing roller 14 is lowered. That is, the pressing roller driving device 12 is in the second STEP state in FIG. In S140, it is determined whether the purge pressure is set to “strong” or “weak”. This setting may be set to either one by default in advance and can be changed by the user by operating the operation panel 6 or automatically based on the amount of time elapsed since the previous recording process was performed. It may be selected and set automatically. In the latter case, for example, the purge pressure may be set to “strong” when a certain threshold time or more has elapsed, and the purge pressure may be set to “weak” when the threshold time has not elapsed.

  If it is determined as “strong” in the process of S140, the process proceeds to S150, and the positive pressure purge (recovery operation) is executed by moving the carriage 4 toward the recording area at the speed a. On the other hand, if it is determined as “weak” in the process of S140, the process proceeds to S160, and the positive pressure purge is executed by moving the carriage 4 toward the recording area at the speed b. Here, the speed a and the speed b are in a relationship of a> b. That is, in the case of “strong” setting, the moving speed of the carriage 4 is increased to increase the pressure on the downstream side of each mesh press member 32, 42, 52, 62, and the ink is ejected more strongly. On the other hand, when “weak” is set, the moving speed of the carriage 4 is slowed down to reduce the pressure on the downstream side of each mesh press member 32, 42, 52, 62, and the ink is ejected weakly.

  After the recovery operation is performed for all the four sub tanks 31, 41, 51, 61 by the processing of S150 or S160, the wiping described above is executed in S170, and the pressing roller 14 is returned to the original retracted position in S180. Returned to In S190, the carriage 4 is moved again in the home position direction so that the recording head 69 is opposed to the waste ink tray 16 and the above-described flushing is performed.

  After the recovery operation and the various operations associated therewith are performed in this way, the process proceeds to S200 and image recording is performed. Then, after the carriage 4 is returned to the home position by the end of image recording, the recording head 69 is capped again by the cap 21 in S210.

<Effects of this embodiment>
According to the ink jet recording apparatus 7 of the present embodiment described above, by simply pressurizing the ink 36 in the sub tank 31 with a simple configuration in which the mesh press member 32 is moved downstream via the connecting member 38. Since the recovery operation can be realized, pressure loss and ink consumption during the recovery operation can be suppressed, and ink can be ejected efficiently and reliably. In addition, since a plurality of ink flow paths 32a are formed in the mesh press member 32, the ink 36 can always be supplied to the recording head 69 via the ink flow paths 32a even during recording on a normal recording medium. . Further, even if the mesh press member 32 is returned to the original stationary position (upstream side) after the recovery operation, the ink 36 flows downstream via the ink flow path 32a, so that ink backflow from the nozzle 37 is prevented. it can.

  Further, the distal end of the connecting shaft 34 is connected to and supported by the elastic support member 35. During the recovery operation, the elastic support member 35 is deformed by receiving an external force (depressed downward), so that the mesh press member 32 is on the downstream side. When the external force applied to the elastic support member 35 is removed after the recovery operation, the elastic support member 35 is restored to its original shape, and the mesh press member 32 is returned to the original stationary position by the urging force at the time of the restoration. Return. Therefore, the mesh press member 32 can be supported and returned after the movement with a simple configuration without bothering the user.

  Moreover, the mesh press member 32 is moved downstream (that is, a load is applied to the elastic support member 35) during the movement of the carriage 4 by utilizing the movement of the carriage normally provided in this type of ink jet recording apparatus. This is realized by bringing the elastic support member 35 into contact with the pressing roller 14 and denting it. Therefore, a mechanism for positively pressing the elastic support member 35 is not necessary, and it is only necessary to move the pressing roller 14 in the vertical direction as needed. Can be configured.

  Further, since the mesh press member 32 has a configuration in which a plurality of ink flow paths 32a having the same shape and cross-sectional area are formed in a mesh shape, the flow of each ink flow path 32a when moving in the ink 36 to the downstream side. The road resistance is uniform over the entire surface of the mesh press member 32, and the entire downstream ink filling region can be evenly pressurized. Therefore, it is possible to pressurize the downstream side with good balance, and to perform more efficient recovery operation.

  In this embodiment, the recording head 69 corresponds to the ejection head of the present invention, the ink cartridge 71 corresponds to the main tank of the present invention, the ink flow path 32a corresponds to the liquid flow path of the present invention, and the pressure roller Configuration for driving the mesh press member 32 to the downstream side by pressing the elastic support members 35, 45, 55 and 65, each comprising the drive device 12, the carriage 4, the guide bar 24, the carriage motor 28, and the endless belt 25. Corresponds to the pressing drive means of the present invention, and the elastic support member 35 corresponds to the elastic support means of the present invention. Further, the pressing of the connecting member 38 via the elastic support member 35 by the pressing roller 14 corresponds to the “operation” of the connecting member in the present invention.

<Modification>
The embodiment of the present invention is not limited to the above embodiment, and it goes without saying that various forms can be adopted as long as they belong to the technical scope of the present invention.

  For example, in the above-described embodiment, the positive pressure application unit 39 that directly pressurizes the ink to perform the positive pressure purge is used as the mesh press member 32 that is a plate-like member in which a plurality of ink flow paths 32a are formed in a mesh shape. However, this configuration is merely an example, and the downstream region can be pressurized by moving the ink 36 to the downstream side, and the ink can be supplied to the upstream side during normal image recording. Any ink flow path may be used as long as the ink flow path is formed so that it can be supplied to the downstream side.

  Specifically, for example, a positive pressure applying portion having a shape as shown in FIGS. 9A to 9D can be considered. First, the positive pressure applying portion 81 shown in FIG. 9A includes a mesh press member 82 in which a plurality of ink flow paths are formed in a mesh shape, and a connecting shaft 83 erected at the center thereof. That is, this is the same as the embodiment in which the support plate 33 is removed from the positive pressure applying portion 39 of the above embodiment and the connecting shaft 34 is directly connected to the mesh press member 32. However, since the mesh press member 82 in FIG. 9A needs to erect the connecting shaft 83 at the central portion, the ink flow path is mesh-like except for the central portion where the connecting shaft 83 is erect. Is formed.

  9B includes a porous press member 87 in which a plurality of ink flow paths 89 having the same cross-sectional area are formed, and a connecting shaft 88 standing at the center thereof. The ink flow paths 89 are formed at equal intervals in a concentric elliptical shape in the porous press member 87.

  Further, the positive pressure applying portion 91 in FIG. 9C is erected at the center portion of the porous press member 92 in which four ink flow paths 94a, 94b, 94c, 94d having the same cross-sectional area and shape are formed. Connecting shaft 93. More specifically, each of the ink flow paths 94a, 94b, 94c, and 94d has a symmetrical positional relationship between the ink flow path 94a and the ink flow path 94d with respect to the central portion of the porous press member 92, and the ink flow path 94b. And the ink flow path 94c have a symmetrical positional relationship.

  Further, the positive pressure applying portion 96 shown in FIG. 9D has a press member 97 in which four notches 99a, 99b, 99c, and 99d are formed on the outer periphery of an elliptical plate-like member, and a central portion thereof. The connecting shaft 98 is provided. When this press member 97 is used, a gap portion between each notch 99a, 99b, 99c, 99d and the inner wall of the sub tank becomes an ink flow path.

  In the positive pressure applying members 81, 86, 91, 86 shown in FIG. 9, the press members 82, 87, 92, 97 are all pressed through the connecting shafts 83, 88, 93, 98 during the recovery operation. Even if it is, it is formed so strong that it is not deformed by the pressure. Therefore, if each of the press members 82, 87, 92, 97 is formed of a flexible material, the connecting shaft is not directly erected and is connected to the connecting shaft with the support plate interposed therebetween as in the above embodiment. It is good to do.

  Conversely, in the positive pressure applying portion 39 of the above embodiment, the support plate 33 is not necessarily required if the mesh press member 32 is formed with a strength that does not deform due to the pressure during the recovery operation. The connecting shaft 34 may be erected directly from the center of the mesh press member 32 in exactly the same manner as in FIG.

In addition, in each positive pressure provision part 81, 86, 91, 96 shown in FIG. 9, the connection shaft 83, 88, 93, 98 which each has corresponds to the connection member of this invention. .
In the above embodiment, the positive pressure applying portion 39 is elastically supported by connecting the tip of the connecting shaft 34 to the central portion of the elastic support member 35 formed in a spherical shape. The configuration for elastically supporting the pressure applying unit 39 is merely an example, and in normal times, the mesh press member 32 is made stationary at a predetermined position, and after moving to the downstream side by the recovery operation, the mesh press member 32 is again in a stationary state. Various configurations can be adopted as long as the positive pressure application unit 39 is urged so as to return to the position.

  For example, as shown in FIG. 10, a connecting shaft 101 is erected at the center of the support plate 33, a flange 102 is provided at the tip of the connecting shaft 101, and a spring 103 is provided between the flange 102 and the sub tank 31. It may be inserted through the connecting shaft 101 and interposed. In this case, as a mechanism for moving the mesh press member 32 to the downstream side, as shown in FIG. 10, a mechanism constituted by a pressing rod 107 and a pressing drive unit 106 that drives the pressing rod 107 may be used. The pressing drive unit 106 may be configured using, for example, a solenoid, or may be configured as a mechanism including a motor and a link, and the specific configuration is not particularly limited.

  When the recovery operation is performed, the pressing rod 107 moves downward and presses the flange 102, so that the mesh press member 32 moves downstream. At this time, the flange 102 receives an upward biasing force by the spring 103. Therefore, when the pressing rod 107 returns to the original retracted position after the recovery operation is performed, the flange 102 is pushed upward by the urging force of the spring 103, whereby the mesh press member 32 returns to the original stationary position. It will be.

  In this case, the downstream pressure of the mesh press member 32 during the recovery operation can be adjusted by setting the speed at which the flange 102 is pressed (pressed) by the pressing rod 107 in two or more stages. Also good. In FIG. 10, the pressing rod 107 and the pressing driving unit 106 constitute the pressing driving means of the present invention.

  In addition to this, for example, in the configuration of the sub tank 31 of FIG. 4B, the elastic support member 35 is formed of a flexible material that can be simply deformed, and the mesh press member 32 and the bottom of the inner wall of the sub tank are formed inside the sub tank 31. The mesh press member 32 may be elastically supported from the lower side in the sub tank 31 by connecting the elastic members such as springs. Alternatively, for example, in the configuration of FIG. In addition, the mesh press member 32 may be elastically supported from the upper side in the sub tank 31 by connecting the support plate 33 and the upper portion of the inner wall of the sub tank with an elastic member such as a spring in the sub tank 31. Needless to say, the former configuration may be applied to FIG. 10, and conversely, the latter configuration may be applied to FIG. 4 (that is, the above embodiment).

  Furthermore, in the above-described embodiment, it has been described that the recovery operation is performed as necessary during the recording process for recording an image on a recording medium (see FIG. 8). However, the execution timing of the recovery operation is limited to this. For example, the recovery operation may be executed every time a predetermined time has elapsed since the previous recovery operation, or the recovery operation is executed every time the recording process is performed a predetermined number of times. It may be set as appropriate. It may be executed at regular intervals regardless of the recording operation, or may be forcibly executed by the user operating the operation panel 6.

  In addition, for each sub-tank 31, 41, 51, 61 for each color, every four colors may be collectively (continuously) performed every time the recovery operation is performed. Alternatively, a recovery operation may be selectively performed. Specifically, when the head unit 11 passes through the lower portion of the pressure roller 14 as the carriage 4 moves, the pressure roller 14 is only used when the sub tank containing the desired color ink to be positively purged passes. When the sub-tank containing ink of other colors passes, the pressing roller 14 is returned to the retracted position. By selectively purging with positive pressure in this way, the amount of waste ink consumed by the recovery operation can be further reduced.

  Further, in the above-described embodiment, a constantly-supply type inkjet recording apparatus configured to always supply the ink 36 from the ink cartridge 71 via the ink supply tube 72 to the sub tank 31 in the head unit 11 mounted on the carriage 4. However, the present invention is not limited to this. For example, the present invention is applied to a station supply type ink jet recording apparatus configured to supply ink by connecting an ink cartridge and a sub tank with an ink supply tube only when ink is supplied. It can also be applied to.

  Furthermore, it goes without saying that the application of the present invention is not limited to the above-described ink jet recording apparatus. For example, soldering to various printed wiring boards or the like is automatically performed by spraying molten solder from a nozzle. When manufacturing a soldering device or an organic EL display, a device for forming an organic film by spraying a polymer organic material (light emitting body) by an ink jet method, or slurrying a resin and spraying it from a nozzle The present invention can be applied to various droplet ejecting apparatuses configured to eject liquid stored in a sub tank as droplets from a nozzle, such as an apparatus.

1 is a perspective view illustrating an appearance of a multi-function device including an ink jet recording apparatus according to an embodiment. FIG. 2 is a cross-sectional view of the multifunction device shown in FIG. 1. FIG. 2 is an explanatory diagram illustrating a schematic configuration of an ink jet recording apparatus included in the multi-function device illustrated in FIG. 1. It is a figure which shows the detailed structure of a head unit, (a) is sectional drawing at the time of seeing from a front direction, (b) is AA sectional drawing of (a). It is explanatory drawing of the mesh press member and connection member which comprise a positive pressure provision part, (a) is the top view and front view of a mesh press member, (b) is the top view and front view of a connection member. It is explanatory drawing showing the flow of recovery operation | movement. It is a block diagram showing schematic structure of a control apparatus. It is a flowchart showing a recording process. It is explanatory drawing (a top view and a front view) showing four types of modifications of a positive pressure provision part. It is explanatory drawing showing the modification of the mechanism which drives and supports a positive pressure provision part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multifunctional device, 2 ... Scanner, 3 ... Paper feed cassette, 4 ... Carriage, 6 ... Operation panel, 7 ... Inkjet recording device, 8 ... Paper feed roller, 11 ... Head unit, 12 ... Pressure roller drive device, 13 DESCRIPTION OF SYMBOLS Roller shaft drive part, 13a ... Roller shaft, 14 ... Pressure roller, 16 ... Waste ink tray, 18 ... Wiper blade, 20 ... Recording paper, 21 ... Cap, 28 ... Carriage motor, 30 ... Paper feeder, 31, 41 , 51, 61 ... Sub tank, 31a ... Ink inlet, 31b ... Ink outlet, 32, 42, 52, 62, 82 ... Mesh press member, 32a ... Ink flow path, 33, 43, 53, 63 ... Support plate, 33a, 33b, 33c, 33d ... through holes, 34, 44, 54, 64 ... connecting shafts, 35, 45, 55, 65 ... elastic support members, 36, 46, 56, 66 ... in 37 ... Nozzle, 38 ... Connecting member, 39, 81, 86, 91, 96 ... Positive pressure applying part, 69 ... Recording head, 71 ... Ink cartridge, 72 ... Ink supply tube, 73 ... Joint, 87, 92 ... Porous Press member, 97 ... Press member, 102 ... Flange, 103 ... Spring, 106 ... Press drive, 107 ... Press rod, 110 ... Control device

Claims (7)

An ejection head having a nozzle capable of ejecting droplets;
A main tank containing liquid;
Provided in a liquid supply path from the main tank to the nozzle of the ejection head, and has an inflow port for allowing the liquid supplied from the main tank to flow into the inside, and temporarily stores the liquid flowing in from the inflow port. A liquid droplet ejecting apparatus comprising: a sub-tank for delivering the stored liquid to the ejecting head;
The sub tank is
A plate-like member provided so as to block the internal liquid supply path on the downstream side of the liquid supply path from the inflow port, and is formed so as to penetrate the member, whereby the liquid supply path A press member capable of directly pressurizing the liquid on the downstream side by forming a plurality of liquid flow paths through which the liquid can pass between the upstream side and the downstream side of the member and moving to the downstream side When,
One end is connected to the upstream surface of the press member and the other end protrudes to the outside of the sub tank, and an external force is applied to the other end by an operation from the outside of the sub tank. A connecting member for pressing and moving the member to the downstream side;
With
The plurality of liquid flow paths are formed at portions other than a portion of the press member where one end of the connecting member is connected, so that each liquid flow between the upstream side and the downstream side of the press member is formed. The liquid is configured to pass through the path,
Furthermore, provided with a pressing drive means that is provided outside the sub tank and moves the pressing member to the downstream side at a predetermined moving speed by operating the connecting member,
The moving speed is such that, as the pressing member moves to the downstream side at the moving speed, the downstream liquid is added while the downstream liquid flows into the upstream side through the liquid flow path. The liquid droplet ejecting apparatus is characterized in that the pressure is such that the liquid droplets can be forcibly ejected from the nozzle. The droplet ejecting apparatus according to claim 1,
The sub tank is
When the connecting member is not operated, the pressing member is brought into a stationary state in the sub-tank, and the connecting member is operated by the pressing driving means so that the pressing member is moved downstream from the stationary state. A liquid droplet ejecting apparatus comprising elastic support means for urging the press member or the connecting member so that the press member returns to the original stationary position while moving to the side . The droplet ejecting apparatus according to claim 2,
The elastic support means is configured such that when the connecting member is released from an operation by the pressing drive means while the pressing member is moved from the stationary position by the pressing drive means , the pressing member is stopped. A liquid droplet ejecting apparatus configured to bias the meniscus in the nozzle even if a negative pressure is generated on the downstream side of the pressing member by returning to the position of the state. . The droplet ejecting apparatus according to claim 1,
The liquid droplet ejecting apparatus according to claim 1 , wherein a plurality of the liquid flow paths having the same cross-sectional area are formed in the press member . The droplet ejecting apparatus according to claim 4 ,
A plurality of sets of two liquid flow paths having the same cross-sectional area formed so as to have a symmetrical positional relationship with respect to the center of the press member are formed on the press member. Injection device. The droplet ejecting apparatus according to claim 4 ,
The droplet ejecting apparatus , wherein the press member has the plurality of liquid flow paths formed in a mesh shape . The droplet ejecting apparatus according to claim 1,
The cross section of the inner wall of the sub-tank is formed so that the outer periphery thereof is a curved line or a shape in which a curved line and a straight line are continuously connected,
The droplet ejecting apparatus according to claim 1, wherein the pressing member is formed in the same shape as a cross section of the inner wall so that an outer peripheral shape thereof is in contact with the inner wall of the sub tank .