JP4755057B2 - Liquid supply device and liquid discharge device - Google Patents

Description

The present invention relates to a liquid a liquid supply device for supplying liquid to the liquid ejecting head capable of ejecting from a nozzle, and to a liquid discharge apparatus for discharging liquid from the liquid discharge head.

  As the liquid discharged from the liquid discharge head, various liquids such as ink and chemical liquid can be used. When ink is used, an image can be recorded by applying the ink to a recording medium.

  Conventionally, as a liquid supply system of a liquid discharge head, for example, an ink supply system that supplies ink to an ink jet recording head (liquid discharge head) has been improved with an increase in recording speed. However, since a filter for trapping foreign matter and bubbles in the ink (liquid) needs to be disposed in the flow path, the pressure loss in the filter portion is large with respect to the ink flow, which hinders high-speed recording. It has become.

  If the filter area is increased to reduce the pressure loss in order to eliminate this problem, bubbles in the liquid chamber may accumulate on the lower surface of the filter, impeding liquid supply.

  For this reason, there is a proposal in which a valve for closing a part of the filter is provided to increase the ink flow rate only during the recovery process of the recording head so as to expel bubbles (Patent Document 1). As a similar example, a proposal has been made to provide a valve that is in close contact with a filter so that air bubbles can be easily driven out by increasing the flow rate of ink during the recovery process of the recording head (Patent Document 2).

Japanese Patent Laid-Open No. 06-064183 Japanese Laid-Open Patent Publication No. 08-118672

  However, according to the methods of Patent Documents 1 and 2, since the valve is provided in the vicinity of the filter, the structure becomes complicated.

An object of the present invention is to provide a liquid supply apparatus and a liquid discharge apparatus that can reduce the flow path resistance and pressure loss of the liquid in the liquid discharge head and increase the supply speed of the liquid to the nozzle.

Another object of the present invention is to provide a liquid supply apparatus and a liquid discharge apparatus that can move bubbles in a liquid chamber of a liquid discharge head to increase the efficiency of removing the bubbles and maintain the liquid supply performance at all times. There is.

The liquid supply apparatus of the present invention is a liquid supply apparatus that supplies liquid to a liquid discharge head that includes a common liquid chamber that stores liquid and a plurality of nozzles that discharge liquid that is communicated with the common liquid chamber. A main liquid supply chamber extending in the arrangement direction of the plurality of nozzles and communicating with the common liquid chamber of the liquid discharge head, and a first liquid supply communicating with the main liquid supply chamber via a first filter A bypass flow that communicates the first liquid supply chamber and the second liquid supply chamber via a third filter; a second liquid supply chamber that communicates with the main liquid supply chamber via a second filter; A first joint opening communicating with the first liquid supply chamber, a second joint opening communicating with the second liquid supply chamber, a liquid supply path connectable to the first joint opening, and the second join A liquid discharge path connectable to the opening, wherein the first liquid supply chamber and the second liquid supply chamber are a plurality of surfaces that define the main liquid supply chamber, and A plurality of nozzles communicate with the main liquid supply chamber via the first filter and the second filter, respectively, on a predetermined plane extending in a direction intersecting with a plane where the plurality of nozzles are arranged and an arrangement direction of the plurality of nozzles. In addition, the first filter and the second filter are disposed so as to be stacked on the predetermined surface side of the main liquid supply chamber, and the first filter and the second filter are separated along the predetermined surface and in the arrangement direction of the plurality of nozzles. And the area of the first filter is set to be larger than the area of the second filter, and the liquid supply path passes through the first liquid supply chamber and the first filter from the first joint opening. The liquid can be supplied from the main liquid supply chamber to the common liquid chamber, and the liquid discharge path includes the liquid supplied from the main liquid supply chamber to the second liquid supply chamber through the second filter and the bypass channel. The liquid supplied from the first liquid supply chamber to the second liquid supply chamber can be discharged from the second joint opening .

A liquid discharge apparatus according to the present invention includes a liquid discharge head that communicates with a common liquid chamber and can discharge liquid from a plurality of nozzles, and the liquid supply apparatus .

  According to the present invention, the liquid supply chamber is arranged to be stacked with the main liquid supply chamber, and the filter interposed between the liquid supply chamber and the main liquid supply chamber has a nozzle arrangement in which a plurality of nozzles are arranged. By extending along a plane substantially parallel to the plane, it is possible to reduce the flow resistance and pressure loss of the liquid in the liquid discharge head, and increase the liquid supply speed to the nozzle.

  Further, by forming an inclined surface portion on the upper wall portion of the main liquid supply chamber, the bubbles in the main ink supply chamber are positively moved to improve the bubble removal efficiency, or always maintain the liquid supply performance. be able to.

  When recording an image by discharging ink from a liquid discharge head, high-speed recording can be realized by supplying ink smoothly. Furthermore, it is possible to efficiently remove bubbles without generating a large amount of waste ink.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 to FIG. 10 are diagrams for explaining a first embodiment of the present invention.
FIG. 1 is a schematic front view for explaining a configuration example of an ink ejection apparatus (liquid ejection apparatus) according to the present invention. The ink ejection apparatus of this example constitutes a recording apparatus that records an image on a recording paper (recording medium) P using six liquid ejection heads 11. The ink ejection apparatus of this example includes a recovery unit 12 corresponding to each head 11, an ink cartridge 13 that stores ink (liquid) to be supplied to each head 11, a transport unit 14, an operation panel unit 15, And a sheet feeder 16 and the like. The recording paper P is fed from the paper feed unit 16 to the transport unit 14 and is transported in the direction of arrow A by the transport unit 14. When the recording paper P moves to a recording position facing each head 11, an image is recorded by ink ejected from each head 11. The heads 11 are arranged along the conveyance direction (arrow A direction) of the recording paper P. Each head 11 is formed with a plurality of ejection openings arranged in a direction intersecting with the conveyance direction of the recording paper P (a direction orthogonal in this example). As will be described later, these discharge ports form a nozzle together with the ink flow path and the discharge energy generating means. Each head 11 is supplied with yellow (Y), light magenta (LM), magenta (M), light cyan (LC), cyan (C), and black (K) ink from the corresponding ink cartridge 13. As will be described later, each head 11 ejects these inks from ejection ports in accordance with drive signals.

  The ink ejection apparatus of this example is an application example as an ink jet recording apparatus using a long head 11 extending over the entire width direction of the recording area of the recording paper P. However, the present invention can also be applied to a serial scanning ink jet recording apparatus that repeats recording scanning in the main scanning direction of the head and conveyance of a predetermined amount of recording paper in the sub-scanning direction that intersects the main scanning direction. it can.

  FIG. 2 is a schematic configuration diagram of an ink supply system (liquid supply system) in the ink ejection apparatus of FIG. The ink in the detachable ink cartridge 13 is supplied to the head 11 through the sub tank 23 so as to form an appropriate ink orifice surface at the ejection port of the head 11. Reference numeral 24 denotes a supply pump for supplying ink from the ink cartridge 13 to the sub tank 23, and reference numeral 25 denotes a pressure pump for supplying ink from the sub tank 23 to the head 11. Reference numeral 26 denotes a recovery valve for closing the ink return path when the head 11 described later is pressurized. The supply pump 24 is also used for a recycle operation described later, and 27 is a supply valve for selecting an ink path during the recycle operation. The recycling operation is an operation for reusing the ink discharged during the recovery process of the head 11, and the recovery rod 28 of the recovery unit 12 is used during the recycling operation. The recovery rod 28 is installed below the discharge surface (discharge port formation surface) of the head 11, and the ink path from the recovery rod 28 to the sub tank 23 is opened and closed by a recycle valve 29.

  The supply pump 24, the pressure pump 25, the recovery valve 26, the supply valve 27, and the recycle valve 29 are relatedly controlled by the control unit (control means) 100 according to an operation mode to be described later.

  Next, the operation mode of the ink supply system in such an ink discharge apparatus will be described.

  There are four operation modes of the ink supply system: a recording mode, an ink supply mode, a circulation mode, and a pressure mode. The recording mode is a mode in which ink is supplied from the sub tank 23 to the head 11 during image recording, and the ink supply mode is a mode in which ink is supplied from the ink cartridge 13 to the sub tank 23. The circulation mode is a mode in which ink is circulated between the sub tank 23 and the head 11, and the pressurization mode is a mode in which ink is pressurized and supplied from the sub tank 23 to the head 11.

  In the recording mode, the ink in the head 11 decreases due to the ejection of ink from the head 11, and the internal pressure decreases. Then, due to the capillary phenomenon in the nozzles of the head 11, the ink in the sub tank 23 is supplied to the head 11 through the pressure pump 25 and the recovery valve 26. In the ink supply mode, the supply pump 24 operates to supply ink from the cartridge 13 into the sub tank 23. In the circulation mode, the pressure pump 25 circulates ink between the sub tank 23 and the head 11. That is, the ink in the sub tank 23 is sent into the head 11 by the pressure pump 25, and the ink in the head 11 is returned to the sub tank 23 through the recovery valve 26. By such ink circulation, bubbles in the head 11 and the flow path are removed as described later, and appropriate recording can be performed. Ink discharged from the discharge port of the head 11 to the recovery bottle 28 in this circulation mode is returned to the sub tank 23 through the recycle valve 29 by the operation of the supply pump 24. As will be described later, the pressurizing mode is performed to discharge bubbles, thickened ink, foreign matter, and the like in the nozzles of the head 11. In this pressurizing mode, the recovery valve 26 is closed and the pressurizing pump 25 is driven, so that ink is forcibly sent from the sub tank 23 to the head 11 and is discharged from the discharge port of the head 11 into the recovery rod 28. Ink is forcibly discharged.

  3 is a front view for explaining a configuration example of the head 11, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is an enlarged view of a V circle portion in FIG. . The head of this example has a recording width of 4 inches (corresponding to the length of the nozzle row).

  In these drawings, a ceramic base plate 31 supports a heater substrate 32 formed of silicon. The heater substrate 32 includes a plurality of electrothermal transducers (heaters) as ink discharge energy generating elements, and a plurality of channel walls for forming ink channels corresponding to these electrothermal transducers. Is formed. A plurality of nozzles N capable of discharging ink from the discharge ports are constituted by these electrothermal converters and ink flow paths. The heater substrate 32 is also formed with a liquid chamber frame for surrounding the common liquid chamber 33 communicating with each nozzle N. A top plate 34 for forming the common liquid chamber 33 is joined on the side wall and the liquid chamber frame of the nozzle N formed in this way. Therefore, the heater substrate 32 and the top plate 34 are laminated and bonded to the base plate 31 in an integrated state. Such lamination adhesion is performed with an adhesive having good thermal conductivity such as silver paste. A mounted PCB (wiring board) 35 is supported by a double-sided tape behind the heater board 32 in the base plate 31 (upper side in FIG. 4). Each discharge energy generating element on the heater substrate 32 and the PCB 35 are electrically connected by wire bonding 36 corresponding to each wiring.

  An ink supply member (liquid supply member) 37 is joined to the top surface of the top plate 34. The ink supply member 37 includes an ink supply case (liquid supply case) 38 and an ink supply case cover (liquid supply case cover) 39. In the ink supply case 38, a liquid chamber and a channel groove communicating with the liquid chamber are formed in advance. When the ink supply case cover 39 closes the upper surface of the ink supply case 38, a tubular flow path is formed as described later. In the case of this example, the ink supply case 38 and the ink supply case cover 39 are joined by a thermosetting adhesive. Thus, ink is supplied to the communication path 34 </ b> A formed in the top plate 34 by the flow path formed in the ink supply member 37.

  The ink supply case 38 is provided with first, second and third filters 40, 41 and 43. The first filter 40 is for the purpose of removing foreign substances in the ink, the second filter 41 is for the purpose of removing bubbles in the main ink supply chamber (main liquid supply chamber) 42, and the third filter 43 is the first ink supply chamber. The purpose is to remove bubbles in the (first liquid supply chamber) 44. Each filter 40, 41, 43 is formed of a material in which stainless fibers are woven in a mesh shape at intervals of 8 μm, and is fixed to the liquid supply case 38 by heat welding. Details of the functions of the filters 40, 41, and 43 will be described later.

  FIG. 6 is a perspective view of a main part of the head 11 in this example. This figure is a perspective view of the head 11 viewed from the ink supply case 38 side, and the ink supply case cover 39 and screws are omitted for convenience of explanation.

  The ink supplied from the sub tank 23 of the ink discharge device is first supplied to the first ink supply chamber 44 through the first joint opening 45 of the head 11. The ink in the first ink supply chamber 44 is supplied to the main ink supply chamber 42 through the first filter 40. The main ink supply chamber 42 is formed by upper and lower wall portions 42A and 42B, and left and right and front and rear wall portions 42C and 42D and 42E and 42F. Of these wall portions 42A to 42F, the wall portion 42F is formed on the ink supply case cover 39, and the other wall portions are formed on the ink supply case 38.

  The ink supplied into the main ink supply chamber 42 passes through the supply port 42G formed in the wall portion 42E, the communication path 34A formed in the top plate 34, and the common liquid chamber 33 (see FIG. 5). The nozzle N is reached. The ink supplied to the main ink supply chamber 42 is sent to the second ink supply chamber (second liquid supply chamber) 46 through the second filter 41, and then returns to the sub tank 23 through the second joint opening 47. .

  In such an ink flow, in order to enable high-speed recording, the ink supply to the nozzles N must be performed smoothly. That is, it is necessary to design the flow path resistance in the ink flow path as small as possible. Therefore, in the head 11 in this example, as shown in FIGS. 3 to 5, the first ink supply chamber 44, the main ink supply chamber 42, the common liquid chamber 33, and the nozzle N are in direct communication. Further, the first joint opening 45, the first ink supply chamber 44, and the nozzle N form a linear flow path from the upper side to the lower side in FIG. Further, in order to reduce the flow path resistance in the head 11, the cross-sectional area of the flow path is set to be equal to or larger than the inner diameter of the first joint opening 45 that is the entrance of the head 11. Thereby, the ink is supplied without any delay. In this example, the entire flow path has a cross-sectional area of φ3 (diameter 3 mm) or more.

  Further, the area of the filter that causes the ink pressure loss in the head 11 is increased so as not to impair the ink supply performance. In this example, by setting the effective area of the first filter 40 to be equivalent to φ20 (diameter 20 mm), the pressure loss due to the filter 40 is minimized. Further, by arranging the first filter 40 on a plane parallel to the nozzle arrangement plane where the rows of nozzles N are located, the enlargement of the head 11 due to the increase in the area of the filter 40 is avoided. In order to obtain such an effect, the filter 40 does not need to be completely parallel to the nozzle array plane, but may be substantially parallel. Therefore, disposing the filter 40 on a plane parallel to the nozzle arrangement plane includes disposing the filter 40 on a plane substantially parallel to the nozzle arrangement plane.

  Since the nozzle N is formed between the heater substrate 32 and the top plate 34, the nozzle array plane extends in the vertical direction in FIGS. 4 and 5 so as to follow the junction between the heater substrate 32 and the top plate 34. Exists. The first filter 40 is located on a plane parallel to the nozzle arrangement plane, that is, on a plane parallel to the paper surface in FIG.

  On the other hand, the biggest problem when a large area filter is employed as the first filter 40 is the removal of bubbles that tend to stay in the upstream portion of the filter. In this example, there is a problem in removing bubbles that are likely to stay in the first ink supply chamber 44. If air bubbles remain in this portion, the air bubbles hinder ink supply, and the entire effective area of the filter 40 cannot be effectively used.

  Therefore, in this example, a bypass flow path 48 that communicates the first ink supply chamber 44 and the second ink supply chamber 46 is provided, and the third filter 43 is provided in the bypass flow path 48, so that Solved the problem. The third filter 43 is designed to have a small area so as to remove bubbles flowing in with the ink from the first ink supply chamber 44. That is, by reducing the area of the third filter 43, the flow rate of ink passing through the third filter 43 from the first ink supply chamber 44 is increased, and bubbles are removed from the first ink supply chamber 44. .

  However, if the area of the third filter 43 is too small, the ink flow resistance passing through the third filter 43 is increased, and there is a possibility that no ink flows into the third filter 43 side. In this case, the bubbles in the first ink supply chamber 44 cannot be removed. On the other hand, when the area of the third filter 43 is too large, the flow resistance in the third filter 43 is smaller than the flow resistance in the first filter 40, and most of the ink in the first ink supply chamber 44 is made. There is a possibility that it flows into the third filter 43 side and is not supplied to the first filter 40 side that should be supplied. In this example, the area of the third filter 43 is φ2 (diameter 2 mm) so that the ink can be efficiently supplied to the main ink supply chamber 42 through the first filter 40 while removing the bubbles in the first ink supply chamber 44. did. By changing the density of the third filter 43, it is possible to increase the flow rate of the ink passing therethrough.

  The ink ejection device of this example requires heat generation energy to eject ink. That is, the ink is foamed by the thermal energy generated by the electrothermal transducer on the heater substrate 32, and the ink is ejected downward from the nozzle in FIG. 5 using the foaming energy. For this reason, when the recording operation is continued for a long time, the thermal energy is accumulated in the ink, the temperature of the ink rises, and there is a possibility that the gas dissolved in the ink accumulates in the head 11. If the bubbles in the head 11 are not removed, the ink cannot be properly discharged. The ejection energy generating means for ejecting ink is not limited to the configuration using the electrothermal converter, and is arbitrary. For example, the configuration may be such that ink is ejected using a piezo element or the like.

  In the head 11 of this example, as shown in FIG. 4, the nozzles N, the common liquid chamber 33, and the main ink supply chamber 42 are directly communicated with each other, so that bubbles generated by the recording operation are supplied to the main ink. It can be stored in the chamber 42. Furthermore, by making the main ink supply chamber 42 a large-capacity liquid chamber, it is possible to store a large amount of bubbles to some extent. In addition, by providing the second filter 41, bubbles present in the main ink supply chamber 42 can be easily removed. That is, in the circulation mode in which the ink is circulated between the sub tank 23 and the head 11 by the pressurizing pump 25, the flow rate of the ink passing through the second filter 41 can be increased. Air bubbles in the main ink supply chamber 42 can be easily removed.

  7 to 10 are diagrams schematically showing an ink supply system between the head 11 and the sub-tank 23, and each represents an ink flow in each ink supply state.

  FIG. 7 is a diagram illustrating the flow of ink when the main ink supply chamber 42 is filled with ink.

  The ink in the sub tank 23 enters the first ink supply chamber 44 through the first joint opening 45 by the operation of the pressurizing pump 25, and flows into the main ink supply chamber 42 through the first filter 40. At that time, since the gas in the main ink supply chamber 42 is discharged from the second joint opening 47 through the second filter 41 and the second ink supply chamber 46, the main ink supply chamber 42 is filled with ink. FIG. 7 schematically shows the ink flow path. In the configuration of the head 11 shown in FIGS. 3 to 6, the gas in the second ink supply chamber 46 is discharged through the flow paths L1, L2, and L3. That is, the gas in the second ink supply chamber 46 flows into the flow path L1 formed in the ink supply case 38, the flow path L2 formed by the groove portion of the ink supply case 38 and the ink supply case cover 39, and the ink supply. The liquid is discharged from the second joint opening 47 through the flow path L3 formed in the case 38.

  Here, in order to smoothly fill the main ink supply chamber 42 with ink, it is desirable to increase the area of the first filter 40 that causes a pressure loss in the head 11. However, on the other hand, the increase in the area of the first filter 40 reduces the flow rate of ink per unit area, so that bubbles existing in the first ink supply chamber 44 are difficult to pass through the first filter 40. As a result, bubbles may accumulate on the upstream side of the first filter 40, which may hinder ink flow. Therefore, as described above, the bypass flow path 48 connecting the first ink supply chamber 44 and the second ink supply chamber 46 is formed, and the third filter 43 is disposed in the flow path 48. Thereby, bubbles in the first ink supply chamber 44 can be discharged from the second joint opening 47 via the third filter 43 and the second ink supply chamber 46. That is, it is possible to remove bubbles from the first ink supply chamber 44 by increasing the ink flow velocity in the third filter 43. Therefore, the ink can be smoothly filled through the entire surface of the first filter 40.

  FIG. 7 schematically shows an ink flow path. In the configuration of the head 11 shown in FIGS. 3 to 6, the ink supply case 38 is provided between the first joint opening 45 and the first ink supply chamber 44. A communicating channel L4 is formed. Further, a flow path L5 is formed by the groove portion of the ink supply case 38 and the ink supply case cover 39, and a flow path L6 that connects the flow path L5 and the above-described flow path L2 is formed in the ink supply case 38. . Accordingly, the bypass flow path 48 in FIG. 7, that is, the flow path communicating between the first and second ink supply chambers 44 and 46 is formed by the flow paths L4, L5, L6, L2, and L1. In short, the bypass channel 48 only needs to be able to discharge the gas in the first ink supply chamber 44 from the second joint opening 47 through the third filter 43. 3 to 6, the space in the ink supply case 38 is defined by the first and second filters 40, 41, so that the first and second ink supply chambers 44, 46 and the main ink supply chamber 42 are formed.

  FIG. 8 shows the flow of ink during pressure recovery for discharging bubbles, thickened ink, foreign matter, and the like present in the nozzles of the head 11. The operation of the ink supply system during the pressure recovery corresponds to the pressure mode described above.

  As described above, the ink ejection device of this example requires heat generation energy for ink ejection. Therefore, when recording is performed continuously for a long period of time, the thermal energy is accumulated in the ink and the temperature of the ink rises, so that gas dissolved in the ink may accumulate in the nozzle. If the bubbles are not removed, ink cannot be properly discharged. Therefore, it is necessary to appropriately remove the bubbles in the nozzle N. The ink in the sub tank 23 enters the first ink supply chamber 44 from the first joint opening 45 by the operation of the pressurizing pump 25, and flows into the main ink supply chamber 42 through the first filter 40. At the time of this pressure recovery, since the recovery valve 26 is closed, the ink supplied to the main ink supply chamber 42 is forced to flow from the common liquid chamber 33 to the nozzle N side. Then, the ink is forcibly discharged from the ejection port of the head 11 nozzle N together with bubbles in the nozzle N, thickened ink, foreign matter, and the like. FIG. 8 also schematically shows the ink flow path. In the configuration of the head 11 shown in FIGS. 3 to 6, the ink in the main ink supply chamber 42 flows through the flow path L7 formed in the ink supply case 38, The liquid is forcibly discharged from the discharge port of the nozzle N through the communication passage 34 </ b> A of the top plate 34 and the common liquid chamber 33.

  FIG. 9 shows the flow of ink during recording. The operation of the ink supply system during recording corresponds to the recording mode described above.

  Due to the ejection of the ink droplet I from the nozzle N during recording, the ink in the head 11 is reduced and the internal pressure is reduced. Then, due to the capillary phenomenon in the nozzle N, the ink in the sub tank 23 is supplied to the head 11 through the pressure pump 25 and the first joint opening 45. At this time, the recovery valve 26 is also opened, and ink also flows into the head 11 from the second joint opening 47. In order to continue high-speed recording during recording, it is necessary to smoothly supply ink to the nozzles N, and it is necessary to reduce the pressure loss in the first filter 40. Therefore, as in the ink filling, bubbles in the first ink supply chamber 44 are eliminated so that ink can be supplied by effectively using the entire surface of the first filter 40. That is, the main ink supply is performed while discharging the bubbles in the first ink supply chamber 44 through the third filter 43 provided in the bypass flow path 48 communicating from the first ink supply chamber 44 to the second ink supply chamber 46. Ink is supplied to the chamber 42. Therefore, the supply of ink to the nozzles N does not stagnate during high-speed recording. FIG. 9 also schematically shows the ink flow path. In the configuration of the head 11 shown in FIGS. 3 to 6, the ink in the main ink supply chamber 42 flows through the flow path L7 formed in the ink supply case 38, The ink is supplied into the nozzle N through the communication passage 34 </ b> A of the top plate 34 and the common liquid chamber 33, and is discharged as an ink droplet I from the discharge port of the nozzle N.

  FIG. 10 shows the flow of ink during circulation recovery in which ink is circulated between the sub tank 23 and the head 11. By this circulation recovery, bubbles generated in the head 11 and the flow path during recording are removed, and proper recording can be maintained. The operation of the ink supply system during the circulation recovery corresponds to the circulation mode described above.

  During this circulation recovery, the ink in the sub tank 23 enters the first ink supply chamber 44 from the first joint opening 45 by the operation of the pressurizing pump 25 and flows into the main ink supply chamber 42 through the first filter 40. . At the same time, the bubbles accumulated in the main ink supply chamber 42 pass through the second filter 42 and are discharged to the second joint opening 47 side. In the head 11 of this example, since the main ink supply chamber 42 is a large-capacity liquid chamber, bubbles generated when recording continuously for a long time can be stored in the main ink supply chamber 42 to some extent. Bubbles accumulated in the main ink supply chamber 42 can be easily removed through the second filter 41 by this circulation recovery operation.

(Second Embodiment)
11 and 12 are diagrams for explaining the second embodiment of the present invention. In these drawings, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  Similar to the above-described embodiment, the main ink supply chamber (main liquid supply chamber) 42 is formed by the wall portions 42A to 42F, and the supply port 43G communicating with the lower wall portion 42B and the common liquid chamber 33 is provided. 11 are formed in parallel in the left-right direction in FIG.

  In the present embodiment, the upper wall portion 42A is formed with an inclined surface that is inclined at an angle θ1 with respect to the horizontal direction, and the inclined surface is directed from the first filter 40 side toward the second filter 41 side. Inclined upward. That is, an inclined surface that is not orthogonal to the direction of gravity is formed on the wall portion 42A. Thus, by forming the inclined surface on the upper wall portion 42A, the bubbles in the main ink supply chamber 42 can be concentrated on the second filter 41 side. That is, bubbles that are lifted by buoyancy in the main ink supply chamber 42 can be moved along the upper wall portion 42A. By setting the angle θ1 to 4 ° or more, the movement of bubbles was confirmed. By inclining the upper wall portion 42A in this way, it is possible to further improve the efficiency of removing the bubbles in the head 11, and it is possible to shorten the time required for implementing the circulation mode. As the angle θ1 becomes larger than 4 °, the action of moving bubbles becomes stronger. However, since the height of the head 11 increases as the angle θ1 increases, it is preferably about 20 ° in practice.

  In this example, the upper wall portion 42A is orthogonal to the nozzle arrangement plane, and an inclined surface portion having an angle θ1 is formed on the wall portion 42A. However, the wall portion 42A only needs to have an inclined surface portion for moving the bubbles in the main ink supply chamber 42.

(Third embodiment)
FIG. 13 is a diagram for explaining a third embodiment of the present invention. In FIG. 13, the same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, a portion (inclined surface) 42A-1 that is inclined at an angle θ1 with respect to the horizontal direction is formed on the right side in FIG. 13 of the upper wall portion 42A. It inclines upward from the 1st filter 40 side toward the 2nd filter 41 side. Further, a portion (inclined surface) 42A-2 that is inclined at an angle θ2 with respect to the horizontal direction is formed on the left side portion of the upper wall portion 42A in FIG. 13, and the portion 42A-2 is a second portion. It inclines upward from the filter 41 side toward the first filter 40 side. By these portions 42A-1 and 42A-2, a vertex portion (vertex) 42A-3 located between the first filter 40 and the second filter 41 is formed.

  If minute bubbles remain in the vicinity of the second filter 41 in the main ink supply chamber 42, the bubbles may hinder ink supply from the second filter 41 during the recording operation. In this example, a position away from the second filter 41 is formed on the upper wall portion 42A by forming a portion 42A-2 that forms an upward angle θ2 from the second filter 41 side toward the first filter side 40. It becomes possible to accumulate bubbles in the apex portion 42A-3 of the wall portion 42A. As a result, it is possible to maintain the ink supply performance during the recording operation without increasing the bubble supply efficiency and without hindering the ink supply by the bubbles remaining in the vicinity of the second filter 41.

1 is a schematic configuration diagram of a liquid ejection apparatus equipped with a liquid ejection head according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a liquid supply system for the liquid ejection head of FIG. 1. FIG. 2 is an enlarged front view of a main part of the liquid ejection head in FIG. 1. It is sectional drawing which follows the IV-IV line of FIG. It is an enlarged view of the V circle part of FIG. FIG. 2 is a perspective view of a main part of the liquid ejection head in FIG. 1. FIG. 2 is an explanatory diagram of ink flow when filling a liquid supply path with respect to the liquid ejection head of FIG. 1. FIG. 2 is an explanatory diagram of an ink flow when pressure is restored in a liquid supply path with respect to the liquid ejection head of FIG. 1. FIG. 2 is an explanatory diagram of ink flow during recording on a liquid supply path for the liquid ejection head of FIG. FIG. 3 is an explanatory diagram of ink flow when removing bubbles in a liquid supply path with respect to the liquid ejection head of FIG. 1. It is an enlarged front view of the principal part of the liquid discharge head in the 2nd Embodiment of this invention. FIG. 12 is a perspective view of a main part of the liquid ejection head in FIG. 11. It is an enlarged front view of the principal part of the liquid discharge head in the 3rd Embodiment of this invention.

Explanation of symbols

11 Ink discharge head (liquid discharge head)
DESCRIPTION OF SYMBOLS 12 Recovery unit 23 Subtank 24 Supply pump 25 Pressure pump 26 Recovery valve 27 Supply valve 28 Recovery tank 29 Recycle valve 32 Heater board 33 Common liquid chamber 34 Top plate 37 Ink supply member (liquid supply member)
38 Ink supply case (liquid supply case)
39 Ink supply case cover (liquid supply case cover)
40 First filter 41 Second filter 42 Main ink supply chamber (main liquid supply chamber)
43 Third filter 44 First ink supply chamber (first liquid supply chamber)
45 First joint opening (first opening)
46 Second ink supply chamber (second liquid supply chamber)
47 Second joint opening (second opening)
48 Bypass channel 100 Control unit (control means)

Claims (3)

In a liquid supply apparatus for supplying a liquid to a liquid discharge head having a common liquid chamber for storing liquid and a plurality of nozzles for discharging the liquid communicating with the common liquid chamber,
A main liquid supply chamber that extends in the arrangement direction of the plurality of nozzles and communicates with the common liquid chamber of the liquid discharge head;
A first liquid supply chamber communicating with the main liquid supply chamber via a first filter;
A second liquid supply chamber communicating with the main liquid supply chamber via a second filter;
A bypass flow path that connects the first liquid supply chamber and the second liquid supply chamber via a third filter;
A first joint opening communicating with the first liquid supply chamber;
A second joint opening communicating with the second liquid supply chamber;
A liquid supply path connectable to the first joint opening;
A liquid discharge path connectable to the second joint opening;
Have
The first liquid supply chamber and the second liquid supply chamber include a direction intersecting with a surface on which the plurality of nozzles of the liquid discharge head are arranged among a plurality of surfaces defining the main liquid supply chamber, and On the predetermined surface side of the main liquid supply chamber so as to communicate with the main liquid supply chamber via the first filter and the second filter on the predetermined surface side extending in the arrangement direction of the plurality of nozzles, respectively. Further, the first filter and the second filter are arranged along the predetermined plane and separated in the arrangement direction of the plurality of nozzles, and the area of the first filter is the second filter. Set wider than the area of the filter,
The liquid supply path can supply liquid from the main liquid supply chamber to the common liquid chamber through the first liquid supply chamber and the first filter from the first joint opening,
The liquid discharge path is supplied from the first liquid supply chamber to the second liquid supply chamber through the liquid supplied from the main liquid supply chamber to the second liquid supply chamber through the second filter and the bypass channel. The liquid supply apparatus is characterized in that the liquid can be discharged from the second joint opening. A liquid discharge apparatus comprising: a liquid discharge head that communicates with a common liquid chamber and can discharge liquid from a plurality of nozzles; and the liquid supply apparatus according to claim 1. The liquid ejection apparatus according to claim 2, wherein the liquid ejection head includes an electrothermal converter that generates thermal energy for ejecting ink from the nozzles.

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