JP5863009B2 - Droplet discharge head and image forming apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head that discharges droplets from a plurality of discharge holes, and an image forming apparatus that forms an image using the droplet discharge head.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a facsimile machine, a printer, or the like, an image is formed by droplets ejected from a plurality of ejection holes of a droplet ejection head, such as an inkjet method. In this type of image forming apparatus, if solids such as dust or pigment residue are mixed in the liquid introduced into the droplet discharge head, the discharge holes may be blocked by the solids, causing a droplet discharge failure. May end up.

  As a liquid droplet ejection head capable of suppressing the occurrence of such ejection failure, the one described in Patent Document 1 previously proposed by the present inventors is known. FIG. 1 is a cross-sectional view showing a droplet discharge head of Patent Document 1. As shown in FIG. FIG. 2 is a longitudinal sectional view showing the A-A ′ section in FIG. 1. In these drawings, the droplet discharge head includes a plurality of individual liquid chambers 3 individually communicating with a plurality of discharge holes 1, a plurality of piezoelectric element columns 15 fixed to the upper wall of each individual liquid chamber 3, and a supply. A liquid chamber 18, a filter member 13, a first liquid introduction path 21, a second liquid introduction path 22 and the like are provided.

  The supply liquid chamber 18 extending in the individual liquid chamber arrangement direction (left-right direction in FIG. 2) includes a front chamber 18a, a rear chamber 18b, a first communication facing surface portion 18c, a first side wall 18d, and a second communication facing surface portion 18e. And the second side wall 18f. The front chamber 18a receives a liquid introduced from a first liquid introduction path 21 and a second liquid introduction path 22 described later. In addition, the rear chamber 18 b individually supplies liquids to the individual liquid chambers 3 in communication with the individual liquid chambers 3. The front chamber 18a and the rear chamber 18b are partitioned by the filter member 13, and the liquid in the front chamber 18a enters the rear chamber 18b after being filtered by the filter member 13. As described above, the liquid is filtered by the filter member 13 and then supplied to the plurality of individual liquid chambers 3, whereby the discharge holes 1 respectively provided in the individual liquid chambers 3 are blocked with solid matter, thereby causing a discharge failure. Can be suppressed.

  A first liquid introduction path 21 for introducing a liquid into the front chamber 18a is connected to a communication port of the front chamber 18a at one end portion (right end portion in the figure) of the front chamber 18a in the individual liquid chamber arrangement direction. Then, the first communication facing portion 18c of the supply liquid chamber 18 faces the communication port. From one end of the first communication facing surface portion 18c in the individual liquid chamber arrangement direction, the first side wall 18d rises toward the first liquid introduction path 21 side. As shown by the arrow B in FIG. 2, the liquid introduced into the front chamber 18a from the first liquid introduction path 21 collides with the first communication facing surface portion 18c and the first side wall 18d. The direction is changed toward the center in the arrangement direction. By this direction change, the liquid is guided toward the rear chamber 18b provided in the central portion of the supply liquid chamber 18 in the individual liquid chamber arrangement direction.

  When the communication port connected to the first liquid introduction path 21 is made to face the rear chamber 18b of the supply liquid chamber 18, the liquid for the specific individual liquid chamber 3 communicating with the facing region of the rear chamber 18b with the communication port. There is a risk that the supply pressure is excessively increased to cause liquid leakage from the discharge hole 1. Therefore, in the illustrated droplet discharge head, the communication port to which the first liquid introduction path 21 is connected does not face the rear chamber 18b but faces the first communication facing portion 18c.

  The other end portion (left end portion in the figure) of the front chamber 18a in the individual liquid chamber arrangement direction has the same configuration as the one end portion. While the liquid introduced into the front chamber 18a from the second liquid introduction path 22 hits the second communicating surface portion 18e and the second side wall 18f, as shown by the arrow C in the drawing, the central portion in the individual liquid chamber arrangement direction Turn to the direction. As indicated by the arrow B in the figure, the liquid whose direction is changed from one end side to the center side of the front chamber 18a, and from the other end side of the front chamber 18a to the center side as indicated by the arrow C in the figure. The liquid whose direction has been changed merges at the center of the front chamber 18b. At this time, these liquids change direction in the direction from the front chamber 18a toward the rear chamber 18b while pushing in the opposite directions in the individual liquid chamber arrangement direction. By such a direction change, the liquid is supplied from the rear chamber 18b to the plurality of individual liquid chambers 3 with an equal force.

  However, in this droplet discharge head, there is a possibility that bubbles generated in the front chamber 18a during the initial introduction of the liquid remain in the individual liquid chamber 3 to cause discharge failure. Specifically, when the liquid is initially introduced into the supply liquid chamber 18, the first communication facing surface portion 18 c and the first side wall as indicated by an arrow B in the drawing at one end portion of the front chamber 18 a in the individual liquid chamber arrangement direction. Bubbles may be generated in the liquid that has been redirected by hitting it. Also, at the other end portion of the front chamber 18a in the individual liquid chamber arrangement direction, bubbles are generated in the liquid which is changed in direction by hitting against the second communicating surface portion 18e or the second side wall 18f as indicated by an arrow C in the drawing. Sometimes. The liquid whose direction has changed as indicated by the arrow B in the figure and the liquid whose direction has changed as indicated by the arrow C in the figure immediately collide with each other and are pressed against each other. Since liquid can stagnate in the vicinity of the first side wall and the second side wall that receive this pressing force, bubbles are not smoothly sent toward the rear chamber 18b, and remain in the vicinity of the first side wall and the second side wall. It becomes easy to do. The bubbles remaining in the vicinity of the first side wall and the second side wall in this way slowly move to the rear chamber 18b along with the print job, and eventually become clogged in the narrow individual liquid chamber 3 and discharge failure. Cause.

  The present invention has been made in view of the above background, and an object thereof is to provide the following droplet discharge head and image forming apparatus. That is, it is a liquid droplet ejection head or the like that can suppress the occurrence of ejection failure due to clogging of ejection holes with a solid material and can also suppress the occurrence of ejection failure due to clogging of bubbles in an individual liquid chamber.

In order to achieve the above object, the present invention is provided separately for each of a plurality of individual liquid chambers that individually store liquids in a state in which they are aligned in a predetermined direction, and for the purpose of discharging liquid droplets. A plurality of discharge holes and a supply liquid chamber for supplying the liquid contained in the internal space extending in the predetermined direction to the individual liquid chambers communicating with the central portion in the predetermined direction. A first liquid introduction path for introducing liquid into the supply liquid chamber in a state connected to a first communication port provided at one end of the supply liquid chamber in the predetermined direction, and the predetermined direction in the supply liquid chamber A second liquid introduction path for introducing liquid into the supply liquid chamber in a state of being connected to a second communication port provided at the other end of the liquid, and filtering the liquid sent toward the plurality of individual liquid chambers in the supply chamber The first liquid introduction path The liquid introduced into the supply liquid chamber is directed from the first communication facing surface portion facing the first communication port or one end of the first communication facing surface portion in the predetermined direction toward the first communication port. The second communication is made by striking the first side wall that rises and changing the direction toward the central portion, and the liquid introduced from the second liquid introduction path into the supply liquid chamber faces the second communication port. In the liquid droplet ejection head that strikes against the second side wall that rises from the other end in the predetermined direction of the facing portion or the second communicating facing portion toward the second communicating port, and changes the direction toward the central portion, The supply liquid chamber is divided into two in the rising direction of the first side wall and the second side wall by the filter member extending over the entire region in the predetermined direction of the supply liquid chamber, and is obtained by this partition. And the front room Of the rear chamber located to the liquid introducing direction downstream side of the front chamber, disposed the first communicating face at one end portion in the predetermined direction of the rear chamber, the other in the predetermined direction of the rear chamber The second communication facing surface portion is disposed at an end portion, and the opening ratio of both end portions in the predetermined direction of the filter member is made lower than the opening ratio of the center portion, respectively. .

  In the present invention, it is possible to suppress the occurrence of ejection failure due to clogging of bubbles in the individual liquid chamber. Moreover, since the liquid is filtered by the filter member and supplied to the plurality of individual liquid chambers as in the conventional apparatus, it is possible to suppress the occurrence of ejection failure due to the ejection holes being blocked with solid matter.

FIG. 9 is a cross-sectional view showing a droplet discharge head of Patent Document 1. The longitudinal cross-sectional view which shows the A-A 'cross section in FIG. FIG. 3 is an exploded perspective view showing the upper half of the droplet discharge head according to the embodiment. FIG. 3 is an exploded perspective view showing a lower half of the droplet discharge head. FIG. 3 is a cross-sectional view showing the droplet discharge head. FIG. 6 is a longitudinal sectional view showing a cross section A-A ′ of FIG. 5 in the droplet discharge head. FIG. 3 is an exploded plan view showing the droplet discharge head. The enlarged plan view which shows the longitudinal direction center part of the filter member of the droplet discharge head. The enlarged plan view which shows the 1st modification of the filter member. The expanded sectional view which shows the 2nd modification of the filter member. The expanded sectional view which shows the 3rd modification of the filter member. The enlarged plan view which shows the longitudinal direction edge part of the filter member of the droplet discharge head. Sectional drawing which shows the modification of the 2nd communicating facing part of the droplet discharge head. The top view which shows the 1st beam formation board in the modification of the droplet discharge head, the 2nd beam formation board, and the 3rd beam formation board. FIG. 2 is a main part configuration diagram showing a main part configuration of the image forming apparatus according to the first embodiment. The top view which shows the principal part structure. The side view which shows the image forming apparatus which concerns on 2nd Embodiment.

Hereinafter, embodiments of a droplet discharge head to which the present invention is applied and a printer as an image forming apparatus will be described.
FIG. 3 is an exploded perspective view showing the upper half of the droplet discharge head according to the embodiment. FIG. 4 is an exploded perspective view showing the lower half of the droplet discharge head. FIG. 5 is a cross-sectional view showing the droplet discharge head. FIG. 6 is a longitudinal sectional view showing an AA ′ section of FIG. 5 in the liquid droplet ejection head. FIG. 7 is an exploded plan view showing the droplet discharge head.

  The droplet discharge head according to the embodiment includes a nozzle plate 2 having a plurality of discharge holes 1, an individual liquid chamber plate 4 having a plurality of individual liquid chambers 3, a vibrating wall forming plate 5, a first beam forming plate 6, Second beam forming plate 7, third beam forming plate 8, first rear chamber forming plate 9, second rear chamber forming plate 10, third rear chamber forming plate 11, fourth rear chamber forming plate 12, liquid introduction portion formation The members 14 and the like are formed by being sequentially stacked.

  The plurality of individual liquid chambers 3 are arranged at a predetermined pitch along the longitudinal direction of the droplet discharge head. The upper walls of the individual liquid chambers 3 are thin vibration walls as shown in FIG. 5, and the piezoelectric element columns 15 are in pressure contact with the respective vibration walls from the outside of the individual liquid chamber 3. . When the vibration wall vibrates by driving the piezoelectric element column 15, the liquid in the individual liquid chamber 3 is discharged as a droplet from the discharge hole 1.

  In the present invention, the liquid means any liquid that can be ejected as droplets from the ejection hole 1, such as ink, colored liquid, fixing treatment liquid DNA sample liquid, photoresist liquid, and resin solution. In the present embodiment, an example in which ink is used as the liquid will be described.

  A plurality of individual liquid chambers 3 communicate with a supply liquid chamber 18 extending in the direction of arranging the individual liquid chambers. The supply liquid chamber 18 includes a front chamber 18a that receives ink as a liquid introduced from a first liquid introduction path 21 and a second liquid introduction path 22 to be described later, and a rear chamber 18b that is located downstream of the ink introduction direction. The first communication facing surface portion 18c, the first side wall 18d, the second communication facing surface portion 18e, the second side wall 18f, the first communication port 18g, the second communication port 18h, and the like.

  The supply liquid chamber 18 is positioned upstream in the ink introduction direction from the liquid introduction path (21, 22) by the filter member 13 extending over the entire area of the supply liquid chamber 18 in the individual liquid chamber arrangement direction. It is partitioned into a front chamber 18a and a rear chamber 18b located on the downstream side. The ink introduced into the front chamber 18a from the first liquid introduction path 21 and the second liquid introduction path 22 passes through the filter member 13 and then enters the rear chamber 18b. It cannot enter the rear chamber 18b without passing through the filter member 13.

  The rear chamber 18 b individually supplies ink to the individual liquid chambers 3 while communicating the central portion in the arrangement direction of the individual liquid chambers with the individual liquid chambers 3. The ink is filtered by the filter member 13 and then supplied to the plurality of individual liquid chambers 3, thereby suppressing the occurrence of defective discharge due to blocking the discharge holes 1 provided in the individual liquid chambers 3 with solid substances. be able to.

  The nozzle plate 2 includes, for example, discharge holes 1 having a diameter of 10 to 30 [μm] that individually communicate with the plurality of individual liquid chambers 3, and the individual liquid chambers forming the plurality of individual liquid chambers 3. It is joined to the plate 4 with an adhesive or the like. Examples of the material of the nozzle plate 2 include metals such as nickel electroforming and stainless steel, resin materials such as polyimide and silicon, and combinations thereof. The surface of the nozzle plate 2 on the ink droplet discharge side is provided with a plating film, a water repellent film, and the like for ensuring water repellency with ink.

  The individual liquid chamber plate 4 forming the plurality of individual liquid chambers 3 is manufactured by punching the plurality of individual liquid chambers 3 by, for example, pressing a stainless steel plate. The vibrating wall forming plate 5 is formed with a plurality of thin vibrating walls that also serve as upper walls of the plurality of individual liquid chambers 3 by half-etching or the like.

  Any of the plurality of piezoelectric element columns 15 provided in the piezoelectric actuator 16 (see FIG. 4) is in pressure contact with the vibrating wall which is the upper wall of each of the plurality of individual liquid chambers 3. The piezoelectric actuator 16 includes a base substrate 17 in addition to the plurality of piezoelectric element columns 15. The plurality of piezoelectric element columns 15 are formed by processing a plurality of slits on a block-like base material bonded to the base substrate 17. Laminate type in which zirconate titanate (PZT) having a thickness of 10 to 50 [μm / layer] and internal electrodes made of silver and palladium (AgPd) having a thickness of [μm / layer] are alternately stacked. It is a piezoelectric element. A flexible wiring board 25 made of FPC or the like for giving a drive signal is connected to the piezoelectric element column 15 of the piezoelectric actuator 16.

  Liquid introducing portion forming member 14, fourth rear chamber forming plate 12, third rear chamber forming plate 11, second rear chamber forming plate 10, first rear chamber forming plate 9, third beam forming member 8, second beam forming Actuator openings (14a, 12a, 11a, 10a, 9a, 8a, 7a, 6a) are formed in the member 7 and the first beam forming member 6, respectively (see FIGS. 3 and 4). The actuator mounting space is formed in the droplet discharge head while these actuator openings communicate with each other. The piezoelectric actuator 16 is bonded to the inner wall of the actuator opening 14a of the liquid introduction portion forming member 14 with an adhesive while being accommodated in the actuator mounting space.

  In addition to the actuator opening 14a, the liquid introduction part forming member 14 includes a front chamber space 14b, a first flow path space 14c, and a second flow path space 14d. The front chamber space 14 b is a space for forming the front chamber 18 a of the supply liquid chamber 18. The first flow path space 14 c is a space for forming the first liquid introduction path 21. The second flow path space 14 d is a space for forming the second liquid introduction path 22.

  Ink is introduced into the front chamber 18 a of the supply liquid chamber 18 from the first liquid introduction path 21 and the second liquid introduction path 22. The introduced ink passes through the filter member 13 and enters the rear chamber 18b, and then is supplied to the plurality of individual liquid chambers 3, respectively. The individual liquid chamber 3 includes a liquid receiving portion 3a for receiving ink sent from the rear chamber 18b, a resistance applying portion 3b, and a pressurized liquid chamber 3c for pressurizing the ink by driving the piezoelectric element column 15. Are provided (see FIG. 7). The resistance imparting portion 3b formed narrower than the liquid receiving portion 3a and the pressurized liquid chamber 3c is interposed between the liquid receiving portion 3a and the pressurized liquid chamber 3c, and extends from the liquid receiving portion 3a to the pressurized liquid chamber 3c. A resistance is given to the ink flowing into the ink.

  When the voltage applied to the piezoelectric element column 15 is lowered below, for example, the reference potential, the piezoelectric element column 15 contracts. With this contraction, when the vibration wall in contact with the piezoelectric element column 15 is deformed away from the individual liquid chamber 3, the volume of the pressurized liquid chamber 3c increases. As a result, ink flows from the liquid receiving portion 3a into the pressurized liquid chamber 3c. Thereafter, when the voltage applied to the piezoelectric element column 15 is pulled up and the piezoelectric element column expands, the vibrating wall in contact with the piezoelectric element column 15 is deformed in a direction approaching the individual liquid chamber 3. As a result, when the volume of the pressurized liquid chamber 3 c decreases, the pressure of the ink in the pressurized liquid chamber 3 c increases, and ink droplets are ejected from the ejection holes 1.

  After the ink droplets are ejected from the ejection holes 1, when the voltage applied to the piezoelectric element column 15 is returned to the reference potential, the size of the piezoelectric element 15 is restored to the reference size. As a result, when the vibration wall is restored to an undeformed state, the volume of the pressurized liquid chamber 3c increases and negative pressure is generated. Thereby, ink is replenished from the liquid receiving part 3a to the pressurized liquid chamber 3c. Then, the vibration of the meniscus surface of the ejection hole 1 is attenuated, and an operation for ejecting the next ink droplet becomes possible.

  Note that the driving method of the droplet discharge head is not limited to the method described so far, and it is possible to perform striking or pushing by devising the way of giving the driving waveform.

Next, a characteristic configuration of the droplet discharge head according to the embodiment will be described.
In FIG. 6, the filter member 13 extends over the entire area of the supply liquid chamber 18 in the individual liquid chamber arrangement direction (left-right direction in the figure) in the supply liquid chamber 18 including the front chamber 18 a and the rear chamber 18 b. It is arranged in the existing posture. In the liquid introduction direction by the first liquid introduction path 21 and the second liquid introduction path 22, the supply liquid chamber 18 is a front chamber 18 a located upstream in the introduction direction, and a rear chamber 18 b located downstream in the introduction direction. It is divided into.

  A first communication facing surface portion 18c is disposed at one end portion (right end portion in the figure) of the rear chamber 18b in the individual liquid chamber arrangement direction, and the first communication port 18g of the front chamber 18a is interposed via the filter member 13. Face to face. Further, a second communication facing surface portion 18e is disposed at the other end portion (left end portion in the figure) of the rear chamber 18b in the individual liquid chamber arrangement direction, and the second chamber of the front chamber 18a is interposed via the filter member 13. It faces the communication port 18h.

  When ink is initially introduced into the droplet discharge head, the ink behaves as described below in the droplet discharge head. That is, the liquid initially introduced from the first liquid introduction path 21 to the front chamber 18a of the supply liquid chamber 18 collides with the filter member 13 and the first side wall 18d. At this time, the inside of the front chamber 18a is not yet filled with ink, and the hydraulic pressure is not so high. For this reason, the liquid that has collided with the filter member 13 or the first side wall 18d does not permeate the filter member 13 and is directed from one end side to the center side in the individual liquid chamber arrangement direction in the supply liquid chamber 18 (from the right side in the figure). Change direction (towards the center). Similarly, the ink initially introduced from the second liquid introduction path 22 into the front chamber 18a of the supply liquid chamber 18 collides with the filter member 13 and the second side wall 18f, and from the other end side in the individual liquid chamber arrangement direction to the center side. Turn towards (from left to center in the figure). Before the front chamber 18a is filled with ink, bubbles may be generated in the vicinity of the first side wall 18d or in the vicinity of the second side wall 18f in the front chamber 18a.

  When the front chamber 18a is filled with ink, the ink in the front chamber 18a begins to permeate the filter member 13 due to an increase in the hydraulic pressure. At this time, of the entire region of the filter member 13 in the individual liquid chamber arrangement direction, one end portion (right end portion in the figure) facing the first communication port 18g that receives the ink from the first liquid introduction path 21, 2 Flow of ink to enter the front chamber 18a from the liquid introduction path with respect to the other end part (left end part in the figure) facing the second communication port 18h that receives the ink from the liquid introduction path 22 The ink is strongly pressed by. For this reason, of the ink filling the front chamber 18a, the ink existing at one end of the front chamber 18a in the individual liquid chamber arrangement direction and the ink existing at the other end are transferred to other regions. It passes through the filter member 13 preferentially over existing ink. Then, the ink existing at one end of the front chamber 18a in the individual liquid chamber arrangement direction passes through the filter member 13 while taking in air bubbles generated in the vicinity of the first side wall 18d. At this time, unlike a normal print job in which ink is consumed little by little, the ink passes through the filter member 13 with a certain degree of momentum, so that the bubbles are finely crushed into fine bubbles. Further, the ink existing at the other end portion of the front chamber 18a in the individual liquid chamber arrangement direction passes through the filter member 13 while taking in bubbles generated in the vicinity of the second side wall 18f. These bubbles are also crushed into finer fine bubbles as they permeate.

  Since it is necessary to supply ink to the rear chamber 18b while being filtered by the filter member 13, the ink supply speed per unit time for the rear chamber 18b is considerably slower than the ink supply speed for the front chamber 18a. . For this reason, the ink moves at a slower flow rate in the rear chamber 18b than in the front chamber 18a. The ink that has passed through the filter member 13 while taking in air bubbles at one end portion of the front chamber 18a in the individual liquid chamber arrangement direction collides with the first communicating surface portion 18c and the first side wall 18d of the rear chamber 18b and moves in the individual liquid chamber arrangement direction. Turn from one end to the center. Since the flow rate is a slow flow rate, the ink whose direction has been changed proceeds from one end side to the center side in a predetermined direction together with the fine bubbles without generating new bubbles. Then, it enters the plurality of individual liquid chambers 3.

  Similarly, at the other end portion of the rear chamber 18b in the individual liquid chamber arrangement direction, the ink whose direction is changed while colliding with the second communication facing surface portion 18e and the second side wall 18f at a slow flow rate is separated with the fine bubbles. Proceeding from the other end side in the chamber arrangement direction toward the center side, it enters the plurality of individual liquid chambers 3.

  As described above, in the liquid droplet ejection head according to the embodiment, when ink is initially introduced, the air bubbles generated in the vicinity of the first side wall 18d and the second side wall 18f in the front chamber 18a are filtered together with the ink without stagnation. After passing through the member 13 to form finer fine bubbles, the bubbles are smoothly sent to the plurality of individual liquid chambers 3. The fine bubbles sent to the plurality of individual liquid chambers 3 are discharged to the outside when the test liquid droplet is discharged during the initial operation. Therefore, it is possible to suppress the occurrence of ejection failure due to clogging of bubbles in the individual liquid chamber 3. In addition, since the ink is filtered by the filter member 13 and then supplied to the plurality of individual liquid chambers 3, it is possible to suppress the occurrence of ejection failure due to the ejection holes 1 being blocked with solid matter.

  FIG. 8 is an enlarged plan view showing the filter member 13. The plate-like filter member 13 includes a plurality of filtration openings 13a penetrating in the thickness direction. Solids can be removed from the ink by passing the ink through the filtration openings 13a. As the plane arrangement mode of the plurality of filtration openings 13a, a staggered plane arrangement mode as shown in the figure may be adopted, or a grid-like plane arrangement mode as shown in FIG. 9 is adopted. May be. As shown in FIG. 10, the filtering opening 13a may be provided with a taper that tapers from the ink receiving side to the ink discharging side. Moreover, you may employ | adopt as a taper taper the taper which gave the horn-like roundness as shown in FIG.

  The horn-like roundness can be easily realized by a nickel Ni electroforming method. The diameter of the filtration opening 13a is the diameter of the opening on the discharge side, which is the narrower one. This diameter is the same as the discharge hole 1 or smaller than the discharge hole 1. Further, the planar shape of the filtration opening 13a is not limited to a circular shape, and may be a polygonal shape or a spline shape. The hexagonal filtration openings 13a may be arranged in a honeycomb shape.

  As described above, the ink permeates more preferentially than the other regions to both ends of the entire region of the filter member 13 in the individual liquid chamber arrangement direction. Therefore, both ends of the filter member 13 in the individual liquid chamber arrangement direction are more likely to be clogged because the amount of ink processing is larger than in other areas. If the difference in the ink processing amount between the both end portions and the other regions is excessively increased, clogging is immediately caused and the life of the filter member 13 is significantly shortened.

  Therefore, in the liquid droplet ejection head according to the embodiment, the aperture ratios at both ends in the individual liquid chamber arrangement direction of the filter member 13 are set lower than the aperture ratios at the center portions. Specifically, the enlarged plane previously shown in FIG. 8 shows the central portion of the filter member 13 in the direction of arranging the individual liquid chambers. At both ends of the filter member 13 in the individual liquid chamber arrangement direction, as shown in FIG. 12, the opening ratio of the filtration openings 13a is low (the arrangement density is low). Thus, by making the aperture ratio of the both ends in the individual liquid chamber arrangement direction of the filter member 13 lower than the aperture ratio of the central portion, the difference between the ink processing amount at the both ends and the ink processing amount at the central portion. Is prevented from becoming excessively large. As a result, it is possible to prevent a significant decrease in the life of the filter member 13 caused by excessively increasing the difference in throughput.

  As a method of varying the aperture ratio of the filtration openings 13a, not a method of varying the diameters of the individual filtration openings 13a, but a method of varying the arrangement density of the filtration openings 13a having the same diameter is adopted. The collection property can be made constant regardless of the position in the individual liquid chamber arrangement direction. Moreover, since the thickness of the filter member 13 is made uniform in the individual liquid chamber arrangement direction, a plate-like member having a uniform thickness can be used as the base material of the filter member 13.

  As described above, since the ink supply speed to the rear chamber 18b is considerably slow, even if the first communication facing surface portion 18c is formed as a flat surface, the generation of bubbles is suppressed and the individual liquid chamber is arranged from the end in the individual liquid chamber arrangement direction. It is possible to move to the central part where the chamber is formed. However, as shown in FIG. 6, the first communication facing portion 18c is arranged from the other end side in the individual liquid chamber arrangement direction to one end side (from the left side to the right side in the illustrated example). It is more preferable to use a stepped shape gradually approaching or an R shape (FIG. 13) described later. By doing in this way, the ink which goes straight in the direction away from the first communication port 18g in the portion of the rear chamber 18b facing the first communication port 18g is positioned closer to the first side wall 18d. In order from the ink that is in contact with the first communication facing surface portion 18c, the direction is changed. Thus, the ink that has passed through the filter member 13 in the region facing the first communication port 18g is smoothly directed from one end side to the other end side in the individual liquid chamber arrangement direction (from the right side to the left side in the drawing). Convert. Thereby, generation | occurrence | production of the new bubble at the time of direction change can be suppressed more.

  The second communication facing surface portion 18e has a shape that gradually approaches the second communication port 18h from one end side to the other end side in the individual liquid chamber arrangement direction (from the right side to the left side in the drawing). In such a configuration, the ink that has passed through the filter member 13 in the region facing the second communication port 18h is directed from the other end side to the one end side in the individual liquid chamber arrangement direction by the same action as the first communication facing surface portion 18c. Change direction smoothly (from left to right in the figure). Thereby, generation | occurrence | production of the new bubble at the time of direction change can be suppressed more.

  In addition, about the 2nd communication facing surface part 18e, about the example which employ | adopted the step-like shape as shown in figure as a shape which gradually approaches the 2nd communication port 18h toward the other end side from the one end side of an individual liquid chamber arrangement direction. Although described, a slope shape or an R shape as shown in FIG. 13 may be adopted. The same applies to the first communication facing portion 18c.

  The first beam forming plate 6, the second beam forming plate 7, and the third beam forming plate 8 form a plurality of beam members 20 in the rear chamber 18b. These beam members 20 receive the filter member 13 that is deflected from the front chamber 18 a side toward the rear chamber 18 b side by being pushed by the ink in the front chamber 18 a, thereby preventing excessive deflection of the filter member 13. When the ink droplets are ejected from the ejection holes 1 by driving the piezoelectric element columns 15, the ribs also serve to block part of the pressure waves propagating from the common liquid chamber 3 into the rear chamber 18 c. Occurrence of so-called fluid crosstalk can be suppressed by blocking the pressure wave.

A predetermined gap is maintained between the plurality of beam members 20 and the filter member 13 that is not bent. Hereinafter, this gap that the beam gap _{G 1.} A gap between the other end (point P _{1 in the} figure) of the first communication facing surface portion 18c in the individual liquid chamber arrangement direction and the filter member 13 in an unbent state (hereinafter referred to as a first communication gap G ₂ ), a second the individual liquid chamber arrangement direction of one end of the communicating face portion 18e (FIG midpoint P _2), bent in the gap between the filter member 13 in the state not (hereinafter, referred to as second communication gap G ₃₎ includes a beam gap G ₁ Are equal. Thus, the flow velocity of the ink when passing through the beam gaps G _1, the flow velocity and the ink toward the first communicating gap G ₂ to the rear chamber 18b central, rear chamber 18b central portion from the second communicating gap G ₃ By making it equal to the flow velocity of the ink toward, the occurrence of turbulent flow in the rear chamber 18b can be suppressed.

The beam gap G _1, the distance between the adjacent beam members 20 (hereinafter, referred Harima distance L ₁₎ is preferably set to approximately the same value as. Thereby, the ink present between the adjacent beam member 20, even when entering the beam gap G ₁ passes over the beam member 20 while moving in the individual liquid chamber arrangement direction, and the flow rate constant turbulent It is because generation | occurrence | production of a flow can be suppressed. In the liquid droplet ejection head according to the embodiment, the arrangement pitch of the plurality of ejection holes 1 is the same as that between 150 [dpi] dots (0.169 mm). The beam members 20 are arranged in the individual liquid chamber arrangement direction at a 4-dot pitch of 150 [dpi]. That is, in the individual liquid chamber arrangement direction the beam member 20, disposed at a pitch of 0.6776, and substantially the same value even beam gap G _1.

  In FIG. 7, the third rear chamber forming plate 11 includes a rear chamber opening 11b in addition to the actuator opening 11a. The rear chamber opening 11b is for forming the rear chamber 18b. One end of the rear chamber opening 11b in the individual liquid chamber arrangement direction (left-right direction in the figure) has a semicircular arc shape. This means that one end of the first communication facing surface portion 18c in the individual liquid chamber arrangement direction is a curved surface that curves in a direction perpendicular to the rising direction of the first side wall 18d. By providing such a curved surface, it is possible to suppress ink stagnation in the vicinity of the first side wall 18d and to reduce the stagnation of fine bubbles in the vicinity of the corner between the first communicating surface portion 18c and the first side wall 18d. Can do.

  The other end of the rear chamber opening 11b in the individual liquid chamber arrangement direction also has a semicircular arc shape. This means that the other end of the second communication facing surface portion 18e in the individual liquid chamber arrangement direction is a curved surface that curves in a direction perpendicular to the rising direction of the second side wall 18f. By providing such a curved surface, it is possible to suppress ink stagnation in the vicinity of the second side wall 18f and reduce the stagnation of fine bubbles in the vicinity of the corner between the second communicating surface portion 18e and the second side wall 18f. Can do.

  FIG. 14 is a plan view showing the first beam forming plate 6, the second beam forming plate 7, and the third beam forming plate 8 in a modified example of the droplet discharge head according to the embodiment. As can be seen from these drawings, in the modified example, the beam members 20 are arranged in a lattice shape. In such a configuration, the propagation of the pressure wave from the individual liquid chamber 3 to the filter member 20 as described above is greater than in the case where the beam member 20 is bridged only in the short direction of the supply liquid chamber 18. The occurrence of fluid crosstalk can be more reliably suppressed by blocking by.

  Next, a first embodiment of an image forming apparatus equipped with a droplet discharge head according to the embodiment will be described. FIG. 15 is a main part configuration diagram showing a main part configuration of the image forming apparatus according to the first embodiment. FIG. 16 is a plan view showing the configuration of the main part.

  The image forming apparatus according to the first embodiment is a serial type printer, and a carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. The main scanning motor (not shown) moves and scans in the arrow direction (carriage main scanning direction) via the timing belt.

The carriage 233 includes a droplet discharge head according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K), and a drive signal to the head. A recording head 234 composed of a droplet ejection head unit in which an electric circuit board that provides the ink and a tank that accommodates ink to be supplied to the head are integrated, and a nozzle row composed of a plurality of ejection holes is arranged along the longitudinal direction of the bed, The ink droplet is ejected in the downward direction.

  The recording head 234 is configured by attaching droplet discharge head units 234a and 234b each having two nozzle rows to one base member, and one nozzle row of one head 234a is a black (K) droplet. The other nozzle row is a cyan (C) droplet, the other nozzle row of the other head 234b is a magenta (M) droplet, and the other nozzle row is a yellow (Y) droplet. Discharge. Here, a configuration in which droplets of four colors are ejected in a two-head configuration is used, but it is also possible to arrange four nozzle rows per head and eject each of the four colors with one head.

  Further, the ink of each color is replenished and supplied from the ink cartridge 210 of each color to the tank 235 of the recording head 234 via the supply tube 236 of each color.

  On the other hand, as a paper feeding unit for feeding the paper 242 stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon-like feeding that separates and feeds the paper 242 one by one from the paper stacking unit 241. A separation pad 244 that is disposed to face the paper roller 243 and the paper feeding roller 243 and is made of a material having a large friction coefficient is provided, and the separation pad 244 is biased toward the paper feeding roller 243 side.

  In order to feed the sheet 242 fed from the sheet feeding unit to the lower side of the recording head 234, a guide member 245 for guiding the sheet 242, a counter roller 246, a conveyance guide member 247, and a tip pressure roller. And a conveying belt 251 which is a conveying means for electrostatically attracting the fed paper 242 and conveying it at a position facing the recording head 234.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction). In addition, a charging roller 256 that is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 256 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251. The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 242 recorded by the recording head 234, a separation claw 261 for separating the paper 242 from the transport belt 251, a paper discharge roller 262, and a paper discharge roller 263 are provided. A paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body. The duplex unit 271 takes in the paper 242 returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, a maintenance / recovery mechanism 281 that is a head maintenance / recovery device according to the present invention includes a recovery means for maintaining and recovering the nozzle state of the recording head 234 in the non-printing area on one side of the carriage 233 in the scanning direction. Is arranged. The maintenance / recovery mechanism 281 includes cap members (hereinafter referred to as “caps”) 282a and 282b (hereinafter referred to as “caps 282” when not distinguished) for capping each nozzle surface of the recording head 234, and nozzle surfaces. A wiper blade 283 that is a blade member for wiping the ink, and an empty discharge receiver 284 that receives liquid droplets for discharging the liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing.

  Further, in the non-printing area on the other side in the scanning direction of the carriage 233, there is an empty space for receiving a liquid droplet when performing an empty discharge for discharging a liquid droplet that does not contribute to the recording in order to discharge the recording liquid thickened during the recording. A discharge receiver 288 is disposed, and the idle discharge receiver 288 is provided with an opening 289 along the nozzle row direction of the recording head 234 and the like.

  In this image forming apparatus configured as described above, the sheets 242 are separated and fed one by one from the sheet feeding tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and is conveyed to the conveyor belt 251 and the counter. It is sandwiched between the rollers 246 and conveyed, and further, the leading end is guided by the conveying guide 237 and pressed against the conveying belt 251 by the leading end pressing roller 249, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately applied to the charging roller 256, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 251 alternates, that is, in the sub-scanning direction that is the circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 242 is fed onto the conveyance belt 251 charged alternately with plus and minus, the sheet 242 is attracted to the conveyance belt 251, and the sheet 242 is conveyed in the sub scanning direction by the circumferential movement of the conveyance belt 251.

  Therefore, by driving the recording head 234 according to the image signal while moving the carriage 233, ink droplets are ejected onto the stopped paper 242 to record one line, and after the paper 242 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 242 has reached the recording area, the recording operation is finished and the paper 242 is discharged onto the paper discharge tray 203.

  Thus, in this image forming apparatus, since the liquid droplet ejection head according to the present invention is provided as a recording head, the reliability is improved.

  Next, a second embodiment of the image forming apparatus according to the present invention including the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 17 is a side view showing the image forming apparatus according to the second embodiment. This image forming apparatus is a line type image forming apparatus, has an image forming unit 402 and the like inside the apparatus main body 401, and can supply a large number of recording media (sheets) 403 on the lower side of the apparatus main body 401. A paper tray 404 is provided, a sheet 403 fed from the sheet feeding tray 404 is taken in, a required image is recorded by the image forming unit 402 while the sheet 403 is conveyed by the conveying mechanism 405, and then the side of the apparatus main body 401. The paper 403 is discharged to a paper discharge tray 406 attached to the printer.

  Also, a duplex unit 407 that can be attached to and detached from the apparatus main body 401 is provided, and when performing duplex printing, the sheet 403 is conveyed into the duplex unit 407 while being transported in the reverse direction by the transport mechanism 405 after one-side (front) printing is completed. Then, the other side (back side) is sent back to the transport mechanism 405 as the printable side, and the paper 403 is discharged to the paper discharge tray 406 after the other side (back side) printing is completed.

  The image forming unit 402 includes, for example, four line-type liquid discharge heads according to the present invention that discharge liquid droplets of each color of yellow (Y), magenta (M), cyan (C), and black (K). The recording heads 411y, 411m, 411c, and 411k (referred to as "recording heads 411" when colors are not distinguished) are configured by integrating subtanks that supply ink to the liquid ejection heads, and each recording head 411 ejects droplets. The head holder 413 is mounted with the nozzle surface on which the nozzle is formed facing downward.

  Note that one recording head 411 is configured by arranging a plurality of sub-tank integrated liquid discharge heads according to the present invention on a base member in a predetermined positional relationship, but is configured by one full line type liquid discharge head. You can also

  In addition, a maintenance / recovery mechanism 412y, 412m, 412c, 412k (referred to as “maintenance / recovery mechanism 412” when colors are not distinguished) corresponding to each recording head 411 is provided to maintain and recover the performance of the head. During the head performance maintenance operation such as wiping processing, the recording head 411 and the maintenance / recovery mechanism 412 are relatively moved so that the capping member constituting the maintenance / recovery mechanism 412 faces the nozzle surface of the recording head 411.

  The paper 403 in the paper feed tray 404 is separated one by one by a paper feed roller (half-moon roller) 421 and a separation pad (not shown) and fed into the apparatus main body 401, and is registered along the guide surface 423 a of the transport guide member 423. It is sent between 425 and the conveyor belt 433, and is sent to the conveyor belt 433 of the conveyor mechanism 405 via the guide member 426 at a predetermined timing.

  The conveyance guide member 443 is also formed with a guide surface 423 b for guiding the paper 403 sent out from the duplex unit 407. Further, a guide member 427 for guiding the sheet 403 returned from the transport mechanism 405 to the duplex unit 407 during duplex printing is also provided.

  The conveyance mechanism 405 includes an endless conveyance belt 433 that is stretched between a conveyance roller 431 that is a driving roller and a driven roller 432, a charging roller 434 that charges the conveyance belt 433, and an image forming unit 402. A platen member 435 that maintains the flatness of the conveyance belt 433 at the opposite portion, a pressing roller 436 that presses the paper 403 fed from the conveyance belt 433 against the conveyance roller 431 side, and other recording liquid that is attached to the conveyance belt 433, although not shown. It has a cleaning roller made of a porous material or the like, which is a cleaning means for removing (ink). As the transport mechanism, for example, a mechanism that sucks the recording medium onto the transport belt by air suction can be used.

  On the downstream side of the transport mechanism 405, a paper discharge roller 438 and a spur 439 for sending the paper 403 on which an image is recorded to the paper discharge tray 406 are provided.

  In the image forming apparatus configured as described above, the conveyance belt 433 moves in the direction indicated by the arrow and is charged by contact with the charging roller 434 to which a high applied voltage is applied. When 403 is fed, the sheet 403 is electrostatically attracted to the conveyance belt 433. In this way, the sheet 403 that is strongly adsorbed to the transport belt 433 is calibrated for warpage and unevenness, and forms a highly flat surface.

  Then, the paper 403 is moved around the conveyor belt 433 and droplets are ejected from the recording head 411, whereby a required image is formed on the paper 403, and the paper 403 on which the image has been recorded is the paper discharge roller 438. As a result, the paper is discharged to the paper discharge tray 406.

  Thus, since the image forming apparatus includes the liquid discharge head according to the present invention as a recording head, stable droplet discharge characteristics can be obtained, and a high-quality image can be stably formed.

  In the present application, the “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, etc., and means a material to which ink droplets or other liquids can be attached. , Recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. “Formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply causing a droplet to land on the medium). ) Also means.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically, for example, includes DNA samples, resists, pattern materials, resins, and the like.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
[Aspect A]
Aspect A includes a plurality of individual liquid chambers that individually store liquids in a state in which they are aligned in a predetermined direction, a plurality of discharge holes that are individually provided in the individual liquid chambers to discharge droplets, A supply liquid chamber that supplies liquid stored in its internal space extending in a predetermined direction to a plurality of individual liquid chambers communicating with the central portion of the predetermined direction, and the supply liquid chamber in the supply liquid chamber A first liquid introduction path for introducing liquid into the supply liquid chamber in a state connected to a first communication port provided at one end in a predetermined direction; and provided at the other end of the supply liquid chamber in the predetermined direction. A second liquid introduction path for introducing the liquid into the supply liquid chamber in a state connected to the second communication port; and a filter member for filtering the liquid sent toward the plurality of individual liquid chambers in the supply chamber; Introduced from the first liquid introduction path into the supply liquid chamber; The liquid is struck against a first communication facing surface portion facing the first communication port or a first side wall rising from one end in the predetermined direction of the first communication facing surface portion toward the first communication port. The second communication facing surface portion that changes the direction toward the central portion and introduces the liquid introduced from the second liquid introduction path into the supply liquid chamber to the second communication port, and the second communication In the droplet discharge head that strikes against the second side wall that rises from the other end of the facing portion in the predetermined direction toward the second communication port and changes the direction toward the central portion, the predetermined direction of the supply liquid chamber The supply liquid chamber is divided into two in the rising direction of the first side wall and the second side wall by the filter member extending over the entire area in the front chamber, the front chamber obtained by the partition, and the front chamber More liquid introduction The first communication facing surface portion is disposed at one end portion in the predetermined direction of the rear chamber among the rear chamber located on the downstream side, and the second communication is provided at the other end portion in the predetermined direction of the rear chamber. The facing portion is provided.

[Aspect B]
Aspect B is characterized in that, in aspect A, the aperture ratios at both ends of the filter member in the predetermined direction are lower than the aperture ratio of the center portion. In such a configuration, as described above, the filter member has a significant lifetime due to excessively large difference between the liquid processing amount at both ends in the predetermined direction of the filter member and the liquid processing amount at the central portion. Generation | occurrence | production of a fall can be prevented.

[Aspect C]
Aspect C is the aspect A or aspect B, wherein the first communication facing surface portion is shaped to gradually approach the first communication port from the other end side in the predetermined direction toward the one end side, and the second communication The facing portion is shaped to gradually approach the second communication port from one end side to the other end side in the predetermined direction. In such a configuration, as already described, in the rear chamber, the liquid is smoothly redirected from one end side to the other end side in the predetermined direction on the first communication facing surface portion, in the vicinity of the first side wall. Generation of new bubbles can be suppressed. Further, in the rear chamber, the direction of the liquid is smoothly changed from the other end side in the predetermined direction toward the one end side on the second communication facing surface portion, and generation of new bubbles in the vicinity of the second side wall is suppressed. You can also.

[Aspect D]
Aspect D includes a plurality of beam members that receive the filter member that bends from the front chamber side toward the rear chamber side when pushed by the liquid in the front chamber in any of the aspects A to C. It is characterized by being provided indoors. In such a configuration, as described above, it is possible to prevent excessive deflection of the filter member due to being pushed by the liquid in the front chamber. Furthermore, the occurrence of fluid crosstalk due to the propagation of the pressure wave described above can be suppressed.

[Aspect E]
Aspect E provides a predetermined gap between the plurality of beam members and the filter member in an unbent state in aspect D, and the other end of the first communication facing surface portion in the predetermined direction; A gap between the filter member in an unbent state and a gap between one end of the second communicating surface portion in the predetermined direction and the filter member in an unbent state are all bent with a plurality of the beam members. It is characterized in that it is equal to the gap with the filter member in the non-locked state. In such a configuration, as previously described, the flow velocity of the ink as it passes through the beam gaps G _1, the flow velocity and the ink toward the first communicating gap G ₂ to the rear chamber central portion, the second communication gap G ₃ By making the ink flow rate equal to the flow rate of the ink toward the center of the rear chamber, generation of turbulent flow in the rear chamber can be suppressed.

[Aspect F]
In aspect F, in any one of aspects A to E, one end of the first communication facing surface portion in the predetermined direction and the other end of the second communication facing surface portion in the predetermined direction are orthogonal to the side wall rising direction, respectively. It is characterized by a curved surface that curves in the direction to be. In such a configuration, as described above, the stagnation of the liquid in the vicinity of the first side wall can be suppressed, and the stagnation of fine bubbles in the vicinity of the corner between the first communicating surface portion and the first side wall can be reduced. In addition, it is possible to suppress the stagnation of the liquid in the vicinity of the second side wall, and to reduce the stagnation of fine bubbles in the vicinity of the corner between the second communicating surface portion and the second side wall.

[Aspect G]
Aspect G is characterized in that, in aspect D or E, a plurality of the beam members are arranged in a lattice shape. In such a configuration, as described above, compared to the case where the beam member is bridged only in the short direction of the supply liquid chamber, the occurrence of fluid crosstalk is further suppressed by blocking more propagation of the pressure wave described above. It can be surely suppressed.

1: Discharge hole 3: Individual liquid chamber 13: Filter member 18: Supply liquid chamber 18a: Front chamber 18b: Rear chamber 18c: First communication facing portion 18d: First side wall 18e: Second communication facing portion 18f: Second side wall 18g: 1st communication port 18h: 2nd communication port 21: 1st liquid introduction path 22: 2nd liquid introduction path 233: Carriage (head moving means)
251: Conveying belt (sheet conveying means)

JP 2011-25663 A

Claims (7)

A plurality of individual liquid chambers for individually storing liquids in a state aligned with each other in a predetermined direction;
A plurality of discharge holes individually provided in the individual liquid chambers for discharging droplets;
A supply liquid chamber that supplies liquid contained in its internal space extending in the predetermined direction to each of a plurality of individual liquid chambers communicating with the central portion of the predetermined direction;
A first liquid introduction path for introducing liquid into the supply liquid chamber in a state connected to a first communication port provided at one end of the supply liquid chamber in the predetermined direction;
A second liquid introduction path for introducing liquid into the supply liquid chamber in a state of being connected to a second communication port provided at the other end in the predetermined direction in the supply liquid chamber;
A filter member for filtering the liquid sent toward the plurality of individual liquid chambers in the supply chamber;
The liquid introduced into the supply liquid chamber from the first liquid introduction path is a first communication facing surface portion facing the first communication port, or the first communication facing surface portion from one end in the predetermined direction. Hit the first side wall that rises toward the communication port and change the direction toward the center,
and,
The liquid introduced into the supply liquid chamber from the second liquid introduction path is the second communication facing surface portion facing the second communication port or the other end in the predetermined direction of the second communication facing surface portion. In the liquid droplet ejection head that strikes the second side wall that rises toward the side of the two communication ports and changes the direction toward the central portion,
By the filter member extending over the entire region in the predetermined direction of the supply liquid chamber, the supply liquid chamber is partitioned into two in the rising direction of the first side wall and the second side wall,
Of the front chamber obtained by this partition and the rear chamber located downstream of the front chamber in the liquid introduction direction, the first communication facing portion is disposed at one end portion in the predetermined direction of the rear chamber. ,
Disposing the second communication facing portion at the other end in the predetermined direction of the rear chamber ;
In addition, the droplet discharge head is characterized in that the aperture ratios at both end portions in the predetermined direction of the filter member are respectively lower than the aperture ratio at the center portion . The droplet discharge head according to claim 1 .
The first communication facing surface portion is shaped to gradually approach the first communication port from the other end side in the predetermined direction toward the one end side,
The liquid droplet ejection head, wherein the second communication facing surface portion is shaped to gradually approach the second communication port from one end side to the other end side in the predetermined direction. The droplet discharge head according to claim 1 or 2 ,
A droplet discharge head comprising: a plurality of beam members that receive the filter member that bends from the front chamber side toward the rear chamber side when pushed by the liquid in the front chamber. . The droplet discharge head according to claim 3 .
While providing a predetermined gap between the plurality of beam members and the filter member in an unbent state,
The gap between the other end in the predetermined direction of the first communication facing surface portion and the filter member in an unbent state, the one end in the predetermined direction of the second communication facing surface portion, and the filter member in an unbent state And a gap between the plurality of beam members and the filter member that is not bent. The droplet discharge head according to any one of claims 1 to 4 ,
One end of the first communication facing surface portion in the predetermined direction and the other end of the second communication facing surface portion in the predetermined direction are respectively curved surfaces that are curved in a direction perpendicular to the side wall rising direction. Droplet discharge head. The droplet discharge head according to claim 3 or 4 ,
A droplet discharge head comprising a plurality of beam members arranged in a lattice shape. A droplet ejection head that ejects droplets from a plurality of ejection holes, a sheet conveyance unit that conveys a recording sheet, and a direction perpendicular to the conveyance direction of the sheet conveyance unit while passing the droplet ejection head along the surface of the recording sheet In an image forming apparatus comprising a head moving means for moving in a direction, and forming an image on a recording sheet by droplets ejected from a plurality of ejection holes,
As the droplet discharge head, an image forming apparatus characterized by using any of the liquid droplet ejection head according to claim 1 to 6.

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