JP6544449B2 - Droplet discharge head - Google Patents

Description

  The present invention relates to a droplet discharge head of a droplet discharge device.

  The droplet discharge device is a device that discharges droplets, for example, a device that prints droplets or the like such as ink on a target by discharging the droplets toward the target. There is an inkjet printer as an example of the droplet discharge device.

  Patent Document 1 discloses an inkjet head of an inkjet printer. The inkjet head described in Patent Document 1 includes a cavity unit in which a cavity plate, a base plate, an insertion plate, two manifold plates, a cover plate, and a nozzle plate are stacked. The insertion plate is formed with a concave recess (damper chamber) opened toward the upper base plate, leaving a bottom plate portion (damper wall) of a thin thickness on the lower surface side. The recess is formed in a length substantially corresponding to the row of pressure chambers substantially along the longitudinal direction of the manifold chamber so that the damper wall forms a part of the upper wall of the manifold chamber (common flow passage). ing.

  Thereby, the pressure fluctuation of the manifold chamber at the time of droplet discharge and the like is absorbed by the vibration of the damper wall, and the change of the droplet ejection characteristics is suppressed to prevent the deterioration of the printing performance (see FIG. 1 of Patent Document 1). ).

  On the other hand, the ink jet head described in Patent Document 2 includes a base plate having a pressure chamber formed therein, a spacer plate, a manifold plate provided at a position where at least a part of the manifold chamber overlaps with the pressure chamber, and a damper having a damper wall. In stacking the plate and the nozzle plate provided with the nozzles, the damper plate is inserted in contact with the upper or lower side of the manifold plate. The damper plate is configured by joining a plate member having a plurality of recessed portions formed adjacent to each other across a partition wall at a portion facing the manifold chamber and a thin film material forming a flexible damper wall separating the manifold chamber and the recessed portion. (See FIG. 2 of Patent Document 2).

JP 2004-106395 A (FIG. 1) Unexamined-Japanese-Patent No. 2006-349036 (FIG. 2)

  However, according to the invention described in Patent Document 1, when the pressure fluctuation in the manifold (common flow channel) becomes large, such as when ink is continuously discharged, the amplitude of the damper wall near the longitudinal center of the damper chamber becomes large. As a result, there is a possibility that ink ejection deviation or the like may occur.

  On the other hand, in the invention described in Patent Document 2, the damper chamber is finely divided, and at the same time the damper wall is similarly divided, so that the damper wall can be sufficiently vibrated in the respectively divided chambers against pressure fluctuation of the manifold. There is a possibility that a sufficient damper effect can not be obtained.

  Therefore, an object of the present invention is to provide a droplet discharge head capable of obtaining a sufficient damper effect while suppressing excessive vibration of the damper wall.

In order to solve the above problems, in the droplet discharge head according to the present invention, a plurality of discharge unit portions that discharge droplets extending in a first direction are disposed in a second direction intersecting the first direction. A droplet discharge head,
The discharge unit portion includes a nozzle row constituted by a plurality of nozzles arranged along the first direction, a droplet discharge surface on which the nozzle row is arranged, and a plurality of nozzles for introducing ink to the plurality of nozzles. A plurality of ink flow inlets, which are disposed between the common flow channel extending in the first direction and the ink supply openings and the nozzles, to which pressure for discharging the ink from the nozzles is applied. A pressure chamber, a position facing the common flow path, and a damper chamber extending along the first direction, a pressure chamber disposed between the damper chamber and the common flow path, and a pressure in the common flow path It has a damper wall which bends according to a change, another wall different from the damper wall in the damper chamber, and a pillar portion which connects the damper wall,
The arrangement of the pillars of at least one of the plurality of discharge unit parts in the first direction is different from the arrangement of the pillars in the other discharge unit parts.

  The droplet discharge head according to the present invention is characterized in that, in the damper chamber, the column extends in the second direction, and the chambers divided by the column communicate with each other.

  In the droplet discharge head according to the present invention, a spacer member having a recess is disposed on the droplet discharge surface side of the damper wall, and the bottom of the recess has another wall different from the damper wall. The damper chamber is formed by the damper wall and the recess.

  Further, in the droplet discharge head according to the present invention, the pillar portion may extend from the spacer member and may be bonded to the damper wall.

  Further, in the droplet discharge head according to the present invention, the pillar portion may extend from the damper wall and may be bonded to the spacer member.

  In the droplet discharge head according to the present invention, the spacer member has a plurality of through holes penetrating in a third direction orthogonal to the droplet discharge surface.

  Further, in the droplet discharge head according to the present invention, in plan view, a plurality of convex portions are formed in two rows along the first direction on the discharge surface, and the spacer member The through hole is formed along the first direction at a position corresponding to at least a row of the two rows of the convex portion.

Further, in the droplet discharge head according to the present invention, the plurality of discharge unit units are configured for each color to be discharged, and the first unit group formed by the discharge unit units that discharge black droplets, and other than black A second unit group formed by a discharge unit portion that discharges the liquid droplets; a damper chamber of the discharge unit portion at one end in the second direction of the first unit group; and a damper of the discharge unit portion at the other end The arrangement of the pillars may be the same between the room and the room.

  Since the present invention is configured as described above, by forming the pillar portion in the damper chamber, it is possible to suppress excessive vibration of the damper wall and to suppress the discharge deviation of the ink. In addition, by shifting the position of the column portion of at least one discharge unit portion with the position of the column portion in the other discharge unit portion, it is possible to suppress the ink discharge failure that may occur due to the line portions being arranged.

It is a perspective view of an important section of an ink jet printer concerning a first embodiment of the present invention. It is a disassembled perspective view which shows the structure of the head unit of the inkjet printer in FIG. It is a disassembled perspective view which shows the structure of the head in the head unit of FIG. (A) is sectional drawing which partially abbreviate | omitted the internal structure after the assembly of the head of FIG. (B) is a partially enlarged view showing the internal structure of (a). It is a disassembled perspective view which shows the structure outline of the flow-path unit of the head of FIG. (A) is a top view of the damper plate which comprises the flow-path unit of FIG. (B) is a top view of the same spacer plate. (C) is a bottom view of the same nozzle plate (a concave plate of a spacer plate and the like are partially indicated by a dotted line). It is a top view of the spacer plate in the channel unit of the head concerning a second embodiment of the present invention.

  Hereinafter, although the embodiment concerning the present invention is described based on a drawing, the present invention is not limited to the following embodiment.

First Embodiment
[1. Configuration of Main Parts of Inkjet Printer 1]
FIG. 1 is a perspective view showing the main part of an ink jet printer 1 provided with a droplet discharge head 14 which is an example of a droplet discharge head according to the present invention. The configuration of the ink jet printer 1 will be described based on FIG. In the present embodiment, the side on which the ink is ejected is the lower surface and the lower side, and the opposite side is the upper surface and the upper side.

  As shown in FIG. 1, the ink jet printer 1 has a pair of guide rails 2 and 3 disposed substantially in parallel, and the head unit 4 can slide on the guide rails 2 and 3 in the scanning direction (second direction) It is supported. The head unit 4 has four ink supply tubes 5 for supplying four colors of ink (for example, black, cyan, magenta, yellow) from four ink cartridges (not shown) placed on the main body side. It is connected.

  In addition, the droplet discharge head 14 (see FIG. 2) is mounted on the head unit 4. The droplet discharge head 14 discharges the ink toward the recording sheet which is conveyed in the sheet feeding direction (first direction) orthogonal to the scanning direction thereunder.

  The head unit 4 is attached to a timing belt 8 wound around a pair of pulleys 6 and 7, and the timing belt 8 is disposed substantially parallel to the guide rail 3. One pulley 7 is provided with a motor 9 for forward and reverse rotation driving, and the timing belt 8 reciprocates by the forward and reverse rotation driving of the pulley 7, and the head unit 4 is along the guide rails 2 and 3. Is scanned.

[2. Configuration of head unit 4]
As shown in FIG. 2, the head unit 4 includes a buffer tank 11, a seal member 16, a carriage 12, a frame 13, a droplet discharge head 14, and a nozzle protection cover 15. The carriage 12 has a substantially box-like shape with the upper part opened, and the buffer tank 11 is accommodated in the carriage 12. Then, on the lower surface side of the bottom wall 12 a of the carriage 12, the droplet discharge head 14 to which the frame 13 and the nozzle protection cover 15 are adhered is fixed by an adhesive.

  Further, a circuit board 4a electrically connected to the main body side of the ink jet printer 1 is supported on the upper surface side of the carriage 12 (see FIG. 1). The buffer tank 11 has each storage chamber (not shown) for storing ink from the ink cartridge and four ink outlets 11b, and the upper surface of the plate-like arm portion 11a connected to each storage chamber A joint member 10 which connects the ink supply tube 5 and the ink storage chamber is connected.

[3. Configuration of Droplet Discharge Head 14]
As shown in FIG. 3, the droplet discharge head 14 has a flow path unit 17 in which a plurality of flow paths are formed, and an actuator 18 stacked on the upper surface. The flow path unit 17 of the droplet discharge head 14 according to an embodiment of the present invention has discharge unit portions B1, B2, C1, M1, and Y1 integrally formed with a flow path structure for each channel. (See FIG. 4).

  Further, in the discharge unit portions B1, B2, C1, M1, and Y1, a plurality of flow paths 40 described later are respectively formed in the paper feeding direction (first direction), and these discharge unit portions B1, B2, C1, C1, M1, and Y <b> 1 is disposed side by side in the scanning direction (second direction) to constitute a flow path unit 17. Further, although the details will be described later, the flow path unit 17 of the present embodiment is configured by laminating a plurality of plates in a paper feeding direction and a third direction orthogonal to the scanning direction, and discharge unit portions B1, B2, C1, M1 and Y1 are integrally formed. Note that the discharge unit portions B1, B2, C1, M1, and Y1 may be separately molded, and these may be combined to form a flow path unit.

  The flow path unit 17 has an ink flow path 40 for guiding the ink from the four ink supply ports 35c to the many nozzles 38b formed on the droplet discharge surface 38a via the pressure chambers 17c. The passage unit 17 has a lower wide portion 17b and an upper narrow portion 17a whose width in the scanning direction and the paper feeding direction is narrower than that, and the narrow portion 17a is on the upper surface of the wide portion 17b. It is arranged. The actuator 18 is a plate-type piezoelectric drive actuator that selectively applies a pressure for discharging the ink to the pressure chamber 17c, and is stacked on the upper surface of the narrow portion 17a.

  One end of a flexible flat cable 19 which makes electrical connection with the circuit board 4a is overlapped and bonded on the upper surface of the actuator 18, and the other end of the flexible flat cable 19 is drawn out in the scanning direction. Further, on the flexible flat cable 19, an IC chip 19a is mounted which transmits print data to the actuator 18 and selectively drives it.

  A plurality of surface electrodes 18 a are formed on the upper surface of the actuator 18, and the surface electrodes 18 a are joined to terminals (not shown) exposed on the lower surface of the flexible flat cable 19, and both are electrically conducted. The other end of the flexible flat cable 19 is drawn upward from the opening 13a of the rectangular frame 13 and passes through a slit (not shown) which penetrates the bottom wall 12a of the carriage 12 to form the circuit board 4a. And the main body side is electrically connected.

  Further, the frame 13 is fixed to the flow path unit 17 by a sheet adhesive, and the actuator 18 is disposed at the central opening 13 a of the frame 13 and exposed upward. Further, four through holes 13 b are provided side by side in the scanning direction in the frame 13, and the through holes 13 b are through the filter 17 d for removing foreign matter in the ink, and the ink supply port of the flow path unit 17 It communicates with 35c.

[4. Configuration of channel unit 17]
(1) Overall Configuration As shown in FIGS. 4 and 5, the flow path unit 17 is composed of the narrow portion 17a and the wide portion 17b as described above, and the pressure chamber plate 31, the cover plate 32, and the throttle The plate 33, the first manifold plate 34, the second manifold plate 35, the damper plate 36, the spacer plate 37 (spacer member), and the nozzle plate 38 are stacked and bonded in this order from the top. The narrow portion 17a is smaller in plan view shape in the long side direction (paper feeding direction) and the short side direction (scanning direction) than the wide portion 17b and has substantially the same size as the plan view shape of the actuator 18 (See Figure 3).

  The nozzle plate 38 of this embodiment is formed of a resin sheet such as polyimide as an example, and the other plates 31 to 37 are formed of a metal plate such as stainless steel as an example. The plate thicknesses of the respective plates 31 to 38 are 50 μm, 50 μm, 50 μm, 125 μm, 125 μm, 50 μm, 100 μm, and 50 μm in this order from the upper layer. In each of the plates 31 to 38, an opening or a recess is formed by, for example, etching, laser processing, plasma jet processing, etc., and the respective openings and grooves communicate with each other by laminating the plates 31 to 38. A flow path 40 is formed.

  The four upper plates 31 to 34 are formed smaller in the long side direction and the short side direction in plan view than the lower four plates 35 to 38, and align the openings and grooves to be the respective ink flow paths 40. In addition, in a state where the ink supply port 35c of the second manifold plate 35 described later is exposed, it is disposed so as to be included in the lower four plates 35 to 38 in a plan view. That is, the upper four plates 31 to 34 constitute the narrow portion 17a, and the lower four plates 35 to 38 constitute the wide portion 17b.

(2) Configuration of Each Plate As shown in FIGS. 5 and 6, the pressure chamber plate 31 is provided with a large number of pressure chamber holes 31 a. The pressure chamber holes 31 a have a long hole shape extending in the short side direction of the pressure chamber plate 31, and five rows are provided in the short side direction along the long side direction of the pressure chamber plate 31. Each row of the pressure chamber holes 31a is provided with two rows for black ink (two rows on the front side in FIG. 4) and one row for cyan ink, magenta ink, and yellow ink. The pressure chamber hole 31a has a pressure chamber 41 having an internal space formed by bonding the actuator 18 to the pressure chamber plate 31 from the upper side and bonding the cover plate 32 from the lower side (see FIG. 4).

  The cover plate 32 is provided with a communication hole 32a communicating with one end (one end in the scanning direction) of the pressure chamber hole 31a of the pressure chamber plate 31, and a through hole 32b communicating with the other end of the pressure chamber hole 31a. It is done.

  A throttle groove 33 a is formed on the top surface side of the throttle plate 33. The throttling groove 33a is in the form of a long groove extending in the direction of the short side of the throttling plate 33. One end of the throttling groove 33a communicates with the communication hole 32a of the cover plate 32, and the other end is a lower surface An ink inlet 33b penetrating to the side is provided. The ink inlet 33b of the present embodiment is formed by a through hole as an example, and serves as an ink inlet for introducing the ink from the common flow path 43 described later to the nozzle 38b. Further, in the diaphragm plate 33, a through hole 33c communicating with the through hole 32b of the cover plate 32 is formed. In the throttling groove 33a, the throttling passage 42 is formed by the throttling plate 33 being sandwiched and bonded between the cover plate 32 and the first manifold plate 34 (see FIG. 4).

  In the first manifold plate 34, manifold holes 34a, which are positioned below the pressure chamber holes 31a and extend along the row direction (paper feed direction) of each row of the pressure chamber holes 31a, penetrate It is formed. The manifold holes 34a are provided in two rows (two rows on the front side in FIG. 5) for black ink and a total of five rows for cyan ink, magenta ink, and yellow ink. Each manifold hole 34 a communicates with the pressure chamber 41 via the throttle passage 42. Further, in the first manifold plate 34, a large number of through holes 34c communicating with the through holes 33c of the throttle plate 33 and having the same shape are formed along the longitudinal direction of each manifold hole 34a.

  In the second manifold plate 35, five manifold holes 35a and through holes 35b having the same shape as the first manifold plate 34 are formed to penetrate. Further, at one end side of the second manifold plate 35 in the long side direction, four ink supply ports 35 c for the ink of each color are formed side by side in the scanning direction.

  Then, the diaphragm plate 33, the first manifold plate 34, the second manifold plate 35, and the damper plate 36, which will be described later, are laminated and bonded, thereby forming five common channels 43 by the manifold holes 34a and 35a (see FIG. 4).

  A communication groove 35d is recessed from the lower surface side between the ink supply port 35c of the second manifold plate 35 and the manifold hole 35a. By bonding the damper plate 36 below the second manifold plate 35, the ink supply port 35c and the manifold hole 35a communicate with each other, and the ink can be supplied from the ink supply port 35c to the manifold hole 35a. Further, among the four ink supply ports 35c, one ink supply port 35c on the near side in FIG. 5 is larger than the other three ink supply ports 35c, and this is used for the frequently used black ink 2 It is in communication with the row of manifold holes 35a.

  The damper plate 36 has five damper walls 36 a to 36 e which are formed thin by recessing the portion corresponding to each common flow channel 43 from the upper surface side. Further, through holes 36f communicating with the through holes 35b of the second manifold plate 35 and having the same shape are respectively formed in the damper plate 36 along the longitudinal direction of each of the damper walls 36a to 36e. .

  The spacer plate 37 has five recesses 37a to 37e formed by recessing portions corresponding to the respective damper walls 36a to 36e from the upper surface side, and the damper plate 36 is bonded to the spacer plate 37, Spaces respectively surrounded by the concave portions 37 a to 37 e and the damper walls 36 a to 36 e form a damper chamber 45. Moreover, the pillar part 37g extended from the bottom face is provided in each recessed part 37a-37e. Further, the spacer plate 37 is provided with a plurality of through holes 37f penetrating in the stacking direction (third direction) of each plate, and when the spacer plate 37 and the nozzle plate 38 are adhered and fixed by the through holes 37f. Control air accumulation in Further, in the spacer plate 37, a communication hole 37h communicating with the through hole 36f of the damper plate 36 and having the same shape is formed. The detailed configuration of the damper plate 36 and the spacer plate 37 will be described later.

  The nozzle plate 38 has a droplet discharge surface 38 a on the lower surface, and the droplet discharge surface 38 a is formed with a nozzle 38 b which is a hole communicating with the through hole 37 h of the spacer plate 37. The nozzles 38b are provided with five nozzle rows in the short side direction along the long side direction, and two rows for black ink (two rows on the near side in FIG. 5), for cyan ink, and magenta ink And one row for yellow ink. Further, a plurality of convex portions 38c are formed on the droplet discharge surface 38a, and the convex portions 38c are arranged in two rows substantially in parallel with the nozzle row in the region corresponding to each damper chamber 45 in plan view. .

  By stacking and bonding such plates 31 to 38, a flow path unit 17 having a convex cross section having a narrow portion 17a at the top and a wide portion 17b at the bottom is formed. The through holes 32b, 33b, 34b, 35b, 36f and 37h formed in the respective plates 32-37 communicate with each other to form an outflow passage 44, and the outflow passage 44 communicates with the nozzle 38b of the nozzle plate 38. ing. Therefore, the ink flowing from the buffer tank 11 into the ink supply port 35c is temporarily stored in the common flow path 43, passes through the ink inlet 33b, and flows in the order of the throttling passage 42, the pressure chamber 41, and the outflow path 44. It is discharged.

  That is, the flow path 40 in the flow path unit 17 is configured by the ink supply port 35 c, the common flow path 43, the throttling path 42, the pressure chamber 41, and the outflow path 44 (see FIG. 4). A filter 17d for removing foreign matter mixed in the ink supplied from the buffer tank 11 is attached to the upper surface of the second manifold plate 35 so as to cover the ink supply port 35c (see FIG. 3). ).

(3) Configuration of Damper Plate 36 and Spacer Plate 37 (A) Arrangement of Column 37 g Next, the damper rate 36 and the spacer plate 37 will be described in detail. As described above, by laminating and bonding the damper plate 36 and the spacer plate 37, spaces respectively enclosed by the recesses 37a to 37e and the damper walls 36a to 36e are formed as the damper chamber 45, respectively. There is.

  As shown in FIG.4 and FIG.5, the pillar part 37g extended from the bottom face is formed in recessed part 37a-37e, respectively. The pillars 37g extend from the bottom of the recesses 37a to 37e in the stacking direction at a height contacting the damper walls 36a to 36e, and reach both wall surfaces of the recesses 37a to 37e in the width direction (scanning direction) of the recesses 37a to 37e. Do not extend the length.

  That is, a clearance is formed between both sides of the column portion 37g and both wall surfaces of the concave portions 37a to 37e, and the chambers divided in the longitudinal direction (paper feeding direction) communicate with each other by the column portion 37g. The upper surface of the column portion 37g and the lower surface of the damper walls 36a to 36e are bonded.

  As shown in FIG. 6, in the present embodiment, the arrangement of the pillars 37g is, for example, slightly offset from the pillars 37g of the recess 37b in the longitudinal direction substantially from the pillars 37g of the recess 37a in the longitudinal direction. In the position where the column 37g of the recess 37c is slightly deviated from the approximate center in the longitudinal direction, the column 37g of the recess 37d in the approximate center of the longitudinal direction and the column 37g of the recess 37e in the offset direction from the approximate center The recess 37c is slightly offset in the opposite direction to the shifting direction.

  In this manner, by displacing and arranging the column portion 37g, the discharge failure portion of the ink that may occur due to the column portion 37g is dispersed, and the defect of the printing on the recording sheet is suppressed. That is, if the positions of the column portions 37g are set to the same positions by the concave portions 37a to 37e, there is a possibility that an unreliable line may be exposed when printing on recording paper, but the position of the column portions 37g is shifted. Prevent the appearance of lines.

  Further, a clearance is provided between the column portion 37g and both wall surfaces of the concave portions 37a to 37e to communicate the chambers divided in the longitudinal direction, and arrange the column portion 37g near the center of the concave portions 37a to 37e. The excessive vibration is suppressed while sufficiently obtaining the damper effect by the vibration of the damper walls 36a to 36e.

  In the present embodiment, the column portion is configured to extend upward from the bottom surface of the recess of the spacer plate, but the same effect can be obtained as a configuration extending downward from the lower surface of the damper wall. In addition, although clearances are provided between both sides of the column portion and both wall surfaces of the recess of the spacer plate to communicate the chambers divided in the longitudinal direction of the recess, the clearance may be provided at the center of the column, or the column Alternatively, the divided chambers may be communicated with each other by providing a through hole.

(B) Arrangement of Through Holes 37f As shown in FIGS. 5 and 6, the spacer plate 37 is provided with a plurality of through holes 37f penetrating in the stacking direction. The plurality of through holes 37 f in the present embodiment are located in a region corresponding to each damper chamber 45 in a plan view, and at a position corresponding to between the rows of convex portions 38 c arranged in two rows on the droplet discharge surface 38 a One row along the longitudinal direction, and one row each on the opposite side in the longitudinal direction, are arranged on the bottom of the recess 37a. Further, in the recesses 37b to 37e, a plurality of through holes 37f are provided in the same arrangement as the recesses 37a.

  As described above, by providing the plurality of through holes 37 f in the spacer plate 37, it is possible to suppress air accumulation when the spacer plate 37 and the nozzle plate 38 are bonded and fixed. In particular, since the through holes 37f are provided at positions corresponding to the rows of the convex portions 38c where air accumulation easily occurs, air accumulation occurring here can be suppressed. By suppressing the air accumulation, the positional deviation between the spacer plate 37 and the nozzle plate 38 can be suppressed, and an improvement in printing accuracy can be expected. Further, when the flow path unit 17 is heated in the manufacturing process of the droplet discharge head 14, damage to the flow path unit 17 that may occur due to expansion of the accumulated air is prevented.

Second Embodiment
Next, a head according to a second embodiment which is an example of the present invention will be described based on FIG. The difference between the head of the second embodiment and the droplet discharge head 14 of the first embodiment is mainly the difference in the configuration of the flow path unit, and in particular, the differences in the configurations of the manifold, the damper wall, the damper chamber, and the nozzle. . Therefore, the flow path unit 117 will be described focusing on these differences.

  The head according to the second embodiment has a flow path unit 117 in which a plurality of plates are stacked, and an actuator (not shown) stacked on the upper surface, and the flow path unit 117 is for four black inks. A total of thirteen discharge unit parts, one for each of the three discharge units for cyan ink, magenta ink, and yellow ink, are integrally formed.

  In the flow path unit 117, a pressure chamber plate, a cover plate, an aperture plate, a first manifold plate, a second manifold plate, a damper plate, a spacer plate (spacer member), and a nozzle plate are stacked and bonded in this order from above It is a structure.

  Further, as shown in FIG. 7, 13 recesses 137 a to 137 m are formed in the spacer plate 137 of the flow path unit 117, and a space surrounded by these recesses and corresponding damper walls is 13 dampers. Construct a room. That is, the flow path unit 117 includes thirteen common flow paths, a damper wall, and a damper chamber.

  In addition, on the droplet discharge surface of the flow path unit 117, 24 rows of nozzles are provided in the short side direction (scanning direction) along the long side direction (paper feeding direction). For black ink, cyan ink It consists of six lines each for magenta ink, magenta ink and yellow ink.

  The arrangement of nozzles for black ink is different from the arrangement of nozzles for other color inks (cyan ink, magenta ink, yellow ink). The arrangement of the nozzles for color ink is configured along the longitudinal direction on both outer sides of the positions corresponding to the respective recesses (damper chambers) 137e to 137m in a plan view. On the other hand, in the arrangement of the nozzles for black ink, at positions corresponding to the middle two rows of concave portions 137b and 137c in the four rows in plan view, one row is formed on both outer sides along the longitudinal direction. At positions corresponding to the two rows of concave portions 137a and 137d at both ends, one side is formed in one row along the longitudinal direction (see the arrangement of the communication holes 137o communicating with the nozzles in FIG. 7).

  Further, as shown in FIG. 7, in the concave portions 137 a to 137 m of the spacer plate 137, pillars 137 n extending from the bottom surface are formed.

  In the present embodiment, the arrangement of the pillars 137n is, for example, from the pillars 137n of the recesses 137a and 137d for black ink in the approximate center of the longitudinal direction and the pillars 137n of the recess 137b and the depression 137c from the approximate center in the longitudinal direction Each is configured in a position slightly shifted in the opposite direction. Further, the pillar portion 137n of the concave portion 137e for cyan ink is configured substantially at the center in the longitudinal direction, and the pillar portion 137n of the concave portion 137f and the concave portion 137g is slightly offset from the approximate center in the longitudinal direction in opposite directions. The arrangement of the concave portions 137h to 137j for magenta ink and the pillars 137n of the concave portions 137k to 137m for yellow ink is configured in the same manner as the concave portions 137e to 137g for cyan ink.

  By displacing the pillars 137n in this manner, the ink discharge failure portion that may occur due to the pillars 137n is dispersed, and the printing trouble on the recording sheet is suppressed. That is, assuming that the positions of the pillars 137n are the same in the concave portions 137a to 137m, there is a possibility that careless lines may be exposed when printing on the recording sheet, but the positions of the pillars 137n are shifted. Prevent the appearance of careless lines.

  On the other hand, the column portions 137n of the concave portions 137a and 137d for black ink are arranged in the same way, while the nozzles corresponding to the respective other concave portions are configured in two rows respectively, while corresponding to the concave portions 137a and 137d This is because the nozzles to be formed are constituted by one row, and therefore the influence of the column portion 137 n on the ejection of the ink is relatively small. The arrangement of the pillars 137n of the recesses 137a and 137d may be offset.

Other Embodiments
As described above, although the preferred embodiments of the present invention have been described with reference to the drawings, various additions, modifications, or deletions can be made without departing from the spirit of the present invention. In particular, in the present embodiment, although the droplet discharge head is constituted by the flow path unit integrally forming the discharge unit parts for black ink and color ink, the discharge unit parts are separately provided. The droplet discharge head may be configured by a flow path unit in which Moreover, in this embodiment, although it is set as the structure which arrange | positions one pillar part in a damper chamber, you may arrange two or more pillar parts, you may change arrangement | positioning of a pillar part, and the shape of a pillar part May be changed.

  Further, in the present embodiment, the ink jet printer is described as the droplet discharge device, but the present invention is not limited thereto. For example, a device that discharges a conductive material to form a wiring pattern on a wiring substrate, a liquid crystal display And the like, a device having a color material jet head used for producing a color filter for a color filter, a device having an electrode material jetting head used for forming an electrode of an organic EL display, etc. The present invention can also be applied to an apparatus equipped with a sample injection head as a precision pipette.

1 Ink jet printer (droplet discharge device)
2 Guide Rail 3 Guide Rail 4 Head Unit 4a Circuit Board 5 Ink Supply Tube 6 Pulley 7 Pulley 8 Timing Belt 9 Motor 10 Joint Member 11 Buffer Tank 11a Arm 11b Ink Flow Out 12 Carriage 12a Bottom Wall 13 Frame (Frame Member)
13a Opening 13b Through-hole 13c Inner side 14 Droplet discharge head 15 Nozzle protection cover 16 Seal member 17 Channel unit 17a Narrow part 17b Wide part 17c Pressure chamber 17d Filter 18 Actuator 18a Surface electrode 19 Flexible flat cable (flexible substrate)
19a IC chip 31 pressure chamber plate 31a pressure chamber hole 32 cover plate 32a communication hole 32b through hole 33 throttle plate 33a throttle groove 33b ink introduction port 34 first manifold plate 34a manifold hole 35 second manifold plate 35a manifold hole 35b through hole 35c Ink supply port 35 d Communication groove 36 Damper plates 36 a to 36 e Damper wall 36 f Through hole 37 Spacer plate (spacer member)
37a to 37e Recess 37f Through hole 37g Column 37h Communication hole 38 Nozzle plate 38a Droplet discharge surface 38b Nozzle 38c Convex part 40 Flow path 41 Pressure chamber 42 Throttling path 43 Common flow path 44 Outflow path 45 Damper chamber B1, B2, C1 , M1, Y1 Discharge unit

Claims (6)

A plurality of first nozzles arranged along a first direction which is a direction parallel to the discharge surface;
A first common flow passage communicating with the plurality of first nozzles and extending along the first direction;
A first damper chamber disposed at a position facing the first common flow channel and extending along the first direction;
A first damper wall which is disposed between the first damper chamber and the first common flow channel, and which bends in response to pressure fluctuation in the first common flow channel;
A first post disposed in the first damper chamber and connected to the first damper wall;
A plurality of second nozzles arranged along the first direction;
A second common flow passage communicating with the plurality of second nozzles and extending along the first direction;
A second damper chamber disposed at a position facing the second common flow channel and extending along the first direction;
A second damper wall which is disposed between the second damper chamber and the second common flow channel, and which bends in response to pressure fluctuation in the second common flow channel ;
And a second pillar disposed in the second damper chamber and connected to the second damper wall.
The first common flow channel and the second common flow channel are arranged in a second direction parallel to the discharge surface and orthogonal to the first direction,
The droplet discharge head according to claim 1, wherein the first column portion and the second column portion are disposed at positions mutually offset in the first direction.   The plurality of first nozzles and the plurality of second nozzles are disposed between the first common channel and the second common channel in the second direction. The droplet discharge head described above.   The first nozzles of the plurality of first nozzles and the second nozzles of the plurality of second nozzles are arranged at positions mutually offset in the first direction. Droplet discharge head. 4. The droplet discharge head according to claim 3, wherein the color of the liquid in the first common flow channel and the color of the liquid in the second common flow channel are the same color. 4. The droplet discharge head according to claim 3, wherein the color of the liquid in the first common flow channel and the color of the liquid in the second common flow channel are different from each other.   The gap is formed in the said 2nd direction between the side wall which defines the said 1st damper chamber, and the said 1st pillar part, The 1st to 5 characterized by the above-mentioned. The droplet discharge head described above.

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