JP2010094880A - Liquid droplet delivering apparatus and process for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a device by shortening a distance from the surface of a channel unit at a side opposite to an actuator to the frame. <P>SOLUTION: A liquid droplet delivering apparatus includes a channel unit 17 which is provided with a plurality of pressure chambers 41 corresponding to a plurality of nozzles 38a delivering ink, respectively, an actuator 18 which is stacked on the channel unit 17 in order to apply transfer pressure to the ink in the pressure chamber 41, and the frame 13 which is stacked on the channel unit 17 wherein the channel unit 17 has a narrow width portion 26 at a side where the actuator 18 is stacked, and a wide width portion 27 which is located at a side opposite to the narrow width portion 26 and wider than the narrow width portion 26, and the frame 13 is stacked on the outside portion 27a of the wide width portion 27 so as to surround the actuator 18 and the narrow width portion 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet discharge device such as an ink jet printer and a manufacturing method thereof.

In a conventional ink jet printer, a small piezoelectric actuator is placed on a flow path unit having a plurality of nozzles formed on the lower surface, and a drive signal is output from the flexible flat cable to the piezoelectric actuator, thereby discharging the ink in the flow path unit. A structure for applying pressure is known (for example, Patent Document 1). The flow path unit forms a flow path inside by laminating and bonding a plurality of thin plates having holes of a required shape, and has a thin flat shape as a whole. All the plates have the same shape and the same size in plan view, and are uniformly bonded between the plates. In addition, in order to increase the rigidity of the flow path unit, a frame-shaped reinforcing frame is laminated on the outer peripheral portion of the upper surface of the flow path unit with an adhesive so as to surround the piezoelectric actuator. It is preventing.
JP 2007-253427 A

  By the way, in recent inkjet printers, there is a tendency for the number of mounted parts to increase with the increase in functionality. Therefore, further miniaturization of parts inside the printer is required. Even when the number of mounted parts does not increase, the entire printer apparatus tends to be downsized, and thus downsizing of the mounted parts is an important development issue.

  Accordingly, an object of the present invention is to reduce the size of the apparatus.

  The present invention has been made in view of the above circumstances, and a droplet discharge device according to the present invention includes a flow path unit provided with a plurality of pressure chambers respectively corresponding to a plurality of nozzles that discharge droplets, An actuator overlaid on the flow path unit to give a transfer pressure to the liquid in the pressure chamber, and a frame overlaid on the flow path unit, the flow path unit having a width on the side where the actuator is overlaid A narrow portion, and a wide portion on the opposite side of the narrow portion and having a width dimension wider than the narrow portion, and the frame surrounds the actuator and the narrow portion. It is characterized by being overlaid on the outer part.

  According to the above configuration, the outer portion where only the wide portion of the flow path unit exists has a lower cross-sectional height than the inner portion where both the wide portion and the narrow portion of the flow path unit exist, and the frame includes the actuator and The outer portion is overlapped so as to surround both of the narrow portions. Therefore, the distance from the surface of the flow path unit opposite to the actuator to the frame is shortened, and the apparatus can be miniaturized. Further, when the surface of the flow path unit opposite to the actuator is disposed downward, the frame approaches the lower surface of the flow path unit, so that the center of gravity of the device is lowered and stability is improved.

  The frame may be bonded with an adhesive to a surface on the actuator side in an outer portion of the wide portion of the flow path unit.

  According to the above configuration, when the adhesive interface is heated to cure the adhesive, the heat is conducted to the actuator through the wide portion of the flow path unit having the adhesive interface. At that time, the outer portion of the wide portion of the flow path unit has a small cross-sectional area through which heat is transmitted and a large thermal resistance, and therefore, it is difficult for heat to be conducted to the actuator. Therefore, the temperature rise of the actuator is suppressed, and the occurrence of problems can be prevented.

  The narrow portion may be provided such that the outer ridge line in the width direction of the narrow portion is positioned at a distance from the inner ridge line in the width direction of the frame.

  According to the above configuration, the heat applied to the adhesive interface to cure the adhesive is increased in distance until it is conducted to the narrow portion, so that the heat is not easily conducted to the actuator, and the temperature of the actuator is increased. It is suppressed.

  The flow path unit is configured by laminating a plurality of plates, the wide portion is configured by a plate on a layer opposite to the actuator among the plurality of plates, and the narrow portion is the It is comprised by the plate of the layer by the side of the actuator among a plurality of plates, and the plate by the side of the actuator may be formed smaller than the plate of the opposite side by plane view.

  According to the said structure, the cross-sectional convex flow path unit which has a narrow part and a wide part can be formed easily.

  The apparatus may further include a flexible flat cable overlaid on the actuator, and the flexible flat cable may be drawn out from a space surrounded by the frame.

  According to the above configuration, since the narrow portion of the flow path unit is located at the position surrounded by the frame, the position of the upper surface of the actuator becomes high, and the flexible flat cable is smooth with less curvature while avoiding the inner peripheral edge of the frame. To the outside. Therefore, it is possible to prevent the flexible flat cable from being damaged by the edge of the frame.

  The method for manufacturing a droplet discharge device according to the present invention includes a flow path unit provided with a plurality of pressure chambers respectively corresponding to a plurality of nozzles for discharging droplets, and a method for applying a transfer pressure to the liquid in the pressure chamber. A method for manufacturing a droplet discharge device, comprising: an actuator overlaid on a flow path unit; and a frame overlaid on the flow path unit, wherein the narrow width portion is wider than the narrow width portion. A step of superimposing the actuator on the narrow portion of the flow path unit having a portion, a step of connecting a flexible flat cable to the actuator, an outer portion of the wide portion of the flow path unit, and the actuator and The method includes a step of overlapping the frame via an adhesive so as to surround the narrow portion, and a step of heating the adhesive.

  According to the manufacturing method, the outer portion where only the wide portion of the flow path unit exists has a lower cross-sectional height than the inner portion where both the wide portion and the narrow portion of the flow path unit exist, and the frame It overlaps with the said outer part so that both of a narrow part may be enclosed. Therefore, the distance from the surface of the flow path unit opposite to the actuator to the frame is shortened, and the apparatus can be miniaturized.

  When the adhesive interface is heated to cure the adhesive, the heat is conducted to the actuator through the outer portion of the wide portion of the flow path unit having the adhesive interface. At that time, the outer part of the wide part of the flow path unit is provided in the narrow part because the cross-sectional area through which heat is transmitted is smaller and the thermal resistance is larger than the inner part where both the narrow part and the wide part exist. Heat is less likely to be transferred to the actuator being operated. In addition, since the actuator is provided in the narrow portion, the distance of the heat transfer path from the adhesive interface to the actuator becomes long, and heat is not easily conducted. Therefore, the temperature rise of the actuator is suppressed, and the occurrence of problems can be prevented.

  The narrow portion may be provided such that the outer ridge line in the width direction of the narrow portion is positioned at a distance from the inner ridge line in the width direction of the frame.

  According to the said manufacturing method, since the distance until the heat | fever applied to the adhesion interface is conducted to a narrow part becomes long, a heat | fever becomes difficult to be conducted to an actuator and the temperature rise of an actuator is suppressed.

  In the heating step, a heater may be brought into contact with the surface of the frame opposite to the adhesive.

  According to the manufacturing method, the heat conducted from the heater to the adhesive through the frame is conducted to the actuator through the outer portion of the wide portion of the flow path unit, but the cross-sectional area is small as described above. Heat is hardly conducted to the actuator by the outer portion of the wide portion, and the temperature rise of the actuator is suppressed.

  In the heating step, a heater may be brought into contact with the surface of the flow path unit opposite to the adhesive.

  According to the manufacturing method, the narrow portion of the flow path unit is not interposed between the heater and the bonding interface, and the distance from the heater to the bonding interface is short. Thereby, the thermal resistance when conducting heat from the heater to the bonding interface is reduced, and the amount of heat generated by the heater required for bonding can be reduced. As a result, the heat conducted from the heater to the actuator via the flow path unit can be reduced, and the temperature rise of the actuator can be suppressed to prevent the occurrence of malfunction.

  As apparent from the above description, according to the present invention, the distance from the surface of the flow path unit opposite to the actuator to the frame is shortened, and the apparatus can be miniaturized. In addition, when the frame is bonded to the outer portion of the wide portion of the flow path unit via an adhesive, the outer portion of the wide portion is heated more than the inner portion where both the narrow portion and the wide portion exist. Since the cross-sectional area to which is transmitted is small and the thermal resistance is large, it is difficult for heat to be conducted to the actuator provided in the narrow portion, and the occurrence of defects can be prevented.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the direction in which ink is ejected from the ejection head is defined as the downward direction, and the opposite side is defined as the upward direction.

  FIG. 1 is a perspective view of a main part of an ink jet printer 1 according to an embodiment of the present invention. As shown in FIG. 1, the ink jet printer 1 (droplet discharge device) has a pair of guide rails 2 and 3 arranged substantially in parallel, and the head unit 4 slides in the scanning direction on the guide rails 2 and 3. Supported as possible. The head unit 4 has four ink supply tubes 5 for supplying four colors of ink (for example, black, cyan, magenta, and yellow) from four ink cartridges (not shown) placed on the main body side. Is connected. The head unit 4 is equipped with an ejection head 14 (see FIG. 2), and the ink supplied from the ink cartridge from the ejection head 14 toward a recording sheet conveyed in a direction perpendicular to the scanning direction below the head is provided. It becomes the structure discharged.

  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 extending direction of the guide rail 3. One pulley 7 is provided with a motor 9 that drives forward and reverse rotation. When the pulley 7 is driven forward and reverse, the timing belt 8 reciprocates, and the head unit 4 moves along the guide rails 2 and 3. Scanned.

  FIG. 2 is an exploded perspective view of the head unit 4 of the inkjet printer 1 shown in FIG. 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 discharge head 14, and a nozzle protection cover 15 in order from the top. The carriage 12 has a substantially box shape with the upper side open, the buffer tank 11 is accommodated in the carriage 12, and a discharge head having a frame 13 and a nozzle protection cover 15 bonded to the lower surface side of the bottom wall 12 a of the carriage 12. 14 is fixed by an adhesive. A circuit board 4 a electrically connected to the main body side of the inkjet printer 1 is supported on the upper surface side of the carriage 12. The buffer tank 11 has storage chambers (not shown) for storing ink from the ink cartridges and four ink outlets 11c, and is provided on the upper surface of the plate-like arm portion 20 connected to the storage chambers. A joint member 21 that connects the ink supply tube 5 and the ink storage chamber is connected.

  The ejection head 14 includes a flow path unit 17 having a plurality of ink flow paths that guide ink from four ink inflow holes 35c (see FIG. 4) to a large number of nozzles 38a (see FIG. 5) through a plurality of pressure chambers 31a. The plate-type piezoelectric drive type that selectively applies the discharge pressure toward the nozzle 38a (see FIG. 5) to the ink in the plurality of pressure chambers 31a in the flow path unit 17 stacked on the upper surface of the flow path unit 17. Actuator 18. The flow path unit 17 is bonded and fixed to a frame plate-like frame 13, and an actuator 18 is disposed in the central opening 13 a of the frame 13 and is exposed upward. Further, the frame 13 is provided with four through holes 13b communicating with the ink inflow holes 35c (see FIG. 4) of the flow path unit 17 side by side in the scanning direction. A through hole 12b is formed in the bottom surface 12a of the carriage 12. When the buffer tank 11 is accommodated in the carriage 12, the ink outlet 11b of the buffer tank 11 and the through hole 13b of the frame 13 are It communicates via a seal member 16 having four through holes 16a. At this time, by inserting attachment screws 11a into attachment holes 11b provided on both sides in the scanning direction of the buffer tank 11, and screwing them into screw holes 13d provided on both sides of the through holes 13b of the frame 13, While being fixed to the frame 13, the seal member 16 is compressed and is brought into close contact with the periphery of the through hole 13 b of the frame 13, thereby liquid-tightly connecting the ink outlet 11 a and the through hole 13 b. By doing so, the ink from the buffer tank 11 can be supplied to the ink inflow hole 35c (see FIG. 4) of the flow path unit 17. The frame 13 receives pressure due to compression of the seal member 16 on a flat surface around the through hole 13b.

  FIG. 3 is an exploded perspective view showing the ejection head 14 of the head unit 4 shown in FIG. As shown in FIG. 3, the ejection head 14 has a flow path unit 17 in which a plurality of plates are stacked. As will be described later, the flow path unit 17 has a convex section having an upper narrow portion 26 having a narrow width in the scanning direction and the paper feeding direction, and a lower wide portion 27 having a wide width in the scanning direction and the paper feeding direction. The narrow portion 26 is arranged in an island shape on the upper surface of the wide portion 27. On the upper surface of the narrow portion 26 of the flow path unit 17, a piezoelectric drive type actuator 18 is overlapped and bonded. The actuator 18 has a plurality of active portions that apply ejection pressure for ejecting ink in a plurality of pressure chambers 41 to be described later, and faces the pressure chambers 31 a of the flow path unit 17 on the wide portion 26. Has been placed. One end of a flexible flat cable 19 for electrical connection with the circuit board 4a is overlapped and bonded to the upper surface of the actuator 18, and the other end of the flexible flat cable 19 is drawn out in the scanning direction.

  The flexible flat cable 19 is mounted with an IC chip 23 having a drive circuit that transmits print data to the actuator 18 and selectively drives it. The flexible flat cable 19 of this embodiment is a COF. A plurality of surface electrodes 24 are formed on the upper surface of the actuator 18, and a terminal (not shown) exposed on the lower surface of the flexible flat cable 19 is joined to the surface electrode 24, so that both are electrically connected. Is done. The other end of the flexible flat cable 19 is drawn upward from the opening 13a of the reinforcing frame 13 (see FIG. 6), passes through a slit (not shown) that penetrates the bottom wall 12a of the carriage 12, and the circuit board 4a. By being connected, it is electrically connected to the main body side.

  4 is an exploded perspective view showing the configuration of the flow path unit 17 of the ejection head 14 shown in FIG. FIG. 5 is a cross-sectional view of a main part after the ejection head 14 shown in FIG. 3 is assembled. 6 is an overall cross-sectional view of the ejection head 14 shown in FIG. 3 after assembly. As shown in FIGS. 4 and 5, the flow path unit 17 includes the narrow portion 26 and the wide portion 27 as described above, and includes the pressure chamber plate 31, the spacer plate 32, the throttle plate 33, and the first manifold. The plate 34, the second manifold plate 35, the damper plate 36, the cover plate 37, and the nozzle plate 38 are stacked and bonded from above in this order. As shown in FIG. 3, the narrow portion 26 has a plan view shape smaller than the wide portion 27 in the long side direction (paper feeding direction) and the short side direction (scanning direction), and the plan view shape of the actuator 18. It is almost the same size.

  The nozzle plate 38 is a resin sheet such as polyimide, and the other plates 31 to 37 are metal plates such as stainless steel. The plate thickness of each of the plates 31 to 38 is 50 μm, 50 μm, 50 μm, 125 μm, 125 μm, 50 μm, 100 μm, and 50 μm in order from the upper layer, and the manifold plates 34 and 35 have the largest thickness. Openings or grooves are formed in each plate 31 to 38 by etching, laser processing, plasma jet processing, or the like, and the respective openings 31 and 38 are communicated by stacking the plates 31 to 38. An ink flow path 40 is formed.

  The upper four plates 31 to 34 are formed smaller than the lower four plates 35 to 38 in the long side direction (paper feeding direction) and the short side direction (scanning direction) in plan view, In addition to aligning the openings and grooves, the ink outlets 35c of the second manifold plate 35, which will be described later, are exposed so as to be included in the lower four plates 35 to 38 in plan view. Therefore, the upper four plates 31 to 34 constitute the narrow portion 26, and the lower four plates 35 to 38 constitute the wide portion 27. The boundary between the narrow portion 26 and the wide portion 27 is set between the first manifold plate 34 and the second manifold plate 35 having the largest thickness.

  The pressure chamber plate 31 is provided with a number of pressure chamber holes 31a. The pressure chamber holes 31a have a long hole shape extending in the short side direction (scanning direction) of the pressure chamber plate 31, and are arranged in parallel along the long side (side in the paper feed direction) of the pressure chamber plate 31. Five rows are provided in the direction. Each of the pressure chamber holes 31a has 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 forms a pressure chamber 41 having an internal space by the actuator 18 being bonded to the pressure chamber plate 31 from above and the spacer plate 32 being bonded from below (see FIG. 5).

  The spacer plate 32 is provided with a communication hole 32a communicating with one end portion (one end portion 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 portion of the pressure chamber hole 31a. It has been.

  The aperture plate 33 has an aperture groove 33a formed on the upper surface thereof. The throttle groove 33a has a long groove shape extending in the short side direction of the diaphragm plate 33. One end of the throttle groove 33a communicates with the communication hole 32a of the spacer plate 32. A hole 33b penetrating to the lower surface side is provided. Further, the aperture plate 33 is formed with a through hole 33 c communicating with the through hole 32 b of the spacer plate 32. In the throttle groove 33a, a throttle passage 42 is formed by the diaphragm plate 33 being sandwiched between the spacer plate 32 and the first manifold plate 34 (see FIG. 5).

  In the first manifold plate 34, manifold holes 34a that are located below and correspond to the pressure chamber holes 31a and extend along the row direction (paper feed direction) of each row of the pressure chamber holes 31a are formed to penetrate therethrough. Has been. The manifold holes 34a are provided in two rows for black ink (two rows on the front side in FIG. 4), and one row each for cyan ink, magenta ink, and yellow ink. Each manifold hole 34 a communicates with the pressure chamber 41 through the throttle passage 42. The first manifold plate 34 is formed with a large number of through-holes 34c that communicate with and have the same shape as the through-holes 33c of the aperture plate 33 along the longitudinal direction of each manifold hole 34a.

  The second manifold plate 35 is formed with five manifold holes 35a and through holes 35b having the same shape as the first manifold plate 34. Further, four ink inflow holes 35c are formed side by side in the scanning direction for each color ink on one end side in the long side direction of the second manifold plate 35.

  Then, the diaphragm plate 33, the first manifold plate 34, the second manifold plate 35, and a damper plate 36, which will be described later, are laminated and bonded to form five common liquid chambers 43 by the manifold holes 34a and 35a (see FIG. 5).

  A communication groove 35d is formed from the lower surface side between the ink inflow hole 35c and the manifold hole 35a of the second manifold plate 35, and the damper plate 36 is bonded to the second manifold plate 35 from below. The ink inflow hole 35c and the manifold hole 35a communicate with each other so that ink can be supplied from the ink inflow hole 35c to the manifold hole 35a. Of the four ink inflow holes 35c, one ink inflow hole 35c on the front side in FIG. 4 is larger than the other three ink inflow holes 35c. It communicates with the manifold holes 35a in the row.

  The damper plate 36 has five damper walls 36a formed by thinning portions corresponding to the common liquid chambers 43 from the lower surface side. The damper plate 36 is formed with a through hole 36b that communicates with and has the same shape as the through hole 35c of the second manifold plate 35 along the longitudinal direction of each damper wall 36a. The damper plate 36 is laminated and bonded to the cover plate 37 to form five damper chambers.

  The cover plate 37 is formed with a through hole 37a that communicates with and has the same shape as the through hole 36b of the damper plate 36. The nozzle plate 38 has a nozzle that is a hole that communicates with the through hole 37a of the cover plate 37. 38a is formed. The nozzles 38a are arranged in parallel along the long side direction, and are provided in five rows in the short side direction, two rows for black ink (two rows on the front side in FIG. 5), cyan ink, and magenta ink And one row for yellow ink.

  By laminating and bonding such plates 31 to 38, the flow path unit 17 having a convex cross section having the narrow portion 26 at the top and the wide portion 27 at the bottom is formed. The through holes 32b, 33b, 34b, 35b, 36b, 37a formed in each of the plates 32 to 37 communicate with each other to form an outflow path 44, and the outflow path 44 communicates with the nozzle 38a of the nozzle plate 38. ing. Therefore, the ink that has flowed into the ink inflow hole 35c from the buffer tank 11 flows in the order of the common liquid chamber 43, the throttle passage 42, the pressure chamber 41, and the outflow passage 44, and is discharged from the nozzle 38a. That is, the flow path 40 in the flow path unit 17 is constituted by the ink inflow hole 35c, the common liquid chamber 43, the throttle passage 42, the pressure chamber 41, and the outflow path 44 (see FIG. 5). Further, a filter 25 for removing foreign matters 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 inflow hole 35c (see FIG. 3 and FIG. 3). 4).

  As shown in FIG. 5, the actuator 18 is configured by laminating a large number of piezoelectric sheets 50 to 55 and an insulating top sheet 56, and the lowermost piezoelectric sheet 50 includes a plurality of the flow path units 17. The pressure chamber hole 31a is covered. In plan view, the outer shape of the actuator 18 is slightly smaller than the outer shape of the narrow portion 26 of the flow path unit 17. The piezoelectric sheets 50 to 55 are made of a lead zirconate titanate (PZT) ceramic material having a thickness of about 30 μm. Among the piezoelectric sheets 50 to 55, the odd-numbered piezoelectric sheets 50, 52, 54 counted upward from the lowermost piezoelectric sheet 50 are arranged so as to correspond to all the pressure chambers 41 of the flow path unit 17. The common electrode 57 thus formed is printed. On the upper surface of the even-numbered piezoelectric sheets 51, 53 counted upward from the lowermost piezoelectric sheet 50, a large number of individual electrodes 58 arranged so as to correspond to the respective pressure chambers 41 are printed. Further, the common electrode 57 and the individual electrode 58 are connected to the upper surface of the top sheet 56 via relay wiring (not shown) provided on the side end surfaces of the piezoelectric sheets 50 to 55 and the top sheet 56 or through holes (not shown). Is electrically connected to the surface electrode 24 (see FIG. 3).

  When a voltage is selectively applied to the plurality of individual electrodes 58 of the actuator 18 from the flexible flat cable 19 (see FIG. 4), a potential difference is generated between the applied individual electrode 58 and the common electrode 57. In addition, an electric field acts on an active portion which is a portion sandwiched between the individual electrode 58 and the common electrode 57 of the piezoelectric sheets 51 to 54, and distortion deformation in the stacking direction occurs. Then, since the lowermost piezoelectric sheet 50 protrudes into the pressure chamber 41, the ink in the pressure chamber 41 is discharged from the nozzle 38a to the outside through the outflow passage 44.

  As shown in FIGS. 5 and 6, as described above, the flow path unit 17 includes an upper narrow portion 26 on which the actuator 18 is stacked, and a lower wide portion 27 having a width that is wider than the narrow portion 26. have. In the outer portion 27a where the narrow portion 26 of the wide portion 27 is not laminated, the ink flow path 40 is not formed except for the ink inflow hole 35c and the communication groove 35d communicating therewith.

  The frame 13 is formed by pressing a metal plate (for example, SUS430) and is thicker than the flow path unit 17 and has rigidity. The outer shape of the frame 13 is a flat rectangular shape, which is larger than the external shape of the flow path unit 17 in plan view, and a flat rectangular opening 13a is formed through the center. This frame plate-like frame 13 connects the through hole 13b to the ink inflow hole 35c, and on the upper surface of the outer portion 27a of the wide portion 27 so as to surround the actuator 18 and the narrow portion 26 with the opening 13a. The adhesive 39 is overlapped and bonded. That is, the actuator 18 and the narrow portion 26 are joined to the outer portion 27a of the wide portion 27 in a state where the actuator 18 and the narrow portion 26 are disposed in the opening 13a. In this state, the upper surface of the actuator 18 is at a position lower than the upper surface of the frame 13. The size of the opening 13a and the narrow portion 26 of the frame 13 is such that the outer ridge line in the width direction (horizontal direction, scanning direction in FIG. 6) of the narrow portion 26 is the inner ridge line in the width direction of the frame 13 (the opening 13a The distance L3 is set to be spaced from the inner ridge line in the width direction.

  Further, since the frame 13 is in fluid-tight communication with the through hole 13b and the ink outlet 11c of the buffer tank 11 by the compression of the seal member 16, the seal is determined depending on the tightening force of the mounting screw 11a. When the amount of crushing of the member 16 increases, the reaction force acting on the frame 13 from the seal member 16 increases. When the reaction force is large, the frame 13 may be locally bent downward in the vicinity of the through hole 13 a, thereby causing the plurality of plates 31 to 38 constituting the flow path unit 17 bonded to the frame 13 to be bent. A vertically downward load acts. Therefore, the strength of the adhesive does not exist between the plurality of plates 31 to 38, or between the frame 13 and the plurality of plates 31 to 38, and peeling may occur at the interface, which may cause ink leakage or the like. . Therefore, the plates 31 to 38 constituting the flow path unit 17 are all the same shape and the same size in plan view, so that the adhesion can be made uniform and the rigidity of the flow path unit can be increased. Since the frame is bonded onto all the plates stacked, the cross-sectional height of the flow path unit at the frame connecting portion becomes L1 + L2, and the size of the frame increases in the plate stacking direction.

  However, according to the configuration of the present invention described above, the cross-sectional height L1 of the outer portion 27a of the wide portion 27 of the flow path unit 17 is the inner side where the narrow portion 26 overlaps the wide portion 27 of the flow path unit 17. The frame 13 is overlapped with the outer portion 27a having a lower cross-sectional height than the cross-sectional height L1 + L2 of the portion. Therefore, from the lower surface of the frame 13 than when the plurality of plates of the conventional flow path unit have the same shape and the same size in plan view (when the cross-sectional height at the frame connecting portion is L1 + L2). The distance L1 to the lower surface of the flow path unit 17 is shortened, and the apparatus can be miniaturized.

  Although the number of the plurality of plates 35 to 38 constituting the wide portion 27 that adheres to the frame 13 and easily peels off the adhesive due to the reaction force of the seal member 16 is small, the largest thickness is the first. Since the two manifold plates 35 are included, the rigidity of the flow path unit 17 can be maintained.

  Further, since the frame 13 approaches the lower surface of the flow path unit 17, the center of gravity of the ejection head 14 is lowered, and the scanning stability is improved. Further, since the narrow portion 26 of the flow path unit 17 is located at the position surrounded by the frame 13, the position of the upper surface of the actuator 18 is increased, and the flexible flat cable 19 is smoothly pulled out from the opening 13a with a small curvature. . Therefore, the force of elastic return so that the flexible flat cable 19 is pressed against the inner peripheral edge 13c of the frame 13 is reduced, and the flexible flat cable 19 can be prevented from being damaged by being pressed against the inner peripheral edge 13c.

  Although the boundary between the narrow portion 26 and the wide portion 27 is set between the first manifold plate 34 and the second manifold plate 35 having the largest thickness, it has rigidity necessary for the flow path unit. If possible, it is not limited to this.

  Next, the manufacturing procedure of the ejection head 14 will be described. 7 to 10 are drawings for explaining the manufacturing procedure of the ejection head 14. First, as shown in FIG. 7, the upper four plates 31 to 34 and the lower four plates 35 to 38 are laminated and bonded with an adhesive, and the narrow portion 26 (thickness L1 + L2) is formed on the inner portion and the outer portion. The actuator 18 is aligned and overlapped on the upper surface of the narrow portion 26 with respect to the flow path unit 17 having the wide portion 27 (thickness L1) having a larger external shape in plan view than the narrow portion 26. Join. Next, as shown in FIG. 8, the flexible flat cable 19 is overlapped on the upper surface of the actuator 18 and is electrically and mechanically joined with solder or the like. Next, as shown in FIG. 9, a thermosetting adhesive 39 made of a sheet-like adhesive is disposed on the upper surface of the outer portion 27a of the wide portion 27 of the flow path unit 17, and the actuator 18 and the narrow portion 26 are opened. The frame 13 is overlapped on the upper surface of the outer portion 27a so as to be surrounded by 13a. The sheet-like adhesive is disposed in an area of the outer portion 27a that adheres to the lower surface of the frame 13, and has a frame shape in plan view excluding the area of the through hole 13b. At this time, a distance L3 is provided between the outer ridge line in the width direction of the narrow portion 26 and the inner ridge line in the width direction of the opening 13a of the frame 13. In this embodiment, the thermosetting adhesive 39 is used, but a thermoplastic adhesive may be used.

  Next, as shown in FIG. 10, the upper heater 61 and the upper heater 61 are heated in order to heat the thermosetting adhesive 39 interposed between the upper surface of the outer portion 27 a of the wide portion 27 of the flow path unit 17 and the lower surface of the frame 13. The frame 13 and the flow path unit 17 are sandwiched by the lower heater 62. Specifically, the planar view frame in which the flow path unit 17 is mounted on the lower heater 62 having a rectangular shape in plan view that is slightly larger than the lower surface of the flow path unit 17 and has a slightly larger external shape than the frame 13. The upper heater 61 having a shape is pressed against the upper surface of the frame 13.

  Since there is a flexible flat cable 19 provided with an actuator 18 and a drive circuit that are exposed upward from the opening 13a in the central portion of the frame 13, the upper heater 61 does not hit the corresponding portion. The upper heater 61 is pressed against only the upper surface of the frame 13 to conduct heat to the region of the thermosetting adhesive 39 arranged in the planar frame shape.

  Also, the heating by the lower heater 62 may be performed by heating only the region in the frame shape of the plan view of the thermosetting adhesive 39 disposed on the outer portion 27a of the wide portion 27. The rectangular shape is in contact with the entire lower surface of the flow path unit 17, and heat is conducted to the region of the thermosetting adhesive 39 disposed on the surface of the flow path unit 17 through the flow path unit 17.

  When the lower heater 62 has a rectangular shape in a plan view in contact with the entire lower surface of the flow path unit 17, not only the region where the thermosetting adhesive 39 of the outer portion 27a of the wide portion 27 is disposed, but also the actuator Heat is also conducted to the inner part of the flow path unit 17 to which the 18 and the flexible flat cable 19 are joined, and the temperature of the actuator 18 and the flexible flat cable 19 is increased to join the flexible flat cable 19 and the actuator 18. There is a possibility that (for example, solder) is remelted and the electrical connection reliability is lowered, or the IC chip 23 is thermally affected.

  However, the reason why the lower heater 62 is not in the shape of a frame in plan view but in the shape of a rectangular shape in plan view that contacts the entire lower surface of the flow path unit 17 is as follows. The first reason is that a required amount of heat can be quickly applied to the thermosetting adhesive 39 and the working time can be shortened by increasing the area where the lower heater 62 contacts the flow path unit 17. It is. In addition, the heat of the frame-shaped heater tends to escape from the outer area of the heating area and the part opening to the center side to the outside, so it is difficult to raise the temperature of the bonding area. It is because it is difficult to do. The second reason is that if the lower heater 62 has a frame shape, the flow path unit 17 is thermally expanded from the outer portion 27 a, and the outer portion 27 a is sandwiched between the upper heater 61 and the lower heater 62. This is because the flow path unit 17 is distorted and the distortion may affect the actuator 18.

  FIG. 11 is an enlarged view illustrating the main part of FIG. The heat of the upper heater 61 and the lower heater 62 conducted to the adhesive 39 is conducted in the laminating direction and the plane direction of the frame 13 or the flow path unit 17, and in FIG. A state in which heat from the upper heater 61 and the lower heater 62 is conducted to the adhesive 39 and to the actuator 18 and the flexible flat cable 19 on the upper surface of the narrow portion 26 of the flow path unit 17 will be described.

  As shown in FIG. 11, heat from the upper heater 61 is conducted downward in the frame 13 and is conducted to the thermosetting adhesive 39 through the frame 13, and the heat is further shown at a position A in FIG. 11. As described above, the outer portion 27a of the wide portion 27 of the flow path unit 17 is conducted in the width direction (right direction in FIG. 11). The thickness of the outer portion 27 a of the flow channel unit 17 is smaller than the thickness of the inner portion where the narrow portion 26 is present, and the cross-sectional area to which heat is transmitted is the flow channel unit 17 in which the narrow portion 26 is laminated on the wide portion 27. Therefore, the heat resistance when heat is conducted in the width direction is increased. That is, the outer portion 27a of the wide portion 27 has a configuration in which heat is not easily conducted in the width direction.

  Further, when the plurality of plates 31 to 38 of the flow path unit 17 are all configured in the same shape and the same size in plan view, the surface to be bonded to the frame 13 and the surface to be bonded to the actuator 18 are the same surface ( The heat transfer path through which the heat from the heaters 61 and 62 is conducted to the actuator 18 and the flexible flat cable 19 is from the inner ridge line of the through hole 13a of the frame 14 to the outer ridge line of the actuator 18. However, in this embodiment, the actuator 18 and the flexible flat cable 19 are further provided on the upper surface side of the narrow portion 26, and the outer ridge line in the width direction of the narrow portion 26 is the frame 13. The upper heater 61 is spaced from the inner ridge line in the width direction by the thickness L2 of the narrow portion 26. Distance of the heat transfer path to the actuator 18 and the flexible flat cable 19 is increased, further heat to the actuator 18 and the flexible flat cable 19 is hard to be conducted.

  Further, the heat from the lower heater 62 is conducted upward to the thermosetting adhesive 39 through the outer portion 27a of the wide portion 27 of the flow path unit 17 at a position B in FIG. Since the outer portion 27a of the wide portion 27 is thinner than the inner portion in which the narrow portion 26 is laminated on the wide portion 27, the distance from the lower heater 62 to the thermosetting adhesive 39 is shortened. The thermal resistance when heat is conducted is reduced. Then, since the heat from the lower heater 62 is efficiently conducted to the adhesive 39, the amount of heat generated by the lower heater 62 required for bonding can be set low. Therefore, in the inner portion of the flow path unit 17 shown at C in FIG. 11, the heat conducted from the lower heater 62 to the actuator 18 and the flexible flat cable 19 through the wide portion 27 and the narrow portion 26 upward. Is reduced. Therefore, the lower heater 62 has a rectangular shape in a plan view that contacts the entire lower surface of the flow path unit 17 for the above-described reason. Conventionally, the actuator 18 and the flexible flat cable 19 are heated to increase the temperature of the actuator 18 and the flexible heater. Although there is a possibility that the flat cable 19 may be affected by heat, according to the present invention, the influence of heat from the lower heater 62 can be suppressed.

  As described above, the discharge head including the frame 13 can be manufactured in a small size, and the temperature rise of the actuator 18 and the flexible flat cable 19 due to the heat from the upper heater 61 and the lower heater 62 can be suppressed. Therefore, it is possible to prevent the bonding agent (for example, solder) between the flexible flat cable 19 and the actuator 18 from being remelted to reduce the electrical connection reliability, and also to suppress the thermal influence on the IC chip 23. Moreover, the internal stress resulting from the difference in the coefficient of thermal expansion of each member can also be reduced, and generation | occurrence | production of the inferior goods by the heat at the time of manufacture can be suppressed.

  It should be noted that the heat source used to heat the thermosetting adhesive 39 may be only the upper heater 61 or the lower heater 62. Even when one of the heaters is used, the above-described effects can be obtained. Therefore, the heat conducted to the actuator 18 and the flexible cable 19 can be suppressed. In the above-described embodiment, the present invention is applied to an ink jet printer. However, an apparatus for manufacturing a color filter of a liquid crystal display device by discharging a liquid other than ink, for example, a colored liquid, or an electric liquid by discharging a conductive liquid. You may apply to the droplet discharge apparatus used for the apparatus etc. which form wiring.

  As described above, the droplet discharge device and the manufacturing method thereof according to the present invention have an excellent effect of reducing the size of the device and preventing the occurrence of defects due to the heat conduction of the actuator. It is beneficial to apply widely to inkjet printers that can demonstrate their significance.

It is a principal part perspective view of the inkjet printer which concerns on embodiment of this invention. FIG. 2 is an exploded perspective view of a head unit of the ink jet printer shown in FIG. 1. It is a disassembled perspective view which shows the discharge head of the head unit shown in FIG. It is a disassembled perspective view which shows the structure of the flow path unit of the discharge head shown in FIG. FIG. 4 is a cross-sectional view of a main part after the ejection head shown in FIG. 3 is assembled. FIG. 4 is an overall cross-sectional view after the ejection head shown in FIG. 3 is assembled. It is drawing of the 1st process explaining the manufacture procedure of the discharge head shown in FIG. It is drawing of the 2nd process explaining the manufacturing procedure of the discharge head shown in FIG. It is drawing of the 3rd process explaining the manufacturing procedure of the discharge head shown in FIG. It is drawing of the 4th process explaining the manufacture procedure of the discharge head shown in FIG. It is drawing explaining the heat conduction which expanded the principal part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 13 Frame 14 Discharge head 17 Flow path unit 18 Actuator 19 Flexible flat cable 26 Narrow part 27 Wide part 27 Common electrode 27a Outer part 35b Through-hole 39 Thermosetting adhesive 41 Pressure chamber 61 Upper heater 62 Lower heater

Claims (9)

A flow path unit provided with a plurality of pressure chambers respectively corresponding to a plurality of nozzles for discharging droplets;
An actuator overlaid on the flow path unit to apply a transfer pressure to the liquid in the pressure chamber;
A frame overlaid on the flow path unit,
The flow path unit has a narrow part on the side where the actuator is overlapped, and a wide part on the opposite side of the narrow part and wider than the narrow part,
The liquid droplet ejection apparatus, wherein the frame is overlapped with an outer portion of the wide portion so as to surround the actuator and the narrow portion.   2. The droplet discharge device according to claim 1, wherein the frame is bonded to an actuator side surface of an outer portion of the wide portion of the flow path unit with an adhesive.   3. The droplet discharge device according to claim 2, wherein the narrow portion is provided such that an outer ridge line in the width direction of the narrow portion is located at a position away from an inner ridge line in the width direction of the frame. . The flow path unit is configured by laminating a plurality of plates,
The wide portion is constituted by a plate on a layer opposite to the actuator among the plurality of plates,
The narrow portion is constituted by a plate of the actuator side layer among the plurality of plates,
4. The droplet discharge device according to claim 1, wherein the actuator side plate is smaller than the opposite side plate in plan view. 5. A flexible flat cable overlaid on the actuator;
5. The droplet discharge device according to claim 1, wherein the flexible flat cable is pulled out from a space surrounded by the frame. A flow path unit provided with a plurality of pressure chambers respectively corresponding to a plurality of nozzles for discharging droplets, an actuator overlaid on the flow path unit to give a transfer pressure to the liquid in the pressure chamber, and the flow path A method of manufacturing a droplet discharge device comprising a frame overlaid on a unit,
A step of superimposing the actuator on the narrow portion of the flow path unit having a narrow portion and a wide portion having a wider width than the narrow portion;
Connecting a flexible flat cable to the actuator;
Superimposing the frame on the outer portion of the wide portion of the flow path unit via an adhesive so as to surround the actuator and the narrow portion;
Heating the adhesive;
A method for manufacturing a droplet discharge device.   The liquid droplet ejection apparatus according to claim 6, wherein the narrow portion is provided such that an outer ridge line in the width direction of the narrow portion is located at a position away from an inner ridge line in the width direction of the frame. Manufacturing method.   The method for manufacturing a droplet discharge device according to claim 6 or 7, wherein in the heating step, a heater is brought into contact with a surface of the frame opposite to the adhesive.   The method for manufacturing a droplet discharge device according to claim 6, wherein in the heating step, a heater is brought into contact with a surface of the flow path unit opposite to the adhesive.

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