JP2010208053A - Liquid jetting head, liquid jetting recording apparatus and using method of liquid jetting recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting head which can perform the initial filling of liquid without the need to move to a service station etc. even if an opening direction of a jetting hole is directed to a gravity direction by improving a collecting capacity of a surplus of the liquid, and to provide a liquid jetting recording apparatus and a using method of the liquid recording jetting apparatus. <P>SOLUTION: A pair of suction channels 60 are formed at both ends of an arrangement direction of nozzle holes 31a. Suction openings 60a of these suction channels 60 are made to contact with a top plate of a nozzle guard. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid jet head, a liquid jet recording apparatus, and a method of using the liquid jet recording apparatus.

  In general, a liquid jet recording apparatus, for example, an ink jet printer that performs various types of printing includes a transport apparatus that transports a recording medium and an ink jet head. As an ink jet head used here, a nozzle body having a nozzle row (injection hole row) composed of a plurality of nozzle holes, a plurality of pressure generation chambers communicating with the nozzle holes in pairs with each nozzle hole, and pressure generation An ink supply system for supplying ink to the chamber and a piezoelectric actuator disposed adjacent to the pressure generating chamber are provided, and the piezoelectric actuator is driven to pressurize the pressure generating chamber, and the ink in the pressure generating chamber is supplied to the nozzle of the nozzle hole. What discharges from a discharge outlet is known.

  One type of such an ink jet printer is one that ejects ink with the opening direction of the discharge port of the ink jet head oriented in the direction of gravity and prints on the upper surface of a recording medium that is conveyed below the ink jet head. . In this type of inkjet printer, a service station for maintenance is provided within the movable range of the inkjet head, the inkjet head is moved to this service station, the nozzle holes are cleaned, and the inkjet head is covered with a cap so that negative pressure is applied. The ink is sucked and the nozzle holes are initially filled with ink (so-called suction filling). As this suction filling, for example, as shown in Patent Document 1, a configuration in which ink in an ink discharge port of a recording head is sucked by a suction pump connected to the cap while the recording head and the cap are in contact with each other. It is disclosed.

JP-A-6-218938

  By the way, when performing printing on a recording medium with the opening direction of the discharge port directed in the direction of gravity, in order to perform maintenance of the inkjet head, it is necessary to move the inkjet head to the service station as described above. is there. However, in the above-described configuration, since it is necessary to add a service station and a configuration for guiding the inkjet head to the service station, there is a problem that the configuration becomes complicated and the manufacturing cost increases.

Therefore, there is a demand for a configuration that allows ink filling without moving the inkjet head to the service station.
However, when responding to the above-described requirements, there is a possibility that excess ink may leak from the nozzle holes because the opening direction of the nozzle holes faces the direction of gravity. As a result, there is a problem that the ink jet head and the vicinity of the ink jet printer are contaminated by excess ink.

  Therefore, the present invention has been made in view of the above-described problem, and even if the opening direction of the injection hole is directed in the direction of gravity by improving the recovery capability of excess liquid, a service station or the like The present invention provides a liquid ejecting head, a liquid ejecting recording apparatus, and a method of using the liquid recording ejecting apparatus that can perform the initial filling of the liquid without moving the head.

In order to solve the above-described problems, the present invention provides the following means.
The liquid ejecting head according to the present invention is a liquid ejecting head that ejects liquid from an ejection hole array, and includes an ejector guard that is formed so as to cover the ejection hole array, and the ejector guard is provided on the ejection hole array. A peripheral wall portion surrounding the periphery, a top plate portion formed so as to be opposed to the injection plate from a peripheral portion of the peripheral wall portion, and a slit formed in the top plate portion and opposed to the injection hole row, A suction channel that communicates with the inner space of the spray guard and is connected to a suction section that sucks the liquid leaked from the spray hole row, and a suction port of the suction flow channel opens the jet hole row. It protrudes in the said top-plate part side rather than.

According to this configuration, when the air in the inner space is sucked by the suction portion, the external air flows into the inner space from the slit, but this air is sucked after reaching the suction port after passing through the inner space. The inner space is depressurized. Thereby, the inner space becomes a negative pressure chamber in which the negative pressure is sufficiently lower than the atmospheric pressure.
In this case, the excess liquid that is supplied from the liquid supply unit during initial filling of the liquid or during normal use and leaks from the injection hole array flows into the negative pressure chamber that communicates with the outside only through the slits, and the gas outside the negative pressure chamber Flows into the negative pressure chamber through the slit. As a result, the excess liquid moves in the negative pressure chamber in a state where it is difficult to leak out from the slit, and is sucked into the suction channel from the suction port and discharged to the outside. can do.
In addition, since the liquid can be continuously discharged by the suction channel, the recovery capability of the excess liquid is extremely high, and even when the excess liquid flows out, contamination with the excess liquid can be prevented, and the liquid Liquid injection after filling can be stabilized.
In particular, since the suction port for sucking excess liquid protrudes to the top plate part side from the injection plate, the suction force for the excess liquid existing in the vicinity of the slit, such as on the top plate part of the injection guard, is improved. The excess liquid existing in the inner space of the guard can be sucked effectively. That is, for example, when the liquid ejecting head is arranged with the opening direction of the ejecting hole directed in the direction of gravity, excess liquid leaking from the ejecting hole may leak from the slit or remain on the inner surface of the ejector guard. Although it is easy, such excess liquid can be collected in the spray guard without leaking from the slit. Accordingly, the surplus liquid can be recovered without providing a service station, so that the initial filling of the liquid can be performed while simplifying the apparatus and reducing the apparatus cost.

Further, a plurality of the suction channels are provided.
According to this structure, the collection | recovery capability of the excess liquid in inner space can be improved by providing multiple suction flow paths. That is, surplus liquid leaking from the injection hole is quickly sucked into the nearby suction flow path, so that the surplus liquid recovery capability can be further improved, and leakage of surplus liquid from the slit can be ensured. Can be prevented.

Further, two suction channels are provided, and the suction ports of the suction channels are respectively disposed at both ends along the arrangement direction of the injection hole arrays.
According to this configuration, by providing suction channels at both ends in the arrangement direction of the injection hole arrays, air flows uniformly toward each suction channel in the inner space, so surplus that exists in the inner space. The liquid can be sucked efficiently.

The projecting portion of the suction channel that protrudes from the ejection plate has a communication portion that penetrates the side surface of the suction channel and communicates the inner space of the spray guard with the inside of the suction channel. It is characterized by being formed.
According to this configuration, the surplus liquid that has been sucked into the suction portion and has reached the protruding portion of the suction passage is quickly sucked into the suction passage from the communicating portion without going around to the suction port. The liquid recovery capability can be further improved.

Moreover, the said communication part is formed in multiple numbers over the side surface of the said protrusion part, It is characterized by the above-mentioned.
According to this configuration, by forming a plurality of communication portions across the side surface of the protruding portion of the suction channel, excess liquid that has reached the protruding portion is quickly sucked into the suction channel from the nearby communicating portion. Will be. As a result, surplus liquid recovery capability can be further improved.

In addition, the communication part is a cut part formed by cutting along the extending direction of the suction flow path from the peripheral edge of the suction port.
According to this configuration, since the slit is continuously cut along the extending direction of the suction channel, it is easy to guide the excess liquid reaching the protruding portion into the suction channel. As a result, surplus liquid recovery capability can be further improved.

Moreover, the said notch part is formed in the whole region of the said protrusion part in the extension direction of the said suction flow path, It is characterized by the above-mentioned.
According to this configuration, by forming the cut portion over the entire protruding portion, it is easy to guide the excess liquid that has reached the protruding portion into the suction channel. As a result, surplus liquid recovery capability can be further improved.

Further, the peripheral edge of the suction port is in contact with the top plate portion.
According to this configuration, it is easy to suck the excess liquid remaining on the top plate portion by bringing the peripheral edge of the suction port into contact with the top plate portion. That is, since the sucked surplus liquid is guided into the suction flow path via the communicating portion, it is possible to further improve the recovery capability of the surplus liquid and reliably prevent the surplus liquid from leaking from the slit.

Further, the communication portion of the suction flow path is formed so as to face the peripheral wall portion disposed on the opposite side of the injection hole array with the suction flow path interposed therebetween.
According to this configuration, the surplus liquid existing on the peripheral wall portion where surplus liquid easily remains or on the boundary portion between the peripheral wall portion and the top plate portion is efficiently recovered by making the communication portion face the peripheral wall portion. be able to.

Further, the protruding portion of the suction channel extends in a state in which a side surface thereof is in contact with the peripheral wall portion disposed on the opposite side of the injection hole array with the suction channel interposed therebetween. It is said.
According to this configuration, by bringing the suction flow path into contact with the peripheral wall portion, it is possible to efficiently remove the surplus liquid that exists on the peripheral wall portion where surplus liquid easily remains or on the boundary portion between the peripheral wall portion and the top plate portion. It can be recovered.

Moreover, the absorber which absorbs the said liquid leaked from the said injection hole row | line | column is arrange | positioned in the said inner space of the said injection guard, It is characterized by the above-mentioned.
According to this configuration, by arranging the absorber between the top plate portion and the ejection plate, it is possible to absorb the excess liquid that could not be immediately sucked by the suction portion, and the excess liquid leaks from the slit. Can be prevented. And the surplus liquid absorbed by the absorber flows through the absorber together with the air flowing toward the suction port, and is sucked from the suction port.

Further, the top plate portion is formed with a recess portion that is recessed toward the inner space, and the slit is formed on a bottom surface of the recess portion.
According to this configuration, when excess liquid remains on the inner surface of the top plate during printing or the like, even if the excess liquid flows toward the slit, the excess liquid is blocked by the depression. , Can stay in the inner space. Then, the surplus liquid that is blocked by the depression is later sucked from the suction port by the suction part. Thereby, it becomes possible to prevent leakage of excess liquid more reliably.

Further, the top plate portion is formed with an annular protruding wall that protrudes toward the inner space and surrounds the slit in an annular shape.
According to this configuration, when excess liquid remains on the inner surface of the top plate during printing or the like, even if the excess liquid flows toward the slit, the excess liquid is blocked by the depression. , Can stay in the inner space. Then, the surplus liquid that is blocked by the depression is later sucked from the suction port by the suction part. Thereby, it becomes possible to prevent leakage of excess liquid more reliably.

Moreover, the opening direction of the said injection hole row | line | column is arrange | positioned toward the gravitational direction, It is characterized by the above-mentioned.
According to this configuration, as described above, the suction port for sucking the excess liquid protrudes toward the top plate part from the injection plate, so that the excess liquid existing in the vicinity of the slit, such as on the top plate part of the ejector guard, is provided. The suction force can be improved, and the excess liquid present in the inner space of the ejector guard can be effectively sucked. Accordingly, when the opening direction of the injection hole is arranged in the direction of gravity, even if liquid leaked from the injection hole is present in the inner space, the excess liquid is collected in the spray guard without leaking from the slit. be able to. As a result, the surplus liquid can be recovered without providing a service station, so that initial liquid filling can be performed while simplifying the apparatus and reducing the apparatus cost.

The liquid jet recording apparatus of the present invention is connected to the liquid jet head of the present invention, a liquid supply unit configured to be able to supply the liquid to the liquid jet head, and the suction flow path. The inner space is a negative pressure chamber, and the suction section sucks the liquid leaked from the ejection hole array through the suction flow path.
According to this configuration, since the liquid ejecting head and the suction unit are separately provided, there is no need to attach the suction unit to the liquid ejecting head side, the configuration of the liquid ejecting head can be simplified, and the liquid The ejection head can be downsized.

Further, the plurality of suction channels are collectively connected to the suction part.
According to this configuration, by connecting each suction channel to the same suction pump, it is possible to reduce the device cost as compared with the case where the suction unit is provided in each suction channel.

Further, the suction channel is connected to the suction part via a flow rate adjusting device.
According to this configuration, the flow rate of air sucked from the suction port can be adjusted, and the suction flow path to be sucked can be arbitrarily selected. For example, in the case where surplus liquid remains on one suction port side, the surplus liquid can be effectively removed together with this air by switching the flow rate adjusting device and intensively sucking air from only one suction port. Can be aspirated.
As described above, by providing the flow rate adjusting device between the suction flow path and the suction portion, the flow rate sucked by the suction portion can be easily adjusted, so that workability can be improved.

Further, the method of using the liquid jet recording apparatus of the present invention is the method of using the liquid jet recording apparatus of the present invention, wherein the suction space is operated by a first output, so that the inner space is a negative pressure chamber. And a liquid filling mode for sucking the liquid leaked from the ejection hole array through the suction channel.
According to this configuration, by operating the suction portion with the first output, the inner space of the ejector guard becomes a negative pressure chamber in which the negative pressure is sufficiently lower than the atmospheric pressure. In this case, the excess liquid that is supplied from the liquid supply unit during initial filling of the liquid or during normal use and leaks from the injection hole array flows into the negative pressure chamber that communicates with the outside only through the slits, and the gas outside the negative pressure chamber Flows into the negative pressure chamber through the slit. As a result, the excess liquid moves in the negative pressure chamber in a state where it is difficult to leak out from the slit, and is sucked into the suction channel from the suction port and discharged to the outside. can do.
Therefore, it is possible to initially fill the liquid while preventing leakage of excess liquid from the slit.

Further, in the above method of using the liquid jet recording apparatus of the present invention, the jet section is formed through the suction flow path by operating the suction section with a first output so that the inner space is a negative pressure chamber. The liquid filling mode for sucking the liquid leaked from the liquid and the suction unit is operated by a second output smaller than the first output, and the liquid is ejected from the ejection hole array to the recording medium. It is characterized by switching control between the normal use mode in which recording is performed.
According to this configuration, in the normal operation mode, by operating the suction portion with a second output smaller than that in the liquid filling mode, surplus liquid that has leaked from the ejection holes at the time of printing or the ejector after the liquid filling Even when surplus liquid remaining in the inner space of the guard exists, leakage of the surplus liquid from the slit can be prevented by sucking the surplus liquid. Therefore, from the initial filling of the liquid to printing can be performed without providing a service station in a state where the opening direction of the injection hole is directed in the direction of gravity.

According to the liquid jet head and the liquid jet recording apparatus according to the present invention, the suction port for sucking the excess liquid protrudes toward the top plate part side from the jet plate, so that the vicinity of the slit, such as on the top plate part of the jet guard. It is possible to improve the suction force with respect to the surplus liquid existing in the nozzle and effectively suck the surplus liquid present in the inner space of the ejector guard. That is, for example, when the liquid ejecting head is arranged with the opening direction of the ejecting hole directed in the direction of gravity, excess liquid leaking from the ejecting hole may leak from the slit or remain on the inner surface of the ejector guard. Although it is easy, such excess liquid can be collected in the spray guard without leaking from the slit. Accordingly, the surplus liquid can be recovered without providing a service station, so that the initial filling of the liquid can be performed while simplifying the apparatus and reducing the apparatus cost.
Further, according to the method of using the liquid jet recording apparatus according to the present invention, in the normal operation mode, the suction portion is operated by the second output smaller than that in the liquid filling mode, thereby leaking from the jet holes during printing. Even when there is surplus liquid that has exited or surplus liquid remaining in the inner space of the ejector guard after filling the liquid, it is possible to prevent the surplus liquid from leaking out of the slit by sucking the surplus liquid. Therefore, from the initial filling of the liquid to printing can be performed without providing a service station in a state where the opening direction of the injection hole is directed in the direction of gravity.

1 is a perspective view illustrating an ink jet recording apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram of an ink jet recording apparatus according to a first embodiment of the present invention. It is a top view of the ink jet head in a 1st embodiment of the present invention. It is a schematic block diagram of the inkjet head seen from the right side surface in 1st Embodiment of this invention. It is the II sectional view taken on the line of FIG. It is a disassembled perspective view of a head chip. It is an expansion perspective view which shows the state which removed the nozzle guard in an inkjet head. It is the J section expanded sectional view of FIG. It is the figure which showed the relationship between the operation | movement timing of a suction pump and a pressurization pump, and space (negative pressure chamber). It is a principal part expanded sectional view of the head chip which showed the operation | movement at the time of initial stage filling. It is a schematic block diagram of the inkjet head in 2nd Embodiment, (a) is a top view, (b) has shown the right view. It is principal part sectional drawing of the inkjet head in 3rd Embodiment of this invention. It is principal part sectional drawing of the inkjet head which shows the modification of 3rd Embodiment. It is principal part sectional drawing of the inkjet head which shows the modification of 3rd Embodiment. It is a schematic block diagram of the inkjet recording device in 4th Embodiment of this invention. It is a schematic block diagram of the inkjet recording device which shows the modification of this invention. It is an expanded sectional view equivalent to the J section of Drawing 4 showing other composition of the present invention. It is an enlarged view which shows the other structure of the communication part of this invention. It is an enlarged view which shows the other structure of the communication part of this invention.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
(Inkjet recording device)
FIG. 1 is a perspective view showing an ink jet recording apparatus (liquid jet recording apparatus) 1 according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the ink jet recording apparatus 1.
As shown in FIGS. 1 and 2, the inkjet recording apparatus 1 is connected to a predetermined personal computer (not shown), and ejects ink (liquid) I based on print data sent from the personal computer ( The box D is printed. The ink jet recording apparatus 1 includes a belt conveyor 2 that conveys the box body D in one direction, an ink discharge unit 3 that includes a plurality of ink jet heads (liquid ejecting heads) 10, and ink in the ink jet head 10 as shown in FIG. An ink supply unit (liquid supply unit) 5 that supplies I and cleaning liquid W for cleaning, and a plurality of (for example, two) suction pumps (suction units) 16 a and 16 b connected to the inkjet head 10 are provided.

  The ink discharge unit 3 discharges the ink I toward the box body D. As shown in FIG. 1, the ink jet unit 3 has a rectangular parallelepiped inkjet head 10 sandwiched between the box body D and the side of the belt conveyor 2. And 2 above each (6 in total). Each inkjet head 10 is disposed with the ink ejection surface 11a of each case 11 facing the belt conveyor 2 side (box D). Note that the two inkjet heads 10 arranged on both sides in the width direction of the belt conveyor 2 are arranged in parallel along the vertical direction and are supported by the support members 7 respectively. The two inkjet heads 10 respectively disposed above the belt conveyor 2 are juxtaposed along the width direction of the belt conveyor 2, and both inkjet heads 10 are supported by a single support member 7. .

(Inkjet head)
Next, the inkjet head 10 of this embodiment will be described. The plurality of inkjet heads 10 described above have the same configuration, and among these inkjet heads 10, the inkjet head 10 disposed above the belt conveyor 2 will be described in the following description.
3 is a front view of the inkjet head 10, FIG. 4 is a schematic configuration diagram of the inkjet head 10 viewed from the right side, and FIG. 5 is a cross-sectional view taken along the line II of FIG.
As shown in FIG. 4, the inkjet head 10 includes a case 11, a liquid supply system 12, a head chip 20, and a drive circuit board 14 (see FIG. 5).

  The case 11 has a thin box shape in which an opening 11b is formed below the ink discharge surface 11a, and three through holes communicating with the internal space are formed in the back surface 11c along the height direction. Yes. More specifically, an ink injection hole 11d is formed at a substantially intermediate position in the height direction, and ink suction holes 11e and 11g are formed so as to sandwich the ink injection hole from above and below. The case 11 includes a base plate 11 f that is erected and fixed to the case 11 in the internal space, and accommodates each component of the inkjet head 10.

The liquid supply system 12 communicates with the ink supply unit 5 through the ink injection hole 11d, and is schematically configured by a damper 17 and an ink flow path substrate 18.
As shown in FIG. 5, the damper 17 is for adjusting the pressure fluctuation of the ink I, and includes a storage chamber 17 a for storing the ink I. The damper 17 is fixed to the base plate 11f, and is connected to the ink intake hole 17b connected via the ink injection hole 11d and the pipe member 17d, and via the ink flow path substrate 18 and the pipe member 17e. And an ink outflow hole 17c.
As shown in FIG. 4, the ink flow path substrate 18 is a vertically formed member. As shown in FIG. 5, a flow path 18a through which the ink I flows is formed so as to communicate with the damper 17 therein. And is attached to the head chip 20.

  As shown in FIG. 5, the drive circuit board 14 includes a control circuit (not shown) and a flexible board 14a. The drive circuit board 14 has a flexible substrate 14a having one end joined to a plate electrode (not shown) described later and the other end joined to a control circuit (not shown) on the drive circuit board 14 so that a ceramic is formed according to the print pattern. A voltage is applied to the piezoelectric plate 21. The drive circuit board 14 is fixed to the base plate 11f.

(Head chip)
FIG. 6 is an exploded perspective view of the head chip 20.
As shown in FIG. 6, the head chip 20 includes a ceramic piezoelectric plate 21, an ink chamber plate 22, a nozzle body 23, and a nozzle guard (ejecting body guard) 24.
The ceramic piezoelectric plate 21 is a substantially rectangular plate-shaped member made of PZT (lead zirconate titanate), and a plurality of long grooves 26 are juxtaposed on one plate surface 21a of the two plate surfaces 21a and 21b. Each long groove 26 is separated by a side wall 27.

  The long grooves 26 extend in the short direction of the ceramic piezoelectric plate 21, and a plurality of the long grooves 26 are arranged in parallel over the entire length of the ceramic piezoelectric plate 21 in the longitudinal direction. A plurality of side walls 27 are juxtaposed along the longitudinal direction of the ceramic piezoelectric plate 21 to divide the long grooves 26. A plate-like electrode (not shown) for applying a driving voltage is extended over the short groove direction of the ceramic piezoelectric plate 21 on the opening side (plate surface 21a side) of the long groove 26 on both wall surfaces of each side wall 27. . As described above, the flexible substrate 14a is joined to the plate electrode.

As shown in FIG. 5, the ceramic piezoelectric plate 21 has a rear surface side of the plate surface 21b fixed to the edge of the base plate 11f, and the extending direction of the long groove 26 faces the opening 11b.
Further, the ink chamber plate 22 is a substantially rectangular plate-like member like the ceramic piezoelectric plate 21, and the longitudinal dimension is substantially the same as the ceramic piezoelectric plate 21, and the lateral dimension is the same. It is short. The ink chamber plate 22 includes an open hole 22 c that penetrates in the thickness direction and is formed along the longitudinal direction of the ink chamber plate 22.

The ink chamber plate 22 is joined to the ceramic piezoelectric plate 21 from the plate surface 21a side so that the front side 22a constitutes a butting surface 25a that is flush with the front side 21c of the ceramic piezoelectric plate 21. In this bonded state, the open holes 22c expose the plurality of long grooves 26 of the ceramic piezoelectric plate 21, and all the long grooves 26 are opened outward, and the long grooves 26 are in communication with each other. Yes.
As shown in FIG. 5, the ink flow path substrate 18 is attached to the ink chamber plate 22 so as to cover the open hole 22c, and the flow path 18a of the ink flow path substrate 18 and each long groove 26 communicate with each other. .

As shown in FIG. 5, the nozzle body 23 is configured by attaching a nozzle plate 31 to a nozzle cap 32.
As shown in FIG. 6, the nozzle plate 31 is a thin plate made of polyimide (for example, about 50 μm thick) and an elongated member, and a plurality of nozzle holes 31a penetrating in the thickness direction are arranged in a row. The nozzle row 31c is configured. More specifically, the same number of nozzle holes 31 a as the long grooves 26 are formed on the same line at the middle position in the short direction of the nozzle plate 31 and at the same intervals as the long grooves 26. Of the two plate surfaces of the nozzle plate 31, a water repellent film having water repellency for preventing adhesion of ink and the like is applied to the plate surface where the discharge port 31 b for discharging the ink I opens. The other plate surface is a joint surface between the butting surface 25 a and the nozzle cap 32.
The nozzle hole 31a is formed using an excimer laser device.

  As shown in FIGS. 5 and 6, the nozzle cap 32 is a thin plate-like member having a shape obtained by scraping the outer peripheral edge of one of the two frame surfaces of the frame plate-like member. The outer frame portion 32a, the inner frame portion 32b formed thicker than the outer frame portion 32a, the inner frame portion 32c formed thinner than the inner frame portion 32b, and the inner frame portion inside the outer frame portion 32a The long hole 32d extends in the longitudinal direction (horizontal direction) while penetrating in the thickness direction at the intermediate portion in the short direction of 32c.

The outer frame portion 32a is formed thinner than the middle frame portion 32b and the inner frame portion 32c, and is formed in a bowl shape over the entire outer periphery of the nozzle cap 32.
A pair of middle frame portions 32b are formed on both sides in the short direction of the inner frame portion 32c, and extend in parallel with each other along the longitudinal direction of the nozzle cap 32 in a state of projecting along the thickness direction from the inner frame portion 32c. Exist. On both sides in the longitudinal direction of the nozzle cap 32, step portions 32k are formed that are thinner in the thickness direction than the middle frame portion 32b so as to bridge both ends of the middle frame portion 32b.
Further, a groove portion 32f cut in the thickness direction from the inner frame surface 32e of the inner frame portion 32c is formed between the middle frame portion 32b and the inner frame portion 32c. The groove 32f is formed so as to surround the entire circumference of the inner frame portion 32c. A pair of discharge holes 32h penetrating in the thickness direction is formed at the bottom 32g of the groove 32f at both longitudinal ends of the nozzle cap 32. These discharge holes 32h are arranged on both ends in the longitudinal direction of the long hole 32d so as to sandwich the long hole 32d.

  The nozzle plate 31 is stuck on the inner frame surface 32e so as to close the long hole 32d, and the annular end portion 24d of the nozzle guard 24 is in contact with the outer frame surface 32i of the outer frame portion 32a. Yes.

Such a nozzle body 23 is accommodated in the internal space of the case 11 and fixed to the case 11 and the base plate 11f so that the discharge holes 32h of the nozzle cap 32 are located on both ends in the longitudinal direction (see FIG. 3). (See FIG. 5).
In this state, a part of the ceramic piezoelectric plate 21 and the ink chamber plate 22 is inserted into the long hole 32d, and the butting surface 25a is butted against the nozzle plate 31.

  In addition, when inserting a part of the ceramic piezoelectric plate 21 and the ink chamber plate 22 into the long hole 32d described above, and when bonding the nozzle plate 31 to the joined body, it is fixed using an adhesive. In this bonding and fixing step, if only a small amount of adhesive is applied, there is a possibility that bonding failure may occur. Therefore, bonding is performed with an amount of adhesive that can be sufficiently bonded. Further, in this case, for example, if excessive adhesive flows into the long groove 26, the volume of the long groove 26 is reduced, so that the amount of ink that can be discharged may be reduced or a discharge failure may occur. There is. As a configuration to avoid such a case, an adhesive flow groove 32j is provided at the opening edge of the long hole 32d of the nozzle cap 32 in the present embodiment, as shown in FIGS. Since the adhesive flow groove 32j is a matching position where the nozzle cap 32, the ceramic piezoelectric plate 21, the ink chamber plate 22, and the nozzle plate 31 are joined, it is possible to effectively surplus by adopting this configuration. The adhesive can be removed. However, the adhesive flow groove 32j is not necessarily a groove portion that must be provided, and may be configured not to be provided.

  With such a configuration, when a predetermined amount of ink I is supplied from the storage chamber 17a in the damper 17 to the ink flow path substrate 18, the supplied ink I is sent into the long groove 26 through the opening hole 22c. It is supposed to be.

(Nozzle guard)
As shown in FIGS. 4 to 6, the nozzle guard 24 is a substantially box-shaped member made of stainless steel or the like, and is formed by press molding. The nozzle guard 24 includes a top plate portion 24a formed in a rectangular plate shape, and a peripheral wall portion 24b extending from the peripheral portion of the top plate portion 24a in a direction substantially orthogonal to the plate surface direction.

The top plate portion 24a includes a slit 24c extending in the longitudinal direction at the middle portion in the short direction. The slit 24c is formed to be slightly longer than the length of the nozzle row 31c, and both end portions (end portion 24i, end portion 24j) are formed in a circular shape.
The width dimension of the slit 24c is set to about 1.5 mm with respect to the nozzle diameter of 40 μm of the nozzle hole 31a. The width dimension of the slit 24c is set to the upper limit of the width dimension that can be made negative pressure by the suction pumps 16a and 16b, and the lower limit of the width dimension that the ink I does not overflow from the slit 24c during the initial filling of the ink I. It is desirable to set in the range. Note that the end 24i and the end 24j are formed in a circular shape with a diameter slightly larger than the width dimension described above.

  As shown in FIG. 6, the nozzle guard 24 has a hydrophilic film 24g formed of titanium coating on an inner surface 24e facing inward, and an outer surface 24f facing away from the inner surface 24e and slits 24c. A water repellent film 24h is formed on the inner surface by fluorine resin coating or Teflon (registered trademark) plating.

  The nozzle guard 24 is arranged so that the top plate portion 24a covers the inner frame portion 32c, the middle frame portion 32b, the groove portion 32f, and the discharge hole 32h of the nozzle cap 32 from below. In the nozzle guard 24, the inner surface 24e along the longitudinal direction of the peripheral wall portion 24b contacts the outer surface of the middle frame portion 32b, and the inner surface 24e along the width direction contacts the outer surface of the step portion 32k. . In this state, the nozzle guard 24 is attached to the nozzle cap 32 by bonding the annular end 24d to the outer frame surface 32i with an adhesive.

  In this state, the slit 24c faces the nozzle row 31c and does not face the discharge hole 32h. The inner space of the nozzle guard 24, specifically, the space between the nozzle guard 24 and the nozzle cap 32 constitutes an inner space S in which the nozzle holes 31a and the slits 24c are opened. The nozzle guard 24 has an upper limit for the distance between the top plate portion 24a and the nozzle plate 31 that can be set to a negative pressure by the suction pumps 16a and 16b, and the ink I is slit when the ink I is initially filled. It is desirable to set within a range where the distance that does not overflow from 24c is the lower limit.

FIG. 7 is an enlarged perspective view showing a state where the nozzle guard 24 is removed from the inkjet head 10, and FIG. 8 is an enlarged view of a portion K in FIG. FIG. 8 shows only one suction channel 60 among the suction channels 60 described later.
Here, as shown in FIGS. 7 and 8, the suction flow paths 60 are fitted in the respective discharge holes 32 h of the nozzle cap 32 described above. These suction channels 60 are tube-tube shaped, are fixed in a state of being inserted into the respective discharge holes 32h, and have outer peripheral surfaces along the inner surface of the stepped portion 32k and the inner surface 24e of the peripheral wall portion 24b. Thus, it extends toward the top plate portion 24a. Specifically, the suction channel 60 has a suction port 60 a at the tip thereof protruding from the bottom 32 g of the nozzle cap 32 and is in contact with the inner surface 24 e of the top plate part 24 a of the nozzle guard 24. On the other hand, the other end of each suction channel 60 is connected to the ink suction holes 11e and 11g on the back surface 11c. Therefore, each suction channel 60 is disposed so as to sandwich both sides in the longitudinal direction (horizontal direction) of the nozzle plate 31 at both ends in the arrangement direction of the nozzle holes 31a.

  Further, a plurality of slit-like cut portions 61 cut along the extending direction of the suction flow path 60 are formed from the peripheral edge of the suction port 60a. These incisions 61 are formed at equal intervals along the circumferential direction of the suction channel 60, and are formed from the protruding portion of the suction channel 60, that is, from the peripheral edge of the suction port 60a to the bottom 32g of the groove 32f. Yes. The inside of the suction channel 60 and the inner space S communicate with each other through the notches 61. Of these cut portions 61, the cut portion 61a is formed in contact with the inner side surface along the short direction of the stepped portion 32k, and among the inner surface 24e along the short direction of the peripheral wall portion 24b, It faces the inner surface 24e on the opposite side of the nozzle row 31c with the suction channel 60 interposed therebetween.

  The suction pumps 16a and 16b are connected to the ink suction holes 11e and 11g via the tube 62, respectively. The suction pumps 16a and 16b suck the air and the ink I in the space S during operation, and make the space S a negative pressure chamber R, respectively. The suction pumps 16a and 16b store the sucked ink I in the waste liquid tank E (see FIG. 2). The suction pumps 16a and 16b may be mounted on the ink jet head 10, or may be separately provided on the apparatus side as an ink jet recording apparatus as in the present embodiment. In this embodiment, since the suction pumps 16a and 16b are provided on the apparatus side, it is not necessary to attach the suction pumps 16a and 16b to the inkjet head 10 side, and the configuration of the inkjet head 10 can be simplified. The inkjet head 10 can be downsized.

Returning to FIG. 2, the ink supply unit 5 includes an ink tank 51 in which the ink I is stored, a cleaning liquid tank 52 in which the cleaning liquid W is stored, a switching valve 53 that can switch between two flow paths, and the ink I or A pressurizing pump 54 that pressurizes and supplies the cleaning liquid W to the inkjet head 10 and an open / close valve 55 that can open and close the flow path are provided.
The ink tank 51 communicates with the pressurizing pump 54 via the supply pipe 57a, the switching valve 53 and the supply pipe 57c, and the cleaning liquid tank 52 communicates with the pressure pump 54 via the supply pipe 57b, the switching valve 53 and the supply pipe 57c, respectively. That is, the switching valve 53 is connected to the supply pipes 57a and 57b as inflow pipes and the supply pipe 57c as outflow pipes.

The pressurizing pump 54 is connected to the supply pipe 57 c and communicates with the inkjet head 10 through the supply pipe 57 d, and supplies the ink I or the cleaning liquid W flowing from the supply pipe 57 c to the inkjet head 10. The pressurizing pump 54 is configured so that fluid does not flow when not in operation, and has a function of an on-off valve.
The open / close valve 55 is connected to a supply pipe 57e that communicates with the supply pipe 57c and serves as an inflow pipe, and a supply pipe 57f that communicates with the supply pipe 57d and serves as an outflow pipe. That is, when the opening / closing valve 55 is opened, the supply pipes 57e and 57f function as bypass pipes for the pressure pump 54.

Next, the operation of the inkjet recording apparatus 1 having the above-described configuration will be described.
(Ink initial filling)
FIG. 9 is a diagram showing the operation timing of the suction pumps 16a and 16b and the pressurizing pump 54 and the relationship with the space S (negative pressure chamber R), and FIG. 10 is a head chip showing the operation at the time of initial filling. FIG.
First, as shown in FIGS. 4 and 9, the suction pumps 16 a and 16 b of the ink jet head 10 are operated (ON 1), and the suction pumps 16 a and 16 b are spaced from the notches 61 of the suction port 60 a through the suction channel 60. The air of S is sucked (time T0 in FIG. 9). At this time, the output of the suction pumps 16a and 16b to be operated is preferably set to such an extent that the space S can be sufficiently negative, and the output at this time is used as the filling output of the suction pumps 16a and 16b. . When the suction pumps 16a and 16b are operated with a filling output (first output), external air flows into the space S from the slit 24c, but the air passes through the space S and then sucks after reaching the cut portion 61. As a result, the space S is depressurized (liquid filling mode). Then, after the predetermined time T1 has elapsed, the space S becomes the negative pressure chamber R in which the negative pressure is sufficiently lower than the atmospheric pressure.

  After the space S becomes the negative pressure chamber R, the ink supply unit 5 pressurizes and fills the inkjet head 10 with the ink I (time T2 in FIG. 9). At this time, the ink supply unit 5 is set as follows. That is, as shown in FIG. 2, the supply pipe 57a and the supply pipe 57c are brought into communication with each other by the switching valve 53, the open / close valve 55 is closed, and the supply pipe 57e and the supply pipe 57f are shut off. In this state, the pressurizing pump 54 is operated. The pressure pump 54 injects the ink I from the ink tank 51 into the ink injection hole 11d of the inkjet head 10 through the supply pipes 57a, 57c, and 57d.

As shown in FIGS. 4 and 5, the ink I injected into the ink injection hole 11 d flows into the storage chamber 17 a through the ink intake hole 17 b of the damper 17, and then flows through the ink outlet hole 17 c. It flows out to the flow passage 18a of the substrate 18. And the ink I which flowed into the flow path 18a flows in into each long groove | channel 26 via the open hole 22c.
The ink I that has flowed into each long groove 26 flows to the nozzle hole 31a side, reaches the nozzle hole 31a, and then flows out from the nozzle hole 31a as excess ink Y, as shown in FIG. The excess ink Y that has flowed out flows on the nozzle plate 31 toward the cut portions 61. Then, the ink I that has reached the notch 61 is sucked into the suction channel 60 from the notch 61 and discharged to the waste liquid tank E.

  In addition, since the opening direction of the discharge port 31b of the nozzle hole 31a faces the direction of gravity in the inkjet head 10 of the present embodiment, excess ink Y is likely to leak out from the slit 24c. In this case, as shown in FIG. 10B, even if the surplus ink Y reaches the vicinity of the slit 24c, the surplus ink Y is sucked into the suction channel 60 from the cut portion 61 of the suction port 60a in the same manner as described above. Then, it is discharged to the waste liquid tank E.

Even if the surplus ink Y flows not only on the nozzle plate 31 but also on the inner surface 24e of the nozzle guard 24, air continuously flows from the slit 24c into the negative pressure chamber R, and the surplus ink Y Is difficult to flow out from the slit 24c. Even if the amount of excess ink Y flowing locally on the inner surface 24e in the vicinity of the slit 24c increases locally and a part of this excess ink Y reaches the vicinity of the outer surface 24f against the air flowing in from the slit 24c, It is repelled by the water repellent film 24h formed on the outer surface 24f. The repelled ink I is guided to the hydrophilic film 24g formed on the inner surface 24e and returned to the negative pressure chamber R again.
Further, at the end 24i and the end 24j of the slit 24c, the surface tension is applied to the ink I due to the contours of the circular ends 24i and 24j (boundaries between the outer surface 24f and the ends 24i and 24j). work. At the end 24i and the end 24j, a strong surface tension acts on the ink I, and the balance of the surface tension is maintained so that the surface of the ink I is not destroyed and does not leak outside. Further, similarly to the above, the water-repellent film 24h formed on the outer surface 24f and the hydrophilic film 24g formed on the inner surface 24e are guided to return to the negative pressure chamber R.
In this way, the excess ink Y flowing out from the nozzle hole 31a is continuously discharged to the waste liquid tank E.

As shown in FIG. 9, the pressurization pump 54 is stopped after a predetermined time T3, and the pressurization and filling of the ink I is completed. As the pressurizing pump 54 stops, the surplus ink Y does not flow out of the nozzle hole 31 a, and the surplus ink Y remaining in the negative pressure chamber R is discharged to the waste liquid tank E through the cut portion 61.
Then, the suction pumps 16a and 16b are stopped after the predetermined time T4 has elapsed. After completion of ink I filling, the long groove 26 is filled with ink I as shown in FIG.

(When printing)
Next, an operation when printing is performed on the box D will be described. First, the setting of the ink supply unit 5 will be described. In other words, as shown in FIG. 2, the supply pipe 57a and the supply pipe 57c are brought into communication with each other by the switching valve 53, and the open / close valve 55 is opened to connect the supply pipe 57e and the supply pipe 57f. In this state, the pressurization pump 54 is inactivated, and the supply pipe 57c and the supply pipe 57d are not communicated with each other via the pressurization pump 54. In this state, the ink I is injected into the ink injection hole 11d of the inkjet head 10 through the supply pipes 57a, 57c, 57e, 57f, and 57d.

The belt conveyor 2 is driven with the ink supply section 5 set as described above (see FIG. 1), and the box D is conveyed in one direction. When passing, that is, when passing in front of the nozzle plate 31 (nozzle hole 31 a), the ink ejection unit 3 ejects ink droplets toward the box body D.
Specifically, based on print data input from an external personal computer, the drive circuit board 14 selectively applies a voltage to a predetermined plate electrode corresponding to the print data. Thereby, the volume of the long groove 26 corresponding to this plate-like electrode is reduced, and the ink I filled in the long groove 26 is discharged toward the box body D from the discharge port 31b.
When the ink I is ejected, the long groove 26 becomes negative pressure, so that the ink I is filled into the long groove 26 through the supply pipes 57a, 57c, 57e, 57f, and 57d.

  In this way, the ceramic piezoelectric plate 21 of the inkjet head 10 is driven according to the image data, and ink droplets are ejected from the nozzle holes 31a and land on the box D. Thus, an image (character) is printed at a desired position of the box D by continuously ejecting ink droplets from the inkjet head 10 while moving the box D.

  Here, in particular, in the inkjet head 10 of the present embodiment, as shown in FIG. 10D, the opening direction of the discharge port 31b of the nozzle hole 31a faces the direction of gravity. In some cases, the excess ink Y leaked from the nozzle cannot be sucked and remains at the boundary portion between the top plate portion 24 a and the peripheral wall portion 24 b of the nozzle guard 24. Further, after the ink I is filled, there is a possibility that the excess ink Y leaks from the nozzle holes 31a, for example, at the time of printing.

Therefore, as shown in FIG. 9, in this embodiment, the suction pumps 16a and 16b are always operated even after the ink I is filled (ON2 in FIG. 9). At this time, the outputs of the suction pumps 16a and 16b are set so as to be weaker than the output (filling output) at the time of ink I filling and to sufficiently suck the excess ink Y existing in the space S at the time of printing (normally). Use mode). As a result, the space S becomes a negative pressure space that is weaker than when the ink I is filled. If the outputs of the suction pumps 16a and 16b are too strong, the flight path of the ink droplets ejected from the nozzle holes 31a during printing is affected, and printing accuracy may be affected. The outputs of the suction pumps 16a and 16b at this time are set as normal outputs (second outputs).
When printing is performed while the suction pumps 16a and 16b are operated at normal output, the excess ink Y leaking from the nozzle holes 31a and the excess ink Y remaining on the inner surface 24e of the nozzle guard 24 are caused to flow into the respective suction channels 60. It flows toward the notch 61. Then, the ink I that has reached the notch 61 is sucked into the suction channel 60 from the notch 61 and discharged to the waste liquid tank E.
Note that the operation of ON2 in FIG. 9 described as the normal use mode is not necessarily performed together with the operation of ON1 in FIG. 9 described as the liquid filling mode, and is appropriately determined depending on the surrounding operating environment and the type of ink I. Just do it.

Thus, in this embodiment, a pair of suction flow paths 60 are provided at both ends in the arrangement direction of the nozzle holes 31a, and the suction ports 60a of these suction flow paths 60 are in contact with the top plate portion 24a of the nozzle guard 24. did.
According to this configuration, the excess ink Y moves in the negative pressure chamber R in a state where it is difficult to leak out from the slit 24c, and is sucked into the suction channel 60 from the cut portion 61 and discharged to the waste liquid tank E. The space for collecting the excess ink Y flowing out from the nozzle hole 31a can be made extremely small, the space factor of the ink jet head 10 can be improved, and the degree of freedom in designing the ink jet recording apparatus 1 can be improved.
Further, since the surplus ink Y can be continuously discharged by the suction flow path 60, the recovery capability of the surplus ink Y is extremely high, and contamination by the surplus ink Y is prevented even when the surplus ink Y flows out. In addition, it is possible to stabilize the ejection of the ink I after the ink I is filled.

  In particular, since the suction port 60a that sucks the excess ink Y is in contact with the top plate portion 24a, the slit 24c on the top plate portion 24a of the nozzle guard 24, the boundary portion between the peripheral wall portion 24b and the top plate portion 24a, or the like. The suction force with respect to the surplus ink Y existing in the vicinity can be improved. Therefore, the excess ink Y existing in the space S of the nozzle guard 24 can be sucked effectively. That is, when the inkjet head 10 is arranged with the opening direction of the nozzle hole 31a in the direction of gravity as in the present embodiment, excess ink Y leaked from the nozzle hole 31a leaks from the slit 24c or the nozzle guard 24. However, such excess ink Y can be collected in the nozzle guard 24 without leaking from the slit 24c. Therefore, since the surplus ink Y can be collected without providing a service station as in the prior art, the initial filling of the ink I can be performed while simplifying the apparatus and reducing the apparatus cost.

  And in this embodiment, the collection | recovery capability of the excess ink Y in the space S can be improved by providing the suction flow path 60 with two or more. That is, since the surplus ink Y leaked from the nozzle hole 31a is quickly sucked into the suction channel 60 in the vicinity, the recovery ability of the surplus ink Y can be further improved, and the surplus ink from the slit 24c can be improved. Y leakage can be reliably prevented. In this case, by providing the suction flow paths 60 at both ends in the arrangement direction (horizontal direction) of the nozzle row 31c, air flows evenly toward each suction flow path 60 in the space S. Excess ink Y present can be efficiently sucked.

In addition, since the suction port 60a of the suction channel 60 is in contact with the top plate portion 24a and the plurality of cut portions 61 are formed in the suction port 60a, the excess ink Y remaining on the top plate portion 24a is removed. It becomes easy to suck. In this case, the excess ink Y sucked by the suction pumps 16a and 16b is quickly sucked into the suction channel 60 from the notch 61 in the vicinity without going to the suction port 60a. In addition, since the cut portion 61 is formed in the entire region of the protruding portion, the opening area of the suction channel 60 is improved and the excess ink Y is easily guided into the suction channel 60.
Further, since the notch 61a of the notch 61 is arranged so as to face the inner surface 24e of the peripheral wall 24b, the peripheral wall 24b and the top plate 24a are arranged on the peripheral wall 24b where excess ink Y easily remains. Therefore, it is possible to efficiently recover the surplus ink Y existing at the boundary portion. As a result, it is possible to improve the collecting ability of the surplus ink Y and reliably prevent the surplus ink Y from leaking from the slit 24c.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 11 is a schematic configuration diagram of an inkjet head 100 according to the second embodiment, where (a) is a plan view and (b) is a right side view. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
As shown in FIGS. 11 and 12, in the inkjet head 100 of the present embodiment, an absorber 101 for absorbing excess ink Y overflowing from the nozzle holes 31 a is disposed inside the nozzle guard 24 (space S). This is different from the first embodiment described above. Specifically, the absorber 101 is a thin film having a rectangular shape in a plan view and having a dimension substantially the same as the dimension of the top plate part 24a of the nozzle guard 24, and a nozzle row 31c at the center in the width direction. A slit 101a having substantially the same shape as the slit 24c of the nozzle guard 24 is formed. Further, at both ends in the longitudinal direction of the absorbent body 101, holes 101b into which the suction channel 60 is inserted are formed.
And the absorber 101 is arrange | positioned so that the inner surface 24e of the top-plate part 24a of the nozzle guard 24 may contact | abut.

  In addition, as a material of the absorber 101, a porous film such as PVA (polyvinyl alcohol) (for example, Kanebo Belita A series) or high-density polyethylene powder (for example, manufactured by Asahi Kasei (Sunfine)) is preferably used. Yes. Moreover, you may stick the absorber 101 to the inner surface 24e of the top-plate part 24a using an adhesive agent. In this case, in order to prevent the absorption capacity of the absorbent body 101 from being lowered, it is preferable to attach a high-viscosity adhesive made of, for example, epoxy or the like. The absorber 101 is arranged between the suction port 60a and the top plate portion 24a, that is, so as to cover the suction port 60a in a plan view (as viewed from the opening direction of the slit 24c) without forming the hole 101b. Also good. In any case, it is desirable that the suction port 60a or the cut portion 61 is in contact with the absorber 101. That is, when the suction port 60a or the cut portion 61 is in contact with the absorber 101, the excess ink Y contained in the absorber 101 can be sucked by directly applying a suction force without interposing a space. Therefore, the surplus ink Y contained in the absorber 101 can be discharged more effectively.

In this case, of the excess ink Y leaked from the nozzle hole 31a (see FIG. 10), the excess ink Y that could not be immediately sucked by the suction pumps 16a and 16b is the inner surface 24e of the nozzle plate 31 and the nozzle guard 24. It hangs down in the direction of gravity. At this time, the surplus ink Y that drips in the direction of gravity is absorbed by the absorber 101 disposed on the top plate portion 24a. The excess ink Y absorbed in the absorber 101 flows through the absorber 101 together with the air flowing toward the suction port 60a in the negative pressure chamber R. The surplus ink Y flowing through the absorber 101 is sucked from the cut portion 61 of the suction port 60a and discharged to the waste liquid tank E.
In addition, surplus ink Y leaked from the nozzle hole 31a during printing or the like, or surplus ink Y exists in the vicinity of the slit 24c such as a boundary portion between the top plate portion 24a and the peripheral wall portion 24b of the nozzle guard 24. Even in this case, the surplus ink Y can be absorbed by the absorber 101. Then, by operating the suction pumps 16 a and 16 b with normal power during printing, the surplus ink Y remaining in the absorber 101 always flows toward the suction port 60 a and is sucked from the cut portion 61.

Therefore, according to the present embodiment, in addition to the same effects as those of the first embodiment described above, the surplus ink Y sucked into the negative pressure chamber R because the absorber 101 is disposed in the space S. Thus, excess ink Y can be prevented from leaking from the slit 24c.
Further, since the hole 101b into which the suction port 60a is inserted is formed in the absorber 101, the cut portion 61 and the absorber 101 are in contact with each other without interposing a space. Therefore, it is possible to continuously suck the surplus ink Y absorbed in the absorber 101, and it is possible to suppress the absorption amount of the absorber 101 from being saturated by quickly drying the absorber 101. . The arrangement position and shape of the absorber 101 can be changed as appropriate.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In addition, about the structure similar to 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.
FIG. 12 is a cross-sectional view illustrating the inkjet head 110 according to the third embodiment.
As shown in FIG. 12, in the nozzle guard 24 of the inkjet head 110, a recess 24x that is recessed toward the space S is formed in the top plate 24a. The recess 24x is formed by press molding (rolling), and a slit 24c is formed on the bottom surface of the recess 24x.
Accordingly, even when the nozzle guard 24 is in contact with the box D, the probability that the water repellent film 24h in the vicinity of the slit 24c contacts the box D is reduced, and the water repellent film 24h is prevented from peeling off. can do.
In particular, when excess ink Y remains on the inner surface 24e of the top plate portion 24a during printing or the like, even if the excess ink Y flows toward the slit 24c, the excess ink Y is allowed to flow through the depression 24x. It can block and stay in the space S. Then, the excess ink Y blocked by the recess 24x is later sucked from the notch 61 by the suction pumps 16a and 16b. Thereby, it becomes possible to prevent leakage of the surplus ink Y more reliably.

(Modification)
FIG. 13 is a cross-sectional view showing an inkjet head 120 according to a modification of the present invention.
As shown in FIG. 13, the nozzle guard 24 of the inkjet head 120 is formed with an annular protruding wall 24 y that protrudes toward the space S and surrounds the slit 24 c in an annular shape.
Even with such a configuration, the same operational effects as those of the third embodiment described above can be achieved.

FIG. 14 is a cross-sectional view showing an inkjet head 130 according to a modification of the present invention.
As shown in FIG. 14, the nozzle guard 24 of the inkjet head 130 is formed with a recess 24x and an annular protruding wall 24y by press molding.
Thereby, there can exist an effect similar to 3rd Embodiment mentioned above.
In addition, if it is press molding, the hollow part 24x and the cyclic | annular protrusion wall 24y can be formed simultaneously, and a productive efficiency will become favorable.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. FIG. 15 is a schematic configuration diagram of an inkjet recording apparatus 150 according to the fourth embodiment. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 15, the inkjet recording apparatus 150 of the present embodiment is different from the above-described embodiments in that only one suction pump 160 is provided for the two suction flow paths 60. ing. Specifically, the ink suction holes 11e and 11g to which the suction channel 60 (see FIG. 4 and the like) is connected are provided with one ends of connection tubes 161a and 161b that connect the suction channel 60 and the suction pump 160. Yes. The other ends of these connection tubes 161a and 161b are assembled and connected to the same suction pump 160, respectively. In this case, when the suction pump 160 is operated, air is sucked from the suction port 60a of each suction flow channel 60 with the same power. Then, the excess ink Y in the space S together with the sucked air can be sucked from the cut portion 61 (see FIG. 4 and the like) and discharged to the waste liquid tank E connected to the downstream side of the suction pump 160.
According to this configuration, the suction channels 60 are connected to the same suction pump 160, so that the suction pumps 16a and 16b are provided in the suction channels 60 as in the first embodiment. The recording device 150 can be manufactured at low cost.

(Modification)
Next, a modification of the fourth embodiment will be described. FIG. 16 is a schematic configuration diagram of an inkjet head recording apparatus 170 according to a modification of the present invention. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 16, in the inkjet recording apparatus 170 of this modification, valves (flow rate adjusting devices) 171 and 172 are connected between the suction flow path 60 and the suction pump 160, that is, to the connection tubes 161a and 161b, respectively. Has been. That is, each suction channel 60 and suction pump 160 are connected via valves 171 and 172, respectively.
In this case, the flow rate of air sucked from the suction port 60a (see FIG. 4 and the like) can be adjusted by the valves 171 and 172. Further, by performing switching control of the valves 171 and 172, the suction port 60a to be sucked can be arbitrarily selected. For example, when surplus ink Y remains on one suction port 60a (see FIG. 4), the valves 171 and 172 are switched to suck air intensively from only one suction port 60a. The excess ink Y can be effectively sucked together with the air.
As described above, by providing the valves 171 and 172 between the suction flow path 60 and the suction pump 160, the flow rate sucked by the suction pump 160 can be easily adjusted, so that workability can be improved. .

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to these embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

FIG. 17 is an enlarged cross-sectional view of an inkjet head 200 showing another configuration of the present invention.
In the above-described embodiment, the case where the suction channel 60 extends along the vicinity of the peripheral wall portion 24b has been described. However, like the inkjet head 200 illustrated in FIG. Of the inner surface 24e along the short side direction of the peripheral wall portion 24b, the inner surface 24e extends toward the top plate portion 24a in a state where the suction channel 60 is sandwiched between the inner surface 24e and the inner surface 24e on the opposite side of the nozzle row 31c. You may let it come out. In this case, by leaving the cut portion 61a of the cut portion 61 in contact with the inner surface 24e of the peripheral wall portion 24b, it remains on the inner surface 24e, the boundary portion between the top plate portion 24a and the peripheral wall portion 24b, or the like. The surplus ink Y can also be sucked efficiently.

In the above-described embodiment, the case where the cut portion 61 (see FIG. 8 and the like) is formed as the communication portion for communicating the inside of the suction channel 60 and the space S has been described. Not limited to this, it can be formed in various shapes. For example, the communication portion shown in FIG. 18 includes a plurality of through-holes 210 penetrating in the thickness direction of the suction channel 60, and the plurality of through-holes 210 are aligned in the extending direction of the suction channel 60. 211 is formed. The through-hole rows 211 are formed at equal intervals along the circumferential direction of the suction channel 60. In this case, it is preferable to form the through-hole row 211 in the entire longitudinal direction of the protruding portion in the suction flow channel 60 in the same manner as the notch 61 described above.
In addition, the formation position of the above-mentioned through-hole 210 can be appropriately changed. For example, as shown in FIG. 19, the through-holes 210 may be formed in a staggered pattern on the entire peripheral surface of the suction channel 60.

  In the above-described embodiment, the configuration in which the peripheral edge of the suction port 60a is in contact with the inner surface 24e of the top plate portion 24a has been described. However, the peripheral edge of the suction port 60a is not necessarily in contact with the top plate portion 24a. . However, it is preferable that the suction flow path 60 protrudes from the suction port 60a to a position where the excess ink Y remaining on the inner surface 24e such as the top plate portion 24a can be sucked.

In the above-described embodiment, the opening direction of the nozzle row 31c of the inkjet head 10 is directed to the direction of gravity, and the row direction of the nozzle holes 31a is directed to the horizontal direction. Not limited to. It is good also as a structure which orient | assigns the arrangement direction of the nozzle hole 31a to a gravitational direction.
In the above-described embodiment, the inkjet recording apparatus 1 is configured by fixing the inkjet head 10. However, the inkjet recording apparatus 1 can also be configured by moving the inkjet head 10.

Furthermore, in the present embodiment, the method of filling the ink I or the cleaning liquid W is performed using both the pressurization pump 54 and the suction pumps 16a and 16b. However, the present invention is not limited to this embodiment. For example, the ink jet head 10 may be filled with the ink I or the cleaning liquid W only by the operation of the suction pumps 16a and 16b.
In this embodiment, the ceramic piezoelectric plate 21 provided with electrodes is provided as an actuator for ejecting the ink I. However, the present invention is not limited to this configuration. For example, an electrothermal conversion element may be used as a mechanism for generating bubbles in a chamber filled with the ink I and discharging the ink I by the pressure.
Further, in the present embodiment, the open holes 22c are formed across the long grooves 26 and the ink I is filled into the long grooves 26 from the open holes 22c. However, the present invention is not limited to this configuration. . For example, the open holes 22 c may not be communicated with all the long grooves 26, and a slit-shaped groove may be provided in the ink chamber plate 22, and the slit may be formed to be half the pitch of the long grooves 26. That is, the slit may correspond to every other long groove 26 and the ink I may be filled only in the long groove 26 corresponding to the slit. By adopting this form, even when the conductive ink I is used, the electrodes are not short-circuited via the ink I, and a wide variety of inks I can be used for printing.

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording device (liquid jet recording device) 5 ... Ink supply part (liquid supply part) 10, 100, 110, 120, 150, 170, 200 ... Inkjet head (liquid jet head) 12 ... Liquid supply system 16a, 16b , 160 ... Suction pump (suction part) 24 ... Nozzle guard 24a ... Top plate part 24b ... Peripheral wall part 24c ... Slit 24x ... Recessed part 24y ... Annular protrusion 31a ... Nozzle hole 31c ... Nozzle array 60 ... Suction flow path 60a ... Suction Mouth 61 ... notch 101 ... absorber 210 ... through-hole I ... ink (liquid) R ... negative pressure chamber S ... space

Claims (19)

In a liquid ejecting head that ejects liquid from an ejection hole array,
An ejector guard formed so as to cover the ejection hole row;
The ejector guard is formed on the top plate portion, a peripheral wall portion surrounding the periphery of the injection hole row, a top plate portion formed so as to face the injection plate from a peripheral portion of the peripheral wall portion, and the injection plate A row of holes and a facing slit,
A suction flow path that communicates with the inner space of the spray guard and is connected to a suction section that sucks the liquid leaked from the spray hole row;
The liquid ejecting head according to claim 1, wherein the suction port of the suction channel protrudes closer to the top plate than the surface on which the ejection hole row opens.   The liquid ejecting head according to claim 1, comprising a plurality of the suction channels.   The two suction channels are provided, and the suction ports of the suction channels are respectively disposed at both ends along the arrangement direction of the injection hole arrays. Liquid jet head.   A communication portion that penetrates the side surface of the suction flow path and communicates the inner space of the spray guard and the inside of the suction flow path is formed at a protruding portion of the suction flow path that protrudes from the injection plate. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is provided.   The liquid ejecting head according to claim 4, wherein a plurality of the communication portions are formed over a side surface of the protruding portion.   The liquid ejecting head according to claim 4, wherein the communication portion is a cut portion formed by cutting along a direction in which the suction flow path extends from a peripheral edge of the suction port.   The liquid ejecting head according to claim 6, wherein the cut portion is formed in the entire region of the protruding portion in the extending direction of the suction flow path.   The liquid ejecting head according to claim 4, wherein a peripheral edge of the suction port is in contact with the top plate portion.   5. The communication portion of the suction channel is formed so as to face the peripheral wall portion disposed on the opposite side of the injection hole array with the suction channel interposed therebetween. Item 9. The liquid jet head according to any one of Items 8 above.   The protruding portion of the suction channel extends in a state in which a side surface thereof is in contact with the peripheral wall portion disposed on the opposite side of the injection hole array with the suction channel interposed therebetween. The liquid ejecting head according to claim 9.   The liquid according to any one of claims 1 to 10, wherein an absorber that absorbs the liquid leaked from the ejection hole array is disposed in the inner space of the ejection guard. Jet head.   12. The hollow plate according to claim 1, wherein a hollow portion that is recessed toward the inner space is formed on the top plate portion, and the slit is formed on a bottom surface of the hollow portion. The liquid ejecting head according to the item.   The annular projection wall which protrudes toward the said inner side space and surrounds the said slit annularly is formed in the said top-plate part, The any one of Claim 1 thru | or 12 characterized by the above-mentioned. Liquid jet head.   14. The liquid jet head according to claim 1, wherein an opening direction of the jet hole row is arranged in a gravitational direction. The liquid jet head according to any one of claims 1 to 14,
A liquid supply unit configured to supply the liquid to the liquid jet head;
A liquid ejecting apparatus comprising: the suction space connected to the suction flow path, the inner space serving as a negative pressure chamber, and sucking the liquid leaked from the ejection hole array through the suction flow path. Recording device.   The liquid jet recording apparatus according to claim 15, wherein a plurality of the suction channels are collectively connected to the suction unit.   The liquid jet recording apparatus according to claim 15, wherein the suction channel is connected to the suction unit via a flow rate adjusting device. A method of using the liquid jet recording apparatus according to any one of claims 15 to 17,
By operating the suction part with a first output, the inner space is set as a negative pressure chamber, and a liquid filling mode for sucking the liquid leaked from the ejection hole array through the suction flow path is provided. To use the liquid jet recording apparatus. A method of using the liquid jet recording apparatus according to any one of claims 15 to 17,
By operating the suction part with a first output, the liquid filling mode for sucking the liquid leaked from the ejection hole array through the suction flow path, with the inner space as a negative pressure chamber;
The suction unit is operated with a second output smaller than the first output, and switching control is performed between a normal use mode in which the liquid is ejected from the ejection hole array to the recording medium and recording is performed on the recording medium. A method of using a liquid jet recording apparatus.

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