JP2003220705A - Inkjet printer head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a branch passage for delivering ink passing through one ink supply passage 4 from an ink supply source to ink supply holes 19, 19, with the structure of the branch passage that an air hardly stays, in an inkjet printer head wherein a head unit 6 provided with the plurality of ink supply holes 19, 19 thereon is attached to a body frame 68 having the ink supply passage 4 thereon. <P>SOLUTION: The ink supply passage 4 is so constituted that the end section at the side of the head unit 6 is expanded in a tapered shape (taper section 51) toward the head unit 6. A joint member 47 is interposed between the body frame 68 and the head unit 6, and then the ink supply passage 4 and the ink supply holes 19, 19 are coupled with the inner space thereof. A partition wall 47b for delivering the ink is formed on the joint member 47. The end section of the partition wall 47b at the side of the ink supply passage 4 is made to have inclined faces 53, 53 corresponding to the tapered expanded shape (the shape of the taper section 51) of the ink supply passage 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a printer head of an inkjet printer.

[0002]

2. Description of the Related Art A printer head of an ink jet recording apparatus such as an ink jet printer has a head unit fixed to a body frame. The head unit includes a plurality of nozzles that eject ink onto the print surface of the head, pressure chambers provided corresponding to the plurality of nozzles, and a common ink that distributes the ink to the plurality of pressure chambers. A chamber and an actuator that is provided corresponding to the plurality of pressure chambers and applies a pressure to each pressure chamber to apply ejection energy to the ink.

Here, conventionally, in one head unit, a large number of nozzles are arranged in, for example, two rows to form a nozzle group for each row, and correspondingly, the pressure chambers are also arranged in two rows and each row is arranged. There is also known a structure for forming a pressure chamber group of the above (for example, Japanese Patent Laid-Open No. 62-111758).
Issue). Two common ink chambers are provided corresponding to the number of pressure chamber groups (two rows in this case, so there are two groups), and one ink supply port is provided for each common ink chamber. Set up. As a result, two ink supply ports are provided for each head unit. By doing so, by supplying ink of different colors to the two ink supply ports, it is possible to perform printing of two colors with one head unit, and by supplying ink of the same color to the two ink supply ports. The common head unit can be used for any of the forms in which one head unit performs printing with a single color and high resolution, and the types of parts and design costs can be reduced.

When this head unit is made to perform the above-mentioned printing form, it is necessary to form an ink flow path so as to branch ink from a single ink supply source to two ink supply ports.

Conventionally, this ink flow path is shown in FIG.
It was formed like. To explain this,
A joint member 47 'made of an elastic material is interposed between the head unit 6 having the nozzles 15 for ejecting ink and the bottom plate 5 of the main body frame 68 fixing and supporting the head unit 6. . The joint member 47 ′ is formed in a tubular shape, and one end surface of the joint member 47 ′ contacts the head unit 6 so as to straddle the two ink supply ports 19 and 19 arranged at positions close to each other in the head unit 6. To do. Joint member 47 '
Has a cylindrical portion 47a and a partition wall 47b that divides the internal space of the cylindrical portion 47a into two parts.
-Two channels corresponding to 19 are formed. The ink supply passage 4 is formed on the body frame 68 side, and an ink supply source inside the ink cartridge is connected to one end of the ink supply passage 4. A long hole-shaped opening 55 is formed at the other end of the ink supply passage 4, and when the joint member 47 ′ is attached to the main body frame 68, the opening 55 causes the two flow paths inside the joint member 47. Connected to the road. A peripheral wall 56 is formed on the main body frame 68 side so as to surround the elongated hole-shaped opening 55, and an inner surface of the peripheral wall 56 is
The joint member 47 is fitted while being in close contact.

In this structure, the ink supplied from the ink supply source reaches the elongated opening 55 through the ink supply passage 4, and the flow of the ink is branched into two at this opening 55 to form a joint. From the ink supply port 19 which is guided to the two flow paths inside the member 47 ′ and connected to each flow path,
The ink is supplied to the corresponding common ink chamber (not shown) inside the head unit 6.

[0007]

However, in the conventional structure shown in FIG. 12, since the ink branch portion is branched at a right angle in a "T" shape, the corner portion of the branch portion (for example, a reference numeral). There was a problem that bubbles (air) were likely to accumulate in the area (A).

As one of the methods for removing the air that has entered the ink flow path, a purging mechanism is provided in the printer body so that the ink can be forcibly sucked from the nozzle 15 side if necessary. What is done is generally known. However, since the branched portion is the long hole-shaped opening 55 and the flow passage cross-sectional area is rapidly increased at that portion, even when ink is forcibly sucked from the nozzle 15 by the purge mechanism, There is a problem that the ink suction flow is weakened at the branch portion, and the air accumulated at the branch portion cannot be strongly sucked and removed.

The present invention has been made in view of the above circumstances, and an object thereof is to gently branch an ink flow path so that air is less likely to be accumulated in the branch part, and a branch part of the ink flow path. It is possible to suppress an increase in the flow passage cross-sectional area, prevent a decrease in the ink suction flow at the branch portion when purging is performed by the purging mechanism, and enable effective air suction removal. To provide a configuration.

[0010]

The problem to be solved by the present invention is as described above, and the means for solving this problem will be described below.

That is, according to the first aspect, a plurality of nozzles for ejecting ink onto the printing surface, pressure chambers provided corresponding to the respective nozzles, and the plurality of pressure chambers are divided into a plurality of groups. A plurality of common ink chambers provided for each of the groups to distribute the ink to the pressure chamber group, and an actuator configured to be able to apply the ejection energy to the ink for each of the pressure chambers, A head unit having an ink supply port formed for each common ink chamber, and a main body frame having an ink supply passage connectable to an ink supply source are provided, and at least one or more head units are provided in the main body frame. Is fixed, and one ink supply passage and a plurality of ink supply ports of one head unit are made to communicate with each other through an internal space of a cylindrical joint member. In the ink jet printer head, the ink supply passage has a shape in which the end on the head unit side is expanded in a tapered shape toward the head unit, and a plurality of inks are supplied to the inner space of the joint member. A partition wall for branching to the mouth is formed, and an end portion of the partition wall on the ink supply passage side is an inclined surface that substantially corresponds to the tapered expanded shape of the ink supply passage.

With this configuration, the branched shape of the ink flow path can be made gentle, and air is less likely to be accumulated in the branched portion. In addition, it is possible to suppress an increase in the flow passage cross-sectional area of the branch portion of the ink flow passage, and when purging is performed by the purging mechanism, a strong ink suction flow can be obtained at the branch portion, which is effective in sucking and removing air. Can be done.

According to a second aspect of the present invention, the periphery of the ink supply passage of the main body frame is formed into a cylindrical shape protruding toward the head unit side, and the joint member is fitted to the outer circumference of the protruding portion. .

With this structure, by fitting the projecting portion into the joint member, the tapered widened portion of the ink supply passage can be easily and smoothly connected to the inner surface of the joint member, and the flow passage cross-sectional area can be increased. A structure that can be easily suppressed can be adopted, air is less likely to accumulate, and air can be sucked and removed more easily.

According to another aspect of the present invention, the joint member is made of an elastic material, and is elastically contacted with the periphery of the ink supply port of the head unit to be held between the head unit and the main body frame. It is what

With this structure, the joint member is closely contacted with and pressed against the periphery of the ink supply port to perform a sealing action, and ink leakage from the portion is prevented.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a color inkjet printer as an inkjet recording apparatus of the present invention. In FIG. 1, the printer head 63 of the color inkjet printer 100 has a total of four print heads arranged for the respective colors in order to eject four color inks (for example, cyan, magenta, yellow, black) onto the main body frame 68 thereof. A plurality of piezoelectric ink jet head units (hereinafter referred to as “head units”) 6 are fixedly attached, and a total of four ink cartridges 61 filled with color inks are detachably attached to a main body frame 68. The main body frame 68 is fixed to a carriage 64 that is reciprocally driven in a linear direction by a drive mechanism 65. The platen roller 66 for feeding the paper is arranged such that its axis extends along the reciprocating direction of the carriage 64 and faces the head unit 6.

The carriage 64 has a guide shaft 71 and a guide plate 7 which are arranged in parallel with the support shaft of the platen roller 66.
It is slidably supported by 2. Pulleys 73 and 74 are supported near both ends of the guide shaft 71, and an endless belt 75 is stretched between these pulleys 73 and 74. The carriage 64 is fixed to the endless belt 75. In such a structure of the drive mechanism 65, when one pulley 73 is rotated in the forward and reverse directions by the drive of the motor 76, the carriage 64 is reciprocally driven linearly along the guide shaft 71 and the guide plate 72 accordingly. The printer head 63 is reciprocated.

The paper 62 is the ink jet printer 10.
Paper is fed from a paper feed cassette (not shown) provided on the side of 0, guided to a space between the head unit 6 and the platen roller 66, and a predetermined printing is performed by the ink ejected from the head unit 6. The paper is ejected after being processed. In FIG. 1, the paper feed mechanism and the paper discharge mechanism for the paper 62 are not shown.

The purging mechanism 67 includes the head unit 6
This is for forcibly sucking and removing defective ink containing air, dust, etc. accumulated in the inside. The purge mechanism 67 is provided on the side of the platen roller 66, and the purge mechanism 67 is disposed so as to face the head unit 6 when the printer head 63 reaches the reset position by the drive mechanism 65 described above. It is set. The purge mechanism 67 includes a purge cap 81,
The head unit 6 is brought into contact with the lower surface of the head unit 6 so as to cover a large number of nozzles (details will be described later) provided on the lower surface of the head unit 6. With this configuration, when the printer head 63 is at the reset position, the nozzle of the head unit 6 provided on the carriage 64 is attached to the purge cap 8
The defective ink containing air and the like, which is covered with No. 1 and is accumulated inside the head unit 6, is driven by the cam 83 to pump the defective ink.
The head unit 6 is restored by sucking with 2 and discarding it to the waste ink reservoir 84.
As a result, the air can be removed when the ink is initially introduced into the head unit 6, or the head unit 6 can be returned to the normal state from the ejection failure state that has been caused by the growth of the internal air accompanying printing. The cap 85 shown in FIG. 1 is for covering a large number of nozzles of the head unit 6 on the carriage 64, which is returned to the reset position after printing is completed, to prevent the ink from drying.

FIG. 2 is a perspective view of the printer head 63 which is turned upside down. The body frame 68 of the printer head 63 is located on the upper surface side (the lower surface side in FIG. 2) as shown in FIG. Is formed into a substantially box shape with an open side, and four ink cartridges 61 are detachably mountable from the open side to form a mounting portion. As shown in FIG.
At one side of the mounting portion of the main body frame 68, ink supply passages 4, 4, 4, 4 that can be connected to the ink discharge portion of each ink cartridge 61 are provided. (The surface on the side to be treated). A joint member 47 made of rubber or the like, which is brought into close contact with the ink supply port 19 of the head unit 6, is attached to the lower surface of the bottom plate 5 so as to correspond to each ink supply passage 4.

As shown in FIG. 2, on the lower surface side of the bottom plate 5,
Four support portions 8 for arranging four head units 6 in parallel are formed in a stepped shape. Each support part 8
In this, a plurality of cavities 9a and 9b for fixing the head unit 6 with a UV adhesive are formed so as to penetrate vertically.

A perspective view of the head unit 6 is shown in FIG. 4. The head unit 6 has a laminated cavity plate 10, and a plate type piezoelectric actuator (hereinafter referred to as “actuator”) is provided for the cavity plate 10. ) 20 are bonded and laminated via an adhesive or an adhesive sheet. Further, on the upper surface of the actuator 20, a flexible flat cable 40 for electrical connection with an external device is overlapped and bonded with an adhesive. A large number of nozzles 15 are opened on the lower surface side of the lowermost cavity plate 10, and ink is ejected downward from each nozzle 15.

FIG. 5 is an exploded perspective view of the cavity plate 10, and FIG. 6 is an exploded enlarged perspective view of the cavity plate 10 (cross section taken along line VI-VI in FIG. 4). As shown in FIG. 5, the cavity plate 10 includes a nozzle plate 11 and two manifold plates 12X.
12Y, the spacer plate 13, and the base plate 14, a total of five thin metal plates are laminated and bonded with an adhesive.

As shown in FIG. 5, a large number of nozzles 15 for ejecting ink having a minute diameter (about 25 μm in this embodiment) are formed on the nozzle plate 11 at minute intervals. The nozzles 15 are arranged in two staggered rows along the longitudinal direction of the nozzle plate 11.

As shown in FIG. 6, the base plate 14 has a plurality of pressure chambers 16 formed in a narrow width such that the longitudinal direction thereof is orthogonal to the longitudinal direction of the base plate 14.
16 ... are punched in two rows in a staggered arrangement.
Further, on the side of the base plate 14 facing the spacer plate 13, there are recessed portions 16d connected to the pressure chambers 16 and ink supply holes 16b connected to the throttle portions 16d. Each ink supply hole 16b is
The spacer plates 13 are communicated with common ink chambers 7 (described later) formed by the manifold plates 12X and 12Y through the ink supply holes 18 formed on both left and right sides of the spacer plate 13.

The one end 16a of each pressure chamber 16 is
The spacer plate 13 and the two manifold plates 12X and 12Y are also communicated with the above-mentioned nozzles 15 of the nozzle plate 11 through through holes 17 of small diameter which are also formed in a staggered arrangement.

Two manifold plates (12X.1
2Y), the manifold plate 12X closer to the spacer plate 13 is attached to the manifold plate 12X.
Two ink chamber half portions 12a and 12a are formed penetrating X. On the other hand, the manifold plate 12Y on the nozzle plate 11 side is the same as the manifold plate 1 on the other side.
Two ink chamber half portions 12b and 12b are formed so as to be opened only toward the 2X side. And
By stacking the three manifold plates 12X and 12Y and the spacer plate 13 in total, the corresponding upper and lower ink chamber half portions 12a and 12b are joined to each other, and as shown in FIG. Two common ink chambers 7 are formed, one on each side of the 17 rows.

The two common ink chambers 7 are provided on both sides of the row of through holes 17 in order to correspond to the pressure chambers 16 arranged in two rows. That is, the pressure chamber group on the one row side of the two rows arranged is communicated with one common ink chamber 7, and the pressure chamber group on the other one row side is communicated with the other common ink chamber 7. By configuring the head unit 6 in this way, inks of different colors are supplied to the two common ink chambers 7, 7 to form one head unit 6.
It is also possible to use it in a printing mode in which two-color printing is performed, and the versatility of the head unit 6 is enhanced to reduce the types of parts. However, in the present embodiment, the same color ink is supplied to both common ink chambers 7 and 7, and the two rows of nozzles 15 perform single-color high-resolution printing.

As shown in FIG. 5, the base plate 14 is provided with two ink supply holes 19a, 19a, and the spacer plate 13 is also provided with ink supply holes 19b, 19b.
19b is provided. By joining the base plate 14 and the spacer plate 13, the corresponding ink supply holes 19a and 19b are connected to each other, and the ink supply port 1 corresponding to each of the two common ink chambers 7 and 7 described above.
9 ・ 19 is formed. Due to the demand for miniaturization of the head unit 6, the ink supply ports 19 and 19 are formed at a position close to the end of the row formed by the plurality of pressure chambers 16 and 16, and two ink supply ports are provided. 19 and 19 are arranged close to each other.

With the configuration of the cavity plate 10 as described above, the common ink chamber 7 is connected to the ink supply ports 19 and 19 described above.
The ink that has flowed into the inside 7 is the ink supply holes 18 and 16
It is distributed from b to the pressure chambers 16 through the throttle portion 16d. Then, the ink in each pressure chamber 16 has one end portion 1
6a to the corresponding nozzle 15 through each through hole 17, 17 ...

FIG. 9 shows an exploded enlarged perspective view of the actuator 20. As shown in FIG. 9, the actuator 20 has a structure in which two types of piezoelectric sheets 21 and 22 and one insulating sheet 23 are laminated. On the upper surface of the one piezoelectric sheet 21, a plurality of narrow drive electrodes 24 corresponding to each pressure chamber 16 in the cavity plate 10,
They are arranged in a staggered arrangement. In addition, one end 24 a of each drive electrode 24 is connected to the front and back surfaces 20 a of the actuator 20.
It is formed so as to be exposed on the left and right side surfaces orthogonal to 20b.

On the upper surface of the other piezoelectric sheet 22, a common electrode 25 common to the plurality of pressure chambers 16 is provided. The one end portion 25a of the common electrode 25 is also formed so as to be exposed on the left and right side surfaces, similarly to the one end portion 24a of each drive electrode 24. A plurality of piezoelectric sheets 21 and 22 are alternately laminated, and the respective regions of the piezoelectric sheets 21 and 22 sandwiched between the drive electrodes 24 and the common electrode 25 are
The pressure generating unit corresponds to each pressure chamber 16.

On the upper surface of the uppermost insulating sheet 23, a surface electrode 26 for each drive electrode 24 and a surface electrode 27 for the common electrode 25 are provided side by side along the left and right side surfaces.

Further, on the left and right side surfaces, a first recessed groove 30 is formed at one end 24a of each drive electrode 24, and a second recessed groove 31 is formed at one end 25a of the common electrode 25 so as to extend in the stacking direction. It is provided. Side electrodes (not shown) that electrically connect the drive electrodes 24 and the surface electrodes 26 are provided in the first recessed grooves 30, and the common electrodes 25 are provided in the second recessed grooves 31. Side electrodes (not shown) that electrically connect to the surface electrodes 27 are formed respectively.
Note that the electrodes 28 and 29 are electrodes in a discarded pattern.

Cavity plate 1 having the above structure
0 and the actuator 20 correspond to the cavity plate 10
The pressure chambers 16 and the driving electrodes 24 of the actuator 20 are laminated so as to correspond to each other. Also, on the upper surface 20a of the actuator 20,
Various wiring patterns (not shown) in the flexible flat cable 40 are electrically joined to the surface electrodes 26 and 27.

In the above structure, when the paper 62 is fed from the paper feed cassette (not shown), the motor 76 is driven and the carriage 64 is moved along the guide plate 72.
Move from the reset position to the specified position.

Then, any drive electrode 2 of the drive electrodes 24 of the actuator 20 in the head unit 6 is selected.
4 is applied between the common electrode 25 and the common electrode 25, a piezoelectric layer 22 is distorted in the stacking direction due to the piezoelectric force in the portion of the piezoelectric sheet 22 where the voltage is applied, that is, the pressure generating portion. Volume is reduced. Thus the pressure chamber 16
Ejection energy is applied to the ink inside, and the ink is ejected in the form of droplets from the nozzle 15 to perform predetermined printing on the paper 62. In this way, printing is performed on the paper 62 while the carriage 64 reciprocates in the linear direction along the guide plate 72. When printing is completed, the carriage 64
The printer head 63 mounted on the printer returns to the purge position (or reset position), and the plurality of nozzles 15 of the head unit 6 are covered with the cap 81 (or 85).

Next, one ink cartridge 6 is inserted into the above-mentioned two ink supply ports 19 and 19 of the head unit 6.
A configuration in which the ink in 1 is branched and supplied will be described.

FIG. 3 shows a state in which four head units 6 are bonded to the bottom plate 5 of the main body frame 68 of the printer head 63. The bottom plate 5 is provided with four vertical ink supply passages 4, 4, 4, 4.

FIG. 10 is an enlarged view of the area shown by the chain double-dashed line in FIG. 3, in which the openings (the ends on the side closer to the head unit 6) formed on the lower surface of the bottom plate 5 by each ink supply passage 4 are formed. The opening) forms a tapered portion 51 as a shape that tapers toward the head unit 6.

The taper portion 51 of the bottom plate 5 and
The joint member 47 described above is provided between the head unit 6 and the head unit 6.
Is interposed and held. The joint member 47 has a tubular portion 47a having an internal space with a long hole in cross section, and a partition wall 47b formed therein. The partition wall 47b divides the internal space of the joint member 47 into two parts. The separated internal space on one side is the ink supply port 19 on one side of the head unit 6, and the internal space on the other side is the ink supply port 19 on the other side. ,
Communicate with each other. When the head unit 6 is adhered to the bottom plate 5 with a UV adhesive, the joint member 47 is formed around the ink supply port 19 in the head unit 6.
The cylindrical portion 47a and the partition wall 47b are in elastic contact with each other. As a result, one end of the joint member 47 comes into close contact with the head unit 6 and is pressed to perform a sealing action, thereby preventing ink leakage from the portion.

As shown in FIG. 11 and FIG. 12 which is an exploded perspective view, parts of the main body frame 68 around the ends of the ink supply passages 4 (around the taper portion 51) are
A fitting portion 52 is formed by projecting in a cylindrical shape toward the head unit 6 side. The joint member 47 is fixed to the main body frame 68 by fitting the inner surface of the cylindrical portion 47 a of the joint member 47 to the outer surface of the fitting portion 52. With this configuration, the joint member 47 can be attached while being surely positioned with respect to the ink supply passage 4 of the main body frame 68. In addition, the size of the fitting portion 52 is made slightly larger than the size of the internal space of the cylindrical portion of the joint member 47, and the joint member 47 is fitted into the fitting fit shape so that the joint member 47 and the fitting portion 52 are fitted together. A seal action is obtained at the connection portion with 52, and the structure is such that ink does not easily leak.

An end portion of the partition wall 47b of the joint member 47 on the ink supply passage 4 side faces the tapered inner wall of the taper portion 51, but the taper is formed at the end portion of the partition wall 47b. Sloped surfaces 53, 53, which substantially correspond to the tapered expanded shape of the portion 51, are formed. By doing so, the ink supplied from the ink supply source inside the ink cartridge 61 and passing through the ink supply passage 4 is
As shown by the thick arrow in FIG. 10, the ink is gradually branched into a “Y” shape through the space between the tapered expanded shape of the tapered portion 51 and the inclined surfaces 53, 53, and the two ink supply ports 19 are provided.・ Distributed to 19 and led. In this way, since the branch channel of the ink can be formed gently, it is possible to configure an inkjet printer in which air is less likely to be accumulated in the branch channel and printing defects such as missing dots do not easily occur.

Further, with this structure, the increase of the flow passage cross-sectional area in the branch portion of the ink flow passage (in the present embodiment, the portion between the inner wall of the taper portion 51 and the inclined surface 53) is suppressed. Therefore, when the purge mechanism 67 sucks the ink from the nozzle 15 side as described above, the suction flow does not become weak even in the branched portion of the ink flow path. Therefore, it is possible to strongly suck and remove the air and dust accumulated in such a branched portion.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. . For example, in the above-described embodiment, the piezoelectric pressure generating unit is used in the actuator 20, but the pressure generating unit is not limited to this, and an electrostatic pressure generating unit or the like may be used. Further, when the joint member 47 is attached to the main body frame 68 side, the end portion of the partition wall 47b of the joint member 47 on the side where the inclined surface 53 is formed may project into the internal space of the tapered portion 51. By doing so, it is possible to further suppress the increase in the flow passage cross-sectional area at the branch portion of the ink flow passage, and a stronger suction flow can be obtained at the branch portion when purging by the purging mechanism 67. Further, the purging mechanism 67 can obtain the same effect not only with the structure for sucking from the nozzle side as described above but also with the structure for pressurizing from the ink supply source side to generate the ink flow.

[0047]

Since the present invention is constructed as described above,
The branch shape of the ink flow path can be made gentle, and it becomes difficult for air to collect in the branch portion. In addition, it is possible to suppress an increase in the flow passage cross-sectional area of the branch portion of the ink flow passage, and when purging is performed by the purging mechanism, a strong ink suction flow can be obtained at the branch portion, which is effective in sucking and removing air. Can be done.

[Brief description of drawings]

FIG. 1 is a perspective view showing a color inkjet printer according to an embodiment of the present invention.

FIG. 2 is a perspective view of a printer head. For convenience of illustration, the state is shown upside down.

FIG. 3 is a cross-sectional view showing a state in which a head unit is fixed to a body frame.

FIG. 4 is a perspective view of each component of the piezoelectric inkjet head.

FIG. 5 is an exploded perspective view of a cavity plate.

FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4, showing a disassembled state of the cavity plate.

FIG. 7 is an enlarged view of a manifold plate.

8 is a cross-sectional view taken along the line VIII-VIII in FIG. 4, showing a cross section of the cavity plate.

FIG. 9 is an exploded enlarged perspective view of the piezoelectric actuator.

FIG. 10 is an enlarged cross-sectional view in which a range surrounded by a chain double-dashed line in FIG. 3 is enlarged.

FIG. 11 is an exploded perspective view showing a main body frame, a head unit, and a joint member.

FIG. 12 is an enlarged cross-sectional view showing the configuration of a conventional ink branch flow channel.

[Explanation of symbols]

4 Ink supply passage 6 head unit 7 common ink chamber 15 nozzles 16 Pressure chamber 19 Ink supply port 20 actuators 47 Joint member 47b partition 51 Tapered part 53 inclined surface 63 printer head 68 Printer head body frame

Claims (3)

[Claims] 1. A plurality of nozzles for ejecting ink onto a printing surface, pressure chambers provided corresponding to the respective nozzles, and the plurality of pressure chambers divided into a plurality of groups. A plurality of common ink chambers that are provided to distribute the ink to the pressure chamber group, and an actuator configured to be able to apply ejection energy to the ink for each of the pressure chambers,
A head unit having an ink supply port formed in each of the common ink chambers, and a main body frame having an ink supply passage connectable to an ink supply source. An ink jet printer head configured such that the above head unit is fixed and one ink supply passage and a plurality of ink supply ports of one head unit are communicated with each other through an internal space of a tubular joint member. In the ink supply passage, the end on the head unit side has a shape that tapers toward the head unit, and the ink is branched into a plurality of ink supply ports in the internal space of the joint member. A partition wall for forming the partition wall is formed, and an end portion of the partition wall on the ink supply passage side has a substantially tapered shape of the ink supply passage. Characterized in that the response was inclined surfaces, the ink jet printer head. 2. The ink jet printer head according to claim 1, wherein the periphery of the ink supply passage of the main body frame is cylindrically projected toward the head unit, and the joint member is provided on the outer periphery of the protruding portion. An inkjet printer head characterized by being fitted together. 3. The ink jet printer head according to claim 1, wherein the joint member is made of a material having elasticity, and the head unit is in elastic contact with a periphery of an ink supply port of the head unit. An inkjet printer head, characterized in that it is held between a unit and the body frame.