JP2003320669A - Ink jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance bonding strength of a head unit 6 and a bottom plate 5 of a head holder. <P>SOLUTION: Adhesive pouring holes 9a and 9b are made through the bottom plate 5 of the head holder oppositely to the back at the side edge part of the head unit 6. A cavity unit 10 comprising a manifold plate, a spacer plate and a base plate laid in layer and constituting a head unit 6 has a side edge part extending along the long side thereof and formed into a level difference part 43a. While opposing the level difference part 43a to the adhesive pouring holes 9a and 9b, UV adhesive 7 is fed from above thus bonding the head unit 6 and the bottom plate 5 of the head holder rigidly. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a piezoelectric type ink jet printer head.

[0002]

2. Description of the Related Art In an on-demand type ink jet printer head of the prior art, an ink jet head unit (hereinafter simply referred to as a head unit) in which nozzle rows are arranged in a direction orthogonal to a printing direction has a plurality of nozzles. A pressure chamber formed for each of the nozzles, a cavity unit having a common ink chamber (manifold chamber) for supplying ink to the plurality of pressure chambers, and the pressure chamber provided on the back side of the cavity unit. And a flexible flat cable that transmits an electric signal to the piezoelectric actuator. As a method of fixing this head unit to the bottom plate of the head holder, the applicant of the present application has previously disclosed in Patent Document 1 that the bottom plate of the head holder is exposed to the side edge of the head unit and the back surface of the protective cover. An agent pouring hole is bored, a plurality of head units are arranged in parallel on the lower surface side of the bottom plate, and a photo-curable adhesive from the adhesive pouring hole,
For example, it has been proposed that a UV adhesive is dripped to fix the head unit and the protective cover to the bottom plate while the periphery of the protective cover is fixed to the bottom plate with a sealant.

Further, this ink jet printer head constitutes a cavity unit by laminating a plurality of plates each having the nozzle, the pressure chamber, the common ink chamber and an opening communicating with them.

[0004]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-144590

[0005]

However, if the cavity unit is formed by laminating a plurality of thin plates having the same shape in plan view as in the technique described in the above-mentioned Patent Document 1, Since the peripheral edge of the cavity unit and the end face in the thickness direction are on the same plane, if this end face portion is adhesively fixed to the bottom plate of the head holder or the like with an adhesive, the adhesive area becomes insufficient and the adhesive strength is increased. There was a problem that became weak.

Further, when each plate of the cavity unit is a conductor such as metal, it is desirable to ground the entire cavity unit to the ground potential. In that case, if the metal cover plate, which is the same as the side end surface of the cavity unit, is adhered and fixed via a conductive adhesive, the grounding work becomes extremely simple.

However, in order to stack the plates in the cavity unit, when the wide surfaces of the adjacent plates are pressure-bonded through the adhesive, the adhesive protrudes to the side end surface of the cavity unit, Since there is a phenomenon in which most of the side end faces are coated (covered) with an adhesive, even if the conductive adhesive is directly attached, the electrical continuity with the side end faces of each plate in the cavity unit becomes poor, There was also a problem that the grounding work was incomplete. In order to eliminate this inconvenience, it is necessary to peel off the coating portion once in a later step and then attach a conductive adhesive, which is troublesome.

The present invention has been made in order to solve the above-mentioned conventional problems, and improves the adhesive strength between the laminated cavity unit and other parts, and ensures the electrical conduction. It is a technical object to provide a printer head.

[0009]

In order to achieve the above-mentioned technical object, an ink jet printer head according to a first aspect of the present invention is provided with a plurality of nozzles arranged in a row on the front surface and a pressure for each nozzle. A cavity unit formed by stacking a plurality of plates each having a chamber and an ink flow path communicating with them, and an actuator for ejecting ink having an active portion that can be selectively driven for each pressure chamber are provided. In the laminated inkjet printer head, a stepped portion is formed between the side edges of a plurality of laminated plates having ink flow passages in the cavity unit so that the upper surface of the lower plate of the laminated layer is sequentially exposed. It is characterized by that.

An ink jet printer head according to a second aspect of the present invention has a plurality of nozzles arranged in a row on the front surface, pressure chambers for each nozzle, and an ink flow passage communicating with them. An ink jet printer head comprising: a cavity unit formed by laminating a plurality of plates; and an actuator that has an active portion that can be selectively driven for each pressure chamber and ejects ink. A flat portion or a side edge portion of a plurality of laminated plates having ink flow passages is provided with a notch portion or a hole portion having a step so that the upper surface of the lower layer plate of the laminated layer is sequentially exposed. It is a feature.

The invention described in claim 3 is the same as claim 1.
In the inkjet printer head according to the second aspect, the back surface of the actuator and the back surface of the cavity unit face the bottom plate of the head holder, and a side edge portion of the back surface of the cavity unit having the step portion or a cut having the step portion is provided. The notch or hole is fixed to the bottom plate with an adhesive.

According to a fourth aspect of the present invention, in the ink jet printer head according to the third aspect, the bottom plate has a side edge portion having the step portion in the cavity unit, or a notch portion having the step or The adhesive pouring hole facing the hole is formed.

Further, the invention according to claim 5 is the ink jet printer head according to any one of claims 1 to 4, wherein a protective cover having an opening window surrounding the nozzle row of the cavity unit is provided in the cavity. It is arranged on the front surface of the unit, and the cavity unit and the protective cover are fixed by the adhesive.

According to a sixth aspect of the present invention, in the ink jet printer head according to any of the first to fifth aspects, a plurality of plates having the step portion or the notch portion having the step or the hole portion. Comprises a base plate in which the pressure chambers are formed in rows, an ink flow passage for supplying ink to each pressure chamber in the base plate, and an ink flow path connecting each pressure chamber to each nozzle in the outermost nozzle plate. And a manifold plate having a manifold for replenishing the ink from the ink supply source with ink via the spacer plate.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a color ink jet printer which is one of the embodiments of the ink jet recording apparatus of the present invention, and FIGS. 2 to 4 are perspective views of a piezoelectric ink jet printer head according to the embodiment of the present invention. FIG. 5 is a side sectional view showing a bonding / fixing view of a head unit and a head holder, FIG. 6 is an enlarged sectional view of an essential part, FIG. 7 is an enlarged sectional view of a head unit, and FIG. 8 is an element of a cavity unit. FIG. 9 is an exploded perspective view, and FIG. 9 is an enlarged perspective view showing a main part of the cavity unit.

The color ink jet printer 100 according to the present invention is for printing on an ink cartridge 61 filled with four color inks of cyan, magenta, yellow and black, and a paper (recording medium) 62, for example. An inkjet printer head 63 including an inkjet head unit (hereinafter simply referred to as a head unit) 6, and a carriage 6 on which the ink cartridge 61 and the inkjet printer head 63 are mounted.
4, a drive unit 65 for reciprocating the carriage 64 in a direction orthogonal to the conveyance direction of the paper 62, a platen roller 66 extending in the reciprocating direction of the carriage 64 and facing the head unit 6, and a purging device. And 67.

The drive unit 65 is arranged at the lower end of the carriage 64 and extends in parallel with the platen roller 66, and a guide plate 72 arranged at the upper end of the carriage 64 and extends parallel to the carriage shaft 71. Two pulleys 73, 7 arranged between the carriage shaft 71 and the guide plate 72 and arranged at both ends of the carriage shaft 71.
4 and a timing belt 75 wound around the pulleys 73 and 74.

The carriage 64 joined to the timing belt 75 by the driving force from one pulley 73 that rotates according to the drive of the motor 76 is the carriage shaft 71.
It is supported by the guide plate 72 and can reciprocate linearly.

The paper 62 conveyed in the direction of the arrow from a paper supply unit (not shown) is introduced between the platen roller 66 and the head unit 6, and a predetermined printing is performed by the ink ejected from the head unit 6 as described later. Then, the sheet is ejected.

The purging device 67 is provided on the side of the platen roller 66 and is arranged so as to face the head unit 6 when the printer head 63 is in the reset position. The purging device 67 includes a purge cap 81 that abuts against an opening surface of a nozzle of the head unit 6 so as to cover a plurality of nozzles 11 a described later, and a pump 82.
And a cam 83 and an ink storage portion 84. When the printer head 63 is in the reset position, the defective ink containing bubbles or the like accumulated inside the head unit 6 is sucked by the pump 82 by the driving of the cam 83 so that the head unit 6 can be recovered. There is. The sucked defective ink is stored in the ink storage unit 84.
Stored in.

Platen roller 6 in purging device 67
A wiper member 86 is arranged adjacent to the purging device 67 at a position on the 6 side. The wiper member 86 is formed in a spatula shape and wipes the nozzle opening surface of the head unit 6 as the carriage 64 moves. When wiping the nozzle opening surface, the wiper member 86 projects upward, and when not wiping the nozzle opening surface, retracts downward.

The cap 85 covers the plurality of nozzles 11a of the head unit 6 mounted on the carriage 64 which is returned to the reset position when printing is completed in order to prevent the ink from drying.

First of Inkjet Printer Head 63
In the embodiment, as shown in FIGS. 2 and 3, the head holder 1, the two head units 6 and 6 arranged in parallel on the lower surface side of the bottom plate 5, and the nozzle row on the surface of each head unit 6 are exposed. The opening windows 44a, 44a which are configured to
4b, and is constituted by the surfaces of the head units 6, 6 and a box-shaped protective cover 44 fixed to the head holder 1.

The head holder 1 in the first embodiment is
As shown in FIGS. 2 to 5, an injection-molded product of synthetic resin material such as polypropylene, polypropylene, etc.
(See 3)). In this opening,
It has a mounting portion 3 on which four ink cartridges 61 as an ink supply source can be detachably mounted from above, and the ink cartridges 6 are provided on one side of the mounting portion 3.
The ink supply passages 4a, 4b, 4c and 4d connectable to the ink discharge portion (not shown) of No. 1 are the bottom plates 5 of the head holder 1.
Is provided so as to communicate with the lower surface of the (see FIG. 3). In addition, each ink supply passage 4a, 4b, 4c, 4d
A rubber packing (not shown) is provided on the outer periphery of the ink cartridge 61 so that the ink cartridges 61 can be brought into close contact with the ink discharge portion.
Are arranged.

The bottom plate 5 is for disposing the head unit 6, and is formed horizontally so as to project one step from the lower surface (the upper surface side in FIG. 4) of the head holder 1. On the lower surface side of the bottom plate 5, two support portions 8 for supporting two head units 6 which will be described later in parallel are formed. A plurality of adhesive pouring holes 9a, 9b for fixing the head unit 6 with the UV adhesive 7 are formed in each of the supporting portions 8 so as to penetrate toward the mounting portion 3 side. The plurality of adhesive injection holes 9a, 9
b is formed at a position where the long side portions of one head unit 6 are fixed at appropriate intervals. In the embodiment, the adhesive pouring hole 9a at a position where one side (long side) of the two supporting portions 8 and 8 adjoins each other is formed wide so as to straddle the back surfaces of the two head units 6 and 6 arranged in parallel. Has been done.

As shown in FIG. 4, the ink supply passages 4a, 4b, 4c, 4 are provided at one side of the support portions 8 as shown in FIG.
An opening 50 communicating with d is provided. A substantially annular fitting groove 46 is formed so as to surround the outer periphery of each opening 50. Then, in each of the fitting grooves 46, a ring-shaped packing 4 made of soft rubber or the like and having a good sealing property is provided.
7 is fitted.

When each head unit 6 is fixed to the lower surface of the bottom plate 5 with a UV adhesive 7 as described later, the tip of the packing 47 is an ink supply port 19a in the head unit 6 (see FIG. 8). ), The contact portion with the ink supply port 19a is sealed and ink leakage can be prevented.

Before that, first, the details of the head unit 6 and each component thereof will be described. Head unit 6
7 to 9, a plurality of metal plate laminated cavity units 10 and an ink impermeable adhesive or adhesive sheet 41 for the cavity units 10 (see FIG. 7). The plate-type piezoelectric actuator 20 is adhered and laminated through the plate-shaped piezoelectric actuator 20, and the flexible flat cable 40 is superposed on the upper surface of the plate-type piezoelectric actuator 20 for electrical connection with an external device.

On the back surface side of the head unit 6 and on the upper surface of the ink supply port 19a formed at one end of the uppermost base plate 14, the ink supplied from the ink cartridge 61 above the ink supply port 19a. A filter 29 for removing dust is previously fixed with an adhesive (see FIG. 8). When the cavity unit 10 is assembled to the head holder 1, the ink supply port 19a presses the periphery of the ink supply port 19a against the packing 47.

The cavity unit 10 is constructed as shown in FIGS. 8 and 9. That is, it has a structure in which five thin metal plates of the nozzle plate 11, the two manifold plates 12, the spacer plate 13, and the base plate 14 are lapped and bonded with an adhesive. In the embodiment, each plate except the nozzle plate 11 is joined. Is
It is made of 42% nickel alloy steel plate and has a thickness of about 50 μm to 150 μm.

The nozzle plate 11 is provided with a plurality of nozzles 11a arranged in a zigzag pattern in two rows along the long side direction (first direction). The base plate 14 has a plurality of pressure chambers 16 arranged in a zigzag pattern in two rows corresponding to the arrangement of the nozzles 11a. Each pressure chamber 16 extends in the short side direction of the base plate 14 from parallel reference lines 14a and 14b in the longitudinal direction. The tip 16a of each pressure chamber 16 located near the center of the base plate 14 in the short side direction is provided with a corresponding nozzle 1 through a spacer plate 13 and a through hole 17 as an ink flow passage formed in the manifold plates 12, 12.
It communicates with 1a.

The other end 16b of each pressure chamber 16 is shown in FIGS.
As shown in FIG. 2, the manifold plates 12, 12 are formed through the through holes 18 formed in the spacer plate 13 so as to be opened so as to open on the lower surface side of the base plate 14.
To the common ink chambers (manifold chambers) 12a and 12b. The common ink chambers 12a and 12b are formed to be long in the respective column directions corresponding to the respective columns of the two pressure chambers 16, and one ends thereof are connected to the ink supply ports 19a and 19b formed in the base plate 14 and the spacer plate 13. It is in communication. Each of the common ink chambers 12a and 12b has an opening 12a formed through the upper manifold plate 12 and a recess 12b formed in the lower manifold plate 12.
And are overlapped with each other, and the upper surface is covered with the spacer plate 13 (see FIG. 7).

As a result, the ink supply ports 19a, 1
The ink that has flowed into the common ink chambers 12a and 12b from 9b is distributed from the common ink chambers 12a and 12b into the pressure chambers 16 through the through holes 18, and then inside the pressure chambers 16a and 16b. From the through holes 17, 17, 1
The nozzle 11a corresponding to the pressure chamber 16 passes through 7 (see FIGS. 7 and 9).

Then, as shown in FIG. 8, the dimension of each plate in the width direction (direction orthogonal to the row of nozzles 11a, short side direction) is defined by the dimension D1 of the base plate 14 and the dimension D2 of the spacer plate 13 ( = D1 + Δd), the dimension D3 (= D2 + Δ) of the upper manifold plate 12
d), the dimension D3 of the lower manifold plate 12 (=
D3 + Δd), the base plate 14 has the smallest width dimension and the lower manifold plate 12 has the largest width dimension. When stacking on the cavity unit 10, each plate 12, 12, 1
The stepped portions 43a are formed so that the pair of long side portions 3 and 14 are stepwise from the lower layer position to the upper layer position (see FIGS. 7 and 6). In other words, the cavity unit 10 is formed with a step portion 43a at its side edge portion so that the upper surface of the lower layer side plate is sequentially exposed.

On the other hand, the piezoelectric actuator 20 has a structure similar to that described in Japanese Patent Application Laid-Open No. 2001-162796, and has a structure in which a plurality of piezoelectric sheets 21 are laminated. Narrow width individual electrodes (not shown) are formed by printing on the upper surface (wide width surface) of a predetermined number of layers of the piezoelectric sheet 21 at each position of each pressure chamber 16 in the cavity unit 10. The upper surface (wide surface) of the piezoelectric sheet 21 that is alternately laminated with the sheet.
A common electrode (not shown) common to the plurality of pressure chambers 16 is also formed on the same. Each individual electrode and the common electrode are electrically connected to a connection terminal (not shown) formed on the upper surface of the top sheet 23 of the uppermost stage via side surface electrodes 32 and 33 extending along the side surface of the piezoelectric actuator 20. ing.

The plate-type piezoelectric actuator 20 having such a structure is used in the cavity unit 10 described above.
On the other hand, each individual electrode in the piezoelectric actuator 20 corresponds to each pressure chamber 1 in the cavity unit 10.
6 are laminated and fixed so as to correspond to each of them. Further, the flexible flat cable 40 is superposed on the upper surface of the piezoelectric actuator 20, so that various wiring patterns (not shown) of the flexible flat cable 40 are electrically connected to the connection terminals. (See FIG. 7).

In this structure, between the individual electrode and the common electrode of the piezoelectric actuator 20, an active portion of the piezoelectric element is formed in which a strain is generated in the stacking direction when a voltage is applied. By selectively generating strain in the active portion, the internal volume of the pressure chamber 16 is reduced, and the ink in the pressure chamber 16 is transferred to the nozzle 11
Predetermined printing is performed by ejecting droplets from a.

Next, the head unit 6 is attached to the head holder 1
A method of firmly fixing the above will be described. The adhesive used for this fixing is a photo-curing adhesive, for example, a viscous UV adhesive 7 such as a modified acrylic resin adhesive as an adhesive having a quick-curing property upon irradiation with ultraviolet rays.
As shown in FIGS. 5 and 6, the two head units 6 and 6 and the protective cover 44, which are arranged in parallel, are fixed to the bottom plate 5 of the head holder 1 with the UV adhesive 7 at the same time, or protected. The cover 44 may be fixed later.

Regarding the method of fixing the head unit 6 to the head holder 1, for example, two positioning holes 54a, 54a separated in the extension direction of the row of the nozzles 11a of the nozzle plate 11 are formed in advance (see FIG. 8). ).

The lower plate 44b of the protective cover 44 is set on the upper surface of the flat jig, and the two nozzle plates 11 are
An opening window 44 formed in the lower plate 44b of the protective cover 44
a, 44a, and positioning holes 54a, 54a in each nozzle plate 11
Locating pin (not shown) protruding from the upper surface of the jig
Fit in. In this case, the lower plate 44b of the protective cover 44
Is preferably slightly thicker than the nozzle plate 11.

In this way, both head units 6, 6
The nozzles 11a are set so that the intervals between the rows are constant and parallel to each other. On top of them, head holder 1
The head units 6, 6 to correspond to the predetermined positions of the supporting portions 8, 8 and then the upper surface of the bottom plate 5, that is, the mounting portion 3
The UV adhesive 7 is poured from the side into the adhesive pouring holes 9a and 9b, and immediately thereafter, UV rays are irradiated from the upper surface of the bottom plate 5 toward the inside of the adhesive pouring holes 9a and 9b to rapidly cure the UV adhesive 7. Two head units 6, 6
The head units 6 and 6, the protective cover 44, and the head holder 1 are fixed at the same time.

In this case, the side end of the long side of the cavity unit 10 in each head unit 6 is formed as a stepped step portion 43a (see FIGS. 6 and 7).
The adhesion area with the V adhesive 7 is increased, and the adhesion strength of this portion can be significantly improved.

The front surface of each head unit 6 and the back surface of the lower plate 44b of the protective cover 44 may be preliminarily adhered and fixed by an adhesive (not shown), or only the protective cover 44 may be adhered and fixed later. You may. Further, as shown in FIG. 5, sealing agents 55a and 55b such as silicone are injected between the inner surface of the four sides of the box-shaped protective cover 44 and the stepped portion of the bottom plate 5 of the head holder 1 to seal them. At the time of printing,
Ink during the wiping by the wiper member 86 is prevented from entering the gap between the head unit 6 and the protective cover 44.

The side surface electrodes 32 and 33 formed on the side surfaces on the long side of the piezoelectric actuator 20 do not come into direct contact with the back surface of the cavity unit 10 having conductivity such as metal to prevent a short circuit. On the back
An insulating groove 95 is formed so as to form a space with the lower end of the side surface electrode 32 (33). Further, as shown in FIG. 6, the adhesive is poured into a portion of the back surface of the cavity unit 10 in each of the head units 6 that is closer to the outer periphery than the outer peripheral edge (the long side edge in the embodiment) of the piezoelectric actuator 20. One or a plurality of recessed grooves 93 for stopping the flow of the UV adhesive 7 are formed on the inner peripheral side of the positions of the holes 9a and 9b.

On the other hand, a portion of the lower surface of the bottom plate 5 near the outer periphery of the adhesive pouring holes 9a, 9b is formed with a close portion 5a having a small gap with respect to the back surface of the head unit 6 (cavity unit 10 in the embodiment). Therefore, the accumulation groove 93 is arranged so as to face the proximity portion 5a. With this configuration, the viscous UV adhesive 7 injected into the adhesive injection holes 9a and 9b
However, since it accumulates in the one or more accumulating grooves 93 in the adjacent portion 5a, a large diffusion such that the uncured portion of the UV adhesive 7 approaches the side edge of the piezoelectric actuator 20 on the back surface side of the head unit 6. Leakage can be reliably prevented. Further, since the reservoir groove 93 is located in the vicinity of the outer periphery of the adhesive pouring holes 9a and 9b, the UV adhesive 7 accumulated in the reservoir groove 93 is more likely to be exposed to ultraviolet rays, and curing can be promoted. It is possible to prevent the uncured portion of the adhesive 7 from being generated.

Incidentally, for example, by arranging the casting holes 9a and 9b in the vicinity of the four corners of the head unit 6 having a rectangular shape in plan view, when the UV adhesive 7 is solidified, the head unit 6 due to the contraction strain of the adhesive is solidified. It is possible to minimize the positional deviation of. Head units 6 and 6 arranged in parallel
When the casting hole 9a is formed wide across the adjacent sides of, the UV adhesive 7 is filled in one casting hole 9a, and the two units 6 and 6 are solidified at one time by ultraviolet irradiation. This can contribute to the reduction of working time and the great improvement of manufacturing efficiency.

Further, in a state where the plurality (single) of cavity units 10 and the protective cover 44 are overlapped with each other, a part of the stepped portion 43a provided in the cavity unit 10, for example, a portion separated from a portion where the UV adhesive 7 is attached. Then, the conductive adhesive 96 is hung down so as to cover the entire thickness direction, and the cavity unit 10 and the protective cover 44 are electrically connected so that they have the same potential (see FIG. 10). Alternatively, the cavity unit 10 and the protective cover 44 may be attached to the head holder 1 using a conductive adhesive instead of the UV adhesive.
Fixed to. As a result, even if the adhesive between the metal plates 12, 12, 13, 14 in the cavity unit 10 protrudes into a part (root portion) of the step 43a, the plates 12, 12, 13, 14 are not formed. Since the side end surface of each plate (the portion in the thickness direction of each plate) is not coated with the protruding portion of the adhesive, the conductive adhesive directly electrically contacts the metal surface of the side end surface of each plate. It can be covered just like a connection, and grounding work can be performed reliably and easily. The protective cover 44 is connected to the ground potential line of the flexible flat cable 40 via a conductive member (not shown). The stepped portion 43a provided in the cavity unit 10 may be provided not on the long side but on the short side.

FIG. 11 shows a second embodiment of the step portion,
The side edges of the plates 12, 12, 13 and 14 are provided with notches 43b having steps so that the upper surfaces of the lower plates are sequentially exposed. In other words, this embodiment is formed such that the area of the cutout portion 43b in the lower layer side plate is small, and the area of the cutout portion 43b becomes larger as going to the upper layer plate 12 → 13 → 14. is there. In this embodiment, in plan view, a part of the upper surface of the lower plate of the notch 43b having a step, for example, the lower plate looks like an L shape in plan view or one side. The notch 43b may have a polygonal shape such as a triangle or a curved shape such as an arc, in addition to a quadrangle. The notch may be omitted only in the lowermost plate.

In the third embodiment of the step portion shown in FIG. 12,
Stacked plates 12, 1 of cavity unit 10
Holes 43c having an arbitrary shape in a plan view such as a quadrangle are formed on the wide surfaces (planar portions) of 2, 13, and 14, and the hole portions 43c are
The upper surface of the plate on the lower layer side of the stack is formed to be sequentially exposed.

The notch portion 43b and the hole portion 43c having the steps of the second and third embodiments are provided with the adhesive pouring holes 9a and 9a.
It is formed at a position facing b. As a result, the adhesive area with the adhesive can be significantly increased without increasing the plane area of each plate, and the adhesive strength can be enhanced. In addition, the cavity unit 10
It is a suitable means for locally strongly bonding.

The number of head units 6 to be arranged in parallel can be arbitrarily set to 2 to 4, and the cavity unit 10 in the head unit 6 may be a metal material or a ceramic material. Further, the driving means of the ink jet printer of the present invention may be another type of the plate-shaped piezoelectric actuator 20 described above, or the vibrating plate covering the back surface of the pressure chamber is vibrated by static electricity so that the ink is ejected from the nozzle 11a. Alternatively, it may be configured to be discharged from.

[0052]

As described above, claim 1
The ink jet printer head of the invention described in (1) above is formed by laminating a plurality of plates each having a plurality of nozzles arranged in a row on the front surface, a pressure chamber for each nozzle, and an ink flow passage communicating with them. In an ink jet printer head in which a cavity unit consisting of the above and an actuator for ejecting ink having an active portion that can be selectively driven for each pressure chamber are stacked, a plurality of ink flow passages in the cavity unit are provided. Between the side edges of the stacked plates, there is a stepped portion such that the upper surfaces of the lower plates of the stacked layers are sequentially exposed.

According to this structure, when the ink jet printer head is fixed with the adhesive, the contact area between the cavity unit and the adhesive increases, and the adhesive strength increases. Also, when the wide surface of each plate is laminated and fixed with an adhesive, the side end surface of each plate will not be coated with the adhesive even if the adhesive protrudes from the end of each plate. Therefore, if each plate is made of a conductive material and a conductive adhesive is attached to the stepped portion, the cavity unit can be reliably connected to the ground potential easily.

An ink jet printer head according to a second aspect of the present invention has a plurality of nozzles arranged in a row on the front surface, a pressure chamber for each nozzle, and an ink flow passage communicating with them. An ink jet printer head comprising: a cavity unit formed by laminating a plurality of plates; and an actuator that has an active portion that can be selectively driven for each pressure chamber and ejects ink. A flat portion or a side edge portion of a plurality of laminated plates having ink flow passages is provided with a notch portion or a hole portion having a step so that the upper surface of the lower layer plate of the laminated layer is sequentially exposed. It is a feature.

According to this structure, the same effect as the effect according to the invention described in claim 1 can be obtained.

The invention described in claim 3 is the same as claim 1
In the inkjet printer head according to the second aspect, the back surface of the actuator and the back surface of the cavity unit face the bottom plate of the head holder, and a side edge portion of the back surface of the cavity unit having the step portion or a cut having the step portion is provided. The notch or hole is fixed to the bottom plate with an adhesive.

The side edge having the step and the notch or hole having the step have a horizontal plane formed by the step more than the case where the side end surfaces in the thickness direction of the plurality of plates are on the same plane. The area is increased by the amount of the area, and therefore, the bottom plate of the head holder and the cavity unit are bonded and glued together.
Since the area of contact with the adhesive at the time of fixing is increased and the adhesive strength is increased, there is an effect that it can be firmly fixed. Further, by providing the cutout portion or the hole portion at an appropriate position of the cavity unit, there is an effect that the adhesive force can be locally strengthened.

According to a fourth aspect of the present invention, in the ink jet printer head according to the third aspect, the bottom plate has a side edge portion of the cavity unit having the step portion, or a notch portion having the step or The adhesive pouring hole facing the hole is formed.

Therefore, when viewed from the side of the adhesive pouring hole formed in the bottom plate, the stepped portion can see the step-like flat surface (upper surface) of each laminated plate, and from this adhesive pouring hole side When the adhesive is poured, the adhesive is surely brought into contact with the entire step portion, the notch, and the flat portion and the side end face portion of the hole, so that the adhesive area is surely increased, thereby ensuring the adhesive strength. It has the effect of being able to increase the size.

Further, the invention according to claim 5 is the ink jet printer head according to any one of claims 1 to 4, characterized in that the protective cover having an opening window surrounding the nozzle row of the cavity unit is provided in the cavity. Since it is arranged on the front surface of the unit and the cavity unit and the protective cover are fixed by the adhesive,
In addition to the effects according to the invention described in claims 1 to 4, a side edge portion having a step in the cavity unit, a notch portion,
The protective cover and the bottom plate can be firmly fixed to the bottom plate by fixing the adhesive to the holes. Also,
The effect that the cavity unit and the protective cover can be simultaneously fixed to the bottom plate of the head holder is achieved.

According to a sixth aspect of the present invention, in the ink jet printer head according to any one of the first to fifth aspects, a plurality of plates having the step portion or the notch portion having the step or the hole portion. Comprises a base plate in which the pressure chambers are formed in rows, an ink flow passage for supplying ink to each pressure chamber in the base plate, and an ink flow path connecting each pressure chamber to each nozzle in the outermost nozzle plate. And a manifold plate having a manifold for replenishing the ink from the ink supply source with ink via the spacer plate. Therefore, it is possible to provide a flat and thin cavity unit in which each plate is laminated, and
The step portion can be easily formed by utilizing the outer circumferences of these plates.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet printer to which the present invention is applied.

FIG. 2 is a perspective view of the inkjet printer head with the nozzle side facing upward.

FIG. 3 is an exploded perspective view of components of the inkjet printer head.

FIG. 4 is an exploded perspective view of components of the inkjet printer head as viewed from above the head holder.

FIG. 5 is a side sectional view of a main part.

FIG. 6 is an enlarged cross-sectional view of a main part of FIG.

FIG. 7 is an enlarged side sectional view of the head unit.

FIG. 8 is a perspective view of each component of the cavity unit.

FIG. 9 is a partially enlarged perspective view of a cavity unit.

FIG. 10 is a cross-sectional view showing a state in which a cavity unit is bonded to a protective cover with a conductive adhesive.

FIG. 11 is a perspective view showing a cutout portion having a step.

FIG. 12 is a perspective view showing a hole having a step.

[Explanation of symbols]

1 head holder 5 bottom plate 5a Proximity part 6 head unit 7 UV adhesive 8 Support 9a, 9b Adhesive pouring hole 10 cavity unit 11 nozzle plate 11a nozzle 12 Manifold plate 13 Spacer plate 14 Base plate 20 Piezoelectric actuator 40 flexible cable 43a Step portion 43b Notch with step 43c Hole with step 44 Protective cover 44a open window

Claims (6)

[Claims] 1. A cavity unit formed by stacking a plurality of plates each having a plurality of nozzles arranged in a row on the front surface, a pressure chamber for each nozzle, and an ink flow passage communicating with them. An ink jet printer head in which an actuator for ejecting ink, which has an active portion that can be selectively driven for each pressure chamber, is stacked, and an ink flow path in the cavity unit is formed. An inkjet printer head having a stepped portion between the side edges so that the upper surface of the lower plate of the stacked layers is sequentially exposed. 2. A cavity unit formed by stacking a plurality of plates each having a plurality of nozzles arranged in a row on the front surface, a pressure chamber for each nozzle, and an ink flow passage communicating with the pressure chamber, An ink jet printer head in which an actuator for ejecting ink, which has an active portion that can be selectively driven for each pressure chamber, is stacked, and an ink flow path in the cavity unit is formed. An ink jet printer head, characterized in that a flat portion or a side edge portion is provided with a notch portion or a hole portion having a step such that the upper surface of the lower layer side plate of the stacked layers is sequentially exposed. 3. The back surface of the actuator and the back surface of the cavity unit are opposed to the bottom plate of the head holder, and a side edge portion of the back surface of the cavity unit having the step portion, or a notch portion or a hole portion having the step portion. The ink jet printer head according to claim 1 or 2, wherein is fixed to the bottom plate via an adhesive. 4. The bottom plate is provided with an adhesive pouring hole facing a side edge portion having the step portion of the cavity unit or a notch portion or a hole portion having the step. The inkjet printer head according to claim 3. 5. A protective cover having an opening window surrounding the nozzle row of the cavity unit is disposed on the front surface of the cavity unit, and the cavity unit and the protective cover are fixed by the adhesive. The inkjet printer head according to any one of claims 1 to 4. 6. The plurality of plates having the step portion or the notch portion having the step or the hole portion,
A spacer having a base plate in which the pressure chambers are formed in rows, an ink flow passage for supplying ink to each pressure chamber in the base plate, and an ink flow path connecting each pressure chamber to each nozzle in the outermost nozzle plate. 5. A plate and a manifold plate provided with a manifold for replenishing ink from an ink supply source to all the pressure chambers via the spacer plate are sequentially stacked, and the plates are sequentially stacked. An inkjet printer head according to claim 1.