JPH09150514A - Actuator unit for lamination type ink jet recording head and ink jet recording head using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To open piezoelectric vibrators from the blocking by a flexible cable and to limit connection work to one place by connecting the flexible cable to one electrodes of piezoelectric vibrators and providing connection terminals arranged so as to substantially become one row. SOLUTION: Terminals 5, 5' for outside connection are ones connected to electrodes 3, 3' and formed in the central region surrounded by two rows of pressure generation chambers so as to keep electrical insulating relation with respect to common electrodes 22, 22" and connected to the drive electrodes 3, 3' through auxiliary terminals 21, 21'. As a result, the flexible cable can be fixed in a central narrow region and, therefore, both sides thereof can be opened and can be raised from piezoelectric vibrators 4, 4' by a support member. Since the connection terminals 5, 5' are arranged in one row within a narrow range, they can be connected by one soldering work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first lid having a piezoelectric vibrator fixed to at least a surface thereof, a spacer forming a pressure generating chamber, a common ink chamber, and a communicating plate communicating with a nozzle plate. Stacking a second lid with holes,
The present invention relates to a stacked ink jet recording head actuator that is fixed to a flow path unit having a nozzle opening and a common ink chamber to form a recording head.

[0002]

2. Description of the Related Art A first lid having a piezoelectric vibrator fixed on its surface, a spacer for forming a pressure generating chamber, a common ink chamber, and a second communicating hole for communicating with a nozzle plate.
An ink jet recording head composed of an actuator unit formed by stacking the above lids and a flow path unit having a nozzle opening and a common ink chamber has a flat shape and the flow path unit and the actuator unit. Since a plurality of actuator units are fixed to a flow path unit that is relatively large in size so as to form a recording head, the large and high recording density recording head can be made compact and The advantage is that it can be manufactured with high yield.

[0003]

Such a recording head supplies the drive signal to the piezoelectric vibrators B and B'formed on the surface of the actuator unit A as shown in FIG. The connection terminals C and C ′ are provided on both sides of the piezoelectric vibrators B and B, and the flexible cable D is connected so as to straddle the piezoelectric vibrators B and B so that the drive signal from the drive circuit can be supplied to the piezoelectric vibrators B and B ′. Has been done.

Therefore, the flexible cable D comes into contact with the piezoelectric vibrators B and B ′ to adversely affect the vibration characteristics of the piezoelectric vibrators B and B ′, and the connection terminals C and C ′ and the flexible cable D are connected. The heat of soldering is piezoelectric vibrator B,
Even if the relative inclination θ between the flexible cable D and the actuator unit A is increased, the characteristics of the piezoelectric vibrator are deteriorated to B ′ and the width W between the connection terminals is increased. A gap of W × sin θ occurs with the terminal, and precise alignment work is required.

Further, such an ink jet type recording head can print at an extremely high resolution by reducing the size of the ink droplets because the dots on the recording medium are composed of ink droplets, but the efficiency is high. In order to print well, it is necessary to increase the number of nozzle openings,
When the piezoelectric vibrator is used as an ink droplet ejection source, miniaturization of the piezoelectric vibrator is a very important requirement.

However, a certain amount of driving force is required to fly the ink droplets, and there is a limit to miniaturization of the piezoelectric vibrator. In order to improve the recording density under these restrictions, a plurality of rows of nozzle openings are provided, and the nozzle openings of each row are arranged in a space of another row in a so-called staggered arrangement. ing.

By arranging the nozzle openings in a zigzag manner in this manner, it becomes possible to improve the recording density up to about 90 dpi to 180 dpi. It is theoretically possible to further increase the recording density up to about 360 dpi by increasing the number of nozzle opening rows, but since the size of the inkjet recording head in the main scanning direction, that is, the paper width direction increases, There is a problem in that the positions of the dots formed by the nozzle opening rows arranged at one end and the other end of the head are noticeably misaligned.

In order to solve such a problem, by arranging a dedicated reservoir for the pressure generating chamber rows communicating with the nozzle openings located at both outermost ends, the distance between the outermost nozzle opening rows is increased. There is proposed an ink jet type recording head in which the positional deviation of dots due to the inclination of the recording head is made as small as possible (Japanese Patent Laid-Open No. 5-84919).

In the recording head having the above-described arrangement, ink is supplied from the ink supply ports to the connection points of the reservoirs by independent supply conduits, so that it is easy to equalize the ink distribution to the reservoirs. However, there is a problem that the flow channel structure becomes complicated.

The present invention has been made in view of such circumstances, and an object thereof is to prevent contact between the piezoelectric vibrator and the flexible cable, and
It is an object of the present invention to provide an actuator unit that can be easily connected to a flexible cable.

Another object of the present invention is to provide an actuator unit which can prevent the deterioration of print quality by equalizing the error between dots due to the mounting error of the recording head without complicating the flow path. Is to provide.

[0012]

In order to solve such a problem, in the present invention, an ink supply port forming substrate having a communication hole communicating with a pressure generating chamber and an ink supply port,
A common ink chamber forming substrate having a common ink chamber communicating with the pressure generating chamber via the ink supply port, and a communication hole communicating with the pressure generating chamber, and another common ink chamber forming substrate. An actuator unit constituting an ink jet recording head fixed to a flow path unit formed by joining a surface and a nozzle plate having a nozzle opening connected to the pressure generating chamber through each of the communication holes. , A spacer made of ceramic forming two rows of pressure generating chambers with the center line as a line of symmetry, and one surface of the spacer is sealed, and the spacer is formed on the surface at a position corresponding to the pressure generating chamber. First with two rows of piezoelectric vibrators
The flexible cable is connected to the cover body and one electrode of the piezoelectric vibrator, and the connection terminals are arranged so as to form substantially one row.

[0013]

Since the connection terminals for the flexible cables for the two rows of the pressure generating chambers are arranged in substantially one row, the piezoelectric vibrator is released from the blockage by the flexible cables.
In addition, the connection work with the flexible cable can be completed at one place.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 is an assembled perspective view showing the entire recording head of the present invention, and FIG. 2 is a cross-sectional view showing the structure in the vicinity of a pressure generating chamber of one actuator unit, in which reference numeral 2 indicates the first. The lid is made of a thin plate of zirconia with a thickness of about 10 μm, and the common electrodes 22 and 22 ′ are formed on at least the region of the surface facing the pressure generating chambers 7 and 7 ′ to the peripheral portion. A common electrode 22, which faces the pressure generating chambers 7 and 7 ',
The piezoelectric vibrators 4 and 4'made of PZT or the like are provided on the surface of 22 '.
Are fixed, and the drive electrodes 3, 3'are further formed on the surface thereof by a film forming means such as sputtering or vapor deposition.

Reference numerals 5 and 5'represent terminals for connecting to the drive electrodes 3 and 3 ', which are shown in FIG. 3 in this embodiment so as to maintain an electrically insulating relationship with the common electrodes 22 and 22'. Is formed in the central region surrounded by the two rows of pressure generating chambers, and is connected to the drive electrodes 3 and 3'via auxiliary terminals 21 and 21 'that are also directly formed on the surface of the lid body 2. There is.

Since the terminals 5 and 5'for external connection are gathered in one place in this way, the connection work with the flexible cable 24 connected to the external device can be simplified as shown in FIG. Becomes That is, since the width W'of the terminals 5 and 5'is smaller than that of the terminals C and C '(FIG. 9) of the recording head having the terminals for connection on both sides,
The relative slight angle deviation between the flexible cable 24 and the recording head can be absorbed by the width of the connection terminals 5, 5 ', and the positioning work during soldering can be simplified.

Further, since the connection terminals 5 and 5'are arranged in a row in a narrow range and are arranged substantially in one row, they can be connected by a single soldering operation by the same heating means. .

As described above, since the flexible cable 24 is fixed in the narrow area in the central portion, both sides of the flexible cable 24 can be opened, and both sides of the flexible cable 24 are supported by the piezoelectric vibrators 4, It is possible to lift it from 4 ', and therefore the piezoelectric vibrators 4 and 4'and the flexible cable 4,
It is possible to reliably prevent contact with 4 '.

Further, since the soldering work can be performed in a small area, the bare I having the drive circuit and the like built therein as shown in FIG.
It is possible to directly fix the C chip to the connection terminals 5, 5 '.

Referring again to FIGS. 1 and 2, reference numeral 6 denotes a spacer, which is a ceramic plate of zirconia (ZrO2) having a thickness suitable for forming the pressure generating chambers 7 and 7 ', for example, 150 μm. The pressure generating chambers 7 and 7'are formed by forming through holes and sealing both surfaces with a second lid body 8 and a first lid body 2 described later. Pressure generating chamber 7, 7 '
Receives the flexural vibrations of the piezoelectric vibrators 4 and 4'and contracts and expands to eject ink droplets from the nozzle openings 18 and 18 '.
Further, the ink in the common ink chamber 16 is sucked through the ink supply ports 12 and 12 '.

Reference numeral 8 denotes a second lid, which is also a ceramic plate made of zirconia or the like, and nozzle communicating holes 9 and 9'which communicate with the nozzle openings 18 and 18 'at positions near the outside of the pressure generating chambers 7 and 7'. In addition, communication holes 10 and 10 'that communicate with the ink supply ports 12 and 12' are formed at the center side.

Each of these members 2, 6 and 8 is formed into a predetermined shape from a clay-like ceramic material, which is laminated and fired to form actuator units 1, 1 and 1 without using an adhesive. It is organized.

Reference numeral 11 denotes an ink supply port forming substrate, which also serves as a fixed substrate for the actuator units 1, 1, 1 and also has a common ink chamber 16 and pressure generating chamber at one end of the central portion of the pressure generating chambers 7, 7 '. Ink supply ports 12 and 12 'for connecting to the nozzles 7 and 7', and nozzle communication holes 13 and 13 'for connecting to the nozzle openings 18 and 18' are formed at positions outside the pressure generating chambers 7 and 7 '. It is constructed and set up.

Further, ink introduction ports 14, 14 and 14 into which ink flows from an ink tank (not shown) are formed at positions outside the fixing area of the actuator unit 1.

A common ink chamber forming substrate 15 has a thickness suitable for forming the common ink chamber 16, for example, 150.
Ink supply ports 12, 1 communicating with the two rows of pressure generating chambers 7, 7'on a plate material having corrosion resistance such as stainless steel of μm
2 ', a communication hole that serves as a common ink chamber 16 and a communication hole 1 that connects the nozzle openings 18, 18' to the outside thereof.
7, 17 'are formed by drilling.

Reference numeral 18 denotes a nozzle plate, which is formed in the nozzle communication holes 9 and 9'of each actuator unit 1, 1 and 1, the communication holes 13 and 13 'of the ink supply port forming substrate 11, and the common ink chamber forming substrate 15. Nozzle openings 18 and 18 'are formed in rows at a position where they can communicate with the communication holes 17 and 17', and a plurality of rows, that is, six rows in this embodiment are formed.

The ink supply port forming substrate 11, the common ink chamber forming substrate 15, and the nozzle plate 18 have an adhesive layer P such as a heat welding film or an adhesive between them.
The flow path unit 20 is assembled by P. Then, each actuator unit 1, 1, 1 is fixed to the flow path unit 20 by the adhesive layer P ′ to form an ink jet recording head.

In this embodiment, the nozzle communication holes 9, 9'of each actuator unit 1, 1, 1 are provided on both sides,
In addition, a communication hole 10, which communicates with the ink supply ports 12, 12 ',
Since 10 'is arranged on the center side, the distance L between the pair of nozzle openings 18, 18' of the nozzle plate 19 is increased as much as possible, and the distance between the actuator units 1, 1, 1 is appropriately set. By adjusting the distance L ′ between the nozzle opening rows of different actuator units to 1
Nozzle opening 1 belonging to one actuator unit 1
It can be set equal to the distance L of 8, 18 '.

When the distances L and L'between the nozzle rows are set to be equal to each other in this way, even if the recording head is tilted with respect to the moving direction of the carriage due to a mounting error of the recording head or the like, the paper feeding direction between the nozzle openings is set. Although the relative distance of changes, the relative error between the nozzle openings remains constant,
It is possible to prevent deterioration of print quality.

In the above embodiment, the terminals 5 and 5'connected to the drive electrodes 3 and 3'of the piezoelectric vibrators 4 and 4'in each row are arranged in different rows. By arranging them on the same straight line as shown, it is possible to further simplify the positioning work with the flexible cable 24 and the soldering work.

Further, in the above-described embodiment, the terminals connected to the flexible cable 24 are arranged in the area surrounded by the pressure generating chambers, but as shown in FIG. The lids 2 are arranged in a line on one side (right side in the figure), connected to the drive electrodes 3, 3'of each pressure generating chamber row by conductive patterns 26, 26 ', and on the other side (left side in the figure). ) And a common electrode 22 ′ (FIG. 2) of the pressure generating chamber row located on the far side is formed on the conductive pattern 28.
You may make it connect by pulling it out.

According to this embodiment, the terminals 5 and 5'to be soldered can be freely formed at positions apart from the pressure generating chamber and the piezoelectric vibrator as shown in FIG. Therefore, it is possible to prevent heat generated during soldering with the flexible cable 24 from reaching the piezoelectric vibrator, and prevent deterioration of the piezoelectric vibrator due to heating.

[0033]

As described above, in the present invention, the spacers made of ceramic forming the pressure generating chambers in two rows in a row with the center line as the symmetry line, and one surface of the spacer are sealed. Stop, and connect the flexible cable to one electrode of the piezoelectric vibrator and the first lid having two rows of piezoelectric vibrators on the surface of the position corresponding to the pressure generating chamber, and substantially one row. Since the connection terminals arranged so that the connection terminals for the flexible cables for two rows of the pressure generating chambers are arranged in substantially one row, the piezoelectric vibrator is released from the blockage by the flexible cable. It is possible not only to eliminate the malfunction of the piezoelectric vibrator caused by the contact of the flexible cable, but also to increase the margin of relative alignment with the flexible cable and to practically perform the connection work. It is possible to simplify the connecting operation of the cable as a one place.

Further, in the present invention, a spacer made of ceramics forming two rows of pressure generating chambers in a line so that the center line is the symmetry line, and one surface of the spacer is sealed.
A first lid provided with a piezoelectric vibrator on the surface of a position corresponding to the pressure generating chamber, and a nozzle communicating hole that seals the other surface of the spacer and communicates with the nozzle opening in the outer region of the pressure generating chamber,
Further, since the second lid having the communication hole communicating with the ink supply port is integrally joined in the region on the symmetry line side, the distance of the nozzle communication hole can be set to about the width of the actuator unit. The dot position error in the paper feed direction can be kept uniform without inviting a complicated path.

[Brief description of the drawings]

FIG. 1 is an assembled perspective view showing an embodiment of a recording head of the present invention, excluding an adhesive layer.

FIG. 2 is a diagram showing the same recording head with a sectional structure in the vicinity of a pressure generating chamber.

FIG. 3 is a diagram showing a structure of an upper surface of an actuator unit.

FIG. 4 is a diagram showing a state in which a flexible cable is connected to the recording head of the above.

FIG. 5 is a diagram showing an embodiment in which an IC chip is directly attached to the recording head.

FIG. 6 is a top view showing another embodiment of the present invention.

FIG. 7 is a top view showing another embodiment of the present invention.

FIG. 8 is a diagram showing a connection relationship between the recording head and a flexible cable of the same.

FIG. 9 is a diagram showing a conventional connection structure between an inkjet recording head and a flexible cable.

[Explanation of symbols]

 1 Actuator Unit 2 First Lid 4, 4'Piezoelectric Vibrator 5, 5'Connecting Terminal 6 Spacer 7, 7'Pressure Generating Chamber 8 Second Lid 9, 9'Nozzle Communication Hole 11 Ink Supply Port Formation Substrate 15 common ink chamber forming substrate 16 common ink chamber 18, 18 'nozzle opening 19 nozzle plate 20 flow path unit 24 flexible cable

Claims (5)

[Claims] 1. A substrate for forming an ink supply port having a communication hole communicating with the pressure generating chamber and an ink supply port, a common ink chamber communicating with the pressure generating chamber via the ink supply port, and the pressure. A common ink chamber forming substrate having a communicating hole communicating with the generating chamber, and a nozzle opening for sealing the other surface of the common ink chamber forming substrate and connecting to the pressure generating chamber via each communicating hole. In an actuator unit that is fixed to a flow path unit that is joined to a nozzle plate that is provided to form an ink jet recording head, two pressure generation chambers are formed in a row with the center line as the symmetry line. A spacer made of ceramic, a first lid body that seals one surface of the spacer, and has two rows of piezoelectric vibrators on the surface corresponding to the pressure generating chamber, and one of the piezoelectric vibrators. As well as connecting a flexible cable to the electrode, the laminated ink jet recording head actuator unit comprising comprising an arrangement connection terminal so as to be substantially one row. 2. The actuator unit for a laminated ink jet recording head according to claim 1, wherein the connection terminal is arranged in a central region sandwiched between the rows of pressure generating chambers. 3. A conductive electrode, wherein the connection terminal is arranged outside a row of pressure generating chambers, and a drive electrode of a piezoelectric vibrator on the far side is formed on the surface of the first lid between the piezoelectric vibrators on the immediate side. The actuator unit for a laminated ink jet recording head according to claim 1, wherein the actuator unit is connected via a pattern. 4. An ink supply port forming substrate having a communication hole communicating with the pressure generation chamber and an ink supply port, a common ink chamber communicating with the pressure generation chamber via the ink supply port, and the pressure. A common ink chamber forming substrate having a communicating hole communicating with the generating chamber, and a nozzle opening for sealing the other surface of the common ink chamber forming substrate and connecting to the pressure generating chamber via each communicating hole. In an actuator unit that is fixed to a flow path unit that is joined to a nozzle plate that is provided to form an ink jet recording head, two pressure generation chambers are formed in a row with the center line as the symmetry line. A spacer made of ceramic, a first lid body having one surface of the spacer sealed and a piezoelectric vibrator provided on the surface at a position corresponding to the pressure generating chamber, and the other surface of the spacer are provided. And a second lid having a communication hole that communicates with the nozzle opening in an area outside the pressure generating chamber and a communication hole that communicates with the ink supply opening in an area on the symmetry line side. An actuator unit for a laminated ink jet recording head, which is bonded to a substrate. 5. An ink supply port forming substrate having a communication hole communicating with the pressure generation chamber and an ink supply port, and a common member located in a central portion so as to communicate with the pressure generation chamber via the ink supply port. Common ink chamber forming substrate having an ink chamber and a communicating hole communicating with the pressure generating chamber, and sealing the other surface of the common ink chamber forming substrate and pressing the pressure through each communicating hole. A flow path unit formed by joining a nozzle plate having a nozzle opening connected to the generation chamber, and a spacer made of ceramic forming two rows of pressure generation chambers in a line with the center line as a symmetry line; The first surface of the spacer is sealed, the first lid having a piezoelectric vibrator on the surface at a position corresponding to the pressure generating chamber, and the other surface of the spacer are sealed, and the pressure generating chamber is sealed. Communicating with the nozzle opening in the outer region of A laminated ink jet type in which an actuator unit formed by integrally joining a nozzle communication hole which is connected to the ink supply port and a second lid body which is connected to the ink supply port in a region on the symmetry line side Recording head.