JP2003276196A - Ink jet recording head, and ink jet printer mounted with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink jet head employing a piezoelectric actuator in which positional shift does not cause variation of characteristics readily at the time of connecting a piezoelectric element with a diaphragm and thereby ejection characteristics are stabilized. <P>SOLUTION: A substrate 1 in which pressurized liquid chambers 4 and 4 are formed, a nozzle plate 8, and a diaphragm 6 bonded with a piezoelectric element 7 are stacked. A pressure converting means, i.e., the piezoelectric element 7, does not exist at a position on the supporting substrate side of the diaphragm 6 facing a barrier wall 20 separating the pressurized liquid chambers 4 and 4 in the longitudinal direction. The barrier wall 20 and the piezoelectric element 7 are separated by 100 μm or longer so that the pressurized liquid chamber 4 is not deformed even if the position for fixing the piezoelectric element 7 to the diaphragm 6 is shifted from a desired fixing position. <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 an ink jet recording head and an ink jet printer equipped with the ink jet recording head, and more particularly to ink ejection characteristics even when a pressure transducer mounting position is displaced from a vibration plate of the ink jet recording head. The present invention relates to an inkjet recording head that can reduce the fluctuation of

[0002]

2. Description of the Related Art In an ink jet recording head, there are the following conventional examples which disclose measures against characteristic fluctuations due to displacement of a mounting position of a pressure converter. The one described in Japanese Patent Laid-Open No. 9-99553 (inkjet head) improves the positional accuracy by forming a concave portion on one surface of a vibration plate (pressurizing plate) and bringing a pressure transducer into contact therewith. is there. In addition, JP 20
No. 01-187448 (Piezoelectric actuator manufacturing method, piezoelectric actuator obtained thereby, and ink jet recording head using the same)
In the method described in (1), the pressure transducer is formed by printing the dispersion liquid of the piezoelectric material on the vibrating plate, whereby the pressure transducer is formed by following the distortion of the vibrating plate and the liquid chamber. It does not cause a gap.

[0003]

An ink jet recording apparatus for ejecting minute ink droplets and adhering the ink droplets to a recording medium such as paper to form image information including characters includes a plurality of ink pressurizing liquid chambers and a plurality of ink pressurizing liquid chambers. Using an inkjet head equipped with a nozzle that communicates with the pressurized liquid chamber to eject ink droplets, and an actuator such as an electromechanical conversion element or an electrothermal converter provided corresponding to each pressurized liquid chamber By changing the pressure inside the pressurized liquid chamber according to a recording signal and ejecting an ink droplet from a nozzle, high-speed, high-density, high-quality recording is performed. It is well known that this actuator uses a piezoelectric element that is in contact with an elastically deformable diaphragm that is a part of the pressurized liquid chamber. This causes the piezoelectric element to be deformed by charging / discharging, and displaces the diaphragm in contact with the piezoelectric element. When the vibrating plate is displaced so as to contract the volume of the pressurized liquid chamber, the pressure inside the pressurized liquid chamber rises and ink droplets are ejected from the nozzle. After ejecting the ink droplet, the piezoelectric element is deformed so as to displace the vibrating plate so as to expand the volume of the pressurized liquid chamber.

FIG. 13 is a diagram schematically showing an ink jet head using a piezoelectric actuator, and FIG.
Is a longitudinal sectional view of the pressurized liquid chamber, and FIG. 13B is a lateral sectional view. A vibrating plate 6 forming a part of the pressurized liquid chamber 4 communicating with the nozzle 3, and a piezoelectric element 7 provided on the base substrate 2.
Are joined. The vibrating plate 6 elastically deforms as the piezoelectric element 7 deforms, but in order to efficiently change the displacement of the piezoelectric element 7 to change the volume of the pressurized liquid chamber 4, the vibrating plate 6 normally moves the pressurized liquid chamber 4. The rigidity is made smaller (= the compliance is made larger) than the other constituent surfaces. Common liquid chamber 9 and pressurized liquid chamber 4
Is filled with ink. The common liquid chamber 9 is connected to an ink tank (not shown).

When a voltage is applied to the piezoelectric element 7 from a drive circuit (not shown), the piezoelectric element 7 is deformed and the diaphragm 6 is deformed so that the volume of the pressurized liquid chamber 4 increases or decreases. When the volume of the pressurized liquid chamber 4 is increased, the internal pressure of the pressurized liquid chamber 4 decreases, so that the ink is replenished in the pressurized liquid chamber 4 from the common liquid chamber 9 through the communicating portion 10. After that, driving is performed so as to increase the internal pressure of the pressurized liquid chamber 4. That is, when the piezoelectric element 7 is driven so as to reduce the volume of the pressurized liquid chamber 4, the internal pressure of the pressurized liquid chamber 4 increases, so that the ink is pushed out from the nozzle 3 to form the ink droplet 12. Recording is performed by flying and ink droplets adhering to a recording medium such as paper (not shown). That is, the formation of ink droplets in the inkjet head is caused by the displacement of the vibration plate, and the configuration of the joint portion with the piezoelectric element that is the driving source thereof is an important factor that influences the characteristics of the inkjet head. I can say.

However, due to the problem of processing accuracy, the attachment position of the piezoelectric element and the vibration plate is inevitably displaced. The amount of displacement (displacement amount) varies, but the displacement force generated by the piezoelectric element is not transmitted to the diaphragm as designed. As a result, there is a difference in the structural deformation of the vibrating plate or the like due to the displacement force generated in the liquid chambers between the liquid chambers, which causes variations in the ejection characteristics and is a factor that deteriorates print quality.

Specific problems that occur when the mounting position of the piezoelectric element is deviated will be described with reference to FIGS. 14 to 16. 14 to 16 are schematic views showing the relationship between the mounting position of the piezoelectric element, that is, the pressure converting means with respect to the pressurized liquid chamber, and the deformation of the pressurized liquid chamber. At the mounting position shown in FIG. 14, the piezoelectric element 7, that is, the pressure converting means is mounted at the prescribed position of the vibrating plate 6, and the displacement of the pressure converting means pushes up the vibrating plate 6 of the pressurized liquid chamber 4 to apply pressure. The pressure in the liquid chamber 4 is increased. The mounting position shown in FIG. 15 is a case where the pressure converting means is mounted slightly displaced from the specified position to the partition wall 20 side. However, when the pressure generating means approaches the partition wall 20, a part of the displacement force of the diaphragm is lost. A force acts in the direction of tilting the partition wall 20. Therefore, the pressurized liquid chamber 4 is deformed, and problems such as pressure fluctuation and nozzle plate displacement occur. FIG. 16 shows the case where the pressure converting means is attached closer to the partition wall 20. In this case, the pressure converting means directly pushes up the partition wall 20, which causes a larger deformation of the pressurized liquid chamber 4.

Therefore, as a method for reducing the influence of this positional deviation, there is a method disclosed in Japanese Patent Laid-Open No. 9-99553. This is to form a concave portion on the diaphragm and to abut the piezoelectric element on the concave portion so that the displacement of the piezoelectric element is absorbed by the concave portion so that the transmission of the displacement force does not vary. However, in this case, it is possible to deal only with the deviation of the range within the width of the recess, and the applicable range is limited. In addition, there is a problem that the process becomes complicated because it is necessary to perform groove processing. On the other hand, Japanese Patent Laid-Open No. 2001-2001
In the method disclosed in Japanese Patent No. 187448, the piezoelectric element is formed in accordance with the displacement of the diaphragm to suppress the displacement itself. However, in this case, the applicable liquid chamber structure, piezoelectric element structure, and manufacturing method are limited. Particularly, regarding the liquid chamber structure, there is a problem that it cannot be formed by the Si process, and it is difficult to achieve multichannel with high precision and high density.

In view of the above problems, it is an object of the present invention to stabilize the jetting characteristics of an ink jet recording head by making it difficult for characteristic variations to occur even when a displacement occurs when connecting a piezoelectric element to a diaphragm. To do. Another object of the present invention is to provide an inkjet printer having uniform printing characteristics by using an inkjet recording head having stable ejection characteristics.

[0010]

In order to solve the above-mentioned problems, an ink jet recording head according to claim 1 has a pressurized liquid chamber, a vibrating plate forming a part of the pressurized liquid chamber, and one surface. Is connected to the vibrating plate and includes pressure converting means for changing the pressure in the pressurized liquid chamber, and a support substrate to which the other surface of the pressure converting means is joined. In the section, two pressurized liquid chambers are arranged to face each other via a longitudinal partition, and the longitudinal partition and the support are provided between respective pressure conversion means connected corresponding to the two pressurized liquid chambers. There is no member for connecting the substrates, and the pressure converting means is provided separately from the longitudinal partition.

The ink jet recording head of claim 2 is
The inkjet recording head according to claim 1, wherein the support substrate and the lateral direction are provided at positions corresponding to lateral direction partition walls separating the pressurized liquid chambers that are adjacent in the lateral direction of the pressurized liquid chamber. It is characterized by having a supporting member for supporting the diaphragm between the partition walls.

An ink jet recording head according to a third aspect is
The ink jet recording head according to claim 1 or 2, wherein the diaphragm has a thin portion and a thick portion, and the thin portion is separated by the thick portion with which the pressure converting means abuts. The flesh portion is formed over the entire longitudinal direction of the diaphragm.

The ink jet recording head of claim 4 is
The ink jet recording head according to any one of claims 1 to 3, wherein the pressure converting means is a laminated piezoelectric driving body in which electrode layers and piezoelectric element layers are alternately laminated, and an electric field is not generated at an end portion in a longitudinal direction. It is characterized by having.

The ink jet recording head of claim 5 is
The ink jet recording head according to any one of claims 1 to 4, wherein a distance between the longitudinal partition and the pressure converting means is 10
It is characterized by being 0 μm or more.

According to another aspect of the present invention, there is provided an ink jet recording head.
The ink jet recording head according to claim 4, wherein a distance between the longitudinal partition and the active layer of the laminated piezoelectric driver is 300 μm or more.

According to a seventh aspect of the present invention, there is provided a printer which is an ink jet printer equipped with the ink jet recording head according to any one of the first to sixth aspects.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates with reference to FIG. FIG. 1 is an exploded perspective view showing an inkjet head according to an embodiment of the present invention. The pressurized liquid chamber substrate 1 having the plurality of pressurized liquid chambers 4, the nozzle plate 8 and the vibrating plate 6 are laminated. The nozzle plate 8 is provided with nozzles 3 that communicate with the pressurized liquid chamber 4. One surface of the piezoelectric element 7 which is a pressure transducer is bonded to the vibration plate 6, and the driver IC 18 is connected to the piezoelectric element 7.
The FPC cable 17 joined with is joined together with electrical connection. A drive signal is supplied from the driver IC 18 to the piezoelectric element 7 via the FPC cable 17 based on an image forming signal (not shown), the piezoelectric element 7 expands and contracts, and the displacement thereof is transmitted to the diaphragm 6 so as to apply a required pressure. By appropriately controlling the internal pressure of the liquid chamber 4, ink droplets are ejected from the nozzle 3. The other surface of the piezoelectric element 7 is joined to the base substrate 2, and the base substrate 2 is further joined to a frame (not shown). A frame (not shown) is mounted on a carriage (not shown), the FPC cable 18 is connected to an electric circuit (not shown), and ink is supplied from the ink cartridge to the pressurized liquid chamber 4 in the main body of the inkjet printer. Absent.

FIG. 2 is a cross-sectional view of the ink jet head according to the embodiment of the present invention in the longitudinal direction of the pressurized liquid chamber (the direction orthogonal to the nozzle row). The two pressurized liquid chambers 4 are separated by a partition wall 20 in the longitudinal direction of the pressurized liquid chambers and are arranged to face each other. Like the base substrate 2, the pressurized liquid chamber substrate 1 is also joined to the frame 19. Frame 19
2 is divided into two parts in the example of FIG. 2, but may be composed of one part. Also, one base substrate 2
Two piezoelectric elements 7 are formed on the base substrate 2
May be divided into two.

FIG. 3 is an enlarged view showing a portion of the ink jet head shown in FIG. 2. FIG. 3A is an enlarged perspective view showing the relationship between the base substrate, the piezoelectric element and the supporting member.
FIG. 3B is an enlarged cross-sectional view in the lateral direction (nozzle row direction) of the pressurized liquid chamber of the inkjet head. Here, although the support member 11 is attached between the piezoelectric elements 7, the support member 11 may not exist. The vibrating plate 6 is composed of a thick portion 15 and a thin portion 16, and is connected to the piezoelectric element 7 by the thick portion 15, and the vibrating plate portion that actually generates pressure in the pressurized liquid chamber 4 is separated. The support member 11 is connected to the partition wall 5 via the thick portion 15 of the diaphragm 6. Vibration plate 6 and base substrate 2
Is joined by both the piezoelectric element 7 and the support member 11, and maintains the rigidity of the pressurized liquid chamber 4 at the upper portion and improves the displacement efficiency of the thick portion 15 of the diaphragm 6 due to the deformation of the piezoelectric element 7. ing.

The shape of the diaphragm will now be described. 4 is a perspective view showing a cross section of one of the pressurized liquid chambers 4 described in FIGS. 1 to 3 in the lateral direction with the diaphragm 6 facing upward, and FIG. 5 is shown in FIG. It is the same perspective view which used the diaphragm of a structure different from a diaphragm. However, FIG. 5 also shows the piezoelectric element 7 connected to the diaphragm. The piezoelectric element not shown in FIG. 4 is bonded to the island-shaped convex portion 14 which is the thick portion 15 whose periphery is separated by the thin portion 16 of the concave portion 13 of the vibration plate 6. On the other hand, in the shape shown in FIG. 5, the diaphragm 6 is composed of the thick portion 15 and the thin portion 16,
Unlike FIG. 4, the thick portion 15 ₁ is not surrounded by the thin portion 16, but conversely, the thick portion 15 ₁ separates the region of the thin portion 16. The thick part 15 ₁ is provided along the longitudinal direction of the pressurized liquid chamber, and the thin part 16 is the thick part 15 _{1 at the} center.
Along the longitudinal direction of the pressurized liquid chamber 4, it is provided in an elongated position at a position symmetrical with respect to. The thick-walled portion 15 ₂ has the pressurized liquid chamber 4 at 1
These are peripheral thick-walled portions that are partitioned by each, and are connected to a base substrate (not shown) via a support member (not shown).
The diaphragm shape of FIG. 5 is longer than the diaphragm shape of FIG. 4 because the island-shaped convex portions 14 connected to the diaphragm are longer, so that the diaphragm can be driven more efficiently. For this reason, if the same liquid chamber pressure is generated, there is an advantage that a lower driving voltage is required, while the structure against the above-mentioned positional deviation is vulnerable. That is, in the case of the diaphragm shape of FIG. 4, the influence of the displacement shown in FIG. 15 is less likely to occur because the diaphragm is divided by the concave portion, while
The shape shown in FIG. 5 causes the problem shown in FIG. In addition,
In both cases, the problem due to the mounting position deviation shown in FIG. 16 occurs.

FIG. 6 is a view for explaining the features of the present invention, and is a cross-sectional view schematically showing a cross section in the longitudinal direction of the pressurized liquid chamber. In the present invention, as shown in FIG. 6, the piezoelectric element 7 as the pressure converting means does not exist at the base substrate 2 side position of the vibrating plate 6 facing the longitudinal partition wall 20 that separates the longitudinal direction of the pressurized liquid chamber. That is, the piezoelectric element 7 is provided so as to be separated from the longitudinal partition 20 by a certain distance. At this time, it is important to keep a sufficient distance between the partition wall 20 and the piezoelectric element 7 so that the pressurized liquid chamber 4 is not deformed even if the mounting position of the piezoelectric element 7 is displaced. Is.
However, if the distance between the two piezoelectric elements 7 is increased more than necessary, that is, if the distance between the two facing piezoelectric elements 7 is increased, the size of the drive unit increases, and as shown in FIG. Between the partition wall 20 and the base substrate 2
When the construction method is simplified and the head is miniaturized by omitting the support member that connects the partition walls, the support member (support member 11 in FIG. 3) that supports the partition wall 20 is separated from the partition wall 20, and the supporting force is insufficient. There is also a problem that the vibration of the pressurized liquid chamber 4 increases. Therefore, a study was conducted to find the optimum size. The results are shown in the graph of FIG. 7 which shows the relationship between the distance between the piezoelectric elements and the displacement amount of the diaphragm.

In this examination, when the variation of the displacement of the mounting position of the piezoelectric element is observed, a case where the difference from the average variation amount is within σ is a good product, and a case where it is deviated is a defective product, and the most deviation occurs in the good product. The deformation degree of the pressurized liquid chamber was evaluated by the deformation amount of the nozzle plate for the sample. As a parameter, the distance between the two piezoelectric elements (using PZT) is taken here, but since the width of the partition wall 20 is 100 μm, (PZT interval −10
0) / 2 is the distance between the partition wall 20 and the piezoelectric element. In addition,
The data of a sample in which no positional deviation occurs is also posted. It can be seen from the graph of FIG. 7 that when the distance between the two piezoelectric elements is changed to 100 to 300 μm, the displacement amount of the vibration plate decreases rapidly, but does not change so much at the boundary of 300 μm. Therefore, it is desirable that the distance between the two piezoelectric elements is 300 μm or more, that is, the distance between the partition wall 20 and the pressure converting means is 100 μm or more. As described above, when comparing FIGS. 4 and 5 showing the shape of the diaphragm, FIG. 5 is particularly affected by the deviation, but the present invention can also obtain a high effect against this. Therefore, it becomes possible to use the shape of the vibration plate shown in FIG. 5, which can drive the pressurized liquid chamber more efficiently, without changing the characteristics due to the positional deviation.

FIG. 8 is a longitudinal view of the pressurized liquid chamber in the ink jet head shown in FIG. 6, in which the piezoelectric element 7 as the pressure converting means is a laminated piezoelectric type driving body having an inactive layer 7 ₂ on the end face in the longitudinal direction. It is sectional drawing which shows a directional cross section typically. Although the position of the pressure converting means has been described above, the pressure converting means has the inert layer 7 on the end face in the longitudinal direction as shown in FIG.
_In the case of a laminated piezoelectric type driving body having ₂ , the distance from the end of the active layer 7 ₁ to the partition wall 20 is important. In this case, taking the distance of the inactive layer into consideration, the distance between the edge of the active layer and the partition wall 20 is 300 μm.
If it is m or more, it is possible to obtain the effect corresponding to the interval of 300 μm in FIG. 7.

(Specific Example 1) As a first specific example of the present invention, a case where the invention is applied to the diaphragm shape shown in FIG. 4 will be described. A Si diaphragm having a thickness of 3 μm is arranged in a pressurized liquid chamber having a height of 80 μm, a length of 3000 μm in the longitudinal direction, and a width of 130 μm in the lateral direction, using Si as a wall constituent member, and a piezoelectric element made of lead zirconate titanate is arranged on the Ni diaphragm. Attach the element. The diaphragm has island-shaped protrusions with a width of 30 μm and a longitudinal length of 1300.
μm. The piezoelectric element has an 18-layer laminated structure in which electrodes made of silver and palladium are vertically sandwiched. The thickness of each layer is 25 μm, and 80 μ is on top of 18 layers.
m, a 220 μm inactive portion is arranged in the lower part, and the height of the piezoelectric element is 750 μm as a whole. The longitudinal width is 1
The width of the active layer is 900 μm and the width in the lateral direction is 50 μm, but an inactive layer of 200 μm is arranged at both ends in the longitudinal direction, and the width of the active layer is 1500 μm. The overall shape is as shown in FIG. 8, but the width of the partition wall is 100 μm. Here, as a conventional technique, a head having a distance between the piezoelectric element and the partition wall of 0 (distance between the piezoelectric elements is 100 μm), and as an application example of the present invention, the same distance is 100 μm (distance between the piezoelectric elements is 300 μm).
heads of (.mu.m) were prepared, and the displacement amount of the nozzle plate was compared when the piezoelectric elements were shifted to the right by 0 to 150 .mu.m in FIG. Figure 9
It is a graph which shows this comparison result. From the graph in Figure 9,
By applying the present invention, it can be seen that the characteristics do not change even if the mounting position of the piezoelectric element is deviated.

(Specific Example 2) As a second specific example of the present invention, a case where the diaphragm shape shown in FIG. 5 is applied will be described. A Si diaphragm having a thickness of 3 μm was placed in a pressurized liquid chamber having a height of 80 μm, a length of 3000 μm in the longitudinal direction, and a width of 130 μm in the lateral direction using Si as a wall constituent member, and a piezoelectric element made of lead zirconate titanate was placed on the Ni diaphragm. Attach the element. The vibrating plate has a convex portion with a width of 30 μm, and is arranged over the entire area in the longitudinal direction of the pressurized liquid chamber in the longitudinal direction. In addition, the piezoelectric element consists of an electrode made of silver and palladium, which is sandwiched between the upper and lower electrodes.
It has a layered laminated arrangement structure. Each layer is 25 μm thick and 1
An inactive portion having a thickness of 80 μm and a thickness of 220 μm are arranged on the upper and lower portions of the eight layers, and the height of the piezoelectric element is 750 μm as a whole. Width in the longitudinal direction is 1900 μm, width in the lateral direction is 50
The width of the active layer is 1500 μm because the inactive layer of 200 μm is arranged at both ends in the longitudinal direction. The overall shape is as shown in FIG. 8, but the width of the partition wall is 1
00 μm. Here, as a conventional technique, a head having a distance between the piezoelectric element and the partition wall of 0 (distance between the piezoelectric elements is 100 μm) and an application example of the present invention are head having a distance of 100 μm (distance between the piezoelectric elements is 300 μm). Then, for each of them, the piezoelectric element is arranged in the right direction in FIG.
The displacement amounts of the nozzle plates were compared when they were shifted by 50 μm. FIG. 10 is a graph showing the comparison result. From the graph of FIG. 10, it can be seen that if the present invention is applied, the characteristics will not change even if the mounting position of the piezoelectric element is deviated.

Next, an ink jet printer equipped with the above ink jet recording head will be described. FIG. 11 is a perspective view showing an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 12 is a side sectional view of a mechanism section of the inkjet recording apparatus. The inkjet recording apparatus according to the present embodiment supplies the ink to the carriage 43 that is movable in the main scanning direction inside the recording apparatus main body 31, the recording head 44 that is the inkjet recording head that embodies the present invention and is mounted on the carriage, and the recording head. A printing mechanism 32 including an ink cartridge 45 and the like is stored, and a paper feed cassette (or a paper feed tray) 34 capable of accommodating a large number of sheets 33 from the front side in a lower portion of the apparatus main body 31. And a manual feed tray 3 for manually feeding the paper 33.
5 can be opened and closed, the paper 33 fed from the paper feed cassette 34 or the manual feed tray 35 is taken in, the desired image is recorded by the printing mechanism 32, and then the paper discharge tray 36 mounted on the rear surface side. Eject the paper.

The printing mechanism 32 includes a main guide rod 41 and a sub guide rod 42, which are guide members which are horizontally mounted on the left and right side plates (not shown), so as to move the carriage 43 in the main scanning direction (see FIG. 1).
The present invention discharges ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk) to the carriage 43 slidably held in the direction 2). A recording head 44, which is an inkjet head, has a plurality of ink ejection ports (nozzles) arranged in a direction intersecting the main scanning direction, and is mounted with the ink droplet ejection direction facing downward. The recording head 4 is attached to the carriage 43.
The ink cartridges 45 for supplying the inks of the respective colors are exchangeably attached to the cartridge 4. The ink cartridge 45 has an air port that communicates with the atmosphere above, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body is used. The ink supplied to the inkjet head is maintained at a slight negative pressure. Although the recording heads of the respective colors are used here as the recording head 44, one head having nozzles for ejecting ink droplets of the respective colors may be used.

Here, the carriage 43 is slidably fitted to the main guide rod 41 on the rear side (downstream side in the sheet conveying direction), and the front side (upstream side in the sheet conveying direction) on the front side (upstream side in the sheet conveying direction).
2 is slidably mounted. Then, since the carriage 43 is moved and scanned in the main scanning direction, the main scanning motor 4
A timing belt 50 is stretched between a drive pulley 48 and a driven pulley 49 which are driven to rotate by 7, and the timing belt 50 is fixed to a carriage 43. It is driven back and forth. On the other hand, in order to convey the paper 33 set in the paper feed cassette 34 to the lower side of the recording head 44, the paper feed roller 51 and the friction pad 52 for separating and feeding the paper 33 from the paper feed cassette 34 and the paper 33 are guided. Guide member 53, a conveying roller 54 that reverses and conveys the fed sheet 33, a conveying roller 55 that is pressed against the peripheral surface of the conveying roller 54, and the sheet 3 from the conveying roller 54.
3 and the tip roller 56 that defines the delivery angle of 3 are provided. The conveyance roller 54 is rotationally driven by the sub-scanning motor 57 via a gear train.

Further, there is provided a print receiving member 59 which is a paper guide member for guiding the paper 33 delivered from the carrying roller 54 below the recording head 44 in correspondence with the movement range of the carriage 43 in the main scanning direction. There is. A transport roller 61 and a spur 62 that are driven to rotate in order to send out the paper 33 in the paper discharge direction are provided on the downstream side of the print receiving member 59 in the paper transport direction, and further, the paper 33 is sent to the paper discharge tray 36. A roller 63, a spur 64, and guide members 65 and 66 that form a paper discharge path are provided. When recording,
The recording head 44 is driven according to an image signal while moving the carriage 43, so that the paper 3 that is stopped
Ink is ejected onto 3 to record one line, and after the paper 33 is conveyed by a predetermined amount, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 33 reaches the recording area, the recording operation is terminated and the sheet 33 is ejected.

A recovery device 67 for recovering the ejection failure of the recording head 44 is arranged at a position outside the recording area on the right end side of the carriage 43 in the moving direction. The recovery device 67 has a cap means, a suction means, and a cleaning means. While waiting for printing, the carriage 43 is moved to the recovery device 67 side and the recording head 44 is capped by the capping means, and the ejection port portion is kept wet to prevent ejection failure due to ink drying. Also,
By ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant, and stable ejection performance is maintained. When an ejection failure occurs, the ejection port (nozzle) of the recording head 44 is sealed by a capping unit, and bubbles and the like are sucked out from the ejection port by the suction unit through a tube, and ink or dust attached to the ejection port surface is sealed. Etc. are removed by the cleaning means, and the ejection failure is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed in the lower portion of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir. As described above, since this inkjet recording apparatus is equipped with the inkjet head embodying the present invention, there is no ink droplet ejection failure due to bubble accumulation, stable ink droplet ejection characteristics are obtained, and image quality is improved. .

[0031]

By arranging the partition wall and the pressure converting means apart from each other, the force for deforming the partition wall can be transmitted even when the pressure converting means approaches the partition wall due to the positional displacement at the time of mounting. Can be prevented. Therefore, it is possible to suppress a change in the deformation of the pressurized liquid chamber and a change in the generated pressure due to the displacement of the pressure converting means, and it is possible to suppress the variation in the injection characteristics.

Effect of Claim 2 By supporting the pressurized liquid chamber by sandwiching the supporting substrate between the piezoelectric elements, the deformation of the pressurized liquid chamber can be suppressed more effectively.

Since the length of the connecting portion between the piezoelectric converting means and the vibration plate can be made longer, the pressurized liquid chamber can be efficiently pressurized.

Action and Effect on Claim 4 By using the laminated piezoelectric type driving body as the pressure generating means, high speed and low voltage driving becomes possible.

Action and Effect on Claim 5 By separating the distance between the partition wall and the pressure generating means by 100 μm or more, it is possible to substantially completely suppress the characteristic variation even if a positional deviation occurs.

Action and Effect on Claim 6 If the distance between the partition wall and the active layer of the piezoelectric type driving member is 300 μm or more, the characteristic variation can be suppressed almost completely even if the position shift occurs.

By applying the recording head according to any one of claims 1 to 6, it is possible to provide a printer in which variations in printing characteristics do not easily occur.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an inkjet head of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the inkjet head in the longitudinal direction of the pressurized liquid chamber (perpendicular to the nozzle row) according to the embodiment of the present invention.

3 is an enlarged view of a portion of the inkjet head shown in FIG. 2, FIG. 3 (A) is an enlarged perspective view showing a relationship between a base substrate, a piezoelectric element, and a supporting member;
FIG. 3 is an enlarged cross-sectional view of an inkjet head in a nozzle row direction.

FIG. 4 is a perspective view showing a cross section of the pressurized liquid chamber shown in FIGS.

5 is a perspective view similar to FIG. 4 using a diaphragm having a configuration different from that of the diaphragm shown in FIG.

FIG. 6 is a cross-sectional view schematically showing a cross section in the longitudinal direction of the pressurized liquid chamber of the inkjet head, which is a view for explaining the characteristic part of the present invention.

FIG. 7 is a graph showing a relationship between a distance between piezoelectric elements and a displacement amount of a diaphragm.

FIG. 8 is an inkjet head shown in FIG.
FIG. 7 is a sectional view similar to FIG. 6, in the case where the pressure converting means is a laminated piezoelectric driver having an inactive layer on the end face in the longitudinal direction.

FIG. 9 is a graph showing a comparison result of Example 1 of the present invention.

FIG. 10 is a graph showing the comparison results of Example 2 of the present invention.

FIG. 11 is a perspective view showing an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 12 is a side sectional view of a mechanism portion of the inkjet recording apparatus of FIG.

13A and 13B are diagrams schematically showing an inkjet head using a piezoelectric actuator, FIG. 13A is a longitudinal sectional view of a pressurized liquid chamber, and FIG. 13B is a lateral sectional view.

FIG. 14 is a schematic view showing a state in which a piezoelectric element is attached to a pressurized liquid chamber at a specified position.

FIG. 15 is a schematic view showing a state in which a piezoelectric element is attached to a pressurized liquid chamber near a partition wall.

FIG. 16 is a schematic view showing a state where the piezoelectric element is attached to the pressurized liquid chamber in contact with the partition wall.

[Explanation of symbols]

1 ... Pressurized chamber substrate, 2 ... Base substrate, 3 ... Nozzle, 4 ...
Pressurized liquid chamber, 6 ... Vibration plate, 7 ... Piezoelectric element, 8 ... Nozzle plate, 9 ... Common liquid chamber, 10 ... Communication part, 11 ... Support member,
Reference numeral 13 ... Recessed portion, 14 ... Island-shaped raised portion, 15 ... Thick portion, 16 ... Thin portion, 17 ... FPC cable, 18 ... Driver IC, 1
9 ... Frame, 20 ... Partition, 31 ... Recording device main body, 32
... printing mechanism section, 33 ... paper, 34 ... paper feed cassette, 36
... Paper ejection tray, 43 ... Carriage, 44 ... Recording head,
45 ... Ink cartridge, 51 ... Paper feed roller, 52 ...
Friction pad, 54 ... Conveying roller, 55 ... Conveying roller, 56 ... Tip roller, 63 ... Discharging roller, 64 ... Spur.

Claims (7)

[Claims] 1. A pressurized liquid chamber, a vibrating plate forming a part of the pressurized liquid chamber, and one surface of which is connected to the vibrating plate to change the pressure inside the pressurized liquid chamber. And a support substrate to which the other surface of the pressure converting means is bonded, the two pressurized liquid chambers are arranged to face each other via longitudinal partition walls at the longitudinal ends. Between the respective pressure conversion means connected corresponding to the two pressurized liquid chambers,
The inkjet recording head is characterized in that there is no member that connects the longitudinal partition and the support substrate, and the pressure converting means is provided separately from the longitudinal partition. 2. The ink jet recording head according to claim 1, wherein the support is provided at a position corresponding to a lateral partition wall separating the pressurized liquid chambers that are adjacent to each other in the lateral direction of the pressurized liquid chambers. An ink jet recording head comprising a support member for supporting a vibrating plate between a substrate and the lateral direction partition. 3. The ink jet recording head according to claim 1, wherein the diaphragm has a thin wall portion and a thick wall portion, and the thin wall portion region is formed by the thick wall portion with which the pressure converting means abuts. The inkjet recording head is characterized in that the thick portion is formed over the entire length of the diaphragm in the longitudinal direction. 4. The ink jet recording head according to any one of claims 1 to 3, wherein the pressure converting means is a laminated piezoelectric driving body in which electrode layers and piezoelectric element layers are alternately laminated, and a longitudinal direction. An inkjet recording head having an inactive region where an electric field does not occur at the end. 5. The ink jet recording head according to claim 1, wherein a distance between the longitudinal partition and the pressure converting means is 100 μm or more. 6. The ink jet recording head according to claim 4, wherein the distance between the longitudinal partition and the active layer of the laminated piezoelectric driver is 300 μm or more. 7. An ink jet printer comprising the ink jet recording head according to any one of claims 1 to 6.