JP2002225261A - Ink jet head and ink jet type recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make piezoelectric characteristics of a thin film actuator and characteristics of film thickness, etc., uniform, to prevent rapture of a film, to improve a yield rate in production, to miniaturize manufacturing equipment and to reduce cost in a line type ink jet head equipped with a high density thin film actuator. SOLUTION: The recorder is provided with a first line head 1 and a second line head 2 aligned in the scanning direction X. Actuator blocks 40 in each of line heads 1, 2 are arranged in the longitudinal direction Y of heads so as to separate from each other at a regular interval. The actuator block 40 of the second line head 2 is located between the actuator blocks 40, 40 of the first line head 1 in the longitudinal direction Y of the heads. The actuator blocks 40 of the first line head 1 and the actuator blocks 40 of the second line head 2 are partially overlapped in the longitudinal direction Y of heads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet head and an ink jet recording apparatus.

[0002]

2. Description of the Related Art Recently, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-264, a high-density inkjet head manufactured using a so-called transfer method has been proposed. The transfer method is an excellent method for producing a high-density head. In the transfer method, first, individual electrodes are formed on a single-crystal MgO substrate, and then P electrodes are formed on the individual electrodes.
A thin-film actuator is manufactured by forming a piezoelectric body of a perovskite-type dielectric thin film made of ZT, and further forming a common electrode and a vibration plate on the piezoelectric body by a sputtering method or the like. Next, the actuator on the substrate is bonded to the pressure chamber plate, and then all or part of the substrate is removed.

[0003]

However, it has been difficult to produce a line type ink jet head by the above transfer method. The reason is as follows.

In the line type ink jet head, the length of the head in the longitudinal direction must be longer than the width of the recording paper. For example, in order to perform recording on A4 size paper, the longitudinal length of the head needs to be 210 mm or more. Therefore, the single crystal MgO substrate also needs to be 210 mm or longer. However, the single-crystal MgO substrate has M
It is made by collecting from a rocky mass of gO, but not all of the rocky mass can be used as it is.
Only some of them are actually available. for that reason,
In order to produce a single-crystal MgO substrate having a length of 210 mm or more, a lump of MgO having a length longer than that must be prepared, and very large facilities are required. Further, even if such a single-crystal MgO substrate is manufactured, the yield is deteriorated, and such a substrate is a very expensive material.

In the transfer method, it is necessary to form PZT on a single-crystal MgO substrate by sputtering or the like.
In order to form T on a large area, very large equipment is required. In addition, if it is desired to obtain a film having uniform characteristics such as piezoelectric characteristics and film thickness without cracking, the yield will be reduced. Therefore, the manufacturing cost becomes very high.

For the reasons described above, it has been difficult to use the transfer method in the conventional line type ink jet head in terms of quality and cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-density line-type ink jet head and a recording apparatus having the same, for the piezoelectric characteristics and film thickness of a thin film actuator. Uniformity of characteristics, prevention of film cracking, improvement of production yield,
The objective is to reduce the size and cost of manufacturing equipment.

[0008]

According to a first aspect of the present invention, there is provided an ink jet head in which a plurality of rows of line heads are arranged in a scanning direction, wherein the line heads in each row store ink. Applying a voltage to the pressure chamber block provided with a common liquid chamber, a plurality of pressure chambers connected to the common liquid chamber, and a plurality of nozzles connected to the pressure chambers, a piezoelectric layer, and the piezoelectric layer Actuator blocks arranged on one surface of the pressure chamber block so as to cover the plurality of pressure chambers of the pressure chamber block with the vibration plate. The actuator blocks of the line heads in each row are arranged along the longitudinal direction of the head and arranged so that adjacent actuator blocks are separated from each other. On the other hand, it is arranged so as to be displaced in the longitudinal direction of the head from the actuator blocks of the line heads in the other rows and to partially overlap the actuator blocks of the line heads in the other rows in the longitudinal direction of the head. .

According to the first aspect, since a plurality of actuator blocks are provided for one pressure chamber block, the size of each actuator block can be small. Therefore, it is possible to make the characteristics such as the piezoelectric characteristics and the film thickness uniform, prevent the film from cracking, improve the production yield, reduce the size of the production equipment, reduce the cost, and the like.

Further, in the line heads of each row, the actuator blocks are separated from each other. Therefore, even if the shape error of the actuator blocks is large or the accuracy of the installation position of the actuator blocks is somewhat coarse, the actuator blocks are not separated. There is no physical overlap. Therefore, the yield can be improved.

The actuator blocks of the line heads in each row are displaced in the longitudinal direction of the head with respect to the actuator blocks of the line heads in the other rows. Therefore, the actuator blocks of the individual row heads in each row are scattered in the longitudinal direction of the head. In spite of this, the actuator blocks are lined up in the longitudinal direction of the head as a whole in a plurality of rows of line heads. In particular, the actuator blocks of the line heads in each row are arranged so as to partially overlap the actuator blocks of the line heads in the other rows in the longitudinal direction of the head, so that the actuator blocks as a whole are arranged without gaps in the longitudinal direction of the head. Become. Therefore, the actuator can be configured at predetermined intervals in the longitudinal direction of the head.

An ink jet head according to a second invention is the ink jet head according to the first invention, wherein
The line head includes a plurality of line heads having the same shape, and the line heads having the same shape are arranged so as to be shifted from each other in the head longitudinal direction.

An ink jet head according to a third invention is the ink jet head according to the second invention, wherein
Each line head having the same shape has a plurality of actuator blocks arranged at a predetermined interval shorter than the length of each actuator block in the head longitudinal direction, and the line heads having the same shape have one line in the head longitudinal direction. The actuator blocks of the head are shifted from each other in the longitudinal direction of the head so as to be located between the actuator blocks of the other line head.

According to the second and third aspects of the present invention, by arranging a plurality of line heads having the same shape so as to be shifted in the longitudinal direction of the head, the actuator blocks as a whole are arranged without gaps in the longitudinal direction of the head. . Since the line heads have the same shape, it is not necessary to manufacture a plurality of types of line heads having different shapes, and the cost can be reduced by unifying the line head shapes.

An ink jet head according to a fourth aspect of the present invention is the ink jet head according to the first aspect, wherein
The line head includes at least a pair of line heads having the same shape, and the pair of line heads are arranged symmetrically with respect to each other.

An ink jet head according to a fifth invention is the ink jet head according to the fourth invention, wherein
In the line heads of the same shape, a plurality of actuator blocks are arranged at predetermined intervals shorter than the length of each actuator block in the head longitudinal direction, and the line heads of the same shape have both ends in the head longitudinal direction. In this arrangement, the actuator blocks of one line head are arranged point-symmetrically with respect to each other so as to be located between the actuator blocks of the other line head in the head longitudinal direction.

According to the fourth and fifth aspects of the present invention, a pair of line heads having the same shape are arranged symmetrically with respect to each other, so that the actuator blocks as a whole are arranged without gaps in the longitudinal direction of the heads. Since the line heads have the same shape, it is not necessary to manufacture a plurality of types of line heads having different shapes, and the cost can be reduced by unifying the line head shapes.

In particular, according to the fifth aspect, since both ends in the longitudinal direction of the line heads are aligned, the longitudinal length of the head is shorter than in the case where both ends are shifted.

According to a sixth aspect of the present invention, in the inkjet head according to the third or fifth aspect, the entire actuator blocks of the plurality of rows of line heads are arranged in a staggered manner.

According to the sixth aspect, since the actuator blocks are arranged in a staggered manner, the actuator blocks are arranged without any gap in the longitudinal direction of the head.

An ink jet head according to a seventh aspect of the present invention is the ink jet head according to any one of the first to sixth aspects, wherein each of the line heads is configured to discharge the same type of ink. It is.

According to the seventh aspect, an ink jet head for discharging a single color ink can be obtained.

An ink jet head according to an eighth aspect of the present invention is the ink jet head according to any one of the first to sixth aspects, wherein the line head comprises a plurality of lines of line heads for ejecting the same type of ink. A head group is formed, and a plurality of the line head groups are provided in the scanning direction so as to eject a plurality of types of ink.

According to the eighth aspect, a line head group is formed by arranging a plurality of lines of line heads for ejecting the same type of ink in the scanning direction. In this group of line heads, the actuator blocks as a whole are arranged without gaps in the longitudinal direction of the head. By providing a plurality of the line head groups in the scanning direction, an ink jet head that discharges a plurality of types of ink is obtained. The plurality of types of ink may be different types of ink of the same color, or may be a plurality of colors of ink. If a plurality of color inks are used, a color image can be formed.

According to a ninth aspect of the present invention, in the ink jet head according to any one of the first to sixth aspects, each of the line heads is configured to discharge a plurality of types of ink. It is what it was.

According to the ninth aspect, each line head discharges a plurality of types of ink, thereby obtaining an ink jet head which discharges a plurality of types of ink.

An ink jet recording apparatus according to a tenth aspect of the present invention includes the ink jet head according to any one of the first to ninth aspects, and moving means for relatively moving the ink jet head and the recording medium in the scanning direction. It is equipped.

According to the tenth aspect, an ink jet recording apparatus having the effects of the first to ninth aspects can be obtained.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1> As shown in FIG. 1, an ink jet recording apparatus 90 according to Embodiment 1 is a so-called line head type recording apparatus. The inkjet head 5 extends in the width direction of the recording medium 9, and the longitudinal direction Y of the head 5 is orthogonal to the scanning direction X. The inkjet head 5 is configured to discharge black ink, and is connected to an ink tank 11 storing the ink via an ink tube 10.

The ink jet head 5 includes two lines of line heads arranged in the scanning direction X, that is, a first line head 1 and a second line head 2.
The configuration of each of the line heads 1 and 2 will be described later.

The ink jet recording apparatus 90 includes a pair of transport rollers 8, 8 and a pair of feed rollers 7, 7, and the recording medium 9 is sandwiched between the feed rollers 7, 7 and the transport rollers 8, 8. I have. The transport rollers 8 constitute a relative moving means for relatively moving the ink jet head 5 and the recording medium 9, and the recording medium 9 is transported by the transport rollers 8.
Are conveyed in the scanning direction X by rotating. Below the inkjet head 5, a flat recording medium holding member 6 is provided. Note that the recording medium holding member 6 is
It is sufficient that the recording medium 9 and the inkjet head 5 face each other at a fixed interval, and the recording medium 9 is not limited to a flat plate shape, and may be, for example, a cylindrical shape. Recording medium 9
Passes between the inkjet head 5 and the recording medium holding member 6. Since the recording medium 9 is conveyed to the conveying rollers 8 while being sandwiched between the feed rollers 7, a tension is applied by the rollers 7 and 8. As a result, the recording medium 9 forms a flat surface on the recording medium holding member 6 without bending. for that reason,
Ink droplets ejected from the inkjet head 5 land on the recording medium 9 with high accuracy.

Although not shown, if static electricity is applied to the recording medium holding member 6 to electrostatically attract the recording medium 9, the portion of the recording medium 9 on the recording medium holding member 6 becomes flatter. Therefore, means for applying static electricity to the recording medium holding member 6 may be provided.

The overall structure of the first line head 1 and the second line head 2 will be described with reference to FIGS. As shown in FIG. 2, each line head 1, 2
It includes one pressure chamber block 41 and a plurality of actuator blocks 40 joined to the pressure chamber block 41. The actuator blocks 40 of the line heads 1 and 2 are arranged at predetermined intervals in the head longitudinal direction Y, and adjacent actuator blocks 40 and 40 are separated from each other. The first line head 1 and the second line head 2 are mutually moved in the head longitudinal direction such that the actuator block 40 of one line head is located between the actuator blocks 40, 40 of the other line head in the head longitudinal direction Y. It is shifted to Y. The actuator blocks 40, 40,... Of the first line head 1 and the second line head 2 are arranged in a staggered shape as a whole. Actuator block 40 of first line head 1 and actuator block 4 of second line head 2
0 is a positional relationship that is separated from each other in the scanning direction X, but is a positional relationship that is partially overlapped in the head longitudinal direction Y. With such an arrangement pattern, as a result, the actuator blocks 40 are continuously arranged as a whole in the head longitudinal direction Y without any gap.

The actuator block 40 is provided with a piezoelectric element 30 of a perovskite dielectric thin film made of PZT having a thickness of 0.5 μm to 8 μm (see FIG. 4). Each surface of the piezoelectric element 30 has a first electrode 15 made of a conductive material (for example, Pt or the like) having a thickness of about 0.1 μm for individually applying a potential, and a thickness for supplying a voltage to the first electrode 15. A lead portion 16 made of a conductive material of about 0.1 μm and an input terminal 17 connected to an FPC 13 as a control plate are arranged.

As shown in FIGS. 5 and 6, the pressure chamber block 41 is configured by laminating a pressure chamber plate 21, a flow path plate 38, and a nozzle plate 36. As shown in FIG. 3, the pressure chamber plate 21 is provided with an ink inlet 12 for introducing the ink of the ink tube 10, and the ink tube 10 is fitted into the ink inlet 12.

As shown in FIG. 4, in the actuator block 40, Pt, Ct is placed on the diaphragm 14 made of nickel, chromium, silicon oxide, ceramics or the like.
A second electrode 50 made of a conductive material such as u or Ti is laminated. The second electrode 50 is a common electrode for applying a common potential to each of the piezoelectric elements 30 in the actuator block 40. The piezoelectric element 30 is provided on the second electrode 50.
Are stacked, and the first electrode 15 and the lead portion 16 are stacked on the piezoelectric element 30. As shown in FIG. 2, each actuator block 40 covers a plurality of pressure chambers 22, 22,... Of a pressure chamber block 41. The upper portion of each pressure chamber 22 in the actuator block 40 is an actuator section that performs flexural deformation to increase or decrease the volume of each pressure chamber 22. Accordingly, each actuator block 40 includes a number of actuators corresponding to the pressure chambers 22, 22,. In order to enable high-density arrangement, the thickness of the actuator block 40 is preferably 8 μm or less.

Next, a detailed configuration of the line heads 1 and 2 will be described. However, since the first line head 1 and the second line head 2 are line heads having the same shape,
Here, only the first line head 1 will be described.
The description of the second line head 2 is omitted.

FIG. 5 is a sectional view taken along the line CC of FIG. FIG.
As shown in (1), the first line head 1 is configured such that one pressure chamber plate 21, a flow path plate 38, and a nozzle plate 36 are joined. These pressure chamber plates 2
1, the flow path plate 38 and the nozzle plate 36 are positioned with high accuracy by the positioning means 25. In the present embodiment, the positioning means 25 is constituted by through holes 23, 24 through which the positioning pins 23a, 24a pass. That is, the nozzle plate 36, the flow path plate 38, and the pressure chamber plate 21 are positioned with high accuracy by overlapping each other so that the positioning pins 23a, 24a pass through the through holes 23, 24 of each plate. ing. The through hole 23 is a circular hole, and the through hole 24 is an elliptical hole.

However, the positioning means 25 is not limited to physical means, and other means may be used. For example, a marker for alignment may be provided on each plate, and the alignment of each plate may be performed by optical means.

FIG. 6 is a perspective view of a main part including a section taken along line AA of FIG. As shown in FIG. 6, a pressure chamber 22 is provided in the pressure chamber plate 21. The channel plate 38 is
A first plate 33 provided with an ink flow path inlet 20 and an ink supply port 19; a second plate 34 provided with an ink flow path 32 and a common liquid chamber 18;
A third hole provided with a hole for introducing ink from the nozzle 37 to the nozzle 37
And a plate 35. Channel plate 38
Is made of a metal material such as SUS, a photosensitive glass or a resin material. Nozzle plate 36
Is made of a metal material such as SUS having a thickness of 20 μm to 150 μm or a resin material such as PI (polyimide). The nozzle 37 is formed in the nozzle plate 36. The ink flows through the head in the order of the common liquid chamber 18 → the ink supply port 19 → the pressure chamber 22 → the ink flow path inlet 20 → the ink flow path 32 → the nozzle 37, flies from the nozzle 37, and lands on the recording medium 9. I do.

As shown in FIG. 3, the pressure chambers 22 are arranged at an interval of 600 dpi (42.3 μm) in the head longitudinal direction Y. However, the pressure chambers 22 are not arranged in a line along the head longitudinal direction Y, but are arranged while being appropriately shifted in the scanning direction X in order to increase the head density. Specifically, the pressure chamber plate 21 is formed with pressure chamber rows 22A and 22B in which four pressure chambers 22 are arranged so as to be inclined with respect to the head longitudinal direction Y.
In other words, each of the pressure chamber rows 22A and 22B is formed by four pressure chambers 22 arranged diagonally downward and rightward in FIG. The pressure chamber row 22A and the pressure chamber row 22B are adjacent to each other in the head longitudinal direction Y. A plurality of pressure chamber rows 22A and 22B are formed at predetermined intervals in the head longitudinal direction Y. 2 and 3 show only two sets of the pressure chamber rows 22A and 22B for simplicity of description, but actually, in the head longitudinal direction Y
Are formed with a number of pressure chamber rows 22A and 22B.

The bottom of each pressure chamber 22 has an ink supply port 1
9 and an ink flow path inlet 20 are provided. The ink supply port 19 allows the common liquid chamber 18 and the pressure chamber 22 to communicate with each other. The inside of the common liquid chamber 18 is filled with ink. The central part of the common liquid chamber 18 is branched into two rows of liquid chambers extending in the head longitudinal direction Y, and these two rows of liquid chambers are united at both ends. At both ends, ink inlets 12 are provided, respectively, and ink is supplied to the common liquid chamber 18 through the ink inlets 12.

FIG. 7 is a process chart for explaining a method of manufacturing each of the line heads 1 and 2, and shows a cross section taken along line BB of FIG. Next, a method for manufacturing a line head using the transfer method will be described with reference to FIG.

First, a 20 mm × 25 mm MgO, S
A substrate 60 made of i, SUS, or the like is prepared. In the case of the present embodiment, an MgO substrate is used.

Next, as shown in FIG. 7A, a first electrode 15 of platinum is formed on the substrate 60 by RF sputtering (high frequency sputtering).

Next, as shown in FIG. 7B, a PZT thin film piezoelectric element 30 is formed on the first electrode 15 by RF sputtering. Here, in particular, a single crystal substrate of MgO is used as the substrate 60, the first electrode 15 made of platinum is formed on the (100) plane of the MgO substrate 60, and then the piezoelectric element 3 is formed.
When the piezoelectric element 30 is manufactured, the piezoelectric element 30 has stable characteristics with high piezoelectricity.

Next, as shown in FIG. 7C, a second platinum electrode 50 is formed on the piezoelectric element 30 by RF sputtering.

Next, as shown in FIG. 7D, the diaphragm 14 made of chromium is formed on the second electrode 50 by RF sputtering. At this stage, the substrate block 61 is completed. The substrate block 61 is for transferring the actuator block 40 from the substrate 60 to the pressure chamber plate 21 and includes the substrate 60 and the actuator block 40.

Next, as shown in FIG. 7E, a uniform electrodeposited resin layer (not shown) is formed on the pressure chamber plate 21 by using an electrodeposition method, and thereafter, the electrodeposited resin layer is formed. The plurality of substrate blocks 61 are joined to the pressure chamber plate 21 such that the vibration plate 14 and the pressure chamber plate 21 are in contact with each other. In joining the substrate blocks 61, the substrate blocks 61 are prevented from contacting each other in order to join the vibration plate 14 to the pressure chamber plate 21 uniformly and reliably. That is, the adjacent substrate blocks 6
The board blocks 61, 61 are arranged apart from each other so as to provide a gap between them (see FIG. 2).

In the line heads 1 and 2 according to the present embodiment, the nozzles 37, 37,... Are arranged at high-density pitch intervals in the head longitudinal direction Y. Therefore, the substrate block 6
1 are arranged in a line without any gap, the substrate block 6
There is a possibility that the substrate blocks 61 overlap with each other due to a slight error in the size or shape of 1 or a slight placement error. Such substrate blocks 61 and 6
If contact between the 1s occurs, the yield will deteriorate. Therefore, in this embodiment, in order to cope with high-density nozzles, the first and second two line heads 1 and 2 are displaced in the head longitudinal direction by a distance half the pitch interval of the substrate block 61. . As a result, the line head 1,
2 as a whole, the nozzles 37, 37,... Are densely arranged at predetermined pitch intervals in the head longitudinal direction Y, and the pressure chambers 22, 22,. Will be. Further, the substrate block 61 is also arranged without a gap in the head longitudinal direction Y.

After the bonding of the substrate block 61 as described above, the substrate 60 is etched away using an acidic solution as shown in FIG.

Next, after a mask (not shown) manufactured with high accuracy by an exposure machine is positioned by a positioning means 25 provided on the pressure chamber plate 21, as shown in FIG. By patterning the first electrode 15,
The electrodes 15 and the leads 16 are formed in a predetermined shape.
As described above, the first electrode 15 and the lead portion 16 can be formed with high accuracy by aligning the pressure chamber plate 21 with the mask using the alignment unit 25.

Next, as shown in FIG. 7 (h), using the positioning means 25 provided on the pressure chamber plate 21,
After positioning the pressure chamber plate 21 and the flow path plate 38 with each other, they are joined.

Next, as shown in FIG. 7 (i), the flow path plate 38 and the nozzle plate 36 are positioned using the positioning means 25 provided on the pressure chamber plate 21 or the flow path plate 38. Join from. This allows
A line head in which each plate is aligned with high precision is completed.

In this embodiment, the pressure chamber plate 2
1 → flow path plate 38 → nozzle plate 36, but after bonding the flow path plate 38 and the nozzle plate 36, the pressure chamber plate 21 and the flow path plate 3
8 may be joined.

In this embodiment, the diaphragm 14 and the second
The electrode 50 was formed separately (see FIG. 4).
4 is made of a conductive material such as chrome,
Can also serve as the second electrode 50, so that the second electrode and diaphragm 14 may be provided without separately providing the diaphragm 14 and the second electrode 50 as shown in FIG.

Further, between the piezoelectric element 30 and the diaphragm 14, Cu is added to improve the withstand voltage and strengthen the bonding force.
A conductive material such as Ti or Ti may be interposed as an intermediate layer.

Further, as shown in FIG. 9, the piezoelectric element 30 may be patterned and divided together with the first electrode 15. In this case, the diaphragm 14 is easily bent, and a larger displacement can be obtained even when the same voltage is applied.

Further, after the first electrode 15 is formed on the substrate 60 of FIG. 7A, patterning of the first electrode 15 is performed immediately, as shown in FIG. Can be arranged around the piezoelectric element 30.
Thereby, the withstand voltage between the first electrode 15 and the lead portion 16 and the diaphragm 14 can be improved.

In the present embodiment, the first electrode and the second electrode are the individual electrode and the common electrode, respectively, but may be reversed. That is, the first electrode may be a common electrode and the second electrode may be an individual electrode.

Further, in this embodiment, the pressure chambers 22, 22,... Of the pressure chamber rows 22A, 22B are arranged in a line as shown in FIG. 3, but, for example, as shown in FIG. , 22,... May be arranged alternately in the head longitudinal direction Y. That is, the pressure chambers 22, 22,... May be arranged in a zigzag manner. By doing so, the pressure chamber 22,
Since the distance between the adjacent 22 becomes longer, crosstalk is less likely to occur. Therefore, the interval between the pressure chambers in the head longitudinal direction Y can be further reduced, and the pressure chambers 22 can be arranged at a higher density.

According to the present embodiment, the actuators are formed by the plurality of actuator blocks 40 and the plurality of actuator blocks 40 are arranged for one pressure chamber block 41. The size can be reduced. Therefore, the transfer method can be effectively used.

The ink jet head 5 is composed of two lines of line heads 1 and 2,
2, the actuator blocks 40 are arranged so as to be separated from each other.
40 can be prevented from overlapping each other. on the other hand,
In view of the line heads 1 and 2 as a whole, since the actuator block 40 is provided without a gap in the head longitudinal direction Y, the actuator can be formed without leakage according to each nozzle 37 and each pressure chamber 22.

In the present embodiment, the first line head 1 and the second line head 2 are line heads having the same shape, and the ink jet head 5 is constructed by combining a plurality of one type of line head. I have. Therefore, since it is not necessary to separately manufacture two types of line heads, the manufacturing cost can be reduced.

Further, when one of the line heads fails, only the line head concerned can be replaced, and the other line head can be used as it is. The maintenance cost is reduced as compared with the conventional head.

As described above, according to this embodiment, the characteristics such as the piezoelectric characteristics and the film thickness of the thin film actuator can be made uniform,
Prevention of film cracking, improvement in production yield, miniaturization of production equipment, reduction in price, and the like can be achieved.

<Embodiment 2> FIG. 12 shows the configuration of an ink jet head 5 according to Embodiment 2. Also in the second embodiment, the first line head 51 and the second line head 52
Are composed of heads having the same shape. However, unlike the first embodiment, the line heads 51 and 52 are not arranged offset from each other, but are arranged point-symmetrically with each other. That is, the inkjet head 5 according to the present embodiment includes two line heads 5 having the same shape.
One (the first line head 51) of the first and second 52 is arranged as it is, and the other (the second line head 52) is arranged by being rotated by 180 degrees with respect to the head center. In FIG. 12, for simplicity of description, only two actuator blocks 40 of the line heads 51 and 52 are shown.
Actually, a large number of actuator blocks 40 are arranged in the head longitudinal direction Y.

The arrangement patterns of the actuator blocks 40, the pressure chambers 22, the nozzles 37 and the like in each of the line heads 51 and 52 are the same as in the first embodiment. In the present embodiment, one end of each of the line heads 51 and 52 is slightly extended in the head longitudinal direction Y.
Both ends of 1, 52 are located at positions aligned in the scanning direction X. First
Since the line head 51 and the second line head 52 are symmetrically installed, the actuator block 40 of one line head becomes movable in the head longitudinal direction Y.
It is located between. The actuator block 40 of one line head partially overlaps the actuator block 40 of the other line head in the head longitudinal direction Y. Also in the present embodiment, the actuator block 40 as a whole of the inkjet head 5 is used.
Are arranged in a staggered pattern.

Therefore, according to the present embodiment, the same effects as in the first embodiment can be obtained. Further, according to the present embodiment, since both ends of the first line head 51 and the second line head 52 are aligned, both line heads 5
The attachment of 1,52 is simplified.

Third Embodiment As shown in FIG. 13, an ink jet recording apparatus 90B according to a third embodiment includes four sets of the first line head 1 and the second line head 2 according to the first embodiment, and An image is formed.

The inkjet head 55 includes a first head group 71 for discharging black ink, a second head group 72 for discharging cyan ink, a third head group 73 for discharging magenta ink, and a third head group 73 for discharging yellow ink. And a four-head group 74. First head group 71, second head group 72, third head group 73, and fourth head group 74
Are sequentially arranged in the scanning direction X. The first to fourth head groups 71 to 74 each include a first line head 1 and a second line head 2, and have the same configuration as the inkjet head 5 of the first embodiment. To the first to fourth head groups 71 to 74, ink tanks 11 for storing black ink, cyan ink, magenta ink, and yellow ink, respectively, are connected via ink tubes 10, respectively.

The ink jet head 5 according to the present embodiment
According to 5, since a plurality of line head groups 71 to 74 for discharging a plurality of colors of ink are provided, the same effect as that of the first embodiment can be obtained in an ink jet recording apparatus for forming a color image.

A part or all of the first to fourth head groups 71 to 74 may be formed by the first line head 51 and the second line head 52 according to the second embodiment. In this case, the same effect as that of the second embodiment can be obtained in an ink jet recording apparatus that forms a color image.

<Fourth Embodiment> As shown in FIG. 14, an ink jet head 62 according to a fourth embodiment is configured such that each of the line heads 63 and 64 discharges ink of four colors.

The ink jet head 6 according to the present embodiment
2 includes a first line head 63 and a second line head 64 having the same shape. The first line head 63 and the second line head 64 are arranged in the scanning direction X and are shifted from each other in the head longitudinal direction Y.

Each of the line heads 63 and 64 has a pressure chamber 22a for black ink and a pressure chamber 22b for cyan ink.
And a pressure chamber 22c for magenta ink and a pressure chamber 22d for yellow ink. The pressure chambers 22a to 22d for the respective color inks are arranged in a zigzag pattern,
They are arranged in the head longitudinal direction Y at a pitch interval of 0 dpi. The pressure chambers 22a to 22d for the inks of the respective colors are arranged at positions aligned in the scanning direction X.

The common liquid chamber 18a for black ink, the common liquid chamber 18b for cyan ink, and the common liquid chamber 1 for magenta ink
8c and the common liquid chamber 18d of yellow ink are arranged in the scanning direction X. The common liquid chambers 18a to 18d each extend in the head longitudinal direction Y, and ink introduction ports 12 are provided on both sides thereof.

The actuator block 40 covers the plurality of pressure chambers 22a to 22d. That is, the pressure chambers 22a for four colors are formed by one actuator block 40.
To 22d are covered together. The arrangement pattern of the actuator blocks 40 is the same as in the first embodiment.

The ink jet head 6 according to the present embodiment
According to 2, since the pressure chambers 22a to 22d for four colors are covered by one actuator block 40, the pressure chambers can be arranged at a higher density. Further, the number of actuators included in the actuator block 40 can be increased. Therefore, the head can be reduced in size, the number of manufacturing steps can be reduced, and the cost can be reduced.

In the present embodiment, the first line head 63 and the second line head 64 are displaced from each other in the head longitudinal direction Y, as in the first embodiment. Head 63 and second line head 6
Of course, 4 may be arranged point-symmetrically.

<Other Embodiments> In the third and fourth embodiments, four sets of the first line head and the second line head are provided, and four color inks of black, cyan, magenta and yellow are used. , The first line head and the second line head may be provided in two, three or five or more sets, and inks of two, three or five or more colors may be used. Further, different types of ink of the same color may be used.

[0083]

As described above, according to the ink jet head of the present invention, a plurality of actuator blocks are provided for one pressure chamber block.
Despite being a line-type head, the size per actuator block can be reduced. Therefore, the characteristics such as the piezoelectric characteristics and the film thickness can be made uniform, the film can be prevented from being cracked, the production yield can be improved, and the production equipment can be reduced in size and cost.

Since a plurality of rows of line heads are arranged in the scanning direction and the actuator blocks are arranged so as to be separated from each other in each line head, even if the shape error or the installation error of the actuator block is large, the Physical contact between them can be prevented. Therefore, since a shape error or an installation error of the actuator block can be considerably allowed, the yield can be improved.

The line heads of a plurality of rows are arranged such that the actuator blocks of the line heads of the respective rows are shifted from the actuator blocks of the line heads of the other rows in the longitudinal direction of the head, and partially overlap in the longitudinal direction of the head. As a result, the actuator blocks can be arranged without gaps in the longitudinal direction of the head as a whole of the plurality of rows of line heads. Therefore, although the actuator blocks are separated from each other in the line heads of each row, the actuators can be arranged at regular intervals in the head longitudinal direction.

If the ink jet head is constituted by disposing a plurality of line heads having the same shape in the longitudinal direction of the head, it is not necessary to separately manufacture a plurality of types of line heads, thereby reducing costs. Can be achieved.

Further, even if the ink jet head is constituted by arranging a plurality of line heads having the same shape symmetrically with respect to a point, it is not necessary to separately manufacture a plurality of types of line heads, thereby reducing costs. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an ink jet recording apparatus according to a first embodiment.

FIG. 2 is a plan view of the inkjet head.

FIG. 3 is a plan view of a pressure chamber block of the inkjet head.

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a sectional view taken along line CC of FIG. 2;

FIG. 6 is a perspective view of a main part of the head including a cross section taken along line AA of FIG. 2;

FIGS. 7A to 7I are process diagrams showing a method for manufacturing a line head.

FIG. 8 is a diagram corresponding to FIG. 4 according to a modification of the first embodiment.

FIG. 9 is a diagram corresponding to FIG. 4 according to another modification of the first embodiment.

FIG. 10 is a diagram corresponding to FIG. 4 according to another modification of the first embodiment.

FIG. 11 is a plan view of a line head according to another modification of the first embodiment.

FIG. 12 is a plan view of an inkjet head according to a second embodiment.

FIG. 13 is a perspective view of a main part of an ink jet recording apparatus according to a third embodiment.

FIG. 14 is a plan view of an inkjet head according to a fourth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first line head 2 second line head 5 inkjet head 6 recording medium holding member 7 feed roller 8 transport roller (moving means) 9 recording medium 10 ink tube 11 ink tank 14 diaphragm 15 first electrode 18 common liquid chamber 22 pressure Chamber 30 piezoelectric element (piezoelectric layer) 37 nozzle 40 actuator block 41 pressure chamber block 50 second electrode 90 ink jet recording apparatus

Continued on the front page (72) Atsushi Soga, Inventor 1006 Kadoma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Reference) 2C057 AF91 AF99 AG15 AG44 AN05 AP24 AP31 AP52 AP72 AQ02 AQ06 BA03 BA14

Claims (10)

[Claims] An ink jet head comprising a plurality of rows of line heads arranged in a scanning direction, wherein the line heads in each row include a common liquid chamber for storing ink and a plurality of liquid heads communicating with the common liquid chamber. A pressure chamber block provided with a pressure chamber, a plurality of nozzles communicating with the pressure chambers, a piezoelectric layer, first and second electrodes for applying a voltage to the piezoelectric layer, and a diaphragm. A plurality of actuator blocks disposed on one surface of the pressure chamber block so as to cover the plurality of pressure chambers of the pressure chamber block with the vibration plate. ,
While being arranged along the longitudinal direction of the head and adjacent actuator blocks are arranged so as to be separated from each other, the other actuator blocks of the line heads are shifted in the longitudinal direction of the head with respect to the actuator blocks of the line heads, and the other An ink jet head arranged so as to partially overlap the actuator blocks of the line heads in the row in the head longitudinal direction. 2. The inkjet head according to claim 1, wherein the line head includes a plurality of line heads having the same shape, and the line heads having the same shape are shifted from each other in a head longitudinal direction. The inkjet head is arranged as follows. 3. The inkjet head according to claim 2, wherein each of the line heads having the same shape has a plurality of actuator blocks arranged at a predetermined interval shorter than the length of each actuator block in the head longitudinal direction. An inkjet head in which the line heads having the same shape are mutually shifted in the head longitudinal direction such that the actuator block of one line head is located between the actuator blocks of the other line head in the head longitudinal direction. 4. The inkjet head according to claim 1, wherein the line head includes at least a pair of line heads having the same shape, and the pair of line heads are arranged point-symmetrically to each other. Inkjet head. 5. The ink jet head according to claim 4, wherein each of the line heads having the same shape has a plurality of actuator blocks arranged at a predetermined interval shorter than the length of each actuator block in the head longitudinal direction. The line heads of the same shape are arranged point-symmetrically with respect to each other such that both ends in the head longitudinal direction are aligned and the actuator block of one line head is located between the actuator blocks of the other line head in the head longitudinal direction. Inkjet head. 6. The ink jet head according to claim 3, wherein the entire actuator blocks of the plurality of rows of line heads are arranged in a staggered manner. 7. The ink jet head according to claim 1, wherein each of the line heads is configured to discharge the same type of ink. 8. The inkjet head according to claim 1, wherein the line heads form a line head group including a plurality of lines of line heads that eject the same type of ink. An inkjet head in which a plurality of the line head groups are provided in a scanning direction so as to eject a plurality of types of ink. 9. The ink jet head according to claim 1, wherein each of the line heads is configured to discharge a plurality of types of ink. 10. An ink jet recording apparatus comprising: the ink jet head according to claim 1; and moving means for relatively moving the ink jet head and a recording medium in a scanning direction.