JPH04247944A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To prevent ink in each liquid chamber from drying by a method wherein the liquid chambers are connected with each other along the arrangement direction thereof in an ink jet recording head in which ink contained in a large number of liquid chambers adjacently arranged is flown from a nozzle by an electric actuation means. CONSTITUTION:A large number of one-side opening liquid chambers 2 are formed on one surface of a substrate 1 made of an piezoelectric substance, such as PZT, by being separated by partition walls 3. On one-side ends of the respective liquid chambers 2, nozzles 4 are arranged in a staggered state. The open surfaces of the liquid chambers 2 are covered with a top plate 5, which is bonded to the surface of the substrate 1 with an adhesive, screws, or the like. A connecting path 6 connecting the liquid chambers 2 with each other is formed between the inner surface of the top plate 5 and the end faces of the partition walls 3 along the arrangement direction of the liquid chambers 2. Furthermore, an electrical actuator means 7 is provided on the substrate 1 for pressurizing ink in the liquid chambers 2 and flying the ink from the nozzles 4.

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.

0002

[Prior Art] As described in Japanese Patent Application Laid-Open No. 63-252750 (US Patent Specification No. 4,887,100), a large number of liquid chambers each partitioned by a partition wall are arranged in the same plane. There is an inkjet recording head that selectively ejects ink from nozzles that are arranged adjacent to each other and provided at the end of each liquid chamber in a direction perpendicular to the arrangement direction of the liquid chambers.

0003

SUMMARY OF THE INVENTION In such an ink jet recording head, the cross-sectional area of the liquid chamber and the arrangement interval must be extremely small in order to form high-density dots. As a result, the ink in the liquid chamber dries and the pigments in the ink precipitate, clogging the liquid chamber and making printing impossible. In addition, it is difficult to clean the minute liquid chambers, and when replacing the inkjet recording head, the electrical actuation means that pressurizes or heats the ink in the liquid chamber to make it fly must also be replaced. It is extremely uneconomical.

0004

[Means for Solving the Problems] The invention as claimed in claim 1 provides a plurality of liquid chambers that are arranged adjacent to each other and partitioned by partition walls, a nozzle provided at one end of these liquid chambers, and a plurality of liquid chambers that are arranged adjacently to each other. The ink supply unit is connected to an ink supply unit, an electrical actuation unit that pressurizes or heats the ink in the liquid chambers, and a communication path that communicates the liquid chambers along the direction in which the liquid chambers are arranged.

[0005] The invention according to claim 2 is characterized in that, in claim 1, a plurality of liquid chambers each having an opening on one side are formed on one surface of a flat base material and partitioned by partition walls, and the top plate is detachably attached to the base plate. A communication path communicating the liquid chamber was formed between the inner surface of the liquid chamber and the end surface of the partition wall.

[0006] The invention according to claim 3 is the invention according to claim 1, in which a large number of liquid chambers each having an opening on one side are partitioned by a partition wall on each of the opposite surfaces of the pair of flat base materials which are connected oppositely to each other to form a pair. The opening surfaces of the liquid chambers and the end surfaces of the partition walls were arranged in a staggered manner so as to face each other, and communication passages connecting the liquid chambers were formed on opposing surfaces of the pair of base materials.

[0007] According to a fourth aspect of the invention, in the third aspect, the paired base materials are detachably connected.

[0008]

According to the first aspect of the invention, the ink in each liquid chamber is prevented from drying because the liquid chambers are communicated with each other by the communication path in a direction perpendicular to the direction in which the ink flies.

[0009] According to the second aspect of the invention, an inkjet recording head can be easily manufactured by forming a liquid chamber by a concave portion only on the base material side and abutting the outer inner surface of this base material against a top plate. Furthermore, since the top plate can be removed from the base material, the opening surface of the liquid chamber can be opened to easily clean pigments, foreign substances, etc. deposited from the ink.

[0010] In the third aspect of the invention, since a large number of liquid chambers are arranged in a staggered manner on the pair of base materials, the flying pressure of ink in the liquid chambers formed on one base material is higher than that on the other base material. It becomes possible to prevent the liquid from escaping into the liquid chambers formed in the material, and moreover, it becomes possible to double the arrangement density of the liquid chambers.

[0011] According to the fourth aspect of the invention, since the pair of base materials can be separated, it becomes possible to open the opening surface of the liquid chamber and easily clean pigments, foreign substances, etc. deposited from the ink.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention according to claim 1 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, on one side of a flat base material 1 made of a piezoelectric material such as PZT,
A large number of liquid chambers 2 that are open on one side and a large number of partition walls 3 that partition these liquid chambers 2 are formed. These liquid chambers 2
Nozzles 4 are arranged in a staggered manner at one end. Further, the opening surface of the liquid chamber 2 is covered by a top plate 5 that is bonded to one surface of the base material 1 by means of adhesive or the like. A communication path 6 is formed between the inner surface of the top plate 5 and the end surface of the partition wall 3, which communicates the liquid chambers 2 along the direction in which the liquid chambers 2 are arranged. Further, the base material 1 is provided with an electrical actuation means 7 that pressurizes the ink 10 in the liquid chamber 2 and causes the ink 10 to be ejected from the nozzle 3. This electrical actuation means 7 is formed by electrodes 8 having a U-shaped cross section fixed to both inner surfaces and the bottom surface of each liquid chamber 2, and the partition wall 3. That is, when the partition wall 3, which is a part of the base material 1 and is made of a piezoelectric material, is polarized in a direction perpendicular to the top plate 5 and a voltage is applied, shear deformation occurs along the communication path 6. Liquid chamber 2
The ink 10 is pressurized. Note that the electrode 8
is connected to a power source via a lead wire 9.

As shown in FIG. 2, a nozzle plate 11 is fixed to the front surfaces of the base material 1 and the top plate 5, and the nozzles 4 are formed on this nozzle plate 11. Further, a pipe 13, which is a part of the ink supply section 12, is sealed and fitted to the side surface of the base material 1. This pipe 13 is connected to an ink tank (not shown) to supply ink 10 to the liquid chamber 2.
It is intended to supply A platen 14 supports the paper 15, and the platen 14 is rotatably held opposite the nozzle plate 11.

In such a configuration, the adjacent liquid chambers 2
When a voltage is applied to the electrode 8, the partition wall 3 between the adjacent liquid chambers 2 is sheared and deformed toward the side of the liquid chamber 2 to which a positive voltage has been applied, thereby increasing the pressure of the ink 10 in the liquid chamber 2. It is raised high and is flown from the nozzle 4. Therefore, the ink 10 in the adjacent liquid chambers 2 is ejected with different timings by alternately applying positive voltages to the electrodes 8 in these liquid chambers 2. By arranging the nozzles 4 in a staggered manner, the ink 10 can be ejected in a line in a direction perpendicular to the feeding direction of the paper 15.

Here, since the respective liquid chambers 2 are communicated with each other by the communication path 6 in a direction perpendicular to the direction in which the ink 10 flies, drying of the ink 10 in each liquid chamber 2 is prevented. Also,
By setting the gap a between the end face of the partition wall 3 and the inner surface of the top plate 5 to a dimension that provides a predetermined flow path resistance against an increase in the pressure in the liquid chamber 2, the pressure caused by the deformation of the partition wall 3 can be reduced. It is possible to direct most of it toward the nozzle 4. Further, by forming the liquid chamber 2 by a recess only on the base material 1 side and abutting the outer inner surface of the base material 1 against the top plate 5, an inkjet recording head can be easily manufactured. Base material 1
Even if the top plate 5 and the top plate 5 are bonded with adhesive, since they are bonded outside the arrangement area of the liquid chamber 2, it is possible to prevent foreign substances such as the adhesive from entering the liquid chamber 2. It is possible.

Furthermore, as shown in FIG. 3, by removably connecting the base material 1 and the top plate 5 with a fastening member such as a screw 16, the top plate 5 can be separated from the base material 1 and the liquid chamber can be opened. The inside of the liquid chamber 2 can be opened, thereby making it possible to easily clean the inside of the liquid chamber 2. Therefore, the life of the inkjet recording head can be extended.

Next, an embodiment of the invention of claim 3 is shown in FIG.
The explanation will be based on. Components that are the same as those described in FIGS. 1 to 3 are designated by the same reference numerals, and description thereof will be omitted. In the present invention, a pair of base materials 1 each having a large number of liquid chambers 2 and partition walls 3 formed thereon and having electrical actuation means 7 are joined together in a facing manner. Here, the liquid chamber 2 of one base material 1 is arranged to face the end surface of the partition wall 3 of the other base material 1. A communication path 6 that communicates the liquid chamber 2 is formed on opposing surfaces of the pair of base materials 1 .

In such a configuration, the pair of base materials 1
Since a large number of liquid chambers 2 are arranged in a staggered manner, the flying pressure of the ink in the liquid chamber 2 formed on one base material 1 escapes to the liquid chamber 2 formed on the other base material 1. This makes it possible to prevent Furthermore, it becomes possible to double the arrangement density of the liquid chambers 2. Furthermore, even if the paired base materials 1 are bonded with adhesive, since they are bonded outside the arrangement area of the liquid chambers 2, foreign substances such as adhesive are prevented from entering the liquid chambers 2. It is also possible.

Furthermore, in the present invention, a heating element is provided in each liquid chamber as an electrical actuation means, and a voltage is applied to these heating elements to heat the ink in the liquid chamber, thereby reducing the pressure caused by the boiling of the ink. It can also be applied to an inkjet recording head in which ink is ejected from a nozzle by rising.

[0020]

Effects of the Invention The invention according to claim 1 is characterized in that a large number of liquid chambers are arranged adjacent to each other and partitioned by partition walls, and the liquid chambers are connected to a nozzle provided at one end of these liquid chambers. Since the structure includes an ink supply section, an electric actuation means for pressurizing or heating the ink in the liquid chambers, and a communication path that communicates these liquid chambers along the arrangement direction of the liquid chambers, each liquid chamber Since the ink chambers are communicated with each other by a communication path in a direction perpendicular to the direction in which the ink flies, the ink in each liquid chamber is prevented from drying, which has the effect of extending the service life.

[0021] The invention according to claim 2 is characterized in that, in claim 1, a plurality of liquid chambers each having an opening on one side are formed on one surface of a flat base material and partitioned by partition walls, and the top plate is detachably attached to the base plate. Since a communication path communicating the liquid chamber is formed between the inner surface of the substrate and the end surface of the partition wall, a liquid chamber is formed by a recess only on the base material side, and the inner surface of the outer side of the base material is pushed against the top plate. The inkjet recording head can be easily manufactured by applying the liquid to the liquid, and since the top plate can be removed from the base material, the opening surface of the liquid chamber can be opened and pigments and foreign substances deposited from the ink can be easily cleaned. It has the effect of being able to.

Claim 3 The invention according to claim 1 provides a plurality of liquid chambers each having an opening on one side and partitioned by a partition wall on each of the opposing surfaces of the pair of flat base materials which are connected oppositely to each other to form a pair. The opening surfaces of the liquid chambers and the end surfaces of the partition walls are arranged in a staggered manner so as to face each other, and communication passages for communicating the liquid chambers are formed on opposing surfaces of the pair of base materials. Because a large number of liquid chambers are arranged in a staggered manner on the base material that forms the base material, the flying pressure of the ink in the liquid chamber formed on one base material is prevented from escaping to the liquid chamber formed on the other base material. In addition, it has the effect of doubling the arrangement density of the liquid chambers. In addition, the pair of base materials 1,
Similar to what is shown in FIG. 3, by detachably connecting the substrates 1 with a fastening member such as a screw, the substrates 1 can be separated from each other and the liquid chamber 2 can be easily cleaned.

[0023] In the invention of claim 4, in claim 3, since the pair of base materials are detachably connected, the pair of base materials can be separated, so that the opening surface of the liquid chamber is opened and the ink is separated. This has the effect of making it possible to easily clean away pigments, foreign substances, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the invention according to claim 1.

FIG. 2 is a perspective view of a portion thereof.

FIG. 3 is a partial longitudinal sectional front view showing a modification of the invention according to claim 1.

FIG. 4 is a longitudinal sectional front view showing an embodiment of the invention according to claim 3.

[Explanation of symbols]

1 Base material 2 Liquid chamber 3 Partition wall 4 Nozzle 5 Top plate 6 Communication path 7 Electric actuation means 10
Ink 12 Ink supply section

Claims (4)

[Claims] 1. A large number of liquid chambers partitioned by partition walls and arranged adjacent to each other, a nozzle provided at one end of these liquid chambers, and an ink supply unit to which the liquid chambers are connected.
An inkjet recording head comprising: an electrical actuation unit that pressurizes or heats ink within the liquid chamber; and a communication path that communicates the liquid chambers along the direction in which the liquid chambers are arranged. 2. A large number of liquid chambers with one side opening partitioned by partition walls are formed on one surface of a flat base material, and the inner surface of a top plate removably attached to the substrate is connected to the end surface of the partition wall. 2. The inkjet recording head according to claim 1, further comprising a communication path that communicates with the liquid chamber. 3. A plurality of liquid chambers each having an opening on one side and partitioned by a partition wall are provided on opposing surfaces of a pair of flat base materials that are connected to face each other and are connected to each other by a partition wall. are arranged in a staggered manner so that the end faces of the
2. The inkjet recording head according to claim 1, wherein a communication path communicating the liquid chamber is formed on opposing surfaces of the pair of base materials. 4. The ink jet recording head according to claim 3, wherein the pair of base materials are detachably connected.