JPH04223175A - Ink jet print head - Google Patents

Abstract

PURPOSE:To obtain a high density ink jet printing head easy to prepare by using an electrostriction element. CONSTITUTION:An ink jet printing head is equipped with a common ink passage 2a receiving the supply of ink from the outside, a substrate 1 having groove parts 2,3 forming the individual ink passages 3a branched from the common ink passage 2a, the piezoelectric elements 4 formed in a comb tooth shape and having the comb tooth parts fitted in the respective groove parts forming the individual ink passages 3a of the substrate 1, the common electrode 5 formed to one surfaces of the electrostriction elements 4, the individual electrodes 6 formed to the comb tooth parts of the other surfaces of the electrostriction elements, the elastic coating layer 8 bonded to the upper surfaces of the electrostriction elements 4 to form the lid body of the substrate 1 and the ink injecting small orifices 9 provided to the front side surfaces of the individual ink passages 3a of the substrate 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printhead that can be used for highly integrated serial and line type inkjet printheads using electrostrictive elements.

0002

2. Description of the Related Art One type of ink jet print head uses an electrostrictive element. Conventionally, as shown in FIG. 6, an inkjet print head using an electrostrictive element supplies ink from an ink source 41 through an ink filter 42 to a common ink chamber 44 of a head 43, and further supplies ink to a plurality of pipes 45. supplying. The individual pipes 45 are surrounded by the same cylindrical electrostrictive element 46 as shown in FIG.
When an electric field is individually applied to 6 by the piezo drive unit 47, the electrostrictive element becomes flat, and the ink in the pipe 45 is ejected from the nozzle 48 at the tip of the pipe.

0003

[Problems to be Solved by the Invention] Although the above-mentioned conventional inkjet printhead using an electrostrictive element has a simpler structure than inkjet printheads based on other principles, it still has problems with the connection between the common ink chamber and individual pipes. It is difficult to connect and manufacture individual pipes, and the pipe support mechanism is also complicated. Although it is possible to realize a serial type with a small number of dots, it is difficult to manufacture highly integrated serial and line type inkjet printheads. Met.

The present invention has been made in view of the above-mentioned problems, and aims to provide a serial or line type inkjet print head that is easy to manufacture and has a high density, using an electrostrictive element. There is.

[0005]

Means and Effects for Solving the Problems The inkjet print head of the present invention includes a base body having grooves forming a common ink path that receives ink from the outside and individual ink paths branching off from the common ink path, and a comb. an electrostrictive element formed in a tooth shape, with each comb tooth-like part fitting into each groove forming an individual ink path of the base body; a common electrode formed on one surface of the electrostrictive element; Individual electrodes formed on each comb-shaped portion on the other surface and the upper surface of the electrostrictive element are attached,
The base body includes an elastic coating layer forming a lid, and a pore for ejecting ink on the front side of the individual ink passages of the base body.

[0006] In this inkjet print head,
When a voltage is applied between a selected individual electrode and the common electrode while ink is being supplied to the common ink path and the individual ink paths, the comb-shaped piece of the electrostrictive element where the individual electrode is located The tip of is displaced downward. This displacement pushes the ink in the individual ink channels, and the ink is discharged from the pores on the front side of the ink channels.

[0007]

[Examples] The present invention will be explained in more detail with reference to Examples below. FIG. 1 is a partially cutaway perspective view of an inkjet print head showing an embodiment of the present invention. In FIG. 1, a substantially rectangular parallelepiped-shaped base 1 has a groove 2 for a common ink path opening on the side surface, and a groove 2 for the common ink path.
Grooves 3 are provided for a plurality of individual ink channels branching off from the ink channel. The grooves 2 and 3 are both open at the top, and the groove 3 is also open at the front.

[0008] On the base 1, an electrostrictive element 4 is provided. As shown in FIG. 2, this electrostrictive element 4 is formed into a comb-like shape by pasting two element plates 4a and 4b, and has a common electrode 5 all over the back surface and individual electrodes 6 on the front surface. is formed. This electrostrictive element 4 covers the entire surface of the groove 2 for the common ink path of the base body 1, and each comb-shaped portion 7 is configured to fit into the groove 3 for the individual ink path. The electrostrictive element 4 and the base 1 form a common ink path 2a and an individual ink path 3a. Further, an elastic and electrically insulating sealing coat 8 is attached to the upper surface of the electrostrictive element 4,
This sealing coat 8 is also adhered to the upper surface of the substrate 1, thereby completely separating the individual ink channels 3a. A side plate 10 having pores 9 for discharging ink is attached to the front surface of the base 1 at positions corresponding to the individual ink passages 3a.

In the inkjet print head of this embodiment, drive signals P1, P2,..., Pn are selected between the individual electrodes 6 and the common electrodes 5 while ink is supplied to the common ink path 2a and the individual ink paths 3a When a specific voltage is applied, the comb-shaped portion 7 where the selected individual electrode 6 is located is displaced in the direction of the individual ink path 3a, as shown in FIG.
This displacement pushes the ink and causes it to fly outward from the pores 9. The ink flying distance is 3 m when the length L of the comb-shaped portion 7 is 3 m.
m, and the downward displacement is about 1 μm, and the rate is 5 to 8 m/sec.

FIG. 3 is a perspective view of a linear ink print head constructed by using a plurality of the ink jet print heads shown in FIG. In this inkjet printhead 10, a plurality of inkjet printheads 11 are arranged in a line on one support plate 12, and a circuit board 13 is also mounted on the support plate 12. The circuit board 13 includes a driver IC 14 for driving each electrostrictive element of the inkjet print head 11.
It is equipped with On the circuit board 13, the driver IC 14 and individual electrodes for driving each inkjet print head 11 are connected by pattern connection and wire bonding, but detailed illustration is omitted. The same applies to the other driver ICs 14, . . . , 14. Note that 15 is a connector for electrostrictive drive. Note that the driver IC 14 has a built-in shift register that arbitrarily drives the individual electrodes of each inkjet printhead 11, 11, thereby easily producing a line type inkjet printhead with a density of about 2 dots/mm. Created in

FIG. 4 shows a high density ink jet print head formed using the ink jet print head 10 of FIG. 3 above. This inkjet printhead includes four line-type inkjet printheads 10 shown in FIG.
-2, . The leftmost pores of the 10-2, 10-3, and 10-4 line print heads are sequentially shifted at equal intervals between the pores, so 0.5 mm is further shifted by 0.125 mm. By stacking 4 sheets, a density of 8 dots/mm can be achieved.
Further, by stacking 8 sheets with a shift of 0.0625 mm, a density of 16 dots/mm can be obtained, and a higher density is also possible.

[0012] In this embodiment, precision can be ensured by creating a single protruding plate by etching or the like. This overlapping head requires data to be processed in memory, but this can be done easily and poses no particular problem.

[0013]

[Effects of the Invention] According to the present invention, grooves for a common ink path and individual ink paths are provided in the substrate, the grooves are covered with a comb-shaped electrostrictive element, and a voltage is selectively applied to the individual electrodes. , which pushes out the ink by displacing the comb teeth,
It is structurally simple, and any number of sheets with a plurality of discharge holes arranged in parallel can be installed vertically and horizontally, making it possible to obtain a high-density serial or line type inkjet print head.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an inkjet print head according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the shape of an electrostrictive element used in the inkjet print head of the above embodiment.

FIG. 3 is a perspective view of a line-type inkjet printhead formed by arranging the inkjet printheads of FIG. 1 in parallel.

4 is a perspective view of a high-density line-type ink print head in which the line-type ink jet print heads of FIG. 4 are further stacked; FIG.

FIG. 5 is a schematic diagram showing the operation of an electrostrictive element.

FIG. 6 is a diagram illustrating a conventional electrostrictive element inkjet print head.

FIG. 7 is a diagram showing an electrostrictive element used in a conventional inkjet print head.

[Explanation of symbols]

1 Base 2a Common ink path 3a Individual ink path 4 Electrostrictive element 5 Common electrode 6 Individual electrodes 7　Pectine-shaped part 8 Sealing coat 9 Pore

Claims (1)

[Claims] 1. A base body having a groove portion forming a common ink path that receives ink supply from the outside and an individual ink path branching from the common ink path; an electrostrictive element that fits into each groove forming an individual ink path, a common electrode formed on one side of this electrostrictive element, and individual electrodes formed on each comb-shaped part on the other side of the electrostrictive element. an elastic coating layer to which the electrostrictive element and the upper surface of the base are attached and forming a lid of the base; and a pore for ejecting ink on the front side of the individual ink passage of the base. An inkjet print head characterized by: