JP3066358B2 - Inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly, to a structure of a print head as a component thereof.

[0002]

2. Description of the Related Art There is an ink jet printer as a terminal device of a computer. Among on-demand type ink jet printers using a piezoelectric element as an actuator, there are, for example, a bimorph type and a piston type depending on the operation mode of the piezoelectric element.

FIG. 3 is a sectional view of a head portion of a bimorph type ink jet printer. The bimorph type has an ink chamber 4 and a piezoelectric element 3 which are formed by stacking stainless steel plates 2.
And The ink chamber 4 and the nozzle 5 communicate with each other via an ink supply chamber 6. The ink supply chamber 6 is also in communication with the ink supply path 7. The bimorph type is provided with a plurality of such head portions facing the recording paper surface. Therefore, a plurality of nozzles 5 are arranged facing the recording paper surface.

Next, the operation of the bimorph type will be described. When a voltage is applied to the piezoelectric element 3, the stainless steel plate 2 fixed to the piezoelectric element 3 is bent, and ink droplets are ejected from the nozzle 5. Information is recorded by operating such an operation independently for each head unit.

Next, the piston type will be described. FIG. 4 is a sectional view of a head portion of a piston type ink jet printer. The piston type includes an ink chamber, a piston 12, and a piezoelectric element 13. Part of the ink chamber is cylinder 1
4 and the ink is stored in the cylinder 14. The cylinder 14 is sealed by a seal 18. The cylinder 14 is in communication with the nozzle 15. The cylinder 14 also communicates with the ink supply path 16. The piston 12 and the piezoelectric element 13 are inserted into the cylinder 14. The piston 12 and the piezoelectric element 13 are fixed, and electrodes are attached to the piezoelectric element 13.
Like the bimorph type, the piston type is provided with a plurality of such head portions facing the recording paper surface.

The operation of the piston type will be described. When the voltage of the electrode is released, the piezoelectric element 13 extends in the lateral direction. As a result, the ink in the cylinder 14 is pressurized, and an ink droplet is ejected from the nozzle 15. Record of information is performed by operating independently of such operations for each head.

[0007]

In order to improve the printing speed, it is necessary to mount a large number of nozzles with the pitch between nozzles being as narrow as possible. However, FIG.
In the bimorph type shown in (1), when the dimension of the piezoelectric element in the vertical direction in the drawing is reduced in order to narrow the pitch between the nozzles, the displacement of the piezoelectric element is reduced. If the amount of displacement of the piezoelectric element is small, ejection of ink droplets is not performed well. In order to increase the amount of displacement of the piezoelectric element in such a state, a high voltage may be applied to the piezoelectric element, but this increases the cost of parts of the drive circuit.

In the piston type shown in FIG. 4 as well, if the dimension of the piezoelectric element in the vertical direction in the drawing is shortened in order to shorten the pitch between the nozzles, buckling occurs due to insufficient strength of the piezoelectric element 13 and ink Drop ejection cannot be performed well.

For the above reasons, the limit of the pitch between nozzles in both types is 1 mm.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a high-speed, low-cost ink jet printer with a high nozzle mounting density.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method in which a vibration plate forming an ink chamber is pressed by a piezoelectric element to bend the vibration plate and communicate with the ink chamber. the ink drops emitted from nozzles to record information, an inkjet printer, by grooving the piezoelectric element unit disposed Ru so as to face via the diaphragm Lee ink filling part of the ink chamber formation Then door
In addition, a base block having an extended portion on which the piezoelectric element portion is not formed is provided, and each of the base blocks is provided on both side surfaces of the piezoelectric element portion.
Electrodes are formed on the extended portion of the base block.
Form a pair of electrode lead-out parts provided on the side
And, wherein the top surface of the piezoelectric element is fixed to the diaphragm, when obtained by extending said piezoelectric element by the lateral effect or longitudinal effect caused by voltage application, and to press the diaphragm in the upper surface.

[0012]

FIG. 1 is a perspective view showing a head section of an embodiment of an ink jet printer according to the present invention. FIG. 2 is an exploded perspective view of a head section of the embodiment of the ink jet printer according to the present invention. An embodiment of the ink jet printer according to the present invention will be described with reference to FIG.

This ink jet printer includes a base block 21, an ink chamber wall 22, and a cover plate 23. The base block 21 is made of lead zirconate titanate. A piezoelectric element 24 is provided on the base block 21.
a and the piezoelectric element 24b are provided. This piezoelectric element exhibits a lateral piezoelectric effect. Piezoelectric elements 24a, 24
b is 8 mm in depth, 0.1 mm in thickness, and 0.5 in height
mm. Base block 21 and piezoelectric element 24
A and 24b are integrally formed by subjecting one lead zirconate titanate plate to groove processing. Piezoelectric element 2
Electrodes 25a are provided on both side surfaces of 4a. Electrodes 25b are also provided on both side surfaces of the piezoelectric element 24b.

The base block 21 is provided with an extension 21a on which the piezoelectric elements 24a and 24b are not provided, and the electrodes 25a and 2 are formed on the upper surface of the extension 21a.
5b is formed.

The ink chamber wall 22 is attached to a vibration plate 26. Diaphragm 26 are made of stainless steel or glass, the ink chamber wall 2 2 is made of glass or resin. The ink chambers 27a and 27 are formed by the ink chamber wall 22.
b are formed. A nozzle 28 is provided in the ink chamber 27a.
a, and a nozzle 28b communicates with the ink chamber 27b. The upper surface 29a of the piezoelectric elements 24a vibrating plate 2
6 is secured to the, is fixed to the upper surface 29b of the piezoelectric element 24b and the vibration plate 26.

The cover plate 23 has an ink supply port 30.
Is provided. The cover plate 23 is made of glass. As shown by A in FIG. 2, in this embodiment, the pitch between the nozzles 28a and 28b is 0.5
mm.

Next, the operation of the ink jet printer will be described with reference to FIG. When a voltage is first applied to the electrode 25a and then the voltage is released, the piezoelectric element 24a expands in the direction shown by the arrow B in FIG. 2 due to the lateral effect. As a result, the side surface 29a presses the diaphragm 26, and ink droplets are ejected from the nozzles 28a. In this case, since the piezoelectric element 24a is elongated in the depth direction, the volume of the ink chamber 27a can be sufficiently changed.

[0018]

As described above, according to the ink jet printer of the present invention, the ink is supplied to the ink filling section of the ink chamber.
Grooves piezoelectric element unit disposed to face each other with a rotation plate
Because it is formed by processing, it simplifies the manufacturing process
Can increase productivity.
You. In addition, a piezoelectric element can be formed simply by forming grooves in the base block.
Parts can be formed.
When forming, make the interval between the piezoelectric element parts a short interval
Therefore, the density of the nozzle can be increased.

In addition, since a pair of electrodes provided on both sides of the piezoelectric element portion are formed in the extended portion of the base block, a simple configuration in which the drawn portion is connected to the power supply portion is provided. Power can be supplied to the electrodes.
For example, by using the extended portion of the base block, a connector or the like can be used for connection with the power supply unit.

[Brief description of the drawings]

FIG. 1 is a perspective view of a head section of an ink jet printer according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a head portion of the ink jet printer according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a structure using a bimorph-type actuator which is an example of a conventional inkjet printer.

FIG. 4 is a cross-sectional view of a structure using a piston type actuator which is an example of a conventional ink jet printer.

[Explanation of symbols]

 21 Base Block 21a Extension 22 Ink Chamber Wall 24a, 24b Piezoelectric Element 26 Vibration Plate 27a, 27b Ink Chamber 28a, 28b Nozzle 29a, 29b Side Surface

Claims (1)

(57) [Claims] 1. An ink jet recording device, wherein a diaphragm that forms an ink chamber is pressed by a piezoelectric element to deflect the diaphragm, eject ink droplets from nozzles communicating with the ink chamber, and record information. a printer, a piezoelectric element portion that will be placed so as to face via the diaphragm Lee ink filling part of the ink chamber together to form a grooving, not pressure photoelectric element unit is formed extending A base block having a portion, wherein electrodes are respectively formed on both side surfaces of the piezoelectric element portion, and electrodes are provided on the both side surfaces in an extended portion of the base block .
Forming a lead-out portions of the pair become electrodes, when the upper surface of the piezoelectric element fixed to the vibrating plate was extending said piezoelectric element by the lateral effect or longitudinal effect caused by voltage application, the vibration in the upper surface An ink jet printer characterized by pressing a plate.