JPH03293143A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To obtain an ink jet device capable of reducing mutual interference without cost increase by providing recording liquid discharge orifices at an equal interval of every n pieces of segmented piezoelectric element in opposition to a side wall between pressure chambers and allowing the orifices to communicate with each pressure chamber. CONSTITUTION:This device discharges a recording medium through a discharge orifice 12 by charging the volume of a pressure chamber 10 with the deformation of a part of a piezoelectric element 6 segmented by a groove 8. Side walls 11, 7, opposed to each other at an interval of n (more than 3) pieces of segmented piezoelectric element, are junctioned through an oscillation plate 3. Discharge orifices 12 communicating with each pressure chamber 10 are arranged at an equal interval. Consequently, the width of groove on both sides is reduced by shortening the length of a support part (piezoelectric element non-driving) and more than two pieces of piezoelectric element for drive are provided between the support parts. Thus an ink jet head capable of reducing mutual interference with nozzles arranged at an equal interval can be constituted with a single piezoelectric element and a single pressure chamber plate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording device, and more particularly to a head portion of an inkjet recording device. For example, it is applied to various recording devices.

Figure 4 is a conventional example described in Japanese Patent Laid-Open No. 60-90770. In the figure, 21 is a piezoelectric body, 22 is a diaphragm, 23 is a pressurizing chamber, 24 is a pressurizing chamber plate, 25 and 26 are electrodes, 27 is a substrate, and 28 is a groove.

By applying voltage to the two electrodes 25 and 26, the piezoelectric body 21 divided by the groove 28 is moved to the pressurizing chamber plate 24 via the diaphragm 22.
The liquid is displaced into the pressurizing chamber 23 formed in the pressurizing chamber 23, and droplets are discharged from the nozzle communicating with the pressurizing chamber due to the pressure change accompanying the volume change at this time.

FIG. 5 is a diagram for explaining mutual interference based on the configuration of FIG. 4, and is given the same reference number as in FIG. The volume change Δv2 of the pressurizing chamber 23 when a voltage is applied only to the convex portion (■) of the body 21, and the convex portions (■, ■, ■) of the piezoelectric body 21.

The ratio of the volume change ΔVT of the pressurizing chamber 23 when a voltage is applied is 1.0 in the absence of mutual interference, but since the pressurizing chamber plate 24 is deformed as shown by the dotted line in the figure. It becomes 1.0 or less. This is because the pressure chamber plate 24 is equivalent to the deformation of a beam having the length SL of the support part and the length Sa of the groove forming part with respect to the substrate 27. The amount of deformation (deflection) of the beam is approximately proportional to the cube of the length S6 of the groove forming portion, and inversely proportional to the cube to fourth power of the thickness H.

When the length S6 of the groove forming part is constant, the length S4 of the supporting part. As we increase the length of the support part, the amount of deformation becomes smaller and the mutual interference becomes smaller, but if the length of the support part, S, exceeds a certain value, even if the length of the support part, S, is increased, the amount of deformation will be negligible. It saturates without decreasing. For this reason, a constant length S of the support part,
When the length Sa of the groove forming portion is increased (the number of nozzles is increased), this deformation gradually increases.

FIG. 6 is a configuration diagram of a conventional head section for preventing mutual interference. In the figure, 32 is a piezoelectric body, 33 is a diaphragm, 34 is a pressurizing chamber plate, 35 is a pressurizing chamber, and 3G is a groove. It is. With this configuration, mutual interference is greatly reduced, but two piezoelectric bodies are required. That is, two piezoelectric bodies each having a groove-forming part with a plurality of grooves and a support part without the grooves are placed on both sides of a pressurizing chamber plate having pressurizing chambers formed on the front and back sides thereof. The pressurizing chambers of the pressurizing chamber plates are arranged to face each other so that they do not overlap with each other in the nozzle row direction.

-In- Flag The present invention was made in view of the above-mentioned circumstances,
The purpose of this invention is to provide an inkjet recording apparatus that reduces mutual interference without varnishing.

Miso-□-Precepts.

In order to achieve the above-mentioned objects, the present invention provides (1) a piezoelectric body having a plurality of grooves formed therein; and a pressurization chamber plate having a pressurization chamber formed opposite to the piezoelectric body divided by the grooves; In an inkjet recording device in which recording liquid is ejected by a change in the volume of the pressurizing chamber due to deformation of the piezoelectric body, a space between the pressurizing chambers is provided for every n (an integer of 3 or more) of the divided piezoelectric bodies. This device is characterized in that recording liquid discharge ports facing the side wall and communicating with the respective pressurizing chambers are provided at equal pitches.

Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a configuration diagram for explaining one embodiment of an inkjet recording apparatus according to the present invention. In the figure, 1 is a substrate, 2 is a piezoelectric body, 3 is a diaphragm, 4 is a pressurizing chamber plate, and 5 is a 6 is a divided piezoelectric body, 7 is a side wall, 8.9 is a groove, 10 is a pressurizing chamber, 11 is a side wall, and 12 is a discharge port. By deforming the portion of the piezoelectric body 6 divided by the grooves 8, the volume of the pressurizing chamber]O is changed and the recording liquid is ejected from the ejection port 12. The side walls 11 and 7 of every n (3 or more) segmented piezoelectric bodies (every 4 in FIG. 1) are opposed to each other and are joined via the diaphragm 3. This joint portion corresponds to the support portion in FIG. The discharge ports 12 communicating with each pressurizing chamber 10 are arranged at equal intervals. As is clear from the figure, if the length S of the support portion is shortened, the interval between the discharge ports will be shortened, and the degree of integration will be improved. However, as explained earlier, if S is shortened, the deflection of the pressurized chamber plate increases and mutual interference increases, so the countermeasure is to reduce the number n of piezoelectric bodies (Sa )
Alternatively, it is necessary to take measures such as changing the material of the pressurizing chamber plate 4 to a material with a high Young's modulus, or increasing the thickness H of the pressurizing chamber plate. Note that reducing the width of the grooves 9 on both sides of the side wall also leads to an increase in the degree of integration.

FIG. 2 shows another embodiment of the invention, which has the same reference numerals as in FIG. In this embodiment, the grooves 8 and 9 are filled with a material having a low Young's modulus (such as silicone rubber) without using a diaphragm.

FIG. 3 shows a further embodiment of the invention, which has the same reference numerals as in FIG. In this embodiment, in order to further increase the nozzle density, piezoelectric bodies having the configuration shown in FIG. 1 are arranged opposite to each other with a pressure chamber plate in between. In the illustrated example, the pressurization chambers and the like are arranged in a staggered manner.

Effects As is clear from the above explanation, according to the present invention, the length of the support part (piezoelectric material = non-residential motion) is shortened, the width of the grooves on both sides of the support part is also shortened, and a driving piezoelectric is inserted between the support parts. By providing two or more bodies, an inkjet head with equal nozzle pitch and little mutual interference can be constructed from one piezoelectric body and one pressure chamber plate. Furthermore, when aiming for high integration, it is possible to increase the amount of displacement by using a laminated piezoelectric body and reduce the width of the piezoelectric body.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining one embodiment of an intarjet recording apparatus according to the present invention, FIGS. 2 and 3 are diagrams showing other embodiments of the present invention, and FIG. 5 is a diagram showing another example of the conventional head part,
FIG. 6 is a configuration diagram of a conventional head section for preventing mutual interference. ] - Substrate, 2 Piezoelectric body, 3... Vibration plate, 4... Pressure chamber plate, 5... Electrode, 6... Segmented piezoelectric body, 7,
11...Side wall, 8,9...Groove, 10 Pressure chamber, 12...
Outlet.

Claims (1)

[Claims] 1. Consisting of a piezoelectric body in which a plurality of grooves are formed and a pressurization chamber plate in which a pressurization chamber is formed by being placed opposite to the piezoelectric body divided by the grooves, the pressure is applied by deformation of the piezoelectric body. In an inkjet recording device that discharges a recording liquid by changing the volume of a chamber, each n (an integer of 3 or more) of the divided piezoelectric bodies is arranged to face a side wall between pressurizing chambers and communicate with each pressurizing chamber. An inkjet recording device characterized in that liquid ejection ports are provided at equal pitches.