JPS63112156A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To feed ink reliably and to enable super high speed printing, by splitting a pressure chamber into main and sub pressure chambers, and feeding ink from both pressure chambers to an ink ejection port. CONSTITUTION:Ink is led through an ink feed port 3 into a sub pressure chamber 1b where a sub piezoelectric ceramic element 8b secured on the sub pressure chamber 1b deforms to bend an upper plate 7 so as to feed the ink to a main pressure chamber 1a and simultaneously to a bypath 5 through a bypass port 4. The ink fed into the main pressure chamber 1a is ejected forward in the form of in drop through an ink ejection port 2 when a main piezoelectric ceramic element 8a on the main pressure chamber 1a deforms to bend the upper plate 7. On the other hand, the ink fed to the bypath 5 is fed through a bypass outlet 6 to the ink ejection port 2. The bending timing can be shifted properly between main and sub pressure chambers 1a, 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device that is one of the non-impact recording methods.

[Prior Art] Conventionally, an inkjet recording apparatus is configured as shown in FIG.

This inkjet recording device has multiple ink jet ports,
Pressure chambers connected to these ink jet ports, and piezoelectric ceramic elements 10 fixed near these pressure chambers.
and an ink supply port 11 for supplying ink to the pressure chamber.
a printer head 12 having a
2, an ink reservoir 15 that supplies ink 14 through an ink supply vibrator 13, and a pulse generator 16 that supplies pulses of a predetermined voltage to the piezoelectric ceramic element 10. Ejects drops 18.

FIGS. 4(a) and 4(b) show the principle of ejecting the ink droplets 18. The printer head 12 usually has a plurality of ink ejection ports 19, and as shown in FIGS.
is a diagram showing a cross section of one of them. Figure (a)
The ink 14 flows from the ink supply port 11 to the pressure chamber 20 as shown in FIG.
is supplied to In the pressure chamber 20, the piezoelectric ceramic element 1
0 is applied with a voltage by a pulse from the pulse generator 16, the upper plate 20a is deflected as shown in FIG. Ink droplets 18 are ejected from the ink ejection port 19. Note that a bypass 21 is provided at the bottom of the pressure chamber 20 to assist in supplying the ink 14.

[Problems to be Solved] The above-described conventional inkjet recording apparatus has the drawback that high-speed printing is not possible. That is, 10 per second
When printing approximately 0 characters, the supply of ink 14 from the bypass 21 and pressure chamber 20 cannot keep up, resulting in one ink droplet.
8 may not be injected.

Additionally, the dimensions of the pressure chamber 20 are designed to obtain a desired velocity of the ink droplets 18, and the dimensions of the pressure chamber 20 determine the resonance frequency of the pressure chamber 20. on the other hand,
The resonance frequency of the pressure chamber 20 is typically about 2 Hz, but if you are trying to print about 100 characters per second, the frequency of the printing will be at the resonance frequency of the pressure chamber 20. Since the values are close to each other, the ejection of the ink droplets 18 becomes unstable, and printing may even become impossible.

Therefore, an object of the present invention is to provide an inkjet recording device that can reliably supply ink and that can perform high-speed printing.

[Means for Solving Problems] The inkjet recording device of the present invention, which solves the above-mentioned conventional problems, has a plurality of ink jet ports, each divided into two, a main pressure chamber and a sub-pressure chamber, and each chamber is connected via a separate passage. Is it connected to the ink jet port? A printer head having a number of 3L pressure chambers, a plurality of piezoelectric elements fixed near each of the main pressure chamber and the sub pressure chamber of these pressure chambers, and an ink supply port for supplying ink to the pressure chamber. , an ink reservoir section that supplies ink from the ink supply port of the printer head to the pressure chamber, and a pulse generator that applies pulses having a predetermined voltage to each of the piezoelectric elements at predetermined time intervals. It has become.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view showing a part of a printer head in an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view thereof. Note that the structure other than the pressure chamber is the same as that of the conventional example, so a description thereof will be omitted.

In the figure, the pressure chamber is divided into two parts: a main pressure chamber 1a and a sub-pressure chamber 1b. The main pressure chamber 1a has an ink jet port 2
On the other hand, the sub pressure chamber 1b is connected to the ink supply port 3. The sub-pressure chamber 1b is connected to the ink jet port 2 via a bypass port 4, a bypass 5, and a bypass outlet 6. Further, a plurality of piezoelectric elements such as a main piezoelectric ceramic element 8a and a sub piezoelectric ceramic element 8b are fixed to the upper parts of the main pressure chamber 1a and the sub pressure chamber 1b, respectively, with the upper plate 7 in between.

Both the main piezoelectric ceramic element 8a and the auxiliary piezoelectric ceramic element 8b are driven by pulses of a predetermined voltage supplied from a pulse generator (not shown).

Next, the operation of this inkjet recording apparatus will be explained. That is, ink is introduced from the ink supply port 3, first enters the sub-pressure chamber 1b, and then enters the main pressure chamber 1a when the upper plate 7 is bent due to the deformation of the sub-piezoelectric ceramic element 7b fixed on the sub-pressure chamber lb. At the same time as it is supplied, it is supplied to the bypass 5 through the bypass population 4.

The ink supplied to the main pressure chamber 1a is ejected as ink droplets from the ink injection port 2 due to the steering force when the upper plate 7 is bent due to the deformation of the main piezoelectric ceramic element 7a on the main pressure chamber 1a.

On the other hand, the ink supplied to the bypass 5 is supplied to the ink jetting port 2 from the bypass outlet 6.

Incidentally, the timing of deflection of the main pressure chamber 1a and the sub-pressure chamber 1b can also be appropriately staggered.

[Effects of the Invention] As described above, the inkjet recording apparatus of the present invention divides the pressure chamber into two, the main pressure chamber and the sub-pressure chamber, and supplies ink to the ink jet port from both pressure chambers. This not only makes it possible to reliably supply ink and enable ultra-high-speed printing, but also by appropriately shifting the timing of voltage application to the main piezoelectric ceramic element and the sub-pressure type ceramic element, the ink injection port This has the effect of supplying ink at the time of suction, completely eliminating the suction of air.

Furthermore, since the dimensions of each of the two pressure chambers are considerably smaller than when there is only one pressure chamber, the resonance frequency increases accordingly, and there is an effect that ultra-high speed printing of 100 characters or more per second is possible.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the configuration of a printer head section of an inkjet recording apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a configuration diagram showing a conventional inkjet recording apparatus. FIGS. 4(a) and 4(b) are cross-sectional views showing the principle of ink jetting of the apparatus shown in FIG. 3. 1a: Main pressure chamber 1b; Sub pressure chamber 2: Ink injection port 3: Ink supply port 4: Bypass port 5: Bypass 6: Bypass outlet 7: Upper plate 8a: Main piezoelectric ceramic element 8b = Sub piezoelectric ceramic element

Claims (1)

[Claims] A plurality of ink jet ports, a plurality of pressure chambers each divided into two, a main pressure chamber and a sub-pressure chamber, each of which is connected to the ink jet port via a separate passage; A printer head having a plurality of piezoelectric elements fixed near each pressure chamber and an ink supply port for supplying ink to the pressure chamber; and a printer head that supplies ink to the pressure chamber from the ink supply port of the printer head. An inkjet recording apparatus comprising: an ink reservoir section for supplying ink; and a pulse generator that applies pulses having a predetermined voltage to each of the piezoelectric elements at predetermined time intervals.