JPH04345857A - Ink jet head - Google Patents

Abstract

PURPOSE:To solve the problem of thermal decomposition of ink by a constitution wherein pressure gas is fed, synchronously with ON/OFF control operation of an ON/OFF valve, from a high pressure gas supply section into the ink channel of a nozzle in order to deliver the ink through the opening of the nozzle thereby eliminating the heating operation of ink. CONSTITUTION:Ink 5 in an ink tank 3 flows through capillary action into the ink channel 8a of a nozzle 2 and fills the ink channel 8a. When an ON/OFF valve 7 of a gas tank 4 is opened by an electrical signal, gas 6 in the gas tank 4 enters into the ink channel 8a filled with the ink 5 which is thereby delivered, together with the gas, through a nozzle opening 8b. Upon subsequent closure of the ON/OFF valve 7, the ink channel 8a is filled again with the ink 5 fed from the ink tank 3. When the ON/OFF valve 7 is operated repeatedly, the ink can be delivered continuously without requiring heating operation.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head, and more particularly to an inkjet structure.

0002

2. Description of the Related Art Some conventional ink jet heads are of a type in which a heating resistor is heated by an electric signal, and ink is ejected by the pressure of bubbles generated by vaporizing ink in the vicinity of the heating resistor.

FIG. 3 is a sectional view showing a conventional inkjet head. The conventional inkjet head 12 operates by applying an electric signal to the heating resistor 13.
The ink 15 near the heating resistor 13 is vaporized, and the pressure of the bubble 14 generated at that time causes the ink 15 in the ink flow path 17 to be ejected from the nozzle opening 16.

0004

[Problems to be Solved by the Invention] In the inkjet head using this conventional heating resistor, since the ink 15 is heated, components in the ink are thermally decomposed and deposited as burnt on the surface layer of the heating resistor 13. This causes a problem in that ink ejection becomes unstable due to this burnt.

An object of the present invention is to provide an inkjet head that achieves stable ink ejection.

[0006]

Means for Solving the Problems In order to achieve the above object, an inkjet head according to the present invention includes a nozzle, an ink supply section, an on-off valve, and a high pressure gas supply section, the inkjet head comprising: The nozzle has an ink channel through which ink is supplied and a nozzle opening through which ink is ejected from the ink channel, and the ink supply section supplies ink into the ink channel of the nozzle. The on-off valve controls the opening and closing between the nozzle and the high-pressure gas supply section, and the high-pressure gas supply section applies gas pressure to the ink flow path of the nozzle in synchronization with the on-off control of the on-off valve. Ink is ejected from a nozzle opening.

[0007] Furthermore, the apparatus includes a plurality of sets of the nozzle, an ink supply section, and an on-off valve.

[0008]

[Operation] Gas pressure is applied within the ink flow path of the nozzle, and ink is ejected from the nozzle opening of the nozzle using the gas pressure.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing an inkjet head according to an embodiment of the present invention.

In the figure, in the inkjet head 1 according to the present embodiment, an ink tank 3 containing ink 5, a gas tank 4, and an ink flow path 8a of the nozzle 2 are opened and closed by a check valve 9 and an electric signal, respectively. It is connected via an on-off valve 7. Further, gas 6 is injected into the gas tank 4 through a gas inlet 10 and sealed with a sealing plug 11 to maintain the gas 6 at a high pressure state.

Next, its operation will be explained. The ink 5 in the ink tank 3 flows into the ink channel 2 by capillary action and is filled. At this time, when the on-off valve 7 of the gas tank 4 is opened by an electric signal, the gas 6 in the gas tank 4 jumps out into the ink channel 8a filled with ink 5, and the ink in the ink channel 8a is caused by the gas pressure. It is discharged together with the gas from the nozzle opening 8b. When the on-off valve 7 is closed, the ink 5 in the ink tank 3 is again filled into the ink channel 8a. Therefore, by repeating the opening and closing operations of the on-off valve 7, continuous ejection of ink becomes possible. In addition, a check valve 9 connects the ink passage from the ink tank 3 to the ink passage 8a so that the ink in the ink passage 8a does not flow back into the ink tank 3 due to the gas pressure generated when the on-off valve 7 is opened. It is located inside.

(Embodiment 2) FIG. 2 is a perspective view showing a multi-nozzle inkjet head according to an embodiment of the present invention.

In the figure, the ink in the ink tank 3 is filled into each of the ink channels 8a, 8a, . It is enclosed in. At this time, by opening and closing the on-off valve 7 corresponding to the nozzle opening 8b from which ink is to be ejected among the plurality of nozzle openings 8b, the specific nozzle opening 8 is controlled by the pressure of the high pressure gas.
Ink is ejected together with gas from b, and after the ink is ejected, the ink flow path 8a is again filled with ink due to capillary action, returning to the ejectable state.

[0015] As described above, the inkjet head of the present invention can easily be made into a multi-nozzle structure. In addition, in FIG. 2, the ink tanks 3 are yellow, magenta, cyan,
By being able to load four colors of black ink, it is possible to perform full-color printing. Furthermore, by using a cartridge type for the gas tank 4 and ink tank 3, the head can be used for a long period of time.

[0016]

Effects of the Invention As explained above, the present invention applies gas pressure to the ink in the ink flow path of the nozzle and uses that gas pressure to eject the ink, eliminating the need for ink heating. This has the effect that problems caused by thermal decomposition can be solved and stable ink ejection can be performed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of an inkjet head of the present invention.

FIG. 2 is a perspective view showing an embodiment of the multi-nozzle inkjet head of the present invention.

FIG. 3 is a sectional view showing a conventional inkjet head.

[Explanation of symbols]

1 Inkjet head 2 Nozzle 3 Ink tank 4 Gas tank 5 Ink 6 Gas 7 On-off valve 8a Ink flow path 8b Nozzle opening 9 Check valve 10 Gas inlet 11 Sealing plug

Claims (2)

[Claims] 1. An inkjet head comprising a nozzle, an ink supply section, an on-off valve, and a high-pressure gas supply section, the nozzle having an ink flow path to which ink is supplied, and an ink flow path through which ink is supplied from the ink flow path. The ink supply section supplies ink into the ink flow path of the nozzle, and the on-off valve controls opening and closing between the nozzle and the high-pressure gas supply section. An inkjet head, characterized in that the high-pressure gas supply section applies gas pressure to the ink flow path of the nozzle in synchronization with the opening/closing control of the on-off valve to eject ink from the nozzle opening. 2. The inkjet head according to claim 1, comprising a plurality of sets of the nozzle, an ink supply section, and an on-off valve.