JPH0245154A - Ink-jet recorder - Google Patents

Abstract

PURPOSE:To facilitate working, and to improve positional accuracy by installing a back electrode mounted at a position opposite to a pulse applied electrode with a recording medium in between the back electrode and the pulse applied electrode and a liquid chamber, in which the pulse applied electrode is formed, and arranging the pulse applied electrode under a level in the liquid chamber. CONSTITUTION:A pulse applied electrode 25 is disposed at a columnar or drill- shaped projection 24 arranged under the level of a shallow ink liquid chamber 22 shaped to an ink-jet head substrate 20 formed of silicon or silicon oxide. The nose section of the projection is covered with ink by the surface tension of ink. A recording body 26 such as printing paper is disposed faced oppositely to the heat substrate 20, and a back electrode 27 is arranged on the rear of the recording body 26. The voltage of an extent that ink does not fly from a head, the voltage of 1-3kV, is applied to the back electrode 27 at all times, and ink on the electrode 25 jets by electrostatic force and is printed onto the recording body 26 when the pulse waves of approximately -300V are applied to the pulse applied electrode 25 disposed onto the projecting section 24.

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.

Figures 3 and 4 are diagrams showing the main parts of a conventional inkjet recording apparatus, respectively. In the example shown in Figure 3, a nozzle 1 is connected to an ink chamber 2, and ink 3 is always supplied to the nozzle 1. Recording paper 5 is wound around the surface of a rotating drum 4 that is supplied with a constant gap from the tip of the nozzle 1, and a bias voltage is applied between the rotating drum 4 and the nozzle 1 by a high-voltage DC power source 6. A signal pulse is applied in series by a voltage and high-voltage amplifier 7, and the ink 3 in the nozzle 1 is caused to fly in response to the signal, thereby recording on the recording paper 5 (Japanese Patent Publication No. 48-6131). (see publication), this requires a nozzle, and the outer diameter of the nozzle is 0.1 to 0.
．． Since it was about 8I, there was a drawback that clogging easily occurred. In addition, in the example shown in FIG. 4, slit-shaped orifices 12 are provided in multiple stages on the front surface of the ink chamber 11, and a plurality of needle electrodes 13 are arranged therein. 14, and apply the needle electrode 1 to the electrode 16 arranged on the back side of the recording paper 15 corresponding to each needle electrode 13.
By applying a voltage of opposite polarity to needle electrode 13
In this method, an electrical suction force is applied to the ink 14 at the tip to print dots on the recording paper 15 (see Japanese Patent Application Laid-Open No. 154170/1983). The positional accuracy when arranging them is poor, and since the slit area is large and the orifice groove is deep, the ink liquid level is shaken due to vibrations, etc., resulting in poor image quality.

■---Five inventions were made in view of the above-mentioned circumstances.
In particular, this invention was made with the aim of providing an electrostatic suction type inkjet recording device that is easy to process and has good positional accuracy.

Configuration In order to achieve the above object, the present invention provides a pulse application electrode, a back electrode provided at a position facing the pulse application electrode across a recording medium, and a liquid chamber in which the pulse application electrode is formed. and the pulse applying electrode is disposed below the liquid level in the liquid chamber. An explanation will be given below based on one embodiment of the present invention.

FIG. 1 is a sectional view of essential parts for explaining an embodiment of an inkjet recording apparatus according to the present invention, and FIGS. 2(a) to (e)
) is a diagram showing each process for manufacturing the head of the inkjet recording apparatus shown in FIG. 1, in which 20 is an inkjet head substrate formed of silicon (Si) or silicon oxide (S i O2) , 21 is ink, 22
23 is a shallow ink chamber formed in the head substrate; 23 is an ink supply port for replenishing ink to the ink chamber 22; and 24 is a columnar or cone-shaped projection disposed below the liquid surface of the ink chamber 22. A pulse application electrode 25 is provided at the tip of the protrusion 24. At this time, the tip of the protrusion is covered with ink due to the surface tension of the ink. A recording medium 26 such as printing paper is arranged opposite to the head substrate 20, and a back electrode 27 is arranged on the back surface of the recording medium 26. A voltage of 1 to 3 kV is always applied to the back electrode 27 so that the ink does not fly away from the head, and a voltage of 1 to 3 kV is always applied to the back electrode 27.
When a pulse wave of about 1,500 V is applied to the ink, the ink on the electrode 25 flies due to electrostatic force and is imprinted on the recording medium 26.

Next, the manufacturing process of the inkjet head will be explained with reference to FIG. A photoresist is coated on a head substrate 20 made of silicon (Si) or silicon oxide (S i O 2 ), and after prebaking, a second resist is applied by exposing it to 1g of light using a photomask, developing, rinsing, and postbaking. As shown in Figure (a), a pattern of the exposed resist 28 is formed. Next, the substrate 2
When etching is performed on the photoresist 28, only the portions not protected by the exposed resist 28 are corroded in the etchant in the shape of a truncated pyramid, forming an ink supply port 23 as shown in FIG. 2(b). 1. Next, as shown in FIG. 2(c), a photoresist is applied to the side of the head substrate 20 opposite to the side where the ink supply port 23 is formed, prebaked, and exposed. When a pattern of the exposed resist 28 is formed and etched, only the portions not protected by the exposed resist 28 are exposed as shown in FIG. 2(d).
A shallow ink liquid chamber 22 is formed by being eroded in the corrosive liquid,
A protrusion 24 in the shape of a truncated square pyramid remains. After etching, the resist 28 is removed, and the electrode 25 and lead wire 29 on the protrusion 24 are exposed to light as shown in FIG. 2(s).
A conductive film is deposited by sputtering or the like, and finally the entire head substrate 20 is covered with a protective insulating film 30.

Effects As is clear from the above explanation, according to the present invention, since the ink chamber and the protrusion are formed on the head substrate made of silicon by photoetching, the position and height can be adjusted.
High-precision protrusions can be obtained accurately and inexpensively, and printing can be performed reliably without clogging as with conventional nozzle plates.The shallow ink chamber allows the ink to By generating surface tension, it is possible to reduce fluctuations in the liquid level, leakage, etc. caused by vibrations of the head, etc., thereby stabilizing the image quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts for explaining an embodiment of an inkjet recording apparatus according to the present invention, and FIGS. 2(a) to (e)
) is a diagram showing each process for manufacturing the head of the inkjet recording apparatus shown in FIG. 1, and FIGS. 3 and 4 are
FIG. 3 is a configuration diagram of main parts of a conventional inkjet recording apparatus. 20... Inkjet head substrate, 21... Ink, 22... Ink liquid chamber, 23... Ink supply port,
24...Protrusion, 25...Pulse application electrode, 26.
...Recording body, 27...Back electrode, 28...Photoresist, 29...Leader line, 30...Protective insulating film.

Claims (1)

[Claims] 1. A pulse application electrode, a back electrode provided at a position facing the pulse application electrode across a recording medium, and a liquid chamber in which the pulse application electrode is formed; An inkjet recording apparatus characterized in that the pulse application electrode is disposed below the liquid surface within the liquid chamber. 2. The ink jet recording apparatus according to claim 1, wherein the electrode pattern of the liquid chamber and the pulse applying electrode is formed by etching a silicon plate.