JPS58179663A - Ink recording head - Google Patents

Abstract

PURPOSE:To accelerate the formation on ink meniscus because of electrostatic force and to improve ink jet characteristics and to simplify the construction of a power supply by providing uneveness on the surface of a liquid in the opening of a slit by an oscillator. CONSTITUTION:When ink is injected in an ink jet port 1 and high tension voltage is supplied from a driving power supply 6 to an electrode 3, the ink is drawn out of the opening of the slit by means of the electrostatic force generated across the electrode 3 and the external opening of the slit for recording purposes. In other words, the ink in the neighborhood of the electrode 3 is jetted from the port 1 and attached to recording paper 5 for recording. An oscillator 8 controlled by the output of an external driving source allows a stationary wave to be produced on the surface of the ink liquid at the jet port 1. The wavelength of the stationary wave is set in such a way that the number of oscillations becomes twice as many as the interval for setting the recording electrodes and that the node, of the stationary wave is adjusted to locate it in the middle of the space between the electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink recording head in an inkjet recording system capable of electronic plane scanning.

There are a variety of existing recording methods, including electrostatic recording, thermal recording, discharge breakdown recording, and electrophotography, but all of these require special recording paper, which increases cost and recording costs. There are problems with the complexity of the mechanism and the longevity of records.

For this reason, recently, attention has been focused on inkjet recording methods that can directly record on plain paper. This jets ink accelerated by the field t[, from the nozzle to which ink is supplied onto the surface of the recording medium that moves relative to the tip of the nozzle while maintaining a constant distance from the tip of the nozzle. It has several advantages such as low cost, selfless sound, and long recording life.

Therefore, in order to solve this problem, the company has recently developed a system for installing a large number of nozzles on the inner wall instead of the nozzles used in the conventional inkjet recording method.
Using an elongated slit-shaped ink jetting port with one pole,
We are proposing a recording method that allows electronic 'XF creeping.

Figure 1 shows the configuration of this recording system [In the parent diagram, 1 is an ink jet opening formed in the shape of a slit, 2m, 2b is an upper plate and a lower plate that form this ink jet opening 1, and 3 is this lower plate. A large number of electrodes are arranged periodically on 2b, 4 is a ground conductor arranged opposite to the ink jet nozzle 1, 5 is a recording paper that moves along this ground conductor 4, and 6 is a ground conductor of the electrode 3. This is a driving power source that supplies high voltage to selected electrodes. In addition,
T is an image signal, and this image signal 7 is applied to the drive power source 6 in the direction of the arrow.
The drive power source 6 is applied to the drive power source 6, and is configured to control the drive power source 6 thereof.

In the system configured as described above, when ink is injected into the ink jet port 1 and a high voltage is supplied from the drive power source 6 to one or more selected electrodes 3, the selected electrode and the outside of the slit-shaped opening The electrostatic force generated between the electrodes draws the ink to the outside through the slit-shaped opening for recording. That is, the selected ink near the piezo electrode is ejected from the ink ejection port 1, adheres to the recording paper 5, and recording is performed.

By providing an ink passage port in the ground conductor 4, the ground conductor 41-
It is also possible to arrange. Further, it goes without saying that the potential of the ground conductor 4 does not necessarily have to be the ground potential, and can be set arbitrarily as long as it is within a range that can form an electric field necessary for ejecting ink.

However, in such a recording method, the ink meniscus is uniformly formed within the ink ejection port, so
In order to eject ink near a selected electrode, a high electric field or a long pulse width is required, the power supply configuration is complicated, and the recording speed cannot be improved.

In view of the above points, the present invention provides an ink recording head designed to solve such problems and eliminate such drawbacks. This is intended to promote the formation of an ink meniscus due to electrostatic force, or to shorten or omit this formation process.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows an example of an ink recording head according to the present invention!
(a) is a plan view showing the recording paper side.
1 and 4, (b) shows the electrode side. However, for ease of explanation, part of the 2m upper plate is omitted =
3- It is shown as follows.

In FIG. 2, the same reference numerals as in FIG. Vibrators 9a, 9bFi which produce irregularities on the ink liquid surface of the eyes (see FIG. 1), liquid surface conditions corresponding to the irregularities, and 10 ink.

Therefore, in the embodiment shown in FIG. 2, a standing wave is generated on the ink liquid surface of the ink ejection port by the vibrator 8 controlled by the output of the drive M# from the outside. . In addition, in this example, the frequency of the standing wave is set so that the wavelength is equal to twice the installation interval of the recording electrodes, and the "node" of the standing wave is adjusted so that it is located at the midpoint between the recording electrodes. do.

In this way, the "antinodes" of the standing wave will be located at the same location as each recording electrode, and for example, when the wavefront reaches a state of 9&, it will correspond to the part that protrudes toward the recording paper 5 side. Recording is performed using one of the selected electrodes in every other recording electrode group 4-8a, and when the wavefront reaches the state 9b, recording is performed using one of the selected electrodes in the recording electrode group 3b.

With this configuration, in the ink meniscus formation process during recording, the time required to form the convex protrusion due to the standing wave can be shortened or omitted, improving the ink jetting characteristics. Since the force for drawing out the ink from the ink jetting port can also be reduced, the power supply configuration can be simplified and the recording speed can be improved.

FIG. 3 is a plan view showing another embodiment of the ink recording head according to the present invention, and (a) shows the recording paper side! D
, (b) shows the electrode side.

In FIG. 3, the same reference numerals as in FIGS. 1 and 2 indicate corresponding parts. In the embodiment shown in FIG. 3, the wavelength of the standing wave is made equal to the interval between recording electrodes 3, and It is configured such that every other "one belly" corresponds to the position of each recording electrode.

In this embodiment, the change in the wavefront of the ink is the same at all recording electrode positions, making it possible to perform simultaneous recording on all recording electrodes at the same time. Also, in this embodiment, recording is performed when the wavefront protrudes convexly toward the recording paper 5 at a position corresponding to the recording electrode, thereby forming an ink meniscus that extends to the convex protrusion. Since the time is omitted and shortened, the ink jetting characteristics are improved, and the electrostatic force that draws the ink from the ink jetting port can also be reduced, so the power supply configuration can be simplified and the recording speed can be improved.

As explained above, according to the present invention, since the ink liquid surface of the slit-shaped opening is made uneven by the vibrator, the formation of the ink meniscus is promoted, or the ink Since the meniscus formation process can be shortened or omitted, the ink jetting characteristics are improved, the power supply configuration is simplified, and the recording speed is increased, so the practical effects are extremely significant.

FIG. 1 is a perspective view showing an example of an inkjet recording system capable of electronic plane scanning, FIG. 2 is a plan view showing an embodiment of an ink recording head according to the invention, and FIG. 3 is another embodiment of the invention. FIG.

1...ee ink ejection port, 2a, 2bψe@-upper plate and lower plate forming the ink ejection port, 3. middle and 9 recording electrodes,
3a, 3b... Recording electrode group (1, 11), 4...
・Grounding conductor, 5... Recording paper, 6... Drive power supply,
8e...@oscillator, 9a, 9b... wavefront state (1,
II), 10. Ink.

Patent applicant: Nippon Telegraph and Telephone Corporation Agent Masaki Yamakawa

Claims (1)

[Claims] When ink is held in an elongated slit-shaped opening having a large number of electrodes on the inner wall and a high voltage is applied to a selected electrode of the electrodes, an electrostatic force is generated between the selected electrode and the electrode outside the slit-shaped opening. An ink recording head that draws the ink out of the slit-shaped opening and performs two recordings, characterized in that a vibrator causes unevenness on the ink liquid surface of the slit-shaped opening.