JPH046550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording device that records an ink image by jetting and depositing liquid ink onto a paper or other recording surface in response to an image signal. The object of the present invention is to solve these problems in view of the phenomenon of clogging of pore nozzles and the difficulty of coloring.

There is an inkjet method as an image recording device for plain paper.The basic principle of this is to eject ink from a nozzle with fine holes and deposit it on the recording paper. An ink-on-demand type in which the amount is modulated by electrical vibration of a piezo element is common.
However, in this ink jet method, the liquid ink dries and the nozzles become clogged, which is the biggest problem for the apparatus. Furthermore, in the case of color printing, clogging becomes an even more serious problem because a large number of fine-hole nozzles are arranged in a row.

The present invention proposes an improved image recording device that solves these problems.

Specifically, the present invention includes a composite body comprising a dielectric material that electroosmoses a liquid ink made of at least a magnetic fluid and a plurality of electrodes disposed on a support body, and a composite body that corresponds to an image signal. means for electroosmoticing the ink by applying a voltage to the electrode; and means for providing a recording surface facing the support with a magnet to cause the ink to bulge and fly; A recording apparatus is characterized in that an image corresponding to the above is recorded on the recording surface.

A liquid ink containing a magnetic fluid is defined as one in which a magnetic powder such as magnetite or γ-ferrite is dispersed in a liquid, and a dye or pigment is dissolved or dispersed therein.

Electroosmosis is an interfacial phenomenon in which when a solid and a liquid material come into contact, an electric double layer is created at the interface, and the liquid material moves relative to the solid in response to an applied voltage. When the material is non-porous, the surface thereof is considered, and when it is a porous material, either the surface and/or the interior thereof is considered.

The implementation of the present invention will be described in detail below.

FIG. 1 is an embodiment of the present invention, and shows a partial perspective view of a recording apparatus. In FIG. 1, reference numeral 1 denotes a support made of a dielectric material, and a large number of grooves 2 are provided in parallel. Electrode wires 3 and 3' are embedded in this groove 2, and the electrode wires 3 and 3' are preferably made of Ni--Fe with a good magnetic permittivity and are commonly called center deltas. 4 is a porous dielectric. 5 is a liquid ink containing a magnetic fluid, and is an oil-based ink having a paraffin base, magnetite dispersed with a surfactant, and a charge control agent and a dye or pigment. 6 is a thin plate-shaped auxiliary electrode having a large number of through holes. 7 is a recording paper, which is moved in the direction of the arrow as shown. 8 is a permanent magnet, which is made of a rubber magnet. These structures are as shown in the figure, in which a recording paper 7 is placed facing a composite body in which a porous dielectric material 4 and an auxiliary electrode 6 are arranged on a support 1 at an appropriate distance. Furthermore, a magnet 8 is arranged on the back side of the recording paper 7. Further, the porous dielectric material 4 and the auxiliary electrode 6 on the support 1 are placed at an appropriate distance (several mm) from the end 9 of the support 1 facing the recording paper 7.

Next, we will outline the operation. First, the ink 5 described above exhibits good electroosmotic properties in the direction of the negative electrode when the support 1 made of a dielectric material and the porous dielectric material 4 are made of borosilicate glass and cellulose acetate, respectively. . Note that the so-called electroosmotic polarity, i.e., whether the ink 5 is electroosmotic toward the positive electrode or toward the negative electrode, is determined by the liquid material and the charge control agent, surfactant, etc. that are mixed as necessary. Furthermore, it is possible to provide an electroosmotic sensitivity of about 10 ^-4 cm ² /v·sec. For example, when a DC voltage is applied between electrode wires 3 and 3', 1 volt per micron (i.e.
At an electric field strength of 10 ⁴ v/cm), the surface of support 1
So-called electroosmosis can occur, moving the ink at a speed of cm/sec. Therefore, by applying a necessary voltage to the electrode wires 3 and 3' centered on the potential of the auxiliary electrode 6, the ink 5 can be sent out along the electrode wire 3 or 3', that is, along the groove 2, in the direction of the recording paper 7. At the same time, a meniscus-shaped bulge of ink 5 is created at the end 9' of the electromagnetic beam 3' by the magnet 8, and further, by appropriately selecting the magnetic force of the magnet 8, the ink 5 is caused to fly in the direction of the recording paper 7. I can do it. In FIG. 1, a bump of ink 5 is formed at the end of the electrode wire 3', and at this time, the electrode wire 3 has a positive potential Vc with respect to the potential of the auxiliary electrode 6.
However, a negative electrode Vc' is also applied to the electrode line 3'. Therefore, on the support 1, there is electroosmosis between the auxiliary electrode 6 and the electrode wires 3 and 3' as shown by the arrow near the end 9 of the support 1, and also electroosmosis near the end 9 of the support 1. Electroosmosis occurs between the electrode wires 3 and 3', and as a result, a meniscus-like bulge of ink 5 can be created at the end 9' of the electrode wire 3' as described above. The permanent magnet 8 tries to create a parallel magnetic field, but since the electrode wires 3 and 3' shown in the figure have magnetic permeability, the magnetic force can be concentrated at their tips, causing the meniscus-shaped ridges of the ink 5 to It is possible to form the meniscus and fly it toward the recording paper 7 from the tip of the meniscus.
That is, at the end 9 of the support 1, a protuberance of the ink 5 can be formed only when the ink 5 reaches the end 9 by electroosmosis. By appropriately selecting the distance between the magnets 7, the ink can be caused to fly by the magnet 8. Therefore, by inputting a signal corresponding to an image signal to the electrode wire 3, it is possible to record an image.

Figure 2 shows electrode lines 3 and 3' used when recording image signals.
2 is a block diagram and a waveform diagram of a drive circuit for driving the auxiliary electrode 6. FIG. In Figure 2a, terminal 1
0 is an input terminal of an image signal, 11 is a serial-parallel converter 12 is a drive stage. The image signal input to the terminal 10 is a serial signal consisting of a shift register.
The electrode wire 3 shown in FIG. 1 in the parallel converter 11
and 3' into image signals corresponding to the number of lines,
One line is output at the same time. By the way, if the recording line 7 is A4 width, and the resolution number is 8 lines/mm, the total number of electrode lines 3 and 3' is about 1600 lines.
That is, one line of image signals is divided into approximately 1600 parts and output to the drive stage 12 at the same time. The signal is then amplified by the drive stage 12 and applied to the electrode lines 3 and 3' in FIG. Figure 2b shows the electrode wire 3.
3' is a signal waveform diagram applied to 3'. When the reference level is O, the auxiliary electrode 6 has a DC potential.
V _B is applied, and a signal with amplitude V _A , that is, an image signal, is applied to electrode lines 3 and 3'. Corresponding to the potential of each electrode shown in FIG. _{1 ,} it is found that the ink 5
goes to the tip of the electrode wire, and the magnet 8 placed on the front
By creating a meniscus and making it fly, it is possible to record on the recording paper 7. Therefore, in the signals 2-1 and 2-2 in FIG. 2b, ink 5 is delivered to the tip of the electrode wire only during the O level period.
During the period of V _A , the ink 5 can be drawn toward the porous dielectric 4, making it possible to record in accordance with the input image signal.

In the above-described recording device, a method is adopted in which the meniscus-shaped bulges of ink are caused to fly by the magnet 8. However, the magnet 8 may be made of a conductive material, or the surface of the magnet 8 may be coated with a conductive material. using
It is also possible to apply a voltage to this conductive magnet and use a coulomb to cause ink to fly in the form of a meniscus. For example, in FIG. 1, by making the magnet 8 from Margan aluminum and applying a DC voltage V _D to it, the meniscus-shaped protuberance of the ink 5 that appears at the end 9' can be recorded by a Coulomba. It can be made to fly toward the paper 7. Since the DC voltage V _D at this time is used to generate a Coulomb force, it can be controlled to be positive or negative with respect to the reference potential. With this configuration, when a bump of ink 5 is formed on the end portion 9', it can be quickly blown away, the response speed can be improved, and the flight time can be extended, resulting in an increase in recording density. will also be connected.

In addition, a plurality of magnets 8 made of this conductive material are provided, and the magnetic force or flying distance is
Matrix driving can be performed by selecting the voltage to be applied to the drive circuit, and the number of drive circuits can be reduced. FIG. 3 is a partial top view of the recording device, and 1 and 2 are the supports and grooves shown in FIG. 1, respectively. 3-1, 3-2,...3-12
corresponds to the electrode wire 3, and 8-1, 8-2...8-4 correspond to the magnets. Further, 7 is recording paper. on the other hand,
Terminals 13, 14, and 15 are image signal input terminals, 1
6, 17, 18, and 19 are conducting magnet selection terminals. In this configuration, the magnet 8 shown in FIG. 1 is divided into a plurality of parts, so that one conductive magnet corresponds to a plurality of electrode wires 3. For example, electrode wire 3-
1 and 3-11..., electrode wires 3-2 and 3-12..., and electrode wires 3-3 and 3-13 (not shown), terminals 13, 14, 15...22 (not shown) are connected. ) and select the terminal 17, the electrodes 3-2, 3-3, 3-4, 3-5,
Only 3-6 ink bumps can be made to fly. FIG. 3 shows an image signal to be recorded only on terminal 14, that is, a state in which terminal 17 is selected when only terminal 14 is negative and all other terminals are positive.

Regarding these flights, it is desirable to always maintain a constant distance between the support 1 and the recording paper 7 in FIGS. 1 and 3. FIG. 4 shows an embodiment that makes this possible. 1, 2 and 3 are the same as those shown in FIG. 1, and are modified at the end 9 in FIG. That is, as shown in FIG.
By providing a step 20 on the side wall corresponding to the recording paper 7 and pressing the recording paper against the side surface of the step 20, the flying distance of the ink can always be kept constant. Further, such a configuration can also be achieved by attaching a solid material to the lower part of the support 1 shown in FIG.

Next, we will discuss colorization. As mentioned above, various colors can be selected from the ink by mixing dyes or pigments, and the yellow, magenta, cyan, and black inks required for colorization can be created. Color printing can be attempted using the recording apparatus shown in FIG. 1 by providing a plurality of composites comprising the support 1, ink 5, etc. This allows the support 1 to be made thin and the porous dielectric 4 disposed on the support 1 to be
This is possible because the auxiliary electrode 6 is very thin. Furthermore, the grooves 2 and electrode wires 3, porous dielectric 4, and auxiliary electrodes 6 disposed on the support 1 can be formed on both sides of the support 1. In this way, by providing two composite bodies including the support 1, coloring can be easily constructed.

The embodiments of the present invention have been described in detail above.According to the present invention, the ink clogging phenomenon can be reduced because a fine-hole nozzle using the inkjet method is not used, and color printing can be easily configured. This is something that can be done.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a recording apparatus according to an embodiment of the present invention, FIGS. 2a and 2b are diagrams showing a drive circuit in the apparatus of the present invention and waveforms for explaining its operation, and FIG. 3 is a matrix configuration. Figure 4 showing an example
The figure is a perspective view of essential parts showing another embodiment of the present invention. 1... Support body, 2... Groove, 3, 3'... Electrode wire,
4... Porous dielectric, 5... Ink, 6... Auxiliary electrode, 7... Recording paper, 8... Magnet, 9,9'...
edge.

Claims (1)

[Scope of Claims] 1. Magnetic fluid supplied by the ink supply means, a dielectric support, and a plurality of electrodes arranged on the support and to which a voltage corresponding to an image signal is applied. a recording head equipped with a means for electroosmoticing liquid ink containing a liquid ink, and a magnet provided on a recording surface facing the end surface of the support having the electrode end surface and raising the ink,
A recording apparatus characterized in that an image corresponding to the image signal is recorded on the recording surface. 2. The recording apparatus according to claim 1, wherein the recording surface faces the end face of the support having the electrode end face with a gap therebetween, and has means for ejecting ink into the gap. 3. A plurality of electrodes are each provided in a large number of parallel grooves provided on the support, and are made of a material having magnetic permeability, and the ink supply means is provided in a thin plate-like groove disposed on the support. A record according to claim 1 or 2, comprising a porous dielectric and an auxiliary electrode provided on a surface of the porous dielectric opposite to the support side. Device. 4. Any one of claims 1 to 3, characterized in that the magnet is made of a conductive material, and includes means for applying a voltage to the conductive material and causing the liquid ink to fly by Coulomb force. Recording device described in . 5. The apparatus according to claim 4, comprising a plurality of magnets made of a conductive material, and means for applying a signal corresponding to an image signal to the magnets and causing the liquid ink to fly by Coulomb force. Recording device. 6. The recording device according to any one of claims 1 to 3, wherein the recording head has an ink supply means and a plurality of electrodes arranged on both sides of a dielectric support. 7. The recording device according to any one of claims 1 to 3, characterized in that it includes a plurality of recording heads.