JPS60262179A - Image recording device - Google Patents

Abstract

PURPOSE:To obtain high magnetic flux density atop of a recording electrode by clamping plural electrodes which constitute a recording electrode array with magnets having the same polarity opposite a recording medium across insulating coatings and magnetic material plates, and covering tip parts of the magnetic material plates with nonmagnetic bodies. CONSTITUTION:Numbers of recording electrodes 7 which are impressed with the voltage of an image signal generator 9 are arrayed in the axial direction of the recording medium composed of a conductive layer 1a and a dielectric layer 1b opposite the recording medium, thus constituting the recording electrode array. The recording electrodes 7 are coated with the insulator 13 and further clamped with identical-polarity parts N (or S) of the magnetic material plates 12 and magnets 8. Parts of the magnetic material plates 12 which project from the magnets 8 are coated with nonmagnetic materials 15. Consequently, the magnetic plates 12 are extended to the tips of the recording electrode 7 and the napping of toner on the magnetic material plates is reduced while the magnetic flux density atop the electrodes 7 is increased; and the installation of a toner removing and conveying means is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an image recording device, and particularly to an image recording device that directly attaches a component conductive magnetic developer (hereinafter abbreviated as toner) to a recording medium in response to an image electrical signal. The present invention relates to improvements in image recording devices that record images.

[Background of the invention]

As a conventional image recording device of this type, US Pat. No. 381
．． Some of them are described in detail in the specification of No. 6840 and Japanese Patent Application Laid-open No. 127578/1983. An outline of this conventional device will be explained with reference to FIG.

In Fig. 2, reference numeral 1 denotes a recording medium, which in this example has a structure in which an alumite-treated dielectric layer 1b is provided on an aluminum cylinder 1a, but it is also possible to use a commercially available electrostatic recording paper or the like. good. Reference numeral 2 denotes a hot spring containing conductive magnetic toner T, and inside thereof is a toner application roller 4 made of a hollow cylinder made of a non-magnetic conductive material. A rolled magnet 3 is placed inside the toner application roller 4 . 6
is powered by a DC power supply. Reference numeral 7 denotes a recording electrode, which is usually made of a magnetic material such as iron or nickel, and faces the recording medium 1, and is made by arranging a large number of thin wires in parallel in the axial direction, or by etching the electrode from a sheet. created by means of. Although not shown, they are electrically insulated from each other and fixed to the body using an insulating adhesive, and are sandwiched between magnets 8 having the same polarity and facing each other. The recording electrode 7 is a character signal generator 9
Each is connected independently.

The recording medium 1 rotates in the direction of arrow A and passes near the toner coating roller 4. As the toner application roller 4 rotates in the direction of arrow B, the toner T in the hopper 2 attracted to the toner application roller 4 by the action of the magnet 3 forms a uniform layer of toner on the roller 4 by the doctor blade 5.

When this toner T comes into contact with the recording medium 1, a direct current voltage is applied to it by the aluminum source 6, so that the toner T acquires a charge and adheres to the recording medium 1.

The recording medium 1 further rotates in the direction of arrow A, and the “1 1
K) Car Tka 88- guy. -01 Oh. Yo. Since most of the charge of the toner has escaped through the dielectric layer 1b before reaching the recording position 10, the toner is not stored in the recording medium 1.
The adhesion force to the toner is mainly caused by intermolecular force. Furthermore, when the toner reaches the recording position 10, a toner spike is formed that spans the recording medium 1 and the recording electrode due to the influence of the magnetic field emitted from the magnet 8.
Since the residual charge of the toner escapes through these spikes, the adhesion force of the toner to the recording medium 1 at the recording position 10 is extremely small. However, at this time, when the character signal generator 9 applies a recording signal voltage selected according to the image pattern to the recording electrode 7, the toner formed between the recording electrode 7 to which the signal voltage is applied and the recording medium 1. Charges of opposite polarity are injected into the conductive layer 1a and the tips of the toner T ears while sandwiching the dielectric layer 1b. This charge is toner T
An electric force is applied to overcome the magnetic binding force of the toner T formed at the tip of the recording electrode 7 and sufficiently adhere the toner T to the recording medium 1. On the other hand, in areas where the recording signal voltage is not applied (non-image areas), there is no charge injection as described above, so the adhesion force between the recording medium 1 and the toner T is mainly due to intermolecular forces, and the spikes of the toner T Since the magnetic binding force is weaker, the toner in that area is removed from the recording medium 1, and is further attracted by the magnetic field emitted from the magnet 8, and moves along the recording electrode 7 near the magnet 8. It is deposited and accumulated 11 on the surface. The adhered and accumulated toner 11 is collected by means (not shown), such as air suction or screw conveyance, and is used for recording again.

Although not shown, the toner image visualized on the recording medium 1 according to the image pattern in this manner is usually transferred and fixed onto paper by corona discharge or pressure transfer, or electrostatic recording paper or the like is transferred to the recording medium 1. If it is used as such, it may be fixed as is.

By the way, in order to obtain a high-quality image without fog in the above configuration, it is necessary to apply a magnetic flux density of about 1100 Gauss to the tip of the recording electrode 7. In order to strengthen the magnetic flux density at the tip of the magnet, a configuration has been proposed in which magnetic plates 12 are arranged between the magnets 8 as shown in FIG. However, near the tip of the magnetic plate 12, as shown in FIG. is forming.

Therefore, if the magnetic plate 12 is brought too close to the tip of the recording electrode needle 7, the tip of the spike 14 will come into contact with the recording medium 1 and cause image disturbance. It must be several inches away from the tip. For this reason, the above-mentioned proposal has a drawback in that even if the magnetic plate 12 is provided, the effect of improving the magnetic flux density at the tip of the recording electrode 7 is not sufficiently exhibited.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks and makes the tip of the magnetic plate
It is an object of the present invention to make it possible to bring the recording electrode closer to the tip of the recording electrode and increase the magnetic flux density there while reducing undesired toner spikes there.

[Summary of the invention]

The present invention provides a recording medium comprising a recording electrode array, a surface dielectric layer and a conductive layer that closely oppose the recording electrode layer and move relative to the recording electrode array, and a recording medium between the recording medium surface and the recording voltage array. means for supplying conductive magnetic toner; and means for applying a recording voltage according to an image pattern between the conductive layer of the recording medium and selected electrodes in the recording electrode array;
In order to generate a magnetic field between the recording medium and the recording electrode array, the recording electrode array is sandwiched between opposing magnets arranged so that the same poles face each other, and further between the magnets and the recording electrode array. This image recording device includes a magnetic plate extending to the vicinity of the electrode tips of a recording electrode array, and is characterized in that a nonmagnetic layer is provided on the outer surface of the magnetic plate.

[Embodiments of the invention]

FIG. 1 is a side sectional view showing one embodiment of the present invention. Its basic configuration is the same as that in FIG. 2, and the same reference numerals as in FIG. 2 indicate parts that perform the same functions.

As the recording medium 1, an aluminum cylinder with a diameter of 100 mm was used as the conductive layer 1a, and the surface of the aluminum cylinder was further processed with alumite to a thickness of 2 μm to form the dielectric 9-layer 1b. 11・゛ to toner T is 1010Ω
Although less conductive magnetic toners can be used, in this example, Imaging 7 powder 355 toner sold by 3M Company was used.

A pure iron wire with a diameter of 20 μm was used as the recording electrode 7.

3,360 of these were arranged in parallel over a width of 210W. An insulating coating 13 was applied to the recording electrode group 7 using an adhesive NOIS-74- (trade name) sold by Cemedine Co., Ltd., and the insulating coating 13 was tightly fixed with an iron plate 12. The iron plate 12 extends over the entire width of the recording electrode group.

In the above points, there is no difference from the conventional example shown in FIGS. 3 and 4, but in this embodiment, as shown in FIG.
A Teflon (trademark) coating 15 (approximately 0.5 - 1 - thickness) is applied to the surface of the magnetic plate to suppress toner spikes on the surface of the magnetic plate.

The recording medium 1 and the recording electrode 7 are arranged to face each other almost at right angles, and the distance therebetween is maintained at 75±25 μm. By providing the non-magnetic material coating 15 on the surface of the magnetic plate 12 in this way, the magnetic binding force on the toner at the tip of the magnetic plate 12 is weakened. Therefore, the spike 1 at the tip of the magnetic plate
'4 is the thickness of the iron plate 12 and the non-magnetic coating 1.
Although it depends largely on the thickness and surface properties of the recording electrode 5, dO1 is about half of that in the case where the non-magnetic coating 15 is not provided. Therefore, the magnetic body 12 can be brought close to the recording medium 1, and the magnetic flux near the tip of the recording electrode is reduced. Density can be increased efficiently. Furthermore, since it is possible to set the distance between the magnet 8 and the recording medium 1 with a margin of about 1 m or more, it is necessary to provide a means for removing toner that accumulates near the magnet 8. A sufficient amount of space can be secured.

Note that in this example, from the viewpoint of saturation magnetization permeability, the iron plate was 12 t.
[Of course, a plate made of other magnetic material such as cobalt, nickel, or molten metal may be used in place of the iron plate 12. In addition, the thinner the magnetic plate is, the less undesired toner build-up can occur at the tip of the magnetic plate, and it is possible to bring the magnetic plate close to the tip of the recording electrode and strengthen the magnetic flux density there. However, if it is too thin, the magnetic flux density at the tip of the magnetic plate will also weaken and the effect will not be fully demonstrated. In this experiment, an iron plate with a thickness of 10 to 30 μm was used, and good results were obtained.

FIG. 5 is a side sectional view showing another embodiment of the present invention. In this embodiment, a piezoelectric element 16 is provided in a part of the non-magnetic layer 15 as described above, and a high frequency AC voltage is applied to the piezoelectric element 16 to generate high frequency vibration (several tens of Hz) at the tip of the magnetic plate 12.
), this makes the movement of the toner at the tip of the magnetic plate smooth, and the toner that cannot be used for recording is immediately transferred to the magnet 8.
It is possible to limit the amount of toner that accumulates near the tip of the magnetic plate 12 by causing the toner to adhere and accumulate near the magnetic plate 11.
In this case, it is desirable that the recording stylus 7 be separated from the magnetic plate 12 and supported by another support means to prevent vibrations from being transmitted to the recording stylus 7. As the vibration means, other than the piezoelectric means 16 shown in FIG. 5, it is of course possible to use any other known suitable vibration means.

〔Effect of the invention〕

As explained above, according to the present invention, in a configuration in which a magnetic plate is arranged between the magnetic poles of magnets facing each other with a recording electrode group in between, a simple means of providing a nonmagnetic layer on the surface of the magnetic plate is adopted. By extending the magnetic plate to the vicinity of the tip of the recording electrode needle, the magnetic flux density at the tip of the recording electrode needle is increased, and at the same time, undesired toner clusters on the magnetic plate are reduced. Furthermore, it is possible to provide a sufficient space between the recording medium and the magnet for installing the toner removing and conveying means.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged cross-sectional view of an embodiment of the present invention, Fig. 2 is a cross-sectional view showing a conventional example of an image recording device to which the present invention relates, and Figs. 3 and 4 are improved prior proposed examples thereof. FIG. 5 is a partially enlarged sectional view of another embodiment of the present invention. 1... Recording medium 2... Toner storage e-3
... Magnet roll 4 ... Toner application roller 6 ...
DC voltage source 7... Recording electrode 8... Magnet 9...
Image signal voltage generator 10... Recording position 11... Accumulated toner 12... Magnetic plate 13... Insulating coating 15
...Non-magnetic material coating No. 2 section Fig. 4

Claims (1)

[Claims] 1. A recording medium comprising a recording electrode array, a surface dielectric layer and a conductive layer that closely oppose and move relative to the recording electrode array, and the recording medium surface and the recording electrode array. means for supplying conductive magnetic toner between the recording medium and a selected electrode in the recording electrode array; means for applying a recording voltage according to an image pattern between the conductive layer of the recording medium and a selected electrode in the recording electrode array; Opposing magnets are arranged so that the same poles face each other with the recording electrode array sandwiched therebetween in order to generate a magnetic field between the recording electrode array and the recording electrode array. What is claimed is: 1. An image recording device comprising a magnetic plate extending close to the tip of an electrode, characterized in that a non-magnetic layer is provided on the outer surface of the magnetic plate. 2. The image recording apparatus according to claim 1, further comprising means for applying vibration to the tip of the magnetic plate.