JPH021308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a recording medium and toner particles having magnetism and conductivity between a recording electrode and a counter electrode that are opposed to each other, and also supplies a magnetic and conductive toner particle between the recording electrode and the counter electrode. The invention relates to a recording apparatus that performs recording by transferring the toner particles to the recording medium by applying a recording voltage according to an image signal during the recording process.

In conventional devices of this type,
As disclosed in Japanese Patent No. 30228, a magnet is housed inside a sleeve that also functions as a counter electrode, and the magnetic force of the magnet creates a so-called toner chain (toner particles are chained) on the outer peripheral surface of the sleeve. When performing recording, a voltage is applied between the sleeve and a recording electrode facing the sleeve, so that the toner particles at the tip of the toner chain are affected by the magnetic force of the magnet. A Coulomb force in the opposite direction is applied, and this Coulomb force causes the particles at the tip of the toner chain to separate from the toner chain against the magnetic force of the magnet, thereby reducing the recording medium supplied between the sleeve and the recording electrode. It was configured to transfer the same particles to the

However, in such conventional recording devices, the direction of the magnetic force for forming the toner chain on the outer peripheral surface of the sleeve and the direction of the Coulomb force for transferring the toner particles at the tip of the toner chain to the recording medium are different. Since the directions were opposite to each other, the Coulomb force must be made sufficiently larger than the magnetic force, especially when the recording speed is high.
The difference in magnitude between the Coulomb force and the magnetic force must be very large.

To achieve this, it is necessary to increase the recording voltage or to weaken the amount of magnetization of the magnet or the magnetic susceptibility of the toner particles as much as possible. However, when the recording voltage is increased, the withstand voltage of the active element must be increased, leading to an increase in cost. On the other hand, when the amount of magnetization and the magnetic susceptibility of the toner particles are weakened, the formation of toner chains and the formation of the sleeve and recording electrode Since it becomes difficult to convey the toner particles to the part facing the recording medium, there is a drawback that it is extremely difficult to perform high-speed recording in practice.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a recording apparatus that can perform high-speed recording without increasing the recording voltage.

The present invention will be described below based on embodiments shown in the drawings.

In the figure, a sleeve 1 made of a conductive non-ferromagnetic material is rotatably supported by a device main body (not shown), and is moved in the direction of arrow A (counterclockwise) by a drive device (not shown). It is designed to be driven and rotated. The sleeve 1 may be made of an insulating material, or may be made of a conductive non-ferromagnetic material whose outer peripheral surface is coated with an insulating material such as plastic. Furthermore, by providing a large number of fine grooves in the axial direction of the sleeve 1 on the outer circumferential surface of the sleeve 1, or by providing countless fine irregularities on the outer circumferential surface of the sleeve 1, the toner conveying force, which will be described later, can be increased. A magnetic roll 2 is fixedly installed in the sleeve 1 coaxially with the sleeve 1. A plurality of S poles and N poles are alternately formed on the outer circumferential surface of the magnetic roll 2 over almost the entire circumference, but a magnetic pole absent area 3 where no magnetic pole exists only at the top of the outer circumferential surface. is provided. Note that both sides of the magnetic pole absent portion 3 are formed to have the same magnetic pole.

A hopper 4 is provided on the side of the sleeve 1, and the tip of a doctor 5 formed at the bottom of the hopper 4 faces the outer peripheral surface of the sleeve 1 via a doctor gap 6. Said hopper 4
Inside, pigment, ferromagnetic material, conductivity modifier, resin, etc. are kneaded in fine powder form (usually particle size 5~5).
A so-called one-component toner 7 made of 40μ) is housed therein.

Immediately above the top of the outer peripheral surface of the sleeve 1,
A number of recording electrodes 8 are attached. These recording electrodes 8 each correspond to one pixel, and are arranged in a line at the same pitch on a straight line parallel to the axis of the sleeve 1. Although these recording electrodes 8 are preferably made of ferromagnetic material, they can also be made of non-ferromagnetic material.

Further, in front of the recording electrode 8, a toner transport guide 9 made of an insulator is provided to guide the toner particles from the outer peripheral surface of the sleeve 1 to the upper end of the recording electrode 8. Further, above the recording electrode 8, a counter electrode 10 is provided on the sleeve 1, facing the recording electrode 8.
The counter electrode 10 is provided separately from the electrode 10, and the counter electrode 10 is grounded.

Further above the counter electrode 10, a magnet 11 is provided. It is desirable that the magnetic poles of the magnet 11 on the recording electrode 8 side be opposite to the magnetic poles on both sides of the magnetic pole absent portion 3 . Reference numeral 12 denotes a dielectric recording body, and the recording body 12 is moved to the opposite electrode 10 with its back surface in contact with the opposite electrode 10 by a recording body conveying mechanism (not shown).
0 and the recording electrode 8 in a direction perpendicular to the axis of the sleeve 1. Note that this recording medium 12 may be electrostatic recording paper, plain paper, or the like. Further, a recording voltage pulse is applied between the recording electrode 8 and the counter electrode 10 from a recording power source 13.

Next, the operation of this embodiment will be explained.

The toner 7 in the hopper 4 is supplied onto the outer peripheral surface of the sleeve 1 from the bottom opening of the hopper 4 via the doctor gap 6. The toner 7 supplied onto the outer circumferential surface is conveyed on the outer circumferential surface in the direction of arrow A by rotating the sleeve 1 in the direction of arrow A, and passes through the toner conveying guide 9 to the recording electrode 8.
reach the top.

Here, particles of the toner 7 supplied onto the outer peripheral surface of the sleeve 1 (hereinafter simply referred to as toner particles)
is under the influence of the magnetic field from the magnetic roll 2 up to the recording electrode 8, and forms a toner chain 14 along the lines of magnetic force generated from the magnetic roll 2. These toner chains 14 are held on the outer circumferential surface of the sleeve 1 by applying a force toward the magnetic roll 2 due to the magnetic force of the magnetic roll 2 .

However, when the toner particles reach above the non-magnetic pole area 3 on the outer circumferential surface of the sleeve 1, that is, on the recording electrode 8, they are no longer affected by the magnetic field from the magnetic roll 2 and come under the influence of the magnetic field from the magnet 11. , along the lines of magnetic force generated from the magnet 11, upward from the outer peripheral surface of the sleeve 1, that is, the counter electrode 10.
A toner chain 14 is formed that extends toward. The magnetic force acting on this toner chain 14 is directed toward the counter electrode 10. That is, in this toner chain 14, the toner magnetized by the magnetic pole immediately before reaching the recording electrode 8 on the magnetic pole absent portion 3 is attracted to the sleeve 1 side of the magnet 11 formed at the opposite magnetic pole. It is formed by

Note that during this misalignment, the tip of the toner chain 14 may lightly contact the recording medium 12, or
Although a slight gap may exist between the leading end of the toner chain 14 and the recording medium 12, the lower end of the toner chain 14 must be brought into contact with the recording electrode 8. In order to bring the toner chain 14 into such a state, the amount of magnetization, size, and position of the magnet 11 or the magnetic permeability of the opposing electrode 10 may be appropriately selected. In addition, to give an example, the recording electrode 8
The voltage of 200 V or less, the distance between recording electrode 8 and magnet 11 is 2 to 3 mm, and the distance between magnet 2 and magnet 11 is 4 mm.
~6 mm, the magnetic force of magnet 2 and magnet 11 is
It should be 800 to 900 Gauss.

In such a state, when a recording voltage pulse is applied from the recording power supply 13 between the recording electrode 8 and the counter electrode 10, an electric charge having the same polarity as that of the recording power supply 13 connected to the recording electrode 8 is generated. (in this embodiment, (+) polarity) appears at the tip of the recording electrode 8, and at the same time, all or part of it is guided to the tip of the toner chain 14, and at the same time, a charge of opposite polarity is applied to the recording medium 12. Trapped. Therefore, a Coulomb force acts between the charges trapped in the recording medium 12 and the toner particles at the tip of the toner chain 14, and this Coulomb force causes the toner chain 1
A force directed toward the recording medium 12 acts on the particle at the tip of the particle 4 .

Therefore, the following four types of forces act on the toner particles at the tip of the toner chain 14.

(i) Upward force due to the magnetic force of the magnet 11.

(ii) The same upward force as in (i) due to the Coulomb force.

(iii) downward force due to gravity;

(iv) Centrifugal force.

Here, since the centrifugal force (iv) is small and can be ignored, if the sum of the magnetic force (i) and the Coulomb force (ii) is greater than the gravitational force (iii), then the particles at the tip of the toner chain 14 The toner leaves the toner chain 14, flies upward, and adheres to the recording medium 12.

The toner particles that have adhered to the recording medium 12 in this way continue to adhere to the recording medium 12 even after passing through the counter electrode 10 due to the movement of the recording medium 12. (not shown) is fixed on the recording medium 12.

Here, the magnitude of the Coulomb force is determined by the magnitude of the recording voltage, but as described above, in this apparatus, the direction of the Coulomb force acting on the toner particles at the tip of the toner chain 14 is determined by the magnitude of the recording voltage. magnet 1
Since the direction of the magnetic force 1 is in the same direction, toner particles can be sufficiently transferred to the recording medium 12 even if the Coulomb force is small or the time during which the Coulomb force acts is short.

Therefore, in this apparatus, high-speed recording can be performed without increasing the recording voltage.

As is clear from the above description, in the recording device according to the present invention, a recording voltage applied between the recording electrode and the counter electrode acts on the toner particles supplied to the opposing portion of the recording electrode and the counter electrode. By providing a magnet that applies a force in the same direction as the Coulomb force, that is, a force directed toward the recording medium, an excellent effect can be obtained in which high-speed recording can be performed without increasing the recording voltage.

[Brief explanation of drawings]

The figure is a schematic sectional view of an embodiment of a recording device according to the present invention. 1... Sleeve, 2... Magnetic roll, 4... Hopper, 7... Toner, 8... Recording electrode, 9...
Toner conveyance guide, 10... directional electrode, 11...
... Magnet, 12 ... Recording body, 13 ... Recording power source.

Claims (1)

[Claims] 1 a recording electrode, a counter electrode provided opposite to the upper part of the recording electrode, a means for supplying a recording medium to a portion facing the recording electrode and the counter electrode, and a means opposite to the facing portion of the recording electrode. a rotatable sleeve provided on a side of the sleeve; a first magnet provided inside the sleeve for transporting toner particles having magnetic and electrical conductivity; a toner conveying guide for conveying the toner particles to the opposing portion side of the recording electrode; A second magnet is provided in which a rear end of the toner chain does not separate from the recording electrode and a tip of the toner chain generates a magnetic force directed toward the recording medium, and the first magnet has a magnetic pole near the opposing portion. A recording device characterized by an absent part.