JPS60112457A - Image recording device - Google Patents

Abstract

PURPOSE:To arrange so that high-density recording may be made at low voltage by applying a magnetized polarity and a reversed polarity created by a magnetic toner carrier means to a recording electrode adjusted to a condition where a voltage applied to a recording electrode is off and the shift of a recording medium in a facsimile unit, etc. CONSTITUTION:If a magnetic roller 12 turns clockwise and a magnetic pole shifts off the back surface of a recording electrode 10, the suction force of a toner chain 14a by magnetic power becomes weak. At the same time, if a switch 18a is closed and a magnetic field is generated by a coil 17 so that the tip of the recording electrode 10 may be magnetized as ''S'' pole and the terminal pole as ''N'' pole, a magnetic line of force from the tip of the recording electrode 10 to a recording medium 11 decreases significantly, and shows a weakened suction force on the toner chain 14a. Under this condition, if the recording medium 11 turns counter-clockwise, the quantity of moving toner particles restrained by Coulomb's force of a negative charge is large, resulting in the formation of a toner image of high concentration. Thus it is possible to obtain a picture of high concentration at low voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image recording device used in facsimiles, printers, and the like.

2. Description of the Related Art Conventional Structures and Their Problems Conventionally, electrostatic recording devices have been widely used which form an electrostatic latent image on a dielectric layer of a recording medium having a dielectric layer and visualize this image with toner or the like.

However, in this electrostatic recording device, it is necessary to apply a high voltage to the recording medium through air or a gap to generate discharge between two pages in which an electrostatic latent image is formed. Furthermore, since a developing device is required to develop this electrostatic latent image, there are disadvantages in that the process becomes complicated and the device becomes larger.

On the other hand, in order to overcome the drawbacks of this electrostatic recording device, a recording device has recently been proposed in which the application of a voltage to the recording electrode and the development are performed at the same time.

A conventional image recording device will be explained.

FIG. 1 is a schematic diagram of a conventional image recording apparatus. A recording electrode 1 is made of a magnetic material, and is provided with a slight gap from the recording medium 2.

Further, the recording electrode 1 is fixed to a sleeve 4 made of a non-magnetic material and fixed to the main body of the apparatus (not shown). A magnetic roll 3 having a plurality of N and S poles alternately formed on its outer peripheral surface is rotatably housed in the sleeve 4 coaxially with the sleeve 4 . This magnetic roll 3 is rotated in the direction of arrow A in the figure. Furthermore, the toner 5 near the outer peripheral surface of the sleeve 4 and the recording electrode 1 is removed from the magnetic roll 3.
(hereinafter referred to as a toner chain) following the lines of magnetic force generated from the 3 +- dimagnetic pole. On the other hand, a power supply γ is connected to the recording electrode 1 and the recording medium 2 via a switch 6, and when the switch 6 is closed, a positive voltage is applied to the recording electrode 1 and a negative voltage is applied to the recording medium 2.

FIG. 2 shows an enlarged view of the main parts of a conventional image recording apparatus.

As shown in the figure, when the N pole or S pole of the magnetic roll 3 is located behind the recording electrode 1 (the figure shows the case where the N pole is behind the recording electrode 1), the recording electrode 1 and the recording medium 2 A toner chain 5a is formed between the two. In this state, when the switch 9 is closed, the toner chain 5 passes through the recording electrode 1.
A current flows through the toner chain 5a, and a positive charge is injected into the tip of the toner chain 5a. On the other hand, negative charges are generated on the recording medium 2. Coulomb attraction acts between these positive charges and negative charges, and the toner particles at the tip of the toner chain 5a are strongly attracted to the recording medium.As shown in FIG. When moving in the direction indicated by the arrow in the figure, the magnetic pole of the magnetic roll 3 is removed from behind the recording electrode 1, the lines of magnetic force passing through the recording electrode 1 are reduced, and the attraction force of the magnetic force on the toner chains 6a is weakened.

Furthermore, when the recording medium 2 moves in the direction shown by the arrow B in the figure at the same time as the magnetic roll 3 moves, a part of the toner chain 6a is transferred to the recording medium 2 by Coulomb attraction due to the negative charge of the recording medium 2.
The toner image 9 is transferred to the top and forms a toner image 9. The toner 5 that has not migrated to the recording medium 2 is conveyed by the magnetic roll 30 rotations in the opposite direction to the magnetic roll 30 rotations, and at the same time, new toner chains 6 are again deposited at the tip of the recording electrode 1 as the next magnetic pole moves.
a is formed.

However, in such a conventional device, the magnetic force of the magnetic roll 3 always acts to hold the toner 5 on the sleeve 4, so in order to increase the amount of toner 6 transferred to the recording medium 2, it is necessary to increase the applied voltage. The disadvantage was that it had to be made high.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and it is an object of the present invention to provide an image recording apparatus that can obtain images of high recording density with a sufficiently low recording voltage.

Page 5 Structure of the Invention The present invention is an image recording apparatus that includes means for magnetizing a recording electrode and conveying magnetic toner to the recording electrode, and means for applying an alternating magnetic field to the recording electrode.

An image with high density can be obtained with a low voltage by applying the opposite polarity to the polarity magnetized by the magnetic toner transport means to the recording electrode in accordance with the turning off of the voltage applied to the recording electrode and the movement of the recording medium. It is.

DESCRIPTION OF EMBODIMENTS FIG. 4 is a schematic diagram of an image recording apparatus according to an embodiment of the present invention. 10 is a recording electrode made of a magnetic material;
It is provided so as to maintain a gap with the recording medium 11. Further, the recording electrode 1o is fixed to a sleeve 13 made of a non-magnetic material and fixed to the main body of the apparatus (not shown).

A magnetic roller 12 having a plurality of N and S poles alternately formed on its outer circumferential surface is accommodated within the sleeve 13 . This magnetic roll 12 is rotated in the direction of arrow C in the figure. Further, the toner 14 near the outer peripheral surface of the sleeve 13 and the recording electrode 6 page 1o forms toner chains 14a along the lines of magnetic force generated from the magnetic poles of the magnetic roll 12. Further, the recording electrode 10 and the recording medium 11 are connected to a power source 16 via a switch 15.

When the switch 16 is closed, a positive signal is applied to the recording electrode 10.

A negative voltage is applied to the recording medium 11. Further, a coil 17 is provided at the end of the recording electrode 1, and a switch 18a
, 18b and power supplies 19a, 19b generate an alternating magnetic field.

FIG. 5 shows an enlarged view of the main parts of the image recording apparatus described above.

As shown in the figure, when the N pole or S pole of the magnetic roller 12 is located behind the recording electrode 10 (the figure shows the case where the N pole is behind the recording electrode 10), the The magnetic lines of force pass through the recording electrode 10, and toner chains 14a are formed between the recording electrode 10 and the recording medium 20. At this time, no current is flowing through the coil 17 provided at the end of the recording electrode 10, and the toner chains at the tip of the recording electrode 10 are strongly attracted by the magnetic force of the magnetic roller 12 passing through the recording electrode 10. . In this state 7, the switch 15 is closed, a current flows through the recording electrode 10 to the toner chain 14, and a positive charge is injected into the tip of the toner chain 14a. On the other hand, negative charges are generated on the recording medium 2, and Coulomb attraction acts between the positive charges and the negative charges to try to attract the toner chains 142L toward the recording medium 2.

Next, as shown in FIG. 6, the magnetic roller 12
When the magnetic roller 12 moves in the direction indicated by , the magnetic pole of the magnetic roller 12 comes off the back side of the recording electrode 10, the number of lines of magnetic force passing through the recording electrode 10 decreases, and the attraction force of the magnetic force on the toner chains 14& becomes weaker. At the same time as the magnetic roller 12 moves, the switch 18 & is closed to generate a magnetic field by the coil 17 so as to magnetize the tip of the recording electrode 10 to the S pole and the end to the N end.

Then, the lines of magnetic force coming out from the back side of the recording electrode 10 of the magnetic roller 12 are concentrated at the magnetic pole (N pole in the figure) at the tip of the recording electrode 10, and the lines of magnetic force coming out from the tip of the recording electrode 10 toward the recording medium 11 are extremely reduced. The force that attracts the toner chains 14& toward the recording electrode 10 becomes extremely weak. When the recording medium 11 moves in the direction indicated by the arrow in the figure in this state, a large amount of toner particles move due to the Coulomb attraction of the negative charge of the recording medium 11, and as a result, a high-density toner image cannot be formed. can. The toner 14 that has not migrated to the recording medium 11 is transported by the rotation of the magnetic roll 12 in the opposite direction to the rotation of the magnetic roll 12, and at the same time, new toner is transferred to the tip of the recording electrode 10 by the movement of the magnetic pole of the magnetic roll 12. A strand 14a is formed. By providing a coil and a current changeover switch, toner can be easily transferred to a recording medium, and an image with high density can be obtained.

In this embodiment, a coil is used as a means for applying an alternating magnetic field to the recording electrode, but it is also possible to use a rotating permanent magnet or the like, and the same effect can be obtained.

Further, in the present invention, the mechanism for conveying toner around the recording electrode is not limited to the previous example, and may be of a type in which a magnetic roll is fixed and a sleeve is rotated, or a mechanism that does not use a sleeve may be used. It may be.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional image recording device, FIGS. 2 and 3 are enlarged configuration diagrams of main parts of a conventional image recording device, and FIG. 4 is an image recording device according to an embodiment of the present invention. , FIG. 5, FIG. 6, and FIG. 7 are enlarged configuration diagrams of the same essential parts, respectively. 11... Recording medium, 12... Magnetic roller, 13... Sleeve, 14... Toner, 15... Switch, 16... ···power supply,
1γ...Coil, 18a. 18b...Switch, 19a, 19b...
·power supply. Name of agent: Patent attorney Kazuo Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] A plurality of recording electrodes made of a magnetic material, a recording medium disposed opposite to the recording electrodes, and a magnetic toner that magnetizes the recording electrodes and has conductivity to the recording electrodes. and means for applying a voltage between the plurality of recording electrodes and the recording medium. and means for applying an alternating magnetic field to the recording electrode.