JPS62980A - Magnetic toner transfer device - Google Patents

Abstract

PURPOSE:To permit an operation of a titled device with a low voltage without requiring a high-voltage power source such as corona discharger by impressing a voltage between a transfer roller and magnetic recording medium and injecting electric charge to a magnetic toner so as to move the magnetic toner sticking to the magnetic recording medium toward a transfer material. CONSTITUTION:The negative charge is injected from the earth side by the transfer bias voltage of a DC power source 25 to the magnetic toner 23 sticking onto the recording medium 21 through a conductive medium base body 26 an the medium 21. On the other hand, a positive charge 29 is introduced via the transfer roller 22 onto the surface 28 of the transfer material 24 on the side opposite from the surface 27 of the material 24 with which the magnetic toner 24 contacts. The electrostatically charged toner 23 injected with the negative charge in the above-mentioned manner receives the force to move toward the material 24 by the electric field formed between the transfer roller 24 an the magnetic recording medium 21 and the toner 23 is transferred onto the material 24 by overcoming the restraining force by the magnetic force of the latent image magnetization pattern formed on the medium 21.

Description

[Detailed Description of the Invention] [Summary] This is an improvement of a transfer device in a magnetic recording device, in which a voltage is applied between a transfer roller on which a transfer material is installed and a magnetic recording medium to cause an electric field to be applied to the toner. A device that injects a polar charge that receives a force that moves in the direction of the transfer material, making it possible to transfer toner to the transfer material with high precision without requiring high voltage like a corona discharger.

[Industrial application field]

The present invention relates to a transfer device for a magnetic recording device, and in particular, by providing a means for injecting charge into magnetic toner attached to a recording medium, the toner adheres to the recording medium without the need for a high-voltage device such as a corona discharger. The present invention relates to a device that easily transfers magnetic toner onto a transfer material with high precision.

A developing roller that forms a magnetic latent image on the recording medium of a rotating recording drum using a magnetic head, and is disposed close to and facing the recording drum. The magnetic toner is transported by the magnetic toner. The magnetic recording device, which magnetically attracts this magnetic toner to the magnetic latent image and develops it, and transfers and records the developed toner image onto recording paper, is used as a non-impact printer in the output device of a computer. There is.

The transfer device of such a magnetic recording device operates at low voltage without using a device that requires a high-voltage power source such as a corona discharger, and moreover, the magnetic toner attached to the magnetic recording medium can be transferred to high definition There is also a need for a transfer device that can transfer and record onto a transfer material with high efficiency.

[Conventional technology]

FIG. 3 is a diagram schematically showing the device configuration of a conventional magnetic recording apparatus.
is used to magnetize the magnetic recording medium 1 so as to have a constant magnetic field in the direction perpendicular to the thickness direction.

Furthermore, the recording drum 2 is rotated along the direction of arrow A, and an excitation current is applied to the coil 5 of the submerged formation head 4 in accordance with the print signal, thereby forming a latent image magnetization pattern on the magnetic recording medium 1. Furthermore, using the developing device 6, the magnetic toner is transferred to the magnetic recording medium 1.
The latent image magnetized pattern is conveyed to the latent image magnetized pattern, and magnetic toner is magnetically attached to the latent image magnetized pattern to perform development.

Further, during this development, excess magnetic toner adhering to the magnetic recording medium 1 is collected by suction using a collection device 7, and furthermore, a transfer device 8 is used to transfer and record the magnetic toner onto a recording paper 9 as a transfer material.

Furthermore, the recording drum 2 is rotated in the direction of arrow A, and the magnetic toner remaining without being transferred to the surface of the recording drum 20 is collected using the cleaner 10.

[Problem that the invention seeks to solve]

By the way, the conventional transfer device is provided with a transfer roller 11 that moves opposite to the recording drum 2, as shown in FIG. There is a pressure transfer device that presses the transfer roller 11 against the recording drum 2 and transfers the magnetic toner 12 attached to the recording medium 1 using the pressure of the transfer roller 11.

However, this pressure transfer device cannot obtain high transfer density unless a considerable amount of pressure is applied, and when transferring with such strong pressure, a phenomenon occurs in which the toner image is crushed, and the periphery of the printed image is blurred and the high density is It has the disadvantage that it is difficult to obtain a fine printed image.

In addition, the toner adhering to the recording medium 1 is charged using a high-pressure corona discharger, and the transfer roller 11 is charged.
A high-voltage corona discharger is also used to apply a charge having a polarity opposite to that of the toner described above to the recording paper 9 placed in the toner. There is a device that transfers the toner to the recording paper using the electrostatic force between the charge applied to the toner and the charge applied to the recording paper, but corona dischargers require high voltage of several KV, so the size of the device increases. , and has the disadvantage of being expensive.

[Means for solving problems]

The present invention eliminates the above-mentioned drawbacks and provides a transfer device that does not require a high-voltage power source like a corona discharger and operates with a simple mechanism and low voltage.

As shown in FIG. 1, the transfer device of the magnetic recording apparatus of the present invention applies transfer material 2, which is paper, to magnetic toner 23 attached to the magnetic recording medium between a magnetic recording medium 21 and a transfer roller 22.
Means 25 is provided for applying a voltage that imparts a polar charge that has a force of movement in the direction 4.

[Effect]

The magnetic toner transfer device of the present invention applies an electric field between the magnetic recording medium 21 and the transfer roller 22 to
An electric charge that moves in the direction of the transfer material 24 is injected into the magnetic toner 23 adhering to the transfer material 24, and the injection of this charge causes the magnetic toner 23 to move in the direction of the electric field in which the transfer material 24 is placed, and the transfer material 24.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1 described above, the magnetic toner transfer device of the present invention has a DC power supply 24 so that a positive voltage is applied to the transfer roller 22 between the magnetic recording medium 21 and the transfer roller 22, and the magnetic recording medium 21 is on the ground side. is installed, and this DC power supply 24 applies 100V between the magnetic recording medium 21 and the transfer roller 22.
Apply a transfer bias voltage of approximately

This transfer bias voltage causes the conductive medium substrate 26 and the recording medium 21 to be passed from the ground side to the recording medium 21.
A negative charge is injected into the magnetic toner 23 adhering thereto.

On the other hand, on the surface 28 of the transfer material 24 opposite to the surface 27 of the transfer material 24 in contact with the magnetic toner 23,
The magnetic toner 2 is supplied from the power source 25 via the transfer roller 22.
A positive charge 29 having a polarity opposite to that of the charge 3 is introduced in a form induced by the negative charge.

The charged toner 23 injected with negative charges is transferred to the transfer material 23 by an electric field formed between the transfer roller 22 and the magnetic recording medium 21 by the transfer bias voltage.
The toner 23 is transferred to the transfer material 24 by receiving a force moving in the direction , overcoming the restraining force due to the magnetic force of the latent image magnetization pattern formed on the magnetic recording medium 21 .

Note that the pressing force of the transfer roller 11 against the recording drum 2 at this time may be considerably lower than the pressure in the case of conventional pressure transfer.

FIG. 2 shows the results of an experiment using the apparatus of the present invention. The vertical axis of the figure shows transfer efficiency or print density, and the horizontal axis shows the applied voltage between the magnetic recording medium and the transfer roller. As shown in the figure, even if the applied voltage is as low as 100 V,
The print density transferred to the recording paper is 0. It was found that D showed a value of about 1.0, which was sufficient for practical use. In addition, the transfer efficiency (weight ratio of the amount of toner on the magnetic recording medium to the amount of toner transferred to the recording paper) in this case is 90%.
It was found that most of the toner adhering to the magnetic recording medium was transferred.

The volume resistivity of the magnetic recording medium 21 used in this example is 10 Ω or less, and the volume resistivity of the magnetic toner 23 used is 10" Ω. In addition, the thickness of the paper used, the toner, The transfer bias voltage was set to 50% depending on the volume resistivity of
By appropriately changing the voltage to about 200 V, a transferred image with a print density comparable to that obtained by an electrophotographic process was obtained.

Note that in this embodiment, a transfer bias voltage was applied such that the recording medium side was negative and the transfer roller side was positive, but conversely, a voltage such that the recording medium side was positive and the transfer roller side was negative could also be applied. good.

〔Effect of the invention〕

As described above, according to the magnetic toner transfer device of the present invention, there is no need to provide the transfer device with a device that operates at high voltage, such as a corona discharger, and the device becomes small and inexpensive. In addition, since the pressing force of the transfer roller is small, it is possible to avoid the phenomenon of blurring the periphery of the toner image and resulting in a printed image with poor resolution, as seen in conventional pressure transfer, and it is possible to obtain high-definition printed images. There is also the effect of

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the toner transfer state in the magnetic toner transfer device of the present invention, Fig. 2 is a relationship diagram between transfer bias voltage and transfer density in the device of the present invention, and Fig. 3 is a conventional diagram. FIG. 4 is a schematic diagram showing the main parts of a transfer device of a conventional magnetic recording device. In the figure,

Claims (1)

[Claims] A magnetic recording medium (21) is provided on a medium base (26), and a magnetic toner (23) is magnetically attached to the magnetic latent image formed on the magnetic recording medium (21), and the transfer material is (24) and a transfer roller (22) disposed through the media substrate (26).
In a device that transfers the magnetic toner (23) to a transfer material (24) by pressing, an electric field is applied between the magnetic recording medium (21) and the transfer roller (22) to transfer the magnetic toner (23) to the transfer material (24). A magnetic toner transfer device characterized in that it is provided with means (25) for injecting electric charge.