JPS62112184A - Magnetic recording type printer - Google Patents

Abstract

PURPOSE:To obtain a high-speed printer of a low cost by providing an eraser for erasing a magnetized latent image by magnetizing a magnetic material layer of a recording sheet in the single direction of a longitudinal direction with respect to the sheet surface and magnet for generating a recording magnetic field to act the recording magnetic field smaller than the coercive force of the magnetic material at an ordinary temp. in the direction opposite from the direction where the magnetic material layer of the recording sheet is preliminarily magnetized to the contact point between the recording sheet and energizing electrode. CONSTITUTION:This printer has the eraser 3 for erasing the magnetized latent image by magnetizing the magnetic material layer of the recording sheet 1 in the single direction of the longitudinal direction with respect to the sheet surface and the magnet 9 for generating the recording magnetic field to act the recording magnetic field smaller than the coercive force of the magnetic material at the ordinary temp. in the direction opposite from the direction where the magnetic material layer 1a of the recording sheet 1 is preliminarily magnetized to the contact point between the recording sheet and the energizing electrode 2a by the eraser 3. The resistor layer of the recording sheet is thereby energized to heat the magnetic material layer of the recording sheet up to the temp. of the Curie point of the magnetic material while the magnetic material layer of the recording sheet is kept applied with the recording magnetic field after magnetization in the single direction. The magnetized latent image is thus formed, developed and fixed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to magnetic recording printers.

[Conventional technology]

Conventionally, in the magnetic recording method, a magnetized latent image is formed on the surface of a magnetic recording sheet formed in the shape of a belt or a drum, and the latent magnetized image is made visible using magnetic ink toner. After being transferred to paper, the transferred visible image is fixed by a fixing device and recorded. At this time, a ring-type or stylus-type magnetic head is used as the recording head that forms the magnetized latent image. The method was common.

A ring-type recording head has a coil wound around a ring-shaped core that has a gap in part. When a current is passed through the coil, a magnetic flux is generated that passes through the core, but because the magnetic resistance is large in the air gap, the magnetic flux spreads outward, and this leaked magnetic flux magnetizes the magnetic recording medium and performs recording. In addition, a stylus-type recording head has a coil wound around a stylus-shaped core. When a current is passed through the coil, a magnetic circuit is formed in the air or through the recording medium, and the magnetic flux density increases at the tip of the stylus. As the size increases, the magnetic recording medium is magnetized and recording is performed.

[Problem that the invention seeks to solve]

When using such a ring-type or stylus-type recording head, when forming a magnetic latent image, if there is only one recording head, it is necessary to move the recording head, the magnetic recording medium, or both. Since it is necessary to perform main scanning and sub-scanning mechanically, there is a drawback that it takes time to form a magnetized latent image.

In order to eliminate this drawback, it has been proposed to make the head multi-head and shorten the time for forming a latent magnetized image. However, the production of the multi-head head itself is difficult, and the production of multi-heads with minute pitch intervals is extremely difficult. Not only is it difficult to manufacture the head, but even if it were possible to manufacture it, the cost of the head would be enormous.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and provide a low-cost high-speed magnetic recording printer that can form a magnetized latent image at high speed and has a low cost recording head.

[Means for solving problems]

The magnetic recording printer of the present invention includes a belt-shaped recording sheet in which three layers, a magnetic layer, a conductive layer, and a resistive layer having a higher resistivity than the conductive layer are formed in this order, and the recording sheet. a plurality of current-carrying electrodes that are arranged to contact the resistor layer of the recording sheet and can be driven independently; a return electrode that is arranged to contact the resistor layer of the recording sheet and is insulated from the current-carrying electrode; A developing device that visualizes the magnetized latent image formed on the recording sheet using magnetic ink toner, a transfer device that transfers the visible image onto paper, and a developer that transfers the visible image onto the recording sheet after the transfer. a cleaner for removing residual ink toner; an eraser for magnetizing the magnetic layer of the recording sheet in a single direction in the longitudinal direction with respect to the sheet surface and erasing the magnetic latent image; and the eraser A recording magnetic field smaller than the coercive force of this magnetic material at room temperature in a direction opposite to the direction in which the magnetic material layer of the recording sheet is previously magnetized by
It is characterized by having a magnet for generating a recording magnetic field to act on the contact point between the recording sheet and the current-carrying electrode, and a fixing device for fixing the visible image transferred to the paper.

[Effect]

A current corresponding to a recording signal is passed through a recording sheet whose magnetic layer has been previously magnetized in a single direction along a path from a current-carrying electrode to a return electrode through a resistor layer and a conductor layer. The current that flows through the recording sheet flows through the path with the least resistance, so it first flows from the current-carrying electrode through the resistor layer in the thickness direction of the recording sheet, reaches the conductor layer, and then returns through the conductor layer. After flowing below the electrode, it flows through the resistor layer in the thickness direction of the sheet and reaches the return electrode. At this time, Joule heat is generated in each part of the resistor layer and conductor layer in proportion to the product of the resistivity and the square of the current density. Because the amount of heat generated in the body layer is large, the magnetic layer under the current-carrying electrode is selectively heated. When the magnetic layer is heated to a temperature close to or above the Curie point of the magnetic material, The coercive force of the magnetic material in the heated part decreases or disappears.In addition, the coercive force of the magnetic material near the energized mold is smaller than the coercive force of this magnetic material at room temperature in the opposite direction to the direction in which it was previously magnetized. Since a recording magnetic field is applied,
The heating portion is magnetized in the opposite direction by this magnetic field, and a latent magnetization image is formed. Since the recording magnetic field is smaller than the coercive force of this magnetic material at room temperature, the magnetization state of the surrounding magnetic material in the unheated portion does not change.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a recording process section according to an embodiment of the present invention. As shown in the figure, an endless belt-shaped recording sheet 1 composed of a magnetic layer, a conductive layer, and a resistive layer laminated in the thickness direction is mounted on a roller 10 and a transfer roller 5a arranged in parallel. It is stretched with the magnetic layer facing outside. Inside the recording sheet 1 near the roller 10,
The recording head 2 is arranged so that the resistor layer of the recording sheet 1 comes into contact with the guide post 12 . A magnet 9 for generating a recording magnetic field is arranged at a position facing a current-carrying electrode of the recording head 2, which will be described later, and on the outside of the recording sheet 1.

Ink toner is applied to the outer side of the recording sheet 1 between the guide boss 12 and the transfer roller 5a.
A developing device 4 is provided with a roller 4a for adhering to the image.

A pressure roller 5b is arranged so that its roller surface is in contact with the roller surface of the transfer roller 5a, and the recording sheet 1 and the paper 8 are sandwiched in a superimposed state between the transfer roller 5a and the pressure roller 5b. has been done. This transfer roller 5
a and the pressure roller 5b constitute a transfer device 5. and,
On the exit side of the recording sheet 1 from the transfer device 5, a cleaner 7 having a roller 7a equipped with a brush and an eraser 3 are arranged in this order, and on the exit side of the paper 8 from the transfer device 5, a fixing device 6 is arranged.
is located.

The recording sheet 1 shown in FIG. 1 has three layers laminated in this order: a magnetic layer 1a, a conductive layer 1b, and a resistive layer IC, as shown in FIG. 2, and is made of a heat-resistant resin. A conductor layer 1b is formed by vapor-depositing metal on a resistor layer IC made by dispersing carbon or metal powder, and then a magnetic material layer 1b is formed by coating a magnetic material together with a binder on top of this. It is.

The recording head 2 shown in FIG. 1 includes a plurality of current-carrying electrodes 2a, which are insulated by an insulating material 2C and stacked at equal intervals at a minute pitch, and a return electrode 2, as shown in FIG.
It is composed of b. The plurality of current-carrying electrodes 2a are
Each can be driven independently.

The operation of this embodiment will be explained below. The recording sheet 1 made in the shape of an endless belt is mounted with the magnetic material ff1la on the outside. First, the magnetic layer 1a of the recording sheet 1 is magnetized in a single direction in the longitudinal direction of the sheet surface by the eraser 3. Ru. The direction of magnetization at this time is schematically shown in FIG. A pulse is applied.At this time, the current first passes through the current-carrying electrode 2a.
□ flows through the resistor layer lc in the thickness direction of the recording sheet 1 to reach the conductor layer 1b, and flows through the conductor layer 1b to the return electrode 2b.
After flowing to the bottom of the resistor layer IC, it flows through the resistor layer IC in the thickness direction of the sheet and reaches the return electrode 2b. This recording current causes the resistor layer 1c and the conductor layer 1 to
Joule heat is generated in each part of b, and the heat generation density of the generated Joule heat is proportional to the product of resistivity and the square of the current density.

Since the contact area of the current-carrying electrode 2a is smaller than the contact area of the return electrode 2b, the current density of the current flowing through the resistor layer 1b becomes larger directly below the current-carrying electrode 2a, and the resistivity of the resistor Jilb is , is larger than the resistivity of the conductor layer 1b, so the generated Joule heat is concentrated near directly below the current-carrying electrode 2a. Therefore, the contact point portion of the current-carrying electrode 2a of the magnetic material N1a of the recording sheet 1 is also heated. magnetic material i1a
When the magnetic material is heated to a temperature near or above the Curie point, the coercive force of the heated portion of the magnetic material decreases or disappears.

In addition, near the current-carrying electrode 2a, a recording magnetic field is applied by the recording magnetic field generating magnet 9 in a direction opposite to the direction in which it was previously magnetized, and which is smaller than the coercive force of this magnetic material at room temperature. This magnetic field causes it to be magnetized in the opposite direction. Since the recording magnetic field is smaller than the coercive force of this magnetic material at room temperature, the magnetization state of the surrounding magnetic material in the unheated portion does not change. Therefore, if the current flowing through the recording sheet l is set so that only the magnetic layer 1a at the contact point of the current-carrying electrode 2a is heated to a temperature close to one Curie point or more than one Curie point, magnetization according to the recording current can be achieved. A latent image is formed. How the recording current flows at this time,
FIG. 4(b) schematically shows the direction of magnetization.

As shown in Fig. 3, the current-carrying electrodes have a structure in which they are integrated at a minute pitch, and each electrode can be driven independently. Therefore, the sub-scanning can be performed electrically, and the recording sheet 1 can be moved to perform the main scanning. Just by doing this, a magnetized latent image is formed at high speed. The magnetic latent image thus formed is visualized by applying magnetic ink, so-called toner, using a developing device 4. The visible image, that is, the ink toner image, is transferred onto the paper 8 by a transfer device 5 composed of a transfer roller 5a and a pressure roller 5b. The ink toner image transferred to the paper 8 is melted and fixed by the fixing device 6. The toner remaining on the recording sheet 1 without being transferred is removed by the cleaner 7, and the same process is repeated again.

In the above embodiments, a pressure transfer device was used as the transfer device, but this does not limit the present invention. Other types of transfer devices, such as a magnetic transfer device or an electrostatic transfer device, may also be used. , does not impair the effects of the present invention. Similarly, although a heat fixing device is used as the fixing device, this does not limit the present invention, and even if a heat pressure fixing device or a pressure fixing device is used, the effects of the present invention will not be impaired in any way. It's not a thing.

〔Effect of the invention〕

As explained above, the present invention first magnetizes the magnetic layer of the recording sheet in a single direction, and then magnetizes the resistive layer of the recording sheet with a current-carrying electrode while applying a recording magnetic field according to the recording pattern. Electricity is applied to heat the magnetic layer of the recording sheet to a temperature near or above the Curie point of the magnetic material, forming a latent magnetized image, which is then developed.

Since the image is fixed, there is no need for time-consuming mechanical sub-scanning of the magnetic head to form a port image, and it is also possible to use multi-magnetic heads with minute pitch intervals, which is extremely difficult and expensive to manufacture. This has the effect that a high-speed, low-cost magnetic recording printer can be constructed.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing the structure of the recording sheet, FIG. 3 is a perspective view showing the structure of the recording head, and FIGS. 4(a) and 4(b) are schematic diagrams showing how the latent magnetized image is formed in the example. . l...Recording sheet 2...Recording head 3...Eraser 4...Developer 5...Transfer device 6...Fuser 7.・・・Cleaner 8・・・Paper

Claims (1)

[Claims] (1) A belt-shaped recording sheet in which three layers, a magnetic layer, a conductive layer, and a resistive layer having a higher resistivity than the conductive layer are laminated in this order, contacts the resistive layer of the recording sheet. a plurality of energized electrodes that are arranged in such a manner and can be driven independently;
A return electrode arranged so as to be in contact with the resistor layer of the recording sheet and insulated from the current-carrying electrode, and for visualizing a magnetized latent image formed on the recording sheet using a magnetic ink toner. a developing device, a transfer device for transferring the visible image onto paper, a cleaner for removing ink toner remaining on the recording sheet after transfer without being transferred, and a magnetic layer of the recording sheet. an eraser that magnetizes the recording sheet in a single direction in the longitudinal direction with respect to the sheet surface and erases the magnetized latent image; a magnet for generating a recording magnetic field for applying a recording magnetic field smaller than the coercive force of the body to the contact point between the recording sheet and the current-carrying electrode;
A magnetic recording printer comprising a fixing device for fixing a visible image transferred to paper.