JPS6260872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermomagnetic recording method in which an image is written on a magnetic recording medium using a heating head, and a magnetic field is simultaneously applied to the magnetic recording medium to form a magnetic latent image. The present invention relates to a method for writing and erasing images.

In the magnetic recording method, a magnetic latent image is formed on a magnetic material in the form of image-like magnetization. For example, magnetic toner is a magnetic toner that contains fine magnetic particles in a polymer resin and is a magnetically detectable colored particle that receives force from a magnetic field. The image is developed by a method such as a method, transferred to paper or the like by an electrostatic method or a magnetic method, and fixed by heat, pressure, etc. to form a permanent image.

The magnetic recording medium, which is a magnetic latent image carrier, is processed by either removing the remaining magnetic toner and moving on to the next development cycle, or by demagnetizing the magnetic latent image and forming a new magnetic latent image. The same process is repeated.

The usual method for forming a magnetic latent image in such a magnetic recording method is to cause a recording current corresponding to an image signal to flow through a magnetic head provided near a magnetic recording medium to magnetize it.

In order to form a magnetic latent image over the entire image width on a magnetic recording medium using such a magnetic head, a magnetic recording track having one or more printing parts for magnetization, that is, recording gaps, is prepared and Generally, magnetic recording is performed using a combination of scanning in the direction of movement of the recording medium (main scanning) and traverse scanning in a direction perpendicular to the direction (sub-scanning).

This method requires precise driving and control methods to keep the sub-scanning interval constant, moves the magnetic recording medium at high speed to shorten scanning time, and requires image formation such as development transfer. Therefore, precise and expensive drive and control methods are required, including many operating modes such as low-speed operation.

For such scanning magnetic head recording, a so-called multi-magnetic head array, in which magnetic recording tracks are densely arranged over the entire image width to satisfy the required resolution of the reproduced image, is used to follow the movement of the magnetic recording medium. A method of recording one pixel column at a time has also been proposed.

However, in order to satisfy the resolution of the reproduced image in this multi-magnetic head array, it is necessary to provide narrow tracks of about 100 μm or less at intervals of about 100 μm.

Moreover, in order to reduce the recording current, it is necessary to have multiple turns of the coil corresponding to each track. It is said that it is difficult to realize such a multi-magnetic head array because of the need for such fine and complicated equipment and electromagnetic interference between adjacent tracks.

The following methods have been proposed to improve the above drawbacks. In other words, an image signal obtained by optically reading a document, etc. is input to a row of heating elements that generate heat using an electric current, and the temperature rise of the heating head is transmitted to a magnetic material, which is a magnetic latent image carrier, by applying a magnetic field to it. This is a method of forming a magnetic latent image that becomes magnetized. A specific example of a method for forming a magnetic latent image using this thermal residual magnetization phenomenon will be explained with reference to FIG.

The magnetic recording body 1 moving in the direction of the arrow in the figure is
After being heated by the heating head 2, it comes under operation of a magnetic field application device during its cooling cycle.

The magnetic field application device consists of a master roll 4 having a magnetic material 5 on a non-magnetic base roll 6 and a contact roll 3. The master roll 4 is rotated so that its surface circumferential speed is the same as that of the magnetic recording medium 1. The master magnetic body 5 on the surface is magnetized so that a recording magnetic field is applied to the magnetic recording body 1 .

That is, in this method of forming a magnetic latent image, the magnetization pattern 10 of the magnetic material 5 is transferred onto the magnetic recording material 1 by a thermal residual magnetization phenomenon, thereby forming a magnetic latent image.

Conventionally, in the erasing method of a magnetic latent image, a magnetic head provided near a magnetic latent image carrier has been used. However, in order to erase the magnetic latent image over the entire image width using a magnetic head, it is necessary to use both main scanning and sub-scanning in combination, as described above, and a precise and expensive drive and control method is required. On the other hand, there is a method of using a multi-magnetic head array to avoid this, but it is difficult to realize because it requires complicated implementation as described above. Further, in the method of using a magnetic head having a long single track for simultaneously erasing the entire width of the image, it is of course impossible to erase only a portion of the latent image.

As mentioned above, the conventional method of using a magnetic head as a latent image erasing means has such drawbacks, and furthermore,
Drive circuits for both the heating head array used as the latent image forming means and the magnetic head used as the erasing means are required, making them complicated and expensive.

The present invention has been made in view of the above-mentioned drawbacks and has been made in order to eliminate them, and it is an object of the present invention to provide a method of erasing a latent image using a heated head array used as a latent image forming means without requiring a magnetic head. The purpose is

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 1 is a wide magnetic tape made of plastic film coated with chromium dioxide, 2 is a heating head in which a row of thermal recording elements is arranged in the width direction of the tape, and 4 is a non-magnetic base roll 6. The master roll 7 is made of a hard magnetic material 5 such as Ni-Co-P that can have sufficient residual magnetization on its surface and whose Curie temperature is at least equal to or higher than that of the magnetic recording material 1. A blank roll 3 having a heat-resistant resin layer such as a polyimide film on the surface of a magnetic base roll 9 is used to bring the magnetic recording material 1 into close contact with the master roll 4 and to convey the magnetic recording material in the direction of the arrow A in the figure. It is a close-fitting roll.

Next, the operation of this embodiment will be explained.

The master magnetic body is magnetized in advance by an alternating current signal of an appropriate value so as to generate a magnetic field necessary for thermal remanent magnetization of the magnetic recording body 1 used. The magnetic recording medium 1 is made of a plastic film coated with chromium dioxide having a relatively low Curie point together with an organic resin binder, has an A4 longitudinal width, and is conveyed in the direction of the arrow A by a master roll 4 and a contact roll 3. The magnetic recording medium 1 moving in the direction of the arrow comes under the operation of the magnetic field application device of the master roll 4 consisting of the master magnetic body 5 and the base roll 6, and is heated in an imagewise manner by the heating head 2 and further magnetically recorded in the direction of the arrow. When the body 1 is transported, it is naturally cooled under the application of a magnetic field, and the master roll 4 and the magnetic recording body 1 are separated from each other at the position of the contact roll 3, and the magnetic field applied to the magnetic recording body 1 is removed.

In this way, a magnetic latent image is formed on the magnetic recording medium 1 by the thermoremanent phenomenon.

Next, a method for erasing the magnetic latent image obtained by the above method will be explained.

The contact roll 3, master roll 4, and blank roll 7 are engaged with each other by a method not shown, and at the time of erasing, they are switched to the positional relationship as shown in FIG. 3 by an electric signal.

That is, the heating head 2 is arranged to face the blank roll 7 via the magnetic recording medium 1 having a magnetic latent image.

Under this arrangement, when a portion of the magnetic recording medium 1 having a magnetic latent image is heated to a temperature above the Curie point by the heating head 2, the heated portion is demagnetized.

Next, the second position is changed from the arrangement shown in Fig. 3 by an electric signal.
By switching to the arrangement shown in the figure and forming a new latent image of another image, magnetic copying was performed using a developing device, transfer device, and fixing device (not shown in the figure), but the high-quality copies had no previous image history. was gotten.

As clearly shown in the above embodiments, the present invention utilizes a heating head that utilizes the thermal residual magnetization phenomenon, a master roll made of a master magnetic material having a uniform magnetization pattern, and a magnetic recording material that is a magnetic latent image carrier. In this magnetic copying apparatus, there is no need to provide a magnetic head for erasing, and the heating head array used as a magnetic latent image erasing means can also be used as a magnetic latent image forming means.

Furthermore, it is clear that according to the present invention, it is possible to selectively erase not only the entire width of the image but also only a certain specific portion.

Furthermore, although the above embodiments have only described the use of chromium dioxide as the magnetic recording medium, it is clear that any magnetic recording medium can be used as long as it is possible to demagnetize the Curie point by at least a heating head.

In addition, the surface resin layer of the blank roll is preferably a layer made of a polymeric resin material with excellent mechanical durability and heat resistance, and polyarylate of polyimide, polyether sulfone, etc. are preferable, but non-magnetic ceramics, metal Of course, it is a good thing.

As described in detail above, according to the present invention, there is no need to provide a magnetic head for erasing, so there is no need for the time required for main scanning and sub-scanning of the magnetic head during erasing, and furthermore, it is not necessary to provide a magnetic head for erasing. Moreover, it is possible to erase not only the entire width of the image but also selectively erase a specific part, and achieve low-cost magnetic latent image erasure.

Although the present invention has been described above with reference to the drawings, the present invention is by no means limited to the details thereof, and can be implemented with various modifications and modifications.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a magnetic latent image forming method using a heated head array. FIGS. 2 and 3 show an embodiment of the present invention, and FIG. 2 is a conceptual diagram of a magnetic latent image forming method. 3 are conceptual diagrams when erasing a magnetic latent image. Codes in the figure: 1...Magnetic recording body, 2...Heating head, 3...Tight roll, 4...Master roll,
5... Magnetic material, 6... Base roll, 7... Blank roll, 8... Resin layer, 9... Base roll, 1
0... Magnetization pattern, A... Recording body moving direction.

Claims (1)

[Claims] 1. A heating head having a row of heating elements arranged in a direction substantially perpendicular to the direction of movement of a magnetizable magnetic recording medium and applying heat from one side of the magnetic recording medium in accordance with an image signal; A master roll whose surface has a magnetic material that can be magnetized and a blank roll whose surface is made of a non-magnetic material are provided in parallel and on the other side of the magnetic recording body, and when writing an image, the magnetic material that can be magnetized is used. A magnetic latent image writing method, characterized in that an image is written by a master roll having a master roll and the heating head, and when the image is erased, at least a partial image is erased by the blank roll whose surface is made of a non-magnetic material and the heating head array. Erase method.