JPS6245994B2 - - Google Patents

Abstract

PURPOSE:To miniaturize a magnetic latent image forming apparatus by housing a magnet for forming a magnetic bias field in a roll facing to a thermal printing head and locally heating a magnetic medium by using a selected heating element in order to form a magnetic latent image having a magnetized pattern different from the other portions. CONSTITUTION:First, a magnetic medium 3 is saturatedly magnetized in the directions of thickness, in-surface and the like to form a uniform magnetized pattern. Then, when coming to directly below a thermal printing head 1, the magnetic medium 3 is locally heated by a selected heating element 11. The temperature of the heated portion is raised above the Curie point or the temperature of the compensation point, so that the magnetization of the heated portion disappears. When the current supply to the heating element 11 stops, the temperature of the magnetic medium 3 lowers, so that the heated portion is magnetized by the magnetic field of a bias magnet 5 at a temperature below the Curie point or the like. The heated portion is magnetized in the direction determined by the magnetic field of the magnet 5. Therefore, a magnetic latent image having a pattern different form the preliminary magnetization can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording device that forms a magnetic latent image on a magnetic medium, and particularly to a magnetic recording device that forms a magnetic latent image on a magnetic medium at a desired location (recorded portion or non-recorded portion) having a uniform magnetization pattern. The present invention relates to a magnetic recording device that forms a magnetic latent image of a recorded image on a magnetic medium by selectively heating the heated portion and making the magnetization pattern of the heated portion different from that of other portions.

In conventional magnetic recording devices of this type (called magnetic photography or magnetography), information is written on a magnetic medium by inverting the magnetization of a desired area of the magnetic medium, which has a uniform magnetization pattern, using a magnetic head. Ta. For this reason, in order to write each line at a density of approximately 10 lines/mm,
It is necessary to arrange approximately 1,000 to 2,000 magnetic heads, but such a high-density arrangement of magnetic heads
Due to its structure, it was extremely difficult to manufacture.

In order to improve the drawbacks of the prior art as described above, the present inventors selectively locally heat desired locations of a magnetic medium having a uniform magnetization pattern above its Curie point or compensation point temperature, In a magnetic recording device that forms a magnetic latent image on a magnetic medium by making a magnetization pattern of a heated portion different from that of other portions, the magnetic medium heating means is arranged one-dimensionally on a support substrate and thereon. The printing head consists of a thermal printing head consisting of a large number of heating elements, and a device that selectively supplies heating current to each heating element depending on the image information to be recorded. He proposed a magnetic recording device configured to generate local heating (Japanese Patent Application Laid-Open No. 115278/1983).

The present invention is an attempt to further improve the above-mentioned proposal and construct the entire apparatus compactly, by arranging an opposing roll on the opposite side of the thermal printing head with a magnetic medium in between, and applying a bias magnetic field inside the roll. It contains magnets.

FIG. 1 shows a schematic configuration of an embodiment of the present invention.

1 is a thermal printing head consisting of a support substrate and a large number of heating elements 11 arranged one-dimensionally (perpendicular to the plane of the paper) on the support substrate; 3 is a magnetic medium; 4 is a magnetic medium facing the thermal printing head 1; Opposing rolls 5 are arranged to sandwich the medium 3, and 5 is a bias magnet housed inside the opposing roll 4.

As the thermal printing head, what is conventionally known as a thermal recording head, that is, one consisting of a support substrate and a large number of heating elements arranged one-dimensionally on the support substrate, can be used almost as is. It is. Of course, means for selectively supplying a heating current to each heating element in accordance with the image signal to be recorded is also required, but a means for a thermal recording head can also be used.

Information writing in this embodiment is performed as follows. As a preliminary process before recording, the magnetic medium 3 is saturated magnetized in the thickness direction or in-plane direction to form a uniform magnetization pattern.

When the magnetic medium 3 comes directly under the thermal printing head 1, it is locally selectively heated by selected heating elements 11. The temperature of the heated portion becomes higher than the temperature of the Curie point or compensation point of the magnetic medium, and the magnetization of the heated portion disappears.

When the current supply to the heating element 11 is interrupted, the temperature of the magnetic medium 3 decreases. When the temperature reaches below the Curie point or the compensation point, the bias magnet 5
magnetized by the magnetic field of

The bias magnet 5 applies a magnetic field to the magnetic medium 3 in a direction different (for example, in the opposite direction) from the preliminary magnetization. Therefore, the heated portion of the magnetic medium 3 is magnetized in a direction determined by the magnetic field of the bias magnet 5, and a magnetization pattern different from the pre-magnetization (for example in the opposite direction) is formed on the magnetic medium 3, which It becomes a magnetic latent image.

As described above, according to the present invention, since the magnet for the bias magnetic field is housed in the opposing roll of the thermal printing head, the space for arranging the parts can be small, and the entire apparatus can be made small and compact.

In addition, if the magnet 5 is made rotatable around the axis 6 in FIG. 1, the direction of the bias magnetic field can not only be changed arbitrarily, but also it can be used to form a uniform magnetization pattern on a magnetic medium. become. Further, if the magnet 5 inside the opposing roll 4 shown in FIG. 1 is an electromagnet and the polarity can be arbitrarily reversed, it is possible to both form and record a uniform magnetization pattern on a magnetic medium. Furthermore, depending on the state of the uniform magnetization pattern of the magnetic medium, the polar direction of the magnet inside the opposing roll 4 may be arranged so as to form a bias magnetic field parallel to the surface of the magnetic medium.
Of course, it is also possible to arrange them so as to form a perpendicular bias magnetic field (FIG. 1). Furthermore, if the opposing roll 4 is used as a heat roll to preheat the magnetic medium 3, less energy is required to be applied to the heating element 11, so that the recording speed can be increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the present invention. 1...Thermal printing head, 3...Magnetic medium, 4...
Opposing roll, 5...bias magnet, 11...heating element.

Claims (1)

[Claims] 1. By selectively locally heating a desired location of a magnetic medium having a uniform magnetization pattern to a temperature higher than its Curie point or compensation point temperature, and making the magnetization pattern of the heated location different from other locations, In a magnetic recording device that forms a magnetic latent image on a magnetic medium, the magnetic medium heating means includes a thermal printing head consisting of a support substrate and a number of heating elements arranged one-dimensionally on the support substrate, and image information to be recorded. In response to the,
a device for selectively supplying a heating current to each heating element; a counter roll arranged to face the thermal printing head and sandwich the magnetic medium; and a device arranged inside the counter roll to heat the magnetic medium. 1. A magnetic latent image forming device comprising: a bias magnet that applies a bias magnetic field to a location.