JPS5852670A - Magnetic recording method - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording method which performs high-density recording with simplified constitution and is suitable for high-speed recording. CONSTITUTION:On a nonmagnetic base 1a, a magnetic recording layer 1b is laminated and on this magnetic recording layer 1b, a semiconductor layer 1c with 10<3>-10<6> surface resistance is laminated to obtain a magnetic recording medium 1. This medium is heated by a heater 2 and also placed in a magnetic field produced by a magnet 3 to direct the magnetic field of the magnetic recording layer 1b in a specified layer direction of the magnetic recording medium 1. Then, the magnetic recording medium 1 is applied by a magnet 4 with a magnetic field in the opposite direction to the magnetic field of the magnetic recording layer 1b. A recording electrode 5 is brought into contact with the semiconductor layer IC of the medium 1 so that it is in the magnetic field of the magnet 4, and a return circuit electrode 6 arranged at a prescribed interval from said recording electrode 5 is also brought into contact; and an impulsive image signal voltage from an image signal voltage applying circuit 7 is applied between those recording electrode 5 and return circuit electrode 6 to power up the semiconductor layer 1c, and thus Joule heat is generated to invert the direction of the magnetic field of the magnetic recording layer 1b facing the recording electrode 5, thereby forming a magnetic latent image.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording method for forming a magnetic latent image on a magnetic recording medium.

Traditionally, magnetic recording methods involve placing a coil wound around a head near the magnetic recording medium, and forming a magnetic latent image on the magnetic recording medium using the magnetic field created by passing a signal current through the coil. It has been known. However, in this magnetic recording method, when performing high-speed recording using a large number of heads, it is necessary to wind a coil for each head, which complicates manufacturing and makes high-density recording difficult.

Also known is a magnetic recording method in which a magnetic recording medium is irradiated with laser light and the magnetic recording medium is heated by the energy of the laser light to form a magnetic latent image.

However, this magnetic recording method has disadvantages in that modulation and scanning of the laser beam are complicated, and a large space is required for arranging the optical system, making it unsuitable for miniaturization.

Further, a magnetic recording method is also known in which a magnetic recording medium is directly heated with a thermal head to form a magnetic latent image. However, this magnetic recording method has the disadvantage that it is not suitable for high-speed recording because it requires a large amount of energy for recording and requires a step to cool the thermal head.

An object of the present invention is to provide a magnetic recording method that has a simple configuration, enables high-density recording, and is suitable for high-speed recording.

The present invention comprises laminating a magnetic recording layer on a non-magnetic support, and
Heat and an external magnetic field are applied to the magnetic recording medium formed by stacking a semiconducting layer on this magnetic recording layer to make the direction of the magnetic field in the magnetic recording layer a certain layer direction of the magnetic recording medium, and then the direction of the magnetic field in the magnetic recording layer is A recording electrode and a return electrode are brought into contact with the semiconducting layer of the magnetic recording medium while an external magnetic field in the opposite direction is applied to the magnetic recording medium, and an additional electrode is added between the recording electrode and the return electrode. A magnetic latent image is formed by reversing the direction of the magnetic field in the magnetic recording layer facing the recording electrode by applying current to the semiconducting layer by applying an image signal voltage to generate Joule heat. .

The present invention will be described in detail below with reference to the drawings.

In FIG. 1, the symbols ] indicate magnetic recording media. This magnetic recording medium 1 consists of a magnetic recording layer 1b laminated on a non-magnetic support 1a, and a semiconducting layer IC laminated on this magnetic recording layer 11).

The non-magnetic support 1a is formed of Cu clay plastic fill, polycarbonate, Mylar, polyimide fill, etc. to a thickness of 5 to 100 μm.

The magnetic recording layer 11) is a material capable of reversing the direction of the magnetic field by applying heat and an external magnetic field, and has a thickness of 0.5 to 50 μm.
It should be formed to a film thickness of nl. The materials forming the magnetic recording layer 11) include rl, which has a Curie temperature of about 130'C, I)) ipe1, which has a Curie temperature of about 601? FeDy, compensation point is 30 [FeQd, compensation point is 8
GdCo which is 0U, Curie temperature is 160'C: (TbF'e)Gd and (',f'bFe)'Dy
Alloys of heavy metals and transition metals such as The two-part magnetic recording layer 1b is formed by sputtering, vapor deposition, or plating.

The semiconducting layer IC has a surface resistance of 10 to 10 Ω and a softening point of 180 tG or more.
c is formed by uniformly dispersing conductive powder in an insulating binder resin. As the resin for the insulating binder of the semiconductive layer IC, polycarbonate, polyethylene, polyester, mylar, polyimide, vinyl chloride, etc. are used. As the conductive powder of the semiconductive layer IC, metal powder, conductive carbon, and conductive plastic powder are used.

First, as shown in FIG. 1, the magnetic recording medium 1 is heated by the heater 2 and placed in the magnetic field of the magnet 3.
is arranged to direct the magnetic field of the magnetic recording layer 1b in a certain layer direction of the magnetic recording medium 1.

Next, as shown in FIG. 2, a magnetic field is applied to the magnetic recording medium 1 by the magnet 4 in a direction opposite to that of the magnetic recording layer 1b of the magnetic recording medium 1. As shown in FIG. A recording layer &5 is brought into contact with the semiconductive layer 1c of the magnetic recording medium 10 so as to be positioned R in the magnetic field of the magnet 4, and a return electrode 6 is placed at a predetermined distance from the recording electrode 5. A pulsed image signal voltage is applied by the image signal voltage applying circuit 7 between the recording electrode 5 and the return path 6, and the semiconductive layer 1C is energized to generate Joule heat. By doing so, the direction of the magnetic field of the magnetic recording layer 1+) facing the recording electrode 5 is reversed to form a magnetic latent image.

The contact area of the recording electrode 5 with the flat conducting box layer 1c is set to be much smaller than the contact area of the return electrode 6 with the semiconductive layer 1c.The diameter of the recording electrode 5 is d, and the return electrode When the contact surface of No. 6 to the semiconductive layer 1c is a square with sides D, 10 d ((It is necessary to satisfy the condition D.

In addition, in order to maintain the strength of the semiconductive layer 1c above a certain level, its thickness must be 171 m or more, and
If it exceeds 0 μm, the energy consumed for purposes other than recording increases, so it is preferable to set it to 50 μtn or less.

Part 1. If the distance between the recording electrode 5 and the return electrode 6 is L, then if it is 2d':)L, the direction of the magnetic field will reach the part of the magnetic recording layer 1b between the recording electrode 5 and the return electrode 6. Since there is a possibility of inversion, it is necessary to satisfy the condition 2d≦T. As L becomes larger, more energy is consumed in the energizing path other than the recording part, so a more preferable condition for the relationship between d and L is 5d≦L≦8.
It is 0d.

In addition, since the practical range of resolution is 8 to 16 dots/penalty, it is necessary that 50 μm≦d≦150/ln1〇Furthermore, the thickness of the semiconductive layer IC is 1, and Tasaku The reason for this is explained below.

The volume resistivity of the above semiconducting layer IC is ρV, the resistance in the thickness direction of the semiconducting layer IC is Rt, and the resistance in the planar direction is R.
When p is R1 and Rp are expressed by the following formula.

1 it t-ρ■×-5□ ・・・・・・(1) Above (1
), Find the ratio KE of up and rtt from equation (2) (
7) Then, KE is expressed by the following formula.

Once KE...... (3) R, t''412 Mainly changing the above, KE is changed in the range of 5 to 10'' to change the recording energy and the magnetic recording layer. 1 b
When the magnification ratio with respect to the area of the recording electrode 5 at the portion where the direction of the magnetic field was reversed was investigated, it was found that the recording energy increased as KE increased, and the magnification ratio decreased as KE increased. In practical terms, it is desirable that the recording energy be 20 rnJ/dot or less, and
Since the magnification ratio is preferably -20% to +100%, it is necessary to satisfy the following conditions: 10≦K I≦105.

Note that a plurality of recording electrodes 5 may be arranged in a single row, or a plurality of recording electrodes 5 may be arranged in a plurality of rows and the recording electrodes 5 in each row may be placed between the recording electrodes 5 in other rows. It may be located.

FIG. 3 shows one embodiment of an apparatus for carrying out the present invention, which will now be described.

(8) In FIG. 3, reference numerals 8 and 9 indicate conveyance rollers, and these conveyance rollers 8 and 9 are driven by driving means (not shown) in the direction of arrow a.

It is rotated in direction b. An endless magnetic recording medium 1 is hung on these transport rollers 8.9. This magnetic recording medium 1 is moved by transport rollers 8, so that the nonmagnetic support 1a is located on the outside and the semiconductive layer IC is located on the inside.
9 and is moved in the direction of arrow C by conveyance rollers 8 and 9.

A heater 2 and a magnet 3 are arranged above the magnetic recording medium 1 located above the transport roller 8.

The heater 2 heats the magnetic recording layer 1b, and the magnet 3 applies a magnetic field to the magnetic recording layer 1b.
A magnetic field is formed in a certain layer direction of the blC magnetic recording medium 1. A plurality of recording electrodes 5 and return electrodes 6 are arranged so as to contact the semiconductive layer IC of the magnetic recording medium 1 located above the transport roller 9. An image signal voltage applying circuit 7 is connected to these recording electrodes 5 and return electrodes 6. Magnetic recording medium 1 facing the recording electrode 5
A magnet 4 is placed above it.

The direction of the magnetic field of the magnet 3 and the direction of the magnetic field of the magnet 4 are opposite. The recording electrode 5 is controlled by the image signal voltage application circuit 7.
By applying an image signal voltage in the form of a selective pressure pulse between the magnetic recording layer 1b and the return electrode 6, a magnetic latent image is formed on the magnetic recording layer 1b as described above.

A developing device w10 is arranged outside the magnetic recording medium 1 located below the transport roller 9.

This developing device 10 includes a container 10a and a toner 10 containing magnetic powder contained in the container 10a! ] and a roller that moves this toner 10b in one direction of the magnetic recording medium]
It consists of Oc. The Kamibake toner 10b has a total volume of 20
% or more of magnetic powder and has a charge of 1 μC/g or more. Since the magnetic field in the portion of the magnetic recording layer 1b where the direction of the magnetic field is reversed is very strong, the toner 10b is attracted to this portion and adheres to the non-magnetic support 1aK of the magnetic recording medium 1, making a magnetic latent image visible. Ru.

Below the conveyance roller 8, a transfer device 11 is disposed outside the magnetic recording medium 1, and a roller 13 for conveying the transfer medium 12 is disposed. "1 Transfer device 1
When the transfer medium 12 is inserted between the transfer device 1 and the magnetic recording medium 1, the toner on the magnetic recording medium 1 is transferred to the transfer medium 12 by the Coulomb force due to the discharge of the transfer device 11. A cleaning device 14 is provided near the conveyance roller 80 for removing toner remaining on the magnetic recording method after transfer.
is located. This cleaning device 14 includes a magnetic roller 14a with hair planted on the outer peripheral surface, an l/ner separation roller 14b in contact with the magnetic roller 14a, and a container 14c containing l/ner.
Toner collection container 1 placed under this container 1.4 c
4. It consists of d.

The hairs of the magnetic roller 14a come into contact with the residual toner on the magnetic recording medium 1 and separate the residual toner from the magnetic recording medium 1, and the magnetic roller 14a attracts the residual toner by magnetic force and removes the residual toner from the magnetic recording medium 1. do. The toner that has landed on this magnetic roller 14a is separated by an I/toner separation roller 14b and dropped into a container 1.4c.

The magnetic recording medium 1 from which residual toner has been removed by the cleaning device @ 14 is heated by the heater 2, and then a magnetic field is applied in a certain direction by the magnet 3, so that it becomes ready for recording again.

The magnetic recording method of the present invention has the same configuration as Tll1i, and is capable of high-density recording and is suitable for high-speed recording.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the present invention, and FIG. 3 is a diagram illustrating an embodiment of an apparatus for carrying out the present invention. 1...Magnetic recording medium, 1a...Nonmagnetic supporting body, ■b
... Magnetic recording layer, 1c... Semiconductor acid layer, 2... Heater, 3, 4... Magnet, 5... Recording electrode, 6...
Return path Tli pole, 7... Image signal voltage application circuit\\-4
4:

Claims (1)

[Claims] A magnetic recording medium in which a magnetic recording layer whose magnetic field direction can be reversed by heat and an external magnetic field is laminated on a non-magnetic support, and a semiconducting layer having a surface resistance of 10 to 10 Ω is laminated on the magnetic recording layer. Heat and an external magnetic field are applied to the magnetic recording layer so that the direction of the magnetic field is in a certain layer direction of the magnetic recording medium, and then an external magnetic field is applied to the magnetic recording medium in the opposite direction to the magnetic field direction of the magnetic recording layer. , a recording electrical contact and a return electrode arranged at a predetermined interval from the semiconductive layer of the magnetic recording medium are brought into contact with each other, and an image signal voltage is selectively applied between these recording electrodes and the return electrode. A magnetic recording method characterized in that a magnetic latent image is formed by reversing the direction of a magnetic field in a magnetic recording layer facing a recording electrode by passing current through a semiconductive layer to generate Joule heat.