JPH02252122A - Magnetic recording and copying device - Google Patents

Abstract

PURPOSE:To strengthen an alternative current bias magnetic field to be impressed in the thickness direction of a master medium and a slave medium and to improve a copying characteristic by composing a facing magnetic pole part of soft magnetic ferrite or soft magnetic alloy liminated body, etc., out of an exciting part, which impresses an alternative current copying bias magnetic field, and the facing magnetic pole part. CONSTITUTION:A master medium 4, to which information are magnetically recorded, and a slave medium 5, to which the information are not recorded, are set to be traveled so that magnetically recorded surfaces can be mutually adhered in an area to pass between an exciting part as a copying bias magnetic field impressing means and a facing magnetic pole part 2. The facing magnetic pole part 2 is constituted as a rotatable drum made of the soft magnetic ferrite and the exciting part 1 is closed to the facing magnetic pole part 2 by air pressure. Then, the bias magnetic field is generated and magnetic recording and copying is executed. At such a time, the eddy current of the facing magnetic pole part 2 is widely reduced and as a result, the suction of an alternative current magnetic flux is improved in the facing magnetic pole part 2. Then, the alternative current bias magnetic field is strengthened to be impressed in the thickness direction of the master medium 4 and slave medium 5, and the copying characteristic of a vertical orientation slave is improved.

Description

Detailed Description of the Invention [1] (Industrial Application Field) The present invention magnetically transfers the recorded contents of a master medium on which predetermined information is magnetically recorded to a slave medium on which information is not magnetically recorded. The present invention relates to a magnetic recording transfer device that performs contact transfer, and particularly to a magnetic recording transfer device capable of high-speed transfer, which is suitable for cases where a slave medium has an easy magnetization direction in the vertical direction, that is, in the thickness direction of the medium.

(Prior Art) With the development of information systems and the spread of magnetic recording devices, the demand for magnetic tapes on which information is magnetically recorded, such as music tapes and videotapes, is rapidly increasing. Incidentally, as part of this series of operations, a magnetic medium, such as a magnetic tape, on which predetermined information is magnetically recorded is used as a master tape, and the recorded information is transferred (copied) to another magnetic tape. However, as a method of magnetic recording transfer or copying, the magnetic recording surface of a slave medium on which information is not magnetically recorded is run in close contact with the magnetic recording surface of a master medium on which information is magnetically recorded. An alternating current transfer bias magnetic field is applied to both media traveling in the traveling area, and information is magnetically transferred from the magnetic recording surface of the master medium to the magnetic recording surface of the slave medium, thereby copying the copy medium in large quantities at high speed. There are known means for creating it.

In this contact magnetic transfer method, a high coercive force, high magnetic flux density, in-plane oriented metal coating medium using ferromagnetic metal needle powder as magnetic powder is used as the master medium, while hexagonal ferrite powder is used as the scraping medium. It is also known that a method of applying an alternating current bias magnetic field perpendicularly to the surface of the medium using a vertically oriented coating medium made of magnetic powder is effective for improving transfer output (JAS Conference " 86 Proceedings A-6).However, in implementing this method, an excitation section consisting of a ring-shaped head and a counter consisting of magnetic soft iron called a transfer drum placed spaced apart and facing this excitation section are required. Generally, a transfer device is used which includes a magnetic pole and a means for causing the master medium and slave medium to run in contact with each other between the excitation section and the opposing magnetic pole.

In this way, since a bias magnetic field is applied to the in-plane oriented master medium in the direction of the hard magnetization axis and to the vertically oriented slave medium in the direction of the easy magnetization axis, the master medium is demagnetized. The medium becomes easily magnetized, and a transfer medium with excellent short wavelength characteristics can be obtained.

(Problems to be Solved by the Invention) However, in the case of the contact magnetic transfer device having the above configuration, the following disadvantages are recognized. That is, an excitation section consisting of a ring-shaped head, and an opposing magnetic pole made of magnetic soft iron called a transfer drum disposed opposite to the excitation section at a distance,
In the case of a conventional magnetic transfer device comprising means for causing the master medium and slave medium to run in opposition between the excitation section and the opposing magnetic poles, the characteristics of the vertical slave medium cannot be fully utilized; Further, there is a problem that there is a limit to the frequency of the transfer bias magnetic field, and therefore there is also a limit to the transfer speed. As a result of various studies on this point, the inventors of the present invention found that in the magnetic transfer device, the occurrence of eddy current loss in the opposed magnetic poles made of magnetic soft iron limits the generation of a vertical magnetic field, causing the above-mentioned problems. It was confirmed.

[Structure of the Invention] (Means for Solving the Problems) The present invention has been made in response to the above-mentioned circumstances, and is directed to a slave medium in which information is not magnetically recorded on the magnetic recording surface of a master medium on which information is magnetically recorded. A medium running means that runs with the magnetic recording surfaces of the medium in close contact with each other, and a medium running means that is disposed on the master medium side so as to sandwich both media that run in an area where the magnetic recording surfaces of the master medium and the slave medium run in close contact with each other. In a magnetic recording transfer device comprising an excitation section and a transfer bias magnetic field applying means constituted by a counter magnetic pole section disposed on the slave medium side opposite to the excitation section, the counter electrode is connected to the counter electrode to reduce eddy current loss. It is characterized by being constructed with a small amount of magnetic material. That is, the main point is that the counter electrode is formed of a laminate including a soft magnetic ferrite or soft magnetic alloy layer that has excellent frequency characteristics even in a bulk state.

(Function) Of the excitation section and opposing magnetic pole section that sandwich the in-plane oriented master medium and the vertically oriented slave medium and apply an AC transfer bias magnetic field to them, the opposing magnetic pole section is made of soft magnetic ferrite or soft magnetic material with excellent frequency characteristics. By constructing the magnet with an alloy laminate or the like, the eddy current in the opposing magnetic pole portions is significantly reduced. As a result, the opposing magnetic poles have improved absorption of alternating magnetic flux,
The AC bias magnetic field applied in the thickness direction (vertical direction) of the master medium and slave medium is further strengthened, thereby greatly improving the transfer characteristics of the vertically oriented slave medium. In addition, as the eddy current is significantly reduced or reduced, the AC bias magnetic field frequency can be increased, so even if the number of magnetic field reversals required for transfer is maintained, the medium (tep) feeding can be increased to speed up the transfer speed. It becomes possible to raise the

(Example) The present invention will be described in detail below with reference to FIG. 1.
The figure is a sectional view showing the main parts of the magnetic recording transfer device according to the present invention, in which 1 is an excitation section (bias magnetic field excitation section) consisting of a ring head with a gap length of 200 μm, and 2 is an excitation section opposite to the excitation section 1. This is the opposing magnetic pole part arranged. In this example, the opposing magnetic pole portion 2 is made of MnZn, which is a type of soft magnetic ferrite.
It is constructed as a rotatable drum made of ferrite, and the excitation section 1 is arranged so as to be able to approach and separate from the circumferential surface of the rotating drum 2 by, for example, air pressure. Further, reference numeral 3 denotes a guide roller, which is a part of a medium running means that causes the magnetic recording surface of the slave medium 5, on which information is not magnetically recorded, to be brought into close contact with the magnetic recording surface of the master medium 4, on which information is magnetically recorded. It is something that can be achieved.

Next, an example of magnetic recording transfer by the magnetic recording transfer device having the above configuration will be explained. First, as a master medium 4 on which information is magnetically recorded, a metal coated in-plane orientation master tape is used.
A 13a ferrite vertically oriented tape was also prepared as a slave medium 5 on which information was not magnetically recorded. These prepared master medium 4 and slave medium 5 are moved through the cell l-L so that their magnetic recording surfaces are in close contact with each other in the region passing between the transfer bias magnetic field applying means, that is, the excitation section 1 and the opposing magnetic pole section 2. ,Ta. On the other hand, excitation part 1
is brought close to the opposing magnetic pole part 2, that is, the circumferential surface of the rotating drum, by air suppression, and maintained at a spacing of about 50 μm, and a bias magnetic field of 250 KIlz (magnetic flux flow 6
) occurred. The results of magnetic recording transfer performed under these conditions and examination of transfer characteristics are shown below. For comparison, the opposite magnetic pole part 2 of the magnetic recording transfer device was made of magnetic soft iron instead of MnZn ferrite, which is a type of soft magnetic ferrite, but the same +M configuration was used, and the transfer conditions were the same. The results of magnetic recording transfer and examination of transfer characteristics are also shown. Figure 2 shows the characteristics of the perpendicular bias magnetic field generated in response to the magnetomotive force in the magnetic transfer.In the case of the comparative example, as shown in curve 1b, due to skin depth formation, a magnetomotive force of OdB or more causes a vertical bias magnetic field. While the magnetic flux suction is saturated and the magnetic flux flows to the opposing magnetic poles in the horizontal direction, in the case of the present invention, the magnetic flux suction in the vertical direction further increases as shown by the curve 1a. As a result, in the case of the present invention, the transfer output characteristics of the slave medium (tape) 5 have a good response to the bias magnetomotive force and a large output, as shown by curve 2a in FIG. As shown by curve 2a' in FIG. 3, the output reduction characteristic becomes difficult to decrease even if the bias magnetomotive force is increased. On the other hand, as shown in FIG. 4, the transfer characteristics of the comparative example do not increase the transfer output of the slave medium (tape) 5 even if the bias magnetomotive force is increased (curve 2b), and The output reduction characteristic is significantly reduced (curve 2b). As described above, the magnetic recording transfer device according to the present invention has good transfer characteristics. However, the reason for this can be considered as follows. The magnetic properties of the MnZn ferrite and magnetic soft iron that constitute the opposing magnetic pole portions in the above are as shown in Table 1.

Table 1 Therefore, 25
The saturation magnetic flux amount at 0 KIlz, that is, the magnetic flux absorption capacity of MnZn ferrite is also 400 times or more compared to that of magnetic soft iron. Therefore, the frequency of the generated transfer bias magnetic field can be increased, and the transfer speed can be increased while maintaining the number of magnetic field inversions required for transfer. In other words, it becomes easier to mass-produce magnetic recording tapes of the same type from one master tape.

In addition, although the example in which the opposing magnetic pole part is made of MnZn ferrite has been shown above, it may be made of a soft magnetic ferrite such as NiZn ferrite. Furthermore, the laminated structure of the magnetic alloy may be a structure in which the eddy current loss is reduced by using small skin tubes, and the shape is not limited to the drum shape. When laminating magnetic alloys, the thickness of each layer is preferably 0.03 mm or less as shown in Table 1. Furthermore, the excitation section is not limited to the ring-shaped head illustrated above.

[Effects of the Invention] As explained above, according to the magnetic recording transfer device according to the present invention, the transfer characteristics of the vertically oriented slave medium are greatly improved, while the transfer output reduction characteristics, that is, demagnetization, of the longitudinally oriented master medium are improved. This has the effect of significantly reducing the transfer bias magnetic field frequency, and since the frequency of the generated transfer bias magnetic field can be further increased, the transfer speed is also improved, making it possible to transfer an even larger amount. Thus, it can be said that the magnetic recording transfer device of the present invention brings many practical advantages.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the main structure of a magnetic recording transfer device according to the present invention, and FIG. 2 is a comparison of vertical bias magnetic field characteristics in transfer by the magnetic recording transfer device according to the present invention and a conventional magnetic recording transfer device. FIG. 3 is a curve diagram showing the transfer output characteristics of the magnetic recording transfer device according to the present invention, and FIG. 4 is a curve diagram showing the transfer output characteristics of the conventional magnetic recording transfer device. 1... Excitation part 2... Opposing magnetic pole part (rotating roller) 3...
・Roller 4 forming part of the medium running means Master medium 5 ...Slave medium Applicant: Toshiba Corporation

Claims (3)

[Claims] (1) A medium running means that travels by bringing the magnetic recording surface of a slave medium on which information is not magnetically recorded into close contact with the magnetic recording surface of a master medium on which information is magnetically recorded; and magnetic recording on the master medium and the slave medium. In a magnetic recording transfer device comprising a transfer bias magnetic field applying means for applying an alternating current transfer bias magnetic field to both media running in a region where their surfaces are in close contact with each other, the transfer bias magnetic field applying means applies an alternating current transfer bias magnetic field to the running media. 1. A magnetic recording transfer device comprising an excitation section arranged to sandwich the excitation section and an opposing magnetic pole section made of soft magnetic ferrite. (2) a medium running means that travels by bringing the magnetic recording surface of a slave medium on which information is not magnetically recorded into close contact with the magnetic recording surface of a master medium on which information is magnetically recorded; and magnetic recording on the master medium and the slave medium. In a magnetic recording transfer device comprising a transfer bias magnetic field applying means for applying an alternating current transfer bias magnetic field to both media running in a region where their surfaces are in close contact with each other, the transfer bias magnetic field applying means applies an alternating current transfer bias magnetic field to the running media. Magnetic recording comprising an excitation section disposed on the slave medium side so as to be sandwiched therebetween, and an opposing magnetic pole section made of soft magnetic ferrite disposed on the master medium side facing the excitation section. Transfer device. (3) a medium running means that travels by bringing the magnetic recording surface of a slave medium on which information is not magnetically recorded into close contact with the magnetic recording surface of a master medium on which information is magnetically recorded; and magnetic recording of the master medium and slave medium. In a magnetic recording transfer device comprising a transfer bias magnetic field applying means for applying an alternating current transfer bias magnetic field to both media running in a region where their surfaces are in close contact with each other, the transfer bias magnetic field applying means applies an alternating current transfer bias magnetic field to the running media. It is composed of an excitation section disposed on the slave medium side so as to be sandwiched therebetween, and an opposing magnetic pole section made of a laminate including a soft magnetic alloy layer and disposed on the master medium side opposite to this excitation section. A magnetic recording transfer device characterized by: