JPS5996505A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record short wavelength by moving the relative positions of a magnetic recording medium and an annular magnetic head at a prescribed relative speed, making the gap length direction of the magnetic head coincide with the moving direction of the relative direction and using the recording medium having a vertically magnetized film. CONSTITUTION:The magnetic head 1 is scanned on a magnetic tape 2 to make recording current flow into a coil 8. If a current waveform is a digital waveform, the recording magnetic pattern is shown in the figure. The arrows 11, 12 show the magnetic vectors obtained by recording the vertically magnetized film 5 at the connection end part of the head advancing direction of a gap part G1 and the arrows 14, 15 show magnetic tracks. Since (y) axis magnetic field y/g is almost symmetrical around the center in case of y/g<=0.2, the interval of the center part of the tracks is about (g). A magnetic vector 13 is recorded in a horizontally magnetized film 6. The recording direction of the magnetic vector 13 is inverted in accordance with the inversion of the vector of the vertically magnetized film 5. The formation of magnetic vectors shown by the magnetic vectors 11, 13, 12 generates a recording magnetic field reducing a demagnetizing function and having magnetizing moment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing apparatus such as a video tape recorder suitable for recording short wavelength signals such as video signals.

Conventional Structure and Problems Conventionally, longitudinal magnetization has been common in magnetic recording and reproducing devices such as video tape recorders. It is known that recording demagnetization and self-demagnetization occur in short wavelength recording of longitudinal magnetization. Therefore, in video tape recorders, etc., these demagnetizations occur from a recording wavelength of about 1 μm. This has made it difficult to put shorter wavelength recording into practical use.

On the other hand, perpendicular magnetization systems aimed at recording at even shorter wavelengths have been studied, and many proposals for practical use have been made. However, most of the perpendicular magnetization methods currently proposed use the obtained main magnetic pole and auxiliary magnetic pole, so although they can obtain a sharp perpendicular magnetic field, they are not suitable for video tape recorders that use a rotating head system. Difficult to apply.

On the other hand, using a ring-shaped head, the direction similar to the longitudinal magnetization,
That is, a method has also been proposed in which perpendicular magnetization is achieved by making the head gap width direction and the recording medium moving direction the same direction. Since this method requires a head to be attached only to one side of the recording medium, it can be applied to video tape recorders that use a rotating head system. However, since it is difficult to obtain a sharp perpendicular magnetic field in this method, there is a problem in that the recording reproduction characteristics are worse than the method using the main magnetic pole and auxiliary magnetic pole described above.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a magnetic recording/reproducing apparatus which solves the above-mentioned conventional problems and enables recording at significantly shorter wavelengths.

In order to achieve the second object of ``Structure of the Invention'', the present invention comprises a magnetic recording medium, a ring-shaped magnetic head, and a moving device for moving their relative positions at a required relative speed, and The gap length direction of the magnetic head and the direction in which the relative position is moved are the same, and a magnetic recording medium having a perpendicular magnetization film is used as the magnetic recording medium.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings. 1st
The figure shows a schematic diagram of the main parts of the tape head system of the present invention, which is composed of a magnetic head 1, a magnetic tape 2, and a magnetic head support 4, and (G1) is a gap section of the magnetic head 1. . Arrow 3 indicates the moving direction of the magnetic head 1, which is the same direction as the gap length direction of the hidden gap portion (G1). Note that there is no problem even if the magnetic tape 2 runs in a direction relatively opposite to the arrow 3. Note that the gap width of the gap portion (G1) is indicated by ((1)).

FIG. 2 is an enlarged cross-sectional view of the vicinity of the gear part of the magnetic head 1 shown in FIG. 1 (the top and bottom are reversed from those shown in FIG. 1) and its coordinate -11.

FIG. 3 is a characteristic diagram showing an example of the magnetic field distribution (Hy) near the gap of the magnetic head 1 using the coordinate axes in FIG. Here, HO is the void center position (x-o, y=
o), which indicates the magnetic field in the Hyby-axis direction.

As shown in FIG. 3, the magnetic field in the y-axis direction of the ring-shaped magnetic head 1 is known to exhibit a very large level in the region of -Z-=8=0.2 or less. In order to record the magnetic field, a magnetic recording medium having a perpendicular magnetization film is used as the magnetic tape 2. The magnetic recording medium having this perpendicular magnetization film preferably has a two-layer film structure consisting of a perpendicular magnetization film 6 and a horizontal magnetization film 6, as illustrated in FIG.

The two-layer membrane structure itself is well known. These membranes are produced on the base 7. As shown in FIG. 1, the magnetic head 1 is scanned over such a magnetic tape 2, and a recording current is caused to flow through the coil 8 of the magnetic head 1. If the waveform of the recording current is, for example, a digital waveform as shown in FIG. 5, the recording magnetization pattern will be as shown in FIG. In FIG. 6, an upward arrow 11 and a downward arrow 12 indicate magnetization vectors recorded by the perpendicular magnetization film 5 at the terminal end in the head traveling direction of the gap a1 of the magnetic head 1;
15 indicates a magnetic track. Where the surface of the magnetic track is pear-shaped, the magnetization vector is directed downward, and where the surface is unmarked, the magnetization vector is directed upward. As shown in FIG. 3, the y-axis magnetic field is approximately symmetrical about g (1) at −≦0.2. Therefore, as shown in FIG. 6, the magnetic track 14. The center spacing of 16 is approximately q. Also, a magnetization vector as shown by 13 is recorded in the horizontal magnetization film 6. The direction of this magnetization vector 13 is reversed as the vector in the vertical magnetization film 6 is reversed. do.

By forming horseshoe-shaped magnetization vectors such as those shown by magnetization vectors 11, 13, and 12, a recording magnetic field with a very large magnetization moment can be obtained with little demagnetization effect. Note that the moving direction of the magnetic head 1 is set to the gap portion ((,1
) by setting it in the same direction as the gap length direction.
A magnetic track as shown in FIG. 6 can be obtained with almost no recording demagnetization.

For example, if the gap width q of the magnetic head 1 is 6 μm,
Assuming that the thickness of the perpendicularly magnetized film 5 is 0.5 μm, the boundary between the perpendicularly magnetized film 5 and the horizontally magnetized film 6 is 1y-- in FIG.
A magnetic field is applied as shown by the curve of 0.1. A magnetic track as shown by the coercive force of the vertically magnetized film 5 and the horizontally magnetized film 6 is obtained.

Effects of the Invention As is clear from the above explanation, according to the present invention, it is possible to obtain a sharp recording magnetic field without being subjected to demagnetizing effects such as recording demagnetization, and to realize significantly short wavelength recording. .

Because a horseshoe-shaped magnetization vector is formed, the magnetization moment is very large. As a result, the output signal level during reproduction is extremely high despite short wavelength recording.

Unfortunately, since the magnetic head can be installed only on one side of the recording medium, it can be easily applied to video tape recorders using a rotating head system, which is a great advantage.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of essential parts showing an example of the configuration of a tape head system according to the present invention, FIG. 2 is an enlarged sectional view of the vicinity of the gear part of the magnetic head of FIG. 1, and FIG. 3 is an example of magnetic field distribution. FIG. 4 is an enlarged perspective view showing an example of the configuration of a magnetic recording medium used in the present invention. FIG. 6 is a waveform diagram showing an example of a recording current waveform. FIG. 2 is an enlarged perspective view showing an example of a magnetic track pattern in a magnetic recording medium. 1...Magnetic head, 2...Magnetic tape,
G1...Gap portion, 5...Vertical magnetization film, 6...Horizontal magnetization film, 11, 12.13...
... Magnetization vector, 14°16 ... Magnetic track. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 1 0θ! ; /, 0 /, 52θ J Figure 4

Claims (1)

[Claims] (1) A magnetic recording medium, a ring-shaped magnetic head, and a moving device that moves the relative positions thereof at a required relative speed, and the gap length direction of the magnetic head is the same as the direction in which the relative positions are moved. 1. A magnetic recording and reproducing apparatus characterized in that a magnetic recording medium having a perpendicular magnetization direction and a perpendicular magnetization film is used as the magnetic recording medium. ? 1.) A magnetic recording and reproducing apparatus according to claim 1, characterized in that a magnetic recording medium having a two-layer structure consisting of a perpendicularly magnetized film and a horizontally magnetized film is used.