JPS6334705A - Magnetic recording method on both sides of floppy disk - Google Patents

Abstract

PURPOSE:To record information on both the sides of a floppy disk without deteriorating mutual information by forming a large azimuth angle between a 1st magnetic head for one recording surface and a 2nd magnetic head for the other recording surface. CONSTITUTION:The azimuth angle of a gap 8 of the 1st magnetic head 5 is zero as regulated by the standard of an electronic still camera and a magnetizing direction based on the gap 8 is parallel with the relative moving direction A of the floppy disk 1. The azimuth angle of a gap 9 of the 2nd magnetic head 6 is -45 deg. when observed from its surface 3 and the magnetizing method based on the gap 9 is inclined by -45 deg. from the relative moving direction A. Thereby, 45 deg. azimuth angle is formed between the two magnetic heads 5 and 6. Consequently, each fifty circular tracks 10i, 11i (i=1-50) are concentrically formed on both the front and rear faces 3, 4 of the floppy disk 1.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to a method for magnetically recording information on both sides of a floppy disk in order to improve recording density.

<Conventional technology> In electronic still camera systems currently in practical use,
According to the standard, (11al recording medium size, diameter 4711I+l+,
(2) Only one side of the floppy disk should be used for recording; (3) The magnetization direction should be parallel to the recording surface; (4) The azimuth angle of the magnetic head should be zero. (5) It is specified that 50 circular tracks with a width of 60 μm are formed concentrically with guard bands of 40 μm apart.

Therefore, the number of frames to be photographed on one floppy disk is only 50 frames for field recording and 25 frames for frame recording.

<Problems to be Solved by the Invention> Therefore, it would be convenient if information could be recorded on both sides of a floppy disk, since the number of frames to be photographed could be doubled.

However, since floppy disks are generally thin, if you record information on one recording surface and then try to record other information on another recording surface, magnetic flux leaks to the opposite recording surface, causing information that has already been recorded on that surface to be recorded. A type of crosstalk problem arises in which the signal deteriorates significantly. This tendency is particularly strong when a large current is passed through the head coil for erasing.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a method that allows information to be magnetically recorded on both sides of a floppy disk without degrading information that has already been recorded.

Means for Solving the Problems〉 (1) A method according to the first invention for achieving the above object involves the relative movement of a floppy disk having magnetic recording surfaces on both sides of the base and two magnetic heads. In a method of magnetically recording information in two concentric tracks of substantially the same diameter on a recording surface of a recording surface, the direction of magnetization is substantially parallel to the recording surface; , recording information by a first magnetic head having an azimuth angle of a constant angle including zero; and a second magnetic head having an azimuth angle with respect to the first magnetic head on a circular track on the other recording surface. It is characterized by recording information.

(2) A method according to a second invention for achieving the above object is based on the relative movement of a floppy disk having magnetic recording surfaces on both sides of the disk and three magnetic heads, so that both recording surfaces have substantially the same diameter and In a method of magnetically recording information on each of two concentric circular tracks, the magnetization direction is substantially parallel to the recording surface, and the azimuth angle of the circular tracks on one recording surface is substantially zero. recording information with a certain first magnetic head; recording information on a circular track on the other recording surface with a second magnetic head having an azimuth angle of substantially 45 degrees with respect to the first magnetic head; and recording information on the circular track on the other recording surface by a third magnetic head having an azimuth angle of substantially 90 degrees with respect to the second magnetic head.

Effect> Generally, on the magnetic recording surface of a floppy disk, acicular magnetic particles (hereinafter abbreviated as magnetic particles) are parallel to the recording surface and randomly oriented. The principle of the present invention is illustrated in FIGS.
This will be explained using FIGS. 1 and 6 (al and bl).

5(a) is a plan view showing the orientation state of magnetic particles on the front recording surface, and FIG. In the figure, arrow A indicates the direction of relative movement between the magnetic head and the floppy disk.

Now, when information is recorded on the surface 3, for example, with the first magnetic head 5 whose azimuth angle is θ, the information is recorded on the surface 3 as shown in FIG.
As shown in al, the magnetization state of the magnetic particles 20 oriented parallel to the magnetization direction 28 due to the gap 8 of the magnetic head 5 easily changes, but the magnetization state of the magnetic particles 21 perpendicular to the magnetization direction 28 hardly changes. The magnetic particles 22 and 23 that intersect the magnetization direction 28 by 45 degrees change slightly.

29 is a part of the circular track. In general, magnetic particles whose crossing angle with the magnetization direction due to the gap of the magnetic head is large are difficult to change their magnetization state. Note that since the magnetic flux from the first magnetic head 5 also leaks to the back surface 4, as shown in FIG.
0 magnetic particles 24 to 27 are affected by leakage magnetic flux. However, magnetic particles 24 parallel to or close to the magnetization direction 28
Although the magnetization state of the magnetic particles 20 tends to change easily, the degree of change in the magnetization state of the magnetic particles 20 is smaller than that of the surface magnetic particles 20 due to spacing loss caused by the thickness of the floppy disk. For the same reason, the magnetization state of the magnetic particles 26 and 27, which intersect with the magnetization direction 28 by, for example, 45 degrees, hardly changes. Furthermore, magnetic particles 25 perpendicular to or close to the magnetization direction 28
The magnetization state hardly changes even if there is no spacing loss.

Next, suppose that after recording by the first magnetic head 5, another information is recorded in the track 30 on the back surface 4 by the second magnetic head 6 having an appropriate azimuth angle α with respect to the first magnetic head 5. . If the azimuth angle of the second magnetic head 6 itself is θ2 when viewed from the surface, then α=1θ1−θ21. Also, θ1. θ2 is positive in the counterclockwise direction. On the back surface 4, as shown in FIG. Magnetic particles intersecting 26°2
7 changes slightly, and the orthogonal or nearly orthogonal magnetic particles 24 do not change. At this time, the magnetic flux of the second magnetic head 6 leaks to the track 29 on the surface 3. But track 2 on surface 3
9, as shown in FIG. 6 (al), the magnetic particles 20 whose magnetization state has changed strongly due to the previous recording are intersecting or, for example, orthogonal to the magnetization direction 31 by the second magnetic head 6, and the floppy disk Since there is a spacing loss due to the thickness, it is hardly affected by leakage magnetic flux and the information is not degraded.The magnetic particles 22 and 23 have a magnetization direction of 31, for example, round circles that intersect at 45 degrees. Due to the spacing loss, the magnetic particles 21 are not affected by the leakage magnetic flux.Since the magnetic particles 21 are parallel to or close to the magnetization direction 31, they are affected by the leakage magnetic flux, but due to the spacing loss, the effect can be ignored.

Let's explain about playback. When reproducing information on the track 29 on the surface 3 by the first magnetic head 5 itself or a magnetic head having the same azimuth angle, the information is mainly parallel to or parallel to the magnetization direction 28 by the magnetic head 5 due to the azimuth effect and spacing loss. The magnetic flux of the magnetic particles 20 close to that acts on the first magnetic head 5. Therefore, the information on the front side 3 can be reproduced without deterioration due to recording on the back side 4. Similarly, when the information on the track 30 on the back surface 3 is reproduced by the second magnetic head 6 itself or a magnetic head having the same azimuth angle, the magnetization direction 31 by the magnetic head 6 is mainly affected by the azimuth effect and spacing loss. The magnetic flux of the magnetic particles 25 parallel to or close to the second magnetic head 6
Therefore, there is no deterioration due to recording on the front side 3, and the back side 4
Can you reproduce the information?

Here, each azimuth angle θ1. of the magnetic heads 5, 6. θ2
In other words, the angle of the magnetization direction 28.31 of each magnetic head with respect to the relative movement direction A (Let's get into it. According to the azimuth angle θ, the effective gap length g widens to g=J (go: original gap length), and that's all. This corresponds to a decrease in relative speed, that is, a decrease in reproduction output.

Therefore, it is usually preferable to set the angle to 0≦101≦60 degrees. Next, it is desirable that the azimuth angle α between the two magnetic heads 5 and 6 be close to 90 degrees, but in practice it may be between 40 and 140 degrees.

From the above azimuth angle inspection, the azimuth angle θ1 of the first magnetic head 5 is set to approximately 0 degrees, and the second magnetic head 5
, 6 is set to approximately 45 degrees, a third magnetic head having an azimuth angle of approximately 90 degrees with respect to the second magnetic head 6 is used to
It can be seen that other information can be recorded over 9.

<Example 1> An example of the first invention will be described with reference to FIGS. 1 and 2. In these figures, floppy disk 1
has magnetic recording surfaces 3 and 4 on both sides of the pace 2, and two magnetic recording surfaces 5 and 6 are arranged facing both the front and back surfaces 3 and 4.

The floppy disk 1 has a thickness of about 40 μm and a diameter of about 47 m in accordance with the standards for electronic still cameras, and is rotated by a motor 7 at 3600 rpm to record video No. 13. Arrow A indicates the direction of rotation. The azimuth angle of the gap 8 of the first magnetic head 5 is zero, which is standard for electronic still cameras, and the direction of magnetization due to the gap 8 is parallel to the direction A of relative movement with the floppy disk 1. The azimuth angle of the gap 9 of the second magnetic head 6 is -45 degrees when viewed from the surface 3, and the magnetization direction due to the gap 9 is tilted at -45 degrees with respect to the relative movement direction A. Therefore, an azimuth angle of 45 degrees is provided between the two magnetic heads 5.6. two magnetic heads 5, 6
is mounted on a carriage (not shown), and in order to determine the track position, the floppy disk 1 is moved in the radius j5 direction B.
The tracks are moved along the track independently or in conjunction with each other to a desired track. Both the front and back sides 3 of the floppy disk 1 are controlled by a head feed control device (not shown).
50 circular tracks 101°11i each at 101°11i
1 to 50) are formed concentrically. However, between the front track 10i and the back track lli,
Items with the same subscript have the same diameter. Also, according to the electronic still camera standard, the track pitch is 100μm.
The width of one track is 60 μm, and guard punts 12 with a width of 40 μm are provided between tracks. In FIG. 2, 13 is the input/output terminal of the first magnetic head 5, and 14 is the input/output terminal of the second magnetic head 5.
These are input/output terminals of the magnetic head 6.

Each circular track 10I of the floppy disk 1.

The type of signal recorded on the 11i may be any video signal, computer digital signal, audio signal, etc., but these signals are usually recorded after being subjected to signal processing such as FM. Signals within the frequency band 1, preferably within the range of about 01 to 20 MHz are preferred, but of course signals outside this range can also be recorded. As for the audio signal, by applying time compression processing, approximately 10 seconds of audio signal can be recorded on one track. Of course, time expansion processing is performed during playback. Stereo audio (C) is recorded on one track by multiplexing left and right audio signals through time-division and frequency-division processing.

As a recording mode, for example, (al) each circular track 10i on the front and back recording surfaces 3, 4
.

111 independently, record a video signal on the circular track 101 on the front side 3, and record the necessary audio signal on the circular track lli on the back side 4 with the same subscript at the same time or later. (e) Recording computer digital signals independently on the circular tracks 101 and 111 on the front and back recording surfaces 3 and 4. In both cases (a) and fbl, the recording on the circular track 10i on the front surface 3 complies with the standard for electronic still cameras because the azimuth angle of the first magnetic head 5 is zero. Also (at, (cl),
Front and back circular track 10i.

The recording order of 11i is arbitrary.

<Example 2> Another embodiment of the first invention will be described with reference to FIG.

The embodiment shown in FIG. 3 differs from the first embodiment shown in FIGS. 1 and 2 only in that the azimuth angle of the first magnetic head 5 is +45 degrees. That is, since the azimuth angle of the second magnetic head 6 is 145 degrees, the first magnetic head 5 and the second
An azimuth angle of 90 degrees is provided between the magnetic heads 6. Other points are shown in FIGS. 1 and 2 (Example 1)
〉 is the same as 〉.

Therefore, recording on either the front or back recording surfaces 3 and 4 does not meet the standards for electronic still cameras, but the types of signals that can be recorded and the manner of recording are the same as in Example 1.

Embodiment 3 The embodiment described here is a method for realizing the functions of the first and second magnetic heads 5 and 6 in FIG. 3 with one magnetic head.

Now, in FIG. 1, attention is focused only on the second magnetic head 6 with an azimuth angle of 145 degrees. After recording information on the circular track Ili on the back surface 4 using this magnetic head 6,
The floppy disk 1 is turned over and information is recorded on the circular track 10i on the front surface 3 using the same magnetic head 6. In this way, the magnetic head 6 naturally functions as the second magnetic head 6 in FIG. 3 when recording on the back surface 4, and functions as the first magnetic head 5 in FIG. 3 when recording on the front surface 3. do the work. However, since the floppy disk l is turned over, there are circular tracks 10I on the front and back sides.

11i cannot record information at the same time.

<Embodiment 4> An embodiment of the second invention will be described with reference to FIG. The embodiment shown in FIG. 4 merely adds a third magnetic head 15 to the <Embodiment 1> shown in FIGS. 1 and 2. However, the third magnetic head 15 is arranged on the back surface 4 of the floppy disk 1 at an azimuth angle of +45 degrees when viewed from the front surface 3, and is provided at an azimuth angle of 90 degrees with respect to the second magnetic head 6. As a result, the second. Each third magnetic head 6.15 has an azimuth angle of 45 degrees with respect to the first magnetic head 5. Note that 16 is a gap of the third magnetic head 15. The third magnetic head 15 is also mounted on a carriage (not shown), and is moved along the radial direction of the floppy disk 1 to determine the track position.

The third magnetic head 15 may be linked with the second magnetic head 5 so that both are always positioned on the same track, may be shifted by one track from each other, or may be positioned completely independently. You can do it like this.

Therefore, recording on the surface 3 meets the standards for electronic still cameras. Further, the type of recording signal may be the same as in <Embodiment 1>. However, as for the recording mode, a second . Third magnetic head 6.15
It is possible to record two types of signals in a superimposed manner. For example, recording a video signal on the circular track 10i on the front surface 3, and recording two different types of video signals in a superimposed manner on the circular track 111 on the back surface 3; (b) recording the video signal on the circular track 101 on the front surface 3; (C) A digital signal is recorded on the circular track 10i on the front side 3, and a digital signal is recorded on the circular track 111 on the back side 4. Examples include overlapping recording of two different types of digital signals, and others. However, the circular trunk 10i on the front and back
, lli may be recorded in any order.

<Effects of the Invention> According to the first invention, since there is a large azimuth angle between the first magnetic head for one recording surface and the second magnetic head for the other recording surface, there is a large azimuth angle between the first magnetic head and the second magnetic head for the other recording surface. The information can be recorded without deterioration, and the recording density is doubled.

Furthermore, according to the second invention, the first. Since the third magnetic head has a large azimuth angle with respect to either of the second magnetic heads, two magnetic heads can be placed on the same track without deteriorating each other's information on the other recording surface of the floppy disk.
It is possible to record different types of signals overlappingly, and the recording density is 3.
Improve twice as much.

Furthermore, according to the electronic still camera video floppy standard, the diameters of floppy disks are in the order of 47, but the present invention can be applied to floppy disks with even larger diameters (for example, 3.0.3.5.5.25 inches, etc.). By doing so, it is possible to record several hundred to several thousand frames per sheet.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the first invention, FIG. 2 is a sectional view taken along the line ■-■ of FIG. 1, and FIG. FIG. 4 is a plan view showing an embodiment of the second invention, and FIG. 5(a). fb) and FIGS. 6(a) and 6(b) are diagrams explaining the principle of the present invention. In the drawing, 1 is the floppy disk, 2 is the pace, 3
is the front recording surface, 4 is the back recording surface, 5 is the first magnetic head, 8 is its gap, 6 is the second magnetic head, 9 is its gap, 101 is the circular track on the front surface, 111 is the back surface A circular track, 15 is a third magnetic head, and 16 is a gap.

Claims (4)

[Claims] (1) By the relative movement of a floppy disk that has magnetic recording surfaces on both sides of the base and two magnetic heads, information is magnetically transferred to two concentric circular tracks of substantially the same diameter on both recording surfaces. In a method for recording magnetically, the direction of magnetization is substantially parallel to the recording surface, and a first magnetic head with an azimuth angle of a constant angle including zero is placed on a circular track on one recording surface.
A method comprising: recording information; and recording information in a circular track on the other recording surface by a second magnetic head having an azimuth angle with respect to the first magnetic head. (2) In claim 1, the floppy disk wherein the azimuth angle of the first magnetic head is zero and the azimuth angle between the first magnetic head and the second magnetic head is substantially 45 degrees. double-sided magnetic recording method. (3) In claim 1, the azimuth angle of the first magnetic head is substantially 45 degrees, and the azimuth angle between the first magnetic head and the second magnetic head is substantially 90 degrees. A double-sided magnetic recording method for floppy disks. (4) By the relative movement of the floppy disk, which has magnetic recording surfaces on both sides of the base, and the three magnetic heads, information is magnetically transferred to two concentric circular tracks of substantially the same diameter on both recording surfaces. In the recording method, the magnetization direction is substantially parallel to the recording surface, and information is recorded on a circular track on one recording surface by a first magnetic head having an azimuth angle of substantially zero. , recording information in the circular tracks on the other recording surface by a second magnetic head having an azimuth angle of substantially 45 degrees with respect to the first magnetic head; and , recording information by a third magnetic head having an azimuth angle of substantially 90 degrees with respect to the second magnetic head.