JPS632158A - Rotary magnetic sheet device - Google Patents

Abstract

PURPOSE:To establish the excellent abutting state of a magnetic head and a magnetic sheet and to prevent the damage of the magnetic sheet due to contact with a pad by constituting a slope face so as to be trailed in a circular arc shape from the most tip of the upperstream in the rotational direction of the magnetic sheet. CONSTITUTION:A pressing face A pressing the magnetic sheet is provided to the upperstream side of the pad in the rotational direction of the magnetic sheet 1 with respect to the magnetic head 3, and the pressing face A is formed in parallel with the rational plane of the magnetic sheet, a tilt face B tilted whose gap is narrowered toward the downstream of the rotational center of the magnetic sheet is provided with respect to the rotational plane at the downstream side in the rotational direction of the pad and a circular arc part is provided so that the trailing point of the slope B at the upperstream tip in the rotational direction of the magnetic sheet is placed nearly at the midpoint of the full width toward the downstream from the downstream end in the rotational direction of the pressing face. Thus, the corner at the end of the slope B is eliminated, then neither chipping nor damage is provided, a stable floating effect to the magnetic sheet is obtained and the damage to the magnetic sheet due to contact is prevented as well.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flexible and rotationally driven magnetic recording carrier;
For example, it relates to a rotating magnetic sheet device that records and reproduces video signals and various digital signals on a magnetic sheet.

2. Description of the Related Art A conventional rotating magnetic sheet device rotates a magnetic sheet at a speed of, for example, 1800 to 3600 rpm in order to record and reproduce high frequencies.
It is necessary to rotate at a high speed such as m, and stable contact between the magnetic sheet and the magnetic head is an essential condition. For this reason, the pad for pressing the magnetic sheet against the magnetic head forms an air film between the magnetic sheet rotating at high speed, and creates a non-contact state to stabilize the contact between the magnetic sheet and the magnetic head and to stabilize the magnetic head. It has been proposed to prevent seat pad friction and ensure longevity.

A conventional rotating magnetic sheet device is shown in FIGS. 4, 5, and 6. FIG. 4 shows a rotating magnetic sheet device comprising a flexible magnetic sheet 1, a motor 2 for rotating the magnetic sheet, a magnetic head 3, and a pad 4, and FIG. 5 shows the rotation direction of the magnetic sheet 1 with respect to the magnetic head 3. A pad provided with a pressing surface A parallel to the rotation plane of the magnetic sheet 1 on the upstream side of the magnetic sheet 1, and an inclined surface B inclined toward the downstream side of the rotation direction so as to narrow the gap with respect to the rotation plane. The configuration of No. 4 is shown below. Furthermore, as shown in FIG. 6, specific configuration conditions have also been proposed. That is, the angle θ1 of the slope B is 2° to 3°, the angle θ2 of the slope B' is 4° to 13°, the distance dl indicating the position of the head 3 is 2.5 to sm, and the distance d2 is 2. 5
7, and the magnetic head 3 is inserted by an appropriate amount on the pad 4 side with respect to the lower surface of the pad 4.

By adopting the shape of the pad 4 and the arrangement conditions of the head as described above, a good contact state between the pad 4 and the head 3 and a long life of the magnetic sheet 1 are ensured.

Problems to be Solved by the Invention However, the conventional device has the following problems in that the above-mentioned pad configuration conditions can be adapted to mass production and to enable stable head contact.

The first problem is that in the configuration shown in FIG. 5, if the head 3 is pushed further toward the pad 4 side due to variations in assembly accuracy during mass production, the magnetic sheet 1 will have a slight error in the amount of pushing of the head 3. Even if the head 3 is in the normal position as shown in FIG.
is the fulcrum of the magnetic sheet 1, so the head 3 is connected to P2 and P
It is desirable to set it to approximately % of the distance of 3.
As shown in the figure, if the head is moved near the center of P2 and P3, the tip of the head is likely to come into contact with the inclined surface B or B', and damage to the head 3 and the magnetic sheet 1 is likely to occur. In addition, if the amount of the head 3 pushed into the pad 4 is unbalanced due to variations in mass production, both fulcrums of the magnetic sheet 1 on the pad 4 side will be at P
3 and P2, or P4 and P2,
The contact angle and pressing force of the magnetic sheet 1 with respect to the head 3 change, and there are many variations in the recording and reproducing characteristics of the device.

The second problem is that since the pressing surface A shown in FIG. 6 is completely flat, the tip end P6 tends to come into contact with the magnetic sheet 1.

This is especially true when the surface runout of the magnetic sheet 1 is very large,
It is easy to understand that this is due to the pad 4 being pushed down too much against the magnetic sheet 1 due to mass production assembly variations or the like.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention changes the inclined surface B to a circular arc, sets the circular arc to fall at approximately the midpoint between the P3 and P2, and furthermore, the magnetic The feature is that the head 3 is disposed directly below or near the falling position of the arc.

Function As described above, in the present invention, since the falling part of the inclined surface B is made into the circular arc P2, the contact between the magnetic sheet 1 is reduced, and the air film between the magnetic sheet 1 and the inclined surface B is easily formed. Furthermore, the falling part of the arc R2 is defined as P3 and 2.
Since the distance between the pads 2 and 2 is set approximately in the middle, the head 3 can also be placed in the vicinity, resulting in an ideal head arrangement and the difference between the magnetic sheet 1 and the inclined surface B due to variations in the amount of pushing of the head 3 into the pad 4. contact will also be reduced. In addition, by providing an arc at the tip of the pressing surface A, the magnetic sheet 1
This reduces contact caused by large surface runout or by pushing down the pad 4 too much against the rotating plane of the magnetic sheet 11. As a result, it is possible to reduce variations in pad position accuracy when assembling the head 3, magnetic sheet 1, and pad 4, and even if variations occur during mass production, there is enough margin for the head pushing amount, and a good magnetic head 3 and magnetic sheet 1 can be obtained. This makes it possible to ensure a state of contact between the pads 4 and 4, and also prevent damage to the magnetic sheet due to contact with the pad 4.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. 1st
An embodiment of the rotating magnetic sheet device of the present invention is shown in FIGS. Also in this example, the pad 4 and the magnetic head 3 are arranged facing each other with a predetermined interval, and the magnetic sheet 1 is arranged between them.

FIGS. 1 and 2 show the structure of the pad 4, which is the main point of the present invention. As shown in the figure, the pad 4 has a pressing surface A that is parallel to the rotation plane of the magnetic sheet 1, and a pressing surface A that is parallel to the rotation plane of the magnetic sheet 1.
The inclined surface B is inclined so as to narrow the gap toward the downstream side in the direction of rotation of the magnetic sheet with respect to the rotating plane of
2, and furthermore, the inclined surface B has a minute plane C parallel to the rotation plane of the magnetic sheet 1 at the end thereof. Further, the minute plane C is arranged on an extension line of the pressing surface A, and the configuration is such that the pressing surface A and the minute plane C can be arranged parallel to the rotation plane of the magnetic sheet 1. Further, the position of the falling portion P1 of the circular arc R2 of the inclined surface B is configured to be located approximately at the midpoint of the distance between the microscopic plane C and the end portion P2 of the pressing surface A.

Further, the magnetic head 3 is installed at a certain distance L5 from the falling part P1 of the circular arc R2 of the inclined part B. The distance L5 is not an absolute condition, and even if it is 0, the state in which the head 3 and the magnetic sheet are still in contact is within a practical range. Further, it can be used even if L5 becomes a slightly negative value. Furthermore, the details of L5 will be explained. FIG. 3 is a schematic diagram showing the contact positional relationship between the head 3 and the magnetic sheet 1.

In FIG. 3, C indicates the position of the minute plane C shown in FIG. 2, and P2 indicates the same position as P2 in FIG. At P2, the head is supported through the air film generated between the magnetic sheets 1, but in order to obtain good contact between the head 3 and the magnetic sheet 1, the distances between L4 and L3 shown in the figure should be approximately the same. In this way, it is desirable that the contact angle of the magnetic sheet 1 with respect to the head 3 becomes bilaterally symmetrical.

As shown in FIG. 2, since an air film is also formed on the inclined surface B, the magnetic sheet 3 is determined in which direction the zero point supporting the magnetic sheet 1 is set as shown in FIG. Become. Therefore, as described above, a better head contact state can be obtained by moving the head 3 by approximately % of the distance C, that is, by L5 shown in the drawing.

Next, the dimensional relationship of each component will be described.

In FIG. 2, the dimensions obtained through experimental study are preferably as follows.

L1 = 0.2 ~ 0.4 [Parrot] L2 = 2 ~ 4 [Wisteria] L3 = 3 ~ 6 [n] L4 = 3 ~ e [Parrot] L6 = O ~ 2 [Gift] θ = 2° ~ 3 R1 = 10 to 20 [Parrot] R2 = 10 to 20 [T] Note that the above dimensional range is a desirable value, and there is enough room for practical use even if the range is slightly changed.

It should be noted that as the value of Ll becomes larger, the effect of attracting the magnetic sheet 1 toward the microplane C side becomes stronger, and the direction in which the magnetic sheets easily come into contact at the intersection of the inclined surface B and the microplane C is determined. It is better not to widen the dimensional conditions too much. still,
The arcs R1 and R2 can function even if they are in the form of slopes instead of circular arcs, but if they are formed into slopes, corners are formed at the intersection with the pressing part A and the intersection with the slope B, and the surface runout of the magnetic sheet 1 is reduced. If the pushing amount of the magnetic head 3 against the pad 4 becomes large, the corner portions and the magnetic sheet 1 will easily come into contact with each other, often causing damage. When the magnetic sheet 1 and the pad 4 are not rotating, the magnetic sheet 1 and the pad 4 are in contact with each other.
As shown in the figure, when the magnetic sheet 1 is rotated at a predetermined rotation speed in the direction of arrow E, the magnetic sheet 1, the pressing surface A, the inclined surface B, and the minute screen are connected by the action of the airflow that is rotated together with the magnetic sheet 1. A stable air film is generated in between. the result,
The magnetic sheet 1 is pressed toward the magnetic head 3 without contacting the pad 4. At this time, the magnetic sheet 1 is deformed into a saddle shape near the magnetic head 3, and has a shape that makes good contact with the magnetic head 3. Furthermore, by becoming a saddle-shaped shape,
The rigidity of the magnetic sheet 1 increases in the vicinity of the magnetic head 3, the vibration of the magnetic sheet 1 becomes extremely small, and the curl of the magnetic sheet 1 is also corrected. As a result, stable contact between the magnetic sheet 1 and the head 3 can be obtained.

Effects of the Invention As explained above with reference to the embodiments, the present invention provides a rotary magnet in which a pad and a magnetic head are arranged to face each other at a predetermined interval, and a magnetic sheet is arranged between the pad and the magnetic head. The sheet device is provided with a pressing surface A for pressing the magnetic sheet on the upstream side of the pad in the direction of rotation of the magnetic sheet with respect to the magnetic head, and the pressing surface A is configured parallel to the rotational plane of the magnetic sheet. , an inclined surface B is provided on the downstream side in the rotational direction of the pad, and the inclined surface B is inclined so as to narrow the gap toward the downstream side of the rotation center of the magnetic sheet with respect to the rotation plane, and the rotation of the magnetic sheet on this inclined surface B is provided. By providing an arc portion at the tip of the upstream side of the direction so that the falling point is located approximately at the midpoint of the eclipse facing downstream from the downstream end of the rotation direction of the pressing surface, the slope of the inclined surface B is There are no corner parts at the end, and there is no damage such as chips or scratches, so a stable floating effect can be obtained for the magnetic sheet, and contact damage to the magnetic sheet can also be prevented. Therefore, according to the present invention,
It is possible to realize a rotating magnetic sheet device that is extremely reliable and has head contact conditions that are suitable for mass production.

[Brief explanation of drawings]

Fig. 1 is a pad-related schematic diagram showing an embodiment of the rotating magnetic sheet device of the present invention, Fig. 2 is a dimensional relationship diagram of the main parts of the device, and Fig. 3 explains the action of the pad on the magnetic sheet. 4 is a perspective view showing a conventional rotating magnetic sheet device, FIG. 6 is a schematic diagram related to pads of the conventional device, and FIG. 6 is a dimensional relationship diagram of the pads of the conventional device. 1... Magnetic sheet, 3... Magnetic head, 4... Band, A... Pressing surface, B...
・・・・Slope surface. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 4
r11J Yo Figure 5 Rape Figure 6

Claims (3)

[Claims] (1) A rotating magnetic sheet device in which a magnetic head and a pad are disposed at positions facing each other via a rotating magnetic sheet, wherein the pad is placed so that the magnetic sheet is placed on the upstream side in the rotational direction of the magnetic sheet, and the pad is placed on the upstream side in the rotational direction of the magnetic sheet. a pressing surface configured parallel to a rotating plane of the magnetic sheet that presses the magnetic sheet;
An inclined surface is provided on the downstream side in the rotational direction of the magnetic sheet, and the inclined surface is inclined with respect to the rotational plane of the magnetic sheet so as to narrow the gap toward the downstream side in the rotational direction of the magnetic sheet, and the inclined surface is The magnetic sheet is configured to fall down in an arc from the most upstream end in the rotational direction of the magnetic sheet, and the falling point of the arc is from the downstream end of the pressing surface in the rotational direction of the magnetic sheet to the downstream end in the rotational direction of the magnetic sheet. A rotating magnetic sheet device characterized in that it is configured to be located approximately at the midpoint of its entire width facing downstream. (2) The distance from the rising point of the inclined surface to the center position of the magnetic head toward the upstream side in the rotational direction of the magnetic sheet is set to 0 or close to it. Rotating magnetic sheet device. (3) A rotating magnetic sheet device in which a magnetic head and a pad are disposed at opposing positions via a rotating magnetic sheet, wherein the pad is arranged such that the magnetic sheet is placed on the upstream side in the rotational direction of the magnetic sheet, and the pad is placed on the upstream side in the rotational direction of the magnetic sheet. a pressing surface configured parallel to a rotating plane of the magnetic sheet that presses the magnetic sheet;
an inclined surface that is inclined with respect to the rotational plane of the magnetic sheet so as to narrow the gap toward the downstream side of the rotational direction of the magnetic sheet, and 1. A rotating magnetic sheet device characterized in that the upstream end of the magnetic sheet in the rotational direction is formed of a circular arc.