JPH0682486B2 - Rotating magnetic sheet device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a flexible and rotationally driven magnetic record carrier,
For example, the present invention relates to a rotating magnetic sheet device for recording and reproducing video signals and various digital signals on a magnetic sheet.

2. Description of the Related Art A conventional rotating magnetic sheet device needs to rotate a magnetic sheet at a high speed, for example, 1800 to 3600 rpm in order to record and reproduce a high frequency, and the magnetic sheet and the magnetic head are in stable contact with each other. Is an indispensable condition. Therefore, the pad for pressing the magnetic sheet against the magnetic head forms an air film between the pad and the magnetic sheet that rotates at a high speed to bring the pad into a non-contact state so as to stabilize contact between the magnetic sheet and the magnetic head, and It has been proposed to prevent pad friction on the seat to ensure longevity.

FIGS. 4, 5, and 6 show a conventional rotating magnetic sheet device. FIG. 4 shows a rotating magnetic sheet apparatus including a flexible magnetic sheet 1, a magnetic sheet rotating motor 2, a magnetic head 3 and a pad 4, and FIG. 5 shows a rotating direction of the magnetic sheet 1 with respect to the magnetic head 3. A pad provided with a pressing surface A parallel to the plane of rotation of the magnetic sheet 1 on the upstream side of the magnetic sheet 1 and an inclined surface B inclined toward the downstream side in the rotation direction so as to narrow the gap with respect to the plane of rotation. 4 shows the configuration of No. 4. Further, as shown in FIG. 6, specific constitutional conditions are also proposed. That is, the angle θ ₁ of the inclined surface B is 2 ° to 3 °,
The angle θ ₂ of the inclined surface B ′ is the position of the head 3 of 4 ° to 13 °. The distance of d ₁ is 2.5 to 5 mm, the distance of d ₂ is 2.5 to 7 mm, and the magnetic head 3 is relative to the lower surface of the pad 4. An appropriate amount is inserted on the pad 4 side. By adopting the above-described shape of the pad 4 and the arrangement condition of the head, the above-mentioned pad 4 can be obtained.
The good contact state of the head 3 and the 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 terms of the above-mentioned pad configuration conditions in terms of mass production and enabling stable head contact.

The first problem is that when the head 3 is further pushed to the pad 4 side due to variations in assembly precision in mass production in the configuration of FIG. 5, the magnetic sheet 1 causes a slight error in the pushing amount of the head 3. in contact with the intersection P ₄ parts of the inclination surfaces B and B 'there is that damage the magnetic sheet 1, also when in the position of normal head 3 as Figure 5 is P ₃ and P ₂ to become a supporting point of the magnetic sheet 1, the head 3 is desirably set in the vicinity of approximately 1/2 of the distance P ₂ and P _3, the head of P ₂ and P ₃ as shown in FIG. 5 If it moves near the center, the tip of the head is likely to come into contact with the inclined surface B or B ′, and damage to the head 3 or the magnetic sheet 1 is likely to occur. When the head 3 is pushed into the pad 4 due to variations in mass production or the like, the fulcrums on the pad 4 side of the magnetic sheet 1 become P ₃ and P ₂ , or P ₄ and P _2. The contact angle of the magnetic sheet 1 with respect to 3 and the pressing force 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. 5 is a completely flat surface, the tip portion P ₅ easily contacts the magnetic sheet 1.

This is especially when the surface runout of the magnetic sheet 1 is very large,
It can be easily understood that it is caused by excessively lowering the pad 4 to the magnetic sheet 1 due to variations in mass-production assembly.

Means the present invention for solving the problems In order to solve the problems described above, and the circular arc to change the inclined surface B 'in an arc is set to fall falling at approximately intermediate position of the P ₃ and P ₂ Furthermore, the magnetic head 3 is characterized in that it is arranged immediately below or in the vicinity of the falling position of the arc.

Action As described above, the present invention makes the falling portion of the inclined surface B into an arc.
Since it is set to P ₂ , the contact between the magnetic sheet 1 is reduced and an air film is easily formed on the magnetic sheet 1 and the inclined surface B. Further, the trailing portion of the arc R ₂ is almost equal to the distance between P ₃ and P _2. Since the head 3 is set in the middle, the head 3 can also be arranged in the vicinity of the head 3, and an ideal head arrangement can be achieved.
The contact between the magnetic sheet 1 and the inclined surface B due to the variation in the pressing amount of the pad 4 is small. Further, by providing an arc at the tip of the pressing surface A, large contact of the surface of the magnetic sheet 1 and contact of the pad 4 with the plane of rotation of the magnetic sheet 1 due to excessive pressing down are reduced. With head 3
When the magnetic sheet 1 and the pad 4 are assembled, variations in the pad position accuracy can be reduced, and even if variations in mass production occur, there is a margin of the head pushing amount, and a good contact state between the magnetic head 3 and the magnetic sheet 1 is obtained. It is possible to secure the above-mentioned property and to prevent the magnetic sheet from being damaged by the contact of the pad 4.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. First
1 to 3 show one embodiment of the rotating magnetic sheet device of the present invention. Also in this example, the pad 4 and the magnetic head 3 are arranged to face each other at a predetermined interval, and the magnetic sheet 1 is arranged between them. 1 and 2 show the structure of the pad 4, which is the main feature of the present invention. As shown,
The pad 4 has a pressing surface A that is parallel to the rotation plane of the magnetic sheet 1, and an inclination that is inclined so as to narrow the gap toward the downstream side in the rotation direction of the magnetic sheet with respect to the rotation plane of the magnetic sheet 1. The surface B and the pressing surface A and the inclined surface B have predetermined arcs R ₁ and R ₂ , respectively, and the inclined surface B is a minute plane parallel to the rotation plane of the magnetic sheet 1 at the end. C is provided. The minute plane C is the pressing surface A.
Of the magnetic sheet 1 and the pressing surface A and the minute plane C can be arranged in parallel to the rotation plane of the magnetic sheet 1. Further, the position of the falling portion P ₁ of the arc R ₂ of the inclined surface B is arranged to be located approximately at the midpoint of the distance between the minute plane C and the end portion P ₂ of the pressing surface A.

The magnetic head 3 is installed at a slight distance L _{5 with} respect to the trailing portion P ₁ of the arc R ₂ of the inclined portion B. The distance L ₅ is not an absolute condition, and even if it is O, the contact state between the head 3 and the magnetic sheet is within the practical range. See also L ₅
Can be used even if becomes a minus value. Further, the L ₅ will be described in detail. FIG. 3 is a schematic diagram showing a contact position relationship between the head 3 and the magnetic sheet 1. In FIG. 3, C represents the position of the small plane C shown in FIG. 2, also P ₂ shows the same position as P ₂ of FIG. 2, the magnetic sheet 1 is pushed up by the head 3 the C and P ₂
The magnetic sheet 1 is supported by an air film generated between the magnetic sheets 1. However, in order to obtain a good contact state between the head 3 and the magnetic sheet 1, the distances L ₄ and L ₃ shown in the figure are substantially the same. Therefore, it is desirable that the contact angle of the magnetic sheet 1 with respect to the head 3 be symmetrical. As shown in FIG. 2, an air film is also formed on the inclined surface B, so that the magnetic sheet 3 supports the magnetic sheet 1 as shown in FIG.
The point will be set substantially in the C'direction. Therefore, as described above, a better head contact state can be obtained when the head 3 is moved by about 1/2 of the distance between C and C ', that is, L ₅ shown in the figure.

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

It is desirable that the dimensions obtained by the experiment in FIG.

L ₁ = 0.2 to 0.4 [mm] L ₂ = 2 to 4 [mm] L ₃ = 3 to 6 [mm] L ₄ = 3 to 6 [mm] L ₅ = 0 to 2 [mm] θ = 2 ° to 3 ° R ₁ = 10 to 20 [mm] R ₂ = 10 to 20 [mm] The above dimensional range is a desirable value, and even if the range is slightly changed, there is a margin for practical use.

The larger the value of L ₁ is, the larger the action of attracting the magnetic sheet 1 to the side of the minute plane C is, so that the magnetic sheet easily contacts at the intersection of the inclined plane B and the minute plane C. It is better not to expand the dimensional conditions too much. It should be noted that the arcs R ₁ and R ₂ exhibit their function even when the shape of the slope is not an arc, but in the case of the slope, the intersection with the pressing portion A and the slope B
When the corner portion is formed at the intersection of the magnetic sheet 1 and the surface deflection of the magnetic sheet 1 or the pushing amount of the magnetic head 3 with respect to the pad 4 becomes large, the corner portion and the magnetic sheet 1 easily come into contact with each other.
More often causes damage.

In FIGS. 1 and 2, when the magnetic sheet 1 is 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 in the direction of arrow E at a predetermined number of revolutions, the magnetic sheet 1 and the pressing surface A, the inclined surface B, and the minute plane C are acted on by the action of the air flow rotated together with the magnetic sheet 1. A stable air film is generated between them. As a result, the magnetic sheet 1 is pressed against the magnetic head 3 side without being adjacent to the pad 4. At this time, the magnetic sheet 1 is deformed into a saddle shape in the vicinity of the magnetic head 3 and has a shape that is in good contact with the magnetic head 3. Further, the saddle shape increases the rigidity of the magnetic sheet 1 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 corrected. As a result, stable contact between the magnetic sheet 1 and the head 3 can be obtained.

EFFECTS OF THE INVENTION As described above with reference to the embodiments, the present invention is a rotary magnetic device in which a pad and a magnetic head are arranged so as to face each other with a predetermined gap, and a magnetic sheet is arranged between the pad and the magnetic head. In the sheet device, a pressing surface A for pressing the magnetic sheet is provided on the upstream side of the magnetic head of the pad in the rotation direction of the magnetic sheet, and the pressing surface A is configured to be parallel to the rotation plane of the magnetic sheet. An inclined surface B that inclines so as to narrow the gap toward the downstream side of the rotation center of the magnetic sheet with respect to the rotation plane is provided on the downstream side of the rotation direction of the pad, and the rotation direction of the magnetic sheet on this inclined surface B is provided. The end of the inclined surface B is provided by providing an arc portion so that the falling point is located at the upstream end of the pressing surface from the downstream end of the pressing surface in the rotational direction toward the downstream side at a substantially midpoint of the entire width. Without the corners Therefore, damage such as chipping or scratching is eliminated, a stable floating effect on the magnetic sheet is obtained, and contact damage to the magnetic sheet can be prevented. Therefore, according to the present invention, it is possible to realize a rotating magnetic sheet apparatus having a head contact condition that is extremely highly reliable and has good mass productivity.

[Brief description of drawings]

FIG. 1 is a schematic diagram relating to a pad showing an embodiment of a rotating magnetic sheet device according to the present invention, FIG. 2 is a dimensional relational diagram of a main part of the device, and FIG. 3 is a diagram explaining the action of the pad on the magnetic sheet. Therefore, a schematic view, FIG. 4 is a perspective view showing a conventional rotating magnetic sheet device, FIG. 5 is a schematic view related to pads of a conventional device, and FIG. 6 is a dimensional relationship diagram of pads of the conventional device. 1 ... magnetic sheet, 3 ... magnetic head, 4 ... pad,
A: pressing surface, B: inclined surface.

Claims (3)

[Claims] 1. A rotary magnetic sheet device in which a magnetic head and a pad are arranged at positions facing each other via a rotating magnetic sheet, wherein the pad has the magnetic sheet on the upstream side in the rotating direction of the magnetic sheet. The magnetic sheet has a pressing surface configured to be parallel to the rotational plane of the magnetic sheet that is pressed toward the head side, and the downstream side of the magnetic sheet in the rotational direction of the rotational direction of the magnetic sheet with respect to the rotational plane of the magnetic sheet. It has an inclined surface that inclines so as to narrow the gap toward the downstream side, and the inclined surface is configured to fall in an arc from the most upstream end in the rotational direction of the magnetic sheet, and the falling point of the arc. Is arranged so as to be located at a substantially midpoint of the entire width of the pressing surface from the downstream end in the rotational direction of the magnetic sheet to the downstream side in the rotational direction of the magnetic sheet. . 2. The distance from the trailing edge of the inclined surface to the central position of the magnetic head toward the upstream side in the rotational direction of the magnetic sheet is set to 0 or in the vicinity thereof. The rotating magnetic sheet device according to the item. 3. A rotating magnetic sheet device in which a magnetic head and a pad are arranged at a position facing each other with a rotating magnetic sheet interposed therebetween, wherein the pad has the magnetic sheet on the upstream side in the rotating direction of the magnetic sheet. The magnetic sheet has a pressing surface configured to be parallel to the rotational plane of the magnetic sheet that is pressed toward the head side, and the downstream side of the magnetic sheet in the rotational direction of the rotational direction of the magnetic sheet with respect to the rotational plane of the magnetic sheet. There is an inclined surface that inclines so as to narrow the gap toward the downstream side, and the inclined surface is configured to stand in an arc from the most upstream end in the rotational direction of the magnetic sheet, and the pressing surface A rotary magnetic sheet device, characterized in that an upstream end portion of the magnetic sheet in the rotational direction is formed of an arc.