JPS6042543B2 - Magnetic sheet recording and reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic sheet recording and reproducing apparatus, and more particularly to a magnetic sheet recording and reproducing apparatus that simultaneously records or reproduces data on both sides of a magnetic sheet.

The magnetic sheet referred to in the present invention (hereinafter abbreviated as "sheet").

) and magnetic sheet recording/reproducing devices (hereinafter referred to as "sheet recorders") are relatively thin, flexible, non-magnetic supports with circular, elliptical, or rectangular outer shapes. A sheet consisting of layers is formed, and the sheet is rotated and floated along the flat surface of a fixed substrate as if it were a rigid disk, and the magnetic layer of the sheet has a spiral or concentric shape. A sheet recorder with tracks for recording and reproducing audio, video, or data signals. The sheet is generally a circular sheet having an outer diameter of 10 cm to 50 cm, with a 3wgn-mark hole formed through the center of the sheet, and the entire sheet is molded into a donut shape.

Further, the thickness of the support of the sheet is 3 .mu.m to 1 wm) Furthermore, the thickness of the magnetic layer is often 0.05 .mu.m to 100 .mu.m.

The magnetic material used in these magnetic sheets, binder J,
Examples of the support include those shown below. First of all,
The ferromagnetic fine powder used is γ-Fe2O3, C
o-containing γ-Fe2oa) Fe3o4, Co-containing Fe
3o4, cro2, Co-Ni-P alloy, Fe-Co-
Known ferromagnetic fine powder such as Ni alloy is used;
As the binder, conventionally known thermoplastic resins, thermosetting resins, reactive resins, and mixtures thereof are used.

As a thermoplastic resin, the softening temperature is 150°C or less, the average molecular weight is 10,000 to 2,000 (1) the degree of polymerization is about 200 to
500, such as vinyl chloride vinyl acetate copolymer, vinyl chloride vinylidene chloride copolymer, vinyl chloride acrylonitrile copolymer, acrylic ester acrylonitrile copolymer, acrylic ester vinyldene chloride copolymer, acrylic ester Styrene copolymer, methacrylic acid ester acrylonitrile copolymer, methacrylic acid ester vinylidene chloride copolymer, methacrylic acid ester styrene copolymer, urethane elastomer, polyvinyl fluoride, vinylidene chloride acrylonitrile copolymer, butadiene acrylonitrile copolymer , polyamide resin polyvinyl, butyral, cellulose derivatives (cellulose◆acetate●butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, nitro●cellulose, etc.), styrene-butadiene copolymer, preester resin, chlorovinyl ether acrylate ester, etc. Polymers, amino resins, various synthetic rubber-based thermoplastic resins, and mixtures thereof are used.

The thermosetting resin or reactive resin has a molecular weight of 2×1 Cf' or less in the state of a coating solution, and when heated after coating and drying, the molecular weight becomes infinite due to reactions such as condensation and addition.

Among these resins, those that do not soften or melt before the resin is thermally decomposed are preferred, such as phenol resins, epoxy resins, polyurethane curable resins, urea resins, melamine resins, alkyd resins, and silicone resins. , acrylic reactive resins, epoxy-polyamide resins, nitrocellulose melamine resins, mixtures of polymeric polyester resins and isocyanate prepolymers, methacrylate copolymers. and diisocyanate prepolymers, mixtures of polyester polyols and polyisocyanates, urea formaldehyde resins, low molecular weight glycols/
These include polymer diol/triphenylmethane triisocyanate mixtures, polyamine resins, and mixtures thereof. These binders may be used alone or in combination, and other additives may be added.

The mixing ratio of the above-mentioned ferromagnetic powder and binder is usually 10 parts by weight of ferromagnetic powder to 10 to 20 parts by weight of binder.
It is used in a range of 0 parts by weight. Additives include dispersants, lubricants, abrasives, and the like. In addition, as a material for the support body,
Polyesters such as polyethylene terephthalate and polyethylene 2,6-naphthalate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate, butyrate, cellulose acetate) topropionate, polyvinyl chloride, In addition to vinyl resins such as vinyldene chloride, plastics such as polycarbonate, polyimide, and polyamideimide, non-magnetic metals such as aluminum and copper, paper, baryta, or polyethylene, polypropylene, and ethylene-butene copolymers, depending on the application. Paper coated with or laminated with α-polyolefin having 2 to 10 carbon atoms is also used.
These supports are transparent or opaque depending on the intended use of the magnetic recording medium.

As mentioned above, methods for applying magnetic coating liquid consisting of ferromagnetic fine powder, binder, additives, etc. to the support described above include air doctor coating, blade coating, air knife coating, squeeze coating, dip coating, reverse slow coating, Transfer roll coating, gravure coating, kiss coating, cast coating, spray coating methods, etc. can be used, and other methods are also possible.Specific explanations of these methods can be found in 1 Coating Technology published by Asakura Shoten, p. 253~
It is described in detail in No. 27 No. 27 (published on March 2, 1972).

Conventional sheet recorders, which perform magnetic recording or reproduction using spiral or concentric tracks on a sheet as described above, usually have a flat top surface and an opening in the center, as shown in Figure 1. Fixed board 1 having a portion 11 drilled therein
2. A motor 13 disposed below the fixed substrate 12, the motor 13 penetrating through the opening 11 and protruding its upper end onto the fixed substrate 12, and having a stator 14 screwed onto the upper end. a rotating shaft 15; the rotating shaft 15 and the stator 14;
A long hole 18 formed through the fixed substrate 12 protrudes from below and approaches or comes into contact with the surface of the magnetic layer 3 of the sheet 1 with the central hole periphery sandwiched therebetween, while being movable in the radial direction of the magnetic sheet. It was equipped with a magnetic head 17 supported by a movable arm mechanism 16.

This sheet recorder 10 normally holds the sheet 1 attached to the upper end of the rotating shaft 15 for a length of 360 to 1800 r''.
- By rotating in the range of PIm●, an arrow A is formed between the opening 11 and the fixed substrate 12 and the magnetic layer 3.
While generating the air flow shown in the sheet 1,
The sheet 1 having the magnetic layer 3 on one side of the flexible support 2 is stretched, floated, and rotated as if it were a rigid disc by applying a centrifugal force to the head 17. is moved in the radial direction of the sheet 1 to perform predetermined recording or reproduction.

The sheet recorder 10 described above solves the problems associated with tape-shaped magnetic recording media, such as the complexity of operations and the difficulty in shortening processing time, such as the fact that rewinding and fast winding are in the operation mode and that it takes a long access time. In addition to solving this problem, it has become possible to use the sheet, which is a relatively inexpensive magnetic recording medium.

However, in the conventional sheet recorder 10, in order to stabilize the rotation and levitation of the sheet 1 on the fixed substrate 12, the head 17 was made to face only one surface of the sheet 1. When switching from one side to the other in a double-sided magnetic layered sheet designed to double the recording capacity per sheet, it is necessary to reverse the direction of adhesion of the sheet to the upper end of the rotating shaft 15. As a result, not only does the idle time increase, but it also has the disadvantage that it is impossible to take advantage of the advantage of having magnetic layers on both sides, that is, to simultaneously record or reproduce on both sides.

The sheet recorder of the present invention eliminates the above-mentioned drawbacks of conventional sheet recorders, does not complicate the mechanism, and therefore is easy to maintain and inspect, and is compatible with the use of sheets with a magnetic layer layered only on one side. The purpose is to provide a sheet recorder that does not cause any problems. Such an object of the present invention is to provide a first fixed substrate having an upper surface of a size equal to or larger than the rotating surface of the seat, and a center of the first fixed substrate above the first fixed substrate and parallel to the upper surface of the fixed substrate. Alternatively, the second fixed substrate extends to the vicinity of the center, and the upper surface of the first fixed substrate covered by the second fixed substrate or the other upper surface of the first fixed substrate and the second fixed substrate are provided. This is achieved by a sheet recorder characterized in that the distance between the clamp level at the rotation axis of the sheet is greater than the lower surface of the fixed substrate.

Hereinafter, embodiments of the sheet recorder of the present invention will be described in detail based on the attached drawings.

Sheet recorder 20 of the present invention shown in FIGS. 2 and 3
is a motor 23 for giving rotation to the seat 40;
The rotating shaft 25 of the motor 23 penetrates from below and rotates around the opening 21, and the first magnetic head 27 supported by the first movable arm mechanism 26 penetrates from below to rotate the seat. 40 radially movable first elongated holes 28 are provided therethrough, and an upper surface having a size equivalent to the rotating surface of the sheet 40 is provided approximately along the straight line C passing through the opening 21. The lower surface portion 29 and the higher surface portion 30 are separated by the stepped region.
a stator 24 that can be screwed onto the upper end of the rotating shaft 25 to fix the periphery of the center hole of the sheet 40 to the rotating shaft 25;
A second magnetic head is held and disposed on suitable support means (not shown) so as to cover the entire lower surface area 29 of the fixed substrate 22 above, and is further supported by a second movable arm mechanism 31. 32 is inserted from above and is movable in the radial direction of the sheet 40 through a second elongated hole 33.
It consists of 4.

To describe in more detail the configurations of the first and second fixed substrates 22 and 34 described above, first, the first fixed substrate 22 and
In this case, the first elongated hole 28 is transparently provided in the high surface area 30, and the distance d1 between the high surface section 30 and the clamp level L of the seat 40 mounted on the rotating shaft 25 is 50.
~1500μ, and the distance D2 of the low surface portion 29 from the clamp level L is set to 67r$t or more, and furthermore, the step area forming the boundary between the high surface portion 30 and the low surface portion 29 is set to 4.
It is defined by an inclined surface 35 having an inclination angle of 5 to 60 degrees. On the other hand, in the second fixed substrate, the distance D3 of the lower surface facing the entire lower surface portion 29 from the clamp level L is set to 50 to 1500μ, and An inclined surface 36 is provided on the peripheral edge so as to be substantially parallel to the inclined surface 35 and cover the inclined surface 35.

Next, the effect will be explained.

First, the area around the central hole of the sheet 40 is fitted onto the upper end of the rotating shaft 25, and then the motor 23 is started to rotate the sheet 40 in one direction. Air flows between the sheet 40 and the first fixed substrate 22 from the opening 21 as shown by arrow A, and is discharged.

When the above-mentioned air flow occurs, the other areas of the seat 40 except for the area around the center hole move from the lower surface portion 29 and the higher surface portion 30 to the clamp level L in response to the cushion pressure caused by the air flow. It begins to float toward the sky.

Since centrifugal force is also applied to the sheet 40 that has begun to float due to rotation, the number of rotations reaches a predetermined value, usually 36.
0~1800r. p. m. When it reaches the clamp level L, it expands like a rigid disk and reaches the clamp level L.
Continue rotating along.

On the other hand, a part of the airflow generated along the upper surface of the sheet 40 in the direction of arrow B as the sheet 40 rotates is caused to flow between the lower surface of the second fixed substrate 34 and the upper surface of the sheet 40. This acts to suppress the sheet 40 from floating above the clamp level L.

This suppressing effect varies depending on the distance D3 between the lower surface of the second fixed substrate 34 and the clamp level L, but if the distance D3 is set outside the range of 50μ to 1500μ, the suppressing effect weakens and the 40 at the desired flying level, ie, clamping level L, becomes difficult.

Further, the above-mentioned suppressing effect has a deep relationship with the form of the first fixed substrate 22 facing each other through the sheet 40, and in particular, when the distance between the lower surface portion 29 and the clamp level L is less than 67TgfL. If the setting is set to Alternatively, recording and reproduction by the first and second magnetic heads 27 and 32 are disabled.

The above-mentioned intense vertical movement of the seat 40 reduces the distance 4 by 6w.
The reason why it stops when it is set to more than un is that the cushioning pressure applied to the sheet 40 from the upper and lower directions by the first and second fixed substrates 22 and 34 mutually significantly impairs the flying ability of the sheet 40. It is presumed that this is because the cushioning properties provided by the lower surface portion 29 function as a buffer for the suppressing action, rather than interfering with each other.

The distance 4 is 10m! It has also been confirmed that the flotability of the sheet 40 becomes even more stable when it is greater than or equal to n.

On the other hand, the airflows passing through the step area of the first fixed substrate 22 and the peripheral edge of the second fixed substrate 34 are not disturbed by the inclined surfaces 35 and 36, and the pressure is smoothed. , the lower surface portion 29
The sheet 40 passing over the boundary between the high surface portion 30 floats more stably and continues to rotate.

As described above, the first and second fixed substrates 22
, 34, the first and second magnetic heads 27, 32 are moved over the sheet 40.
A desired signal is recorded or reproduced simultaneously or at an appropriate time by being placed in close proximity to or in contact with the respective magnetic layers 42 and 42 provided on both sides of the magnetic layer.

Note that the upper surface of the first fixed substrate 22 is connected to the sheet 40.
Even if it is larger than the rotating surface of the sheet 40, it does not impede the rotation and floating properties of the sheet 40 in any way. Further, the first fixed substrate 22
The area ratio of the low surface portion 29 to the high surface portion 30 may be changed as appropriate depending on the rigidity of the sheet 40 and the recording/reproducing span. The fixed substrate 34 is connected to the rotating shaft 25 of the seat 40.
It is desirable that the lower surface area 29 does not extend beyond the opening 21 so as not to interfere with attachment/detachment operations.

As described above, the sheet recorder of the present invention provides the following novel effects.

That is, the second fixed substrate 34 is disposed above the first fixed substrate 22, and the lower surface portion 29 of the first fixed substrate 22 covered by the second fixed substrate 34 is located above the first fixed substrate 22. The high surface portion 30 of the fixed substrate 22 and the second fixed substrate 34
Since the distance between the clamp level L of the sheet 40 and the lower surface of the sheet 40 is set to be larger than the lower surface of the sheet 40, that is, ↓>d1 and y, the distance between the lower surface portion 29 and the lower surface of the second fixed substrate 34 is also As a result, the magnetic heads 27 and 32 are inserted into the high surface portion 30 and the second fixed substrate 34, respectively, and the magnetic heads 27 and 32 are inserted into both sides of the sheet 40 at the same time or as desired. It became possible to record or play back signals. Further, since the respective inclined surfaces 35 and 36 smoothly apply pressure changes without disturbing the flow of each air moving along the surface of the sheet 40, the air passes over the step area on the first fixed substrate 22. It has become possible to further stabilize the floating of the sheet 40.

In addition, as described above, the mechanism of the sheet recorder 20 of the present invention has an extremely simple structure, so maintenance, inspection, and operation are easy, and it is also superior to the conventional sheet 1, which has a magnetic layer on only one side. It has become possible to record and reproduce desired signals by providing stable levitation and rotation.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of the main part of a conventional sheet recorder, FIG. 2 is a plan view of the main part of the sheet recorder of the present invention, and FIG. 3 is a side view of FIG. 2. 22 is a first fixed substrate, 29 is a low surface portion, 30 is a high surface portion,
34 is a second fixed substrate, and 40 is a sheet.

Claims (1)

[Scope of Claims] 1. A first fixed substrate having an upper surface having a size equal to or larger than the rotating surface of the magnetic sheet, and a first fixed substrate above the first fixed substrate and parallel to the upper surface of the fixed substrate. The second fixed substrate extends to the center or near the center, and the upper surface of the first fixed substrate covered by the second fixed substrate covers the other upper surface of the first fixed substrate and the second fixed substrate. A magnetic sheet recording/reproducing device characterized in that the distance from the clamp level of the magnetic sheet is greater than the lower surface of the fixed substrate. 2. A patent claim characterized in that the first fixed substrate has an upper surface divided into a high surface portion that is 50 to 1500 μm away from the clamp level of the magnetic sheet and a low surface portion that is 6 mm or more away from the clamp level. A magnetic sheet recording/reproducing device according to item 1. 3. The magnetic sheet recording/reproducing device according to claim 1 or 2, wherein the second fixed substrate has a lower surface spaced from a clamp level of the magnetic sheet by 50 to 1500 μm. .