JPH0512768A - Pressure pad and magnetic recording and reproducing device using the same - Google Patents

Abstract

PURPOSE:To perform stable and excellent magnetic recording and reproduction by perform excellent recording and obtaining a head output by the magnetic recording and reproducing device by stably pressing a magnetic tape against a magnetic head, and also suppressing time-base variation such as a wow and a flutter as trouble in a recording and reproducing process. CONSTITUTION:The pad 1 supported by a pad support part 10 contacts the magnetic tape at a part A and is pressed against the magnetic head across the magnetic tape. The magnetic head and magnetic tape contact each other to perform the magnetic recording and reproduction. A material with a low coefficient of friction such as fluororesin (PTFE: tetrafluoroethylene resin, etc.) is used for a decrease in the friction coefficient of the part A to decrease the coefficient of friction between the magnetic tape and pad 1 and further reduce the difference between the dynamic friction coefficient and stationary friction coefficient. Consequently, the generation of a stick slip is suppressed to perform the stable and excellent magnetic recording and reproduction without deterioration such as a wow and a flutter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure pad used in a magnetic recording / reproducing apparatus having a fixed magnetic head and a magnetic recording / reproducing apparatus having the pressure pad.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus using a fixed type magnetic head, in order to improve the magnetic interaction (recording / reproducing) between the magnetic tape and the magnetic head, It is necessary to reduce the distance (so-called spacing). For this purpose, the following method is adopted.

FIG. 5 shows an example of a conventional magnetic recording / reproducing apparatus using a tape medium. The magnetic tape 60 wound around the supply reel 22 serves as the capstan 31 and the pinch roller 3.
It is pinched by 2 and driven, and is transferred to the take-up reel 21 and wound up. A magnetic head 50 is arranged in the middle of the tape transfer path, and magnetic recording and reproduction are performed. At this time, a tape tension T is applied to the magnetic tape 60 as shown in FIG.
By wrapping it around 0, the spacing is reduced, and good recording and reproduction are performed. However, this method requires a means for generating the tape tension T. For example, various controls are required to generate a stable and constant tape tension, such as controlling the torque so as to apply a torque to the take-up reel 22 in the opposite direction to the tape feeding direction.

Another method is, for example, the method shown in FIG. This is a method used for audio compact cassette tapes and the like. That is, the pressure pad 1 is used to press the magnetic tape 60 against the magnetic head 50. in this way,
As mentioned above, it has the advantage that the tape tension does not have to be highly stabilized. This felt pad is
Since a material using wool or rabbit hair is used, there is almost no problem when used for a usual audio cassette tape or the like.

[0005]

However, in response to the recent increase in recording density in magnetic recording, the track width has been reduced and the recording wavelength has been shortened. It has become difficult to secure a stable head touch so that magnetic recording and reproduction can be performed satisfactorily and stably.

Further, due to friction between the felt pad and the tape, an abnormal noise called tape squeal is generated, which causes a hearing problem. At the same time, the vibration of the tape causes disturbances such as wow flutter and jitter in the time axis direction of the magnetic recording / reproducing process. The magnetic recording and reproducing may be adversely affected. In particular, this phenomenon is apt to appear when the running speed of the tape or the material of the tape is changed, which is a serious problem.

In view of these problems, it is an object of the present invention to provide a pressure pad for a magnetic recording / reproducing apparatus which secures a stable head touch and has good characteristics without tape squeaking.

[0008]

In order to achieve the above object, the present invention is directed to a pressure pad for pressing a magnetic tape against a magnetic head, and a difference between a dynamic friction coefficient and a static friction coefficient at a portion abutting the magnetic tape. Is a pressure pad characterized by using a small material.

The present invention is also a pressure pad for pressing a magnetic tape against a magnetic head, characterized in that a material having a low friction coefficient is used in a portion contacting the magnetic tape.

Further, the present invention is a magnetic recording / reproducing apparatus having the above-mentioned pad.

[0011]

The pad is configured so that the difference between the dynamic friction coefficient and the static friction coefficient is small at the portion contacting the magnetic tape and the magnetic head, so that the pad can be connected to the pad regardless of the change of the tape speed or the tape material. Since the frictional force between the tapes is almost constant while the tapes are running, the stick-slip phenomenon does not occur and the tape squeal is suppressed. The stick-slip here refers to an intermittent relative movement that occurs due to the difference between the dynamic friction and the static friction between the tape and the pad, which causes the vibration of the tape and the squeaking of the tape.

Further, by reducing the friction coefficient, the difference between the dynamic friction and the static friction is inevitably reduced, and the same effect as the above can be obtained. As a result, a stable head touch can be obtained, and good magnetic recording and reproduction can be performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In each embodiment, the same symbol is given to a portion having the same function.

<First Embodiment> FIG. 1A shows a first embodiment. This is one in which the pad material 1a is arranged on the pad supporting portion 10a, and the portion A contacts the magnetic head via the tape. The arrangement of the pad support portion 10a and the pad material 1a is the same as in the example of FIG. The pad support portion 10a also elastically deforms and has a function of adjusting the pressing force for pressing the pad material 1a against the magnetic tape 60 and the magnetic head 50. The cross-sectional view is shown in FIG. For example, a non-woven fabric, a felt-like material, or a porous material is used so that the elastic modulus of the pad material 1a has a value such that the portion A is deformed along the head when pressed against the head. The material of the pad material 1a includes, for example, PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), FEP (tetrafluoroethylene hexafluoropropylene copolymer resin) and the like. A low friction coefficient material is used to reduce the frictional force between the tape surface and the magnetic head, or to reduce the difference between static friction and dynamic friction.

For example, the pad material 1a is a felt composed of PTFE fibers, and in order to improve the flatness of the surface, the surface is compressed and smoothed, and the lower part has a double structure composed of a normal felt. By using it, the contact state with the tape is made uniform, and the frictional force and the difference between static friction and dynamic friction are reduced.

In the conventional wool and rabbit felts, the coefficient of friction with respect to the magnetic tape 60 is 0.3 to 0.6, and the difference between the dynamic friction coefficient and the static friction coefficient is 0.1 to 0.2. It was In the pad of this embodiment, the friction coefficient is 0.
It is 1 to 0.25, and the difference between the dynamic friction coefficient and the static friction coefficient is a value of approximately 0 to 0.05, which shows that the value is extremely low.

As described above, the pad material 1a is deformed when it is pressed against the magnetic head 50 with the magnetic tape 60 interposed therebetween, and the elastic modulus is selected so as to follow the surface shape of the magnetic head 50. As a result, the distance (spacing) between the magnetic head 50 and the magnetic tape 60 can be stably maintained at a good value, and a good head touch can be obtained.

On the other hand, it is the vibration of the magnetic tape 60 that causes tape squeal and wow and flutter, and the stick slip between the magnetic tape 60 and the pad 1a induces this vibration. Stick-slip is a phenomenon caused by a large difference between the dynamic friction coefficient and the static friction coefficient.

In this embodiment, the contact portion A and the magnetic tape 60 are used.
The difference between the frictional force and the dynamic friction is small.
Therefore, stick-slip does not occur, and good recording and reproduction can be performed without problems such as tape squeal, wow and flutter, and deterioration of jitter.

The felt-like material may be prepared by needle punching or the like, and the porous material may be foamed sponge-like material.

<Second Embodiment> FIG. 2 shows a sectional view of a second embodiment. In this, a support 2b made of a material having a low elastic modulus (for example, foaming resin (sponge-like), rubber, sponge-like rubber, felt, etc.) is arranged on the pad support portion 10b, and a magnetic tape and a magnetic head are provided on the support 2b. A sheet-shaped contact member 1b (for example, a fluororesin sheet, a fluororesin cloth, or the like) made of a material having a low friction coefficient is arranged. As the material, PTFE (4
Fluorinated ethylene resin), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), FEP (4
Low friction coefficient materials such as fluorinated ethylene hexafluoride propylene copolymer resin) are used. For example, a GORE-TEX sheet manufactured by Japan GORE-TEX Co., Ltd. and having a thickness of about 0.1 mm is used.

When the pad is pressed against the magnetic head 50 with the magnetic tape 60 sandwiched therebetween, the support 2b having a low elastic modulus is deformed together with the sheet-shaped contact member 1b so that the surface shape of the magnetic head 50 is formed. It comes along. As a result, a good head touch can be obtained as in the first embodiment. Further, as in the case of Example 1, the pad of this example has a friction coefficient of 0.1 to 0.25.
And the difference between the coefficient of dynamic friction and the coefficient of static friction is approximately 0
The value is 0.05, which is a very low value. Therefore, the friction coefficient at the contact portion A is low,
The difference between the dynamic friction and the static friction of the generated frictional force is small, so that stick-slip does not occur, and good recording and reproduction can be performed without problems such as tape squeaking.

Further, in FIG. 2, the contact member 1b wraps around the side surface of the support body 2b to a position where it contacts the pad support portion 10b, but only the surface portion contacting the tape is contact member 1b.
May be formed so as not to go around the side surface of the support 2b.

The sheet-like contact member 1b may be, for example, a cloth-like woven product or a product which has undergone processing such as surface smoothing processing by calendering.

<Third Embodiment> FIG. 3 shows a sectional view of a third embodiment. This is one in which a loop-shaped member 1c made of a fibrous material having a low friction coefficient with respect to the magnetic tape 60 and the magnetic head 50 is formed on the pad support portion 10c. As the fibrous material, P as in the case of Example 1
TFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin),
Low friction coefficient materials such as FEP (tetrafluoroethylene hexafluoropropylene copolymer resin) are used. The loop-shaped member 1c has a structure in which fibers are embedded in a pile shape. The loop-shaped member 1c comes into contact with the magnetic head 50 via the magnetic tape 60 at the portion A. For this reason,
When the member 1c is pressed against the magnetic head 50, bending deformation of the fiber occurs, and this bending deformation easily occurs, so that the surface shape of the magnetic head 50 is easily followed.

As a result, a good head touch is obtained, and the difference between the dynamic friction and the static friction of the frictional force generated due to the low friction coefficient at the contact portion A is small as in the first embodiment, which causes stick-slip. In addition, good recording and reproduction can be performed without problems such as squeaking of tape.

<Fourth Embodiment> FIG. 4 shows a sectional view of a fourth embodiment. This is a sheet-shaped material fixed on the pad support portion 10d at the peripheral edge portion 3d. Pad support 1
A portion 2d surrounded by 0d and the sheet material 1d is kept airtight, and a gas such as air or a viscous fluid is sealed. The sheet material 1d is made of a material having a low friction coefficient with respect to the magnetic tape and the magnetic head (for example, a fluorine resin sheet, a rubber sheet having a low friction coefficient material mixed therein). The fluororesin used for the sheet material 1d will be described in more detail, for example, PTFE (tetrafluoroethylene resin), PFA.
(Tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), FEP (tetrafluoroethylene hexafluoropropylene copolymer resin), and other materials. Part 2
The gas or liquid sealed in d is deformed when the contact portion A is pressed against the magnetic head with the magnetic tape sandwiched therebetween, and follows the surface shape of the magnetic head. As a result, a good head touch is obtained, and the difference between the dynamic friction and the static friction of the friction force generated due to the low friction coefficient at the contact portion A is small as in the first embodiment. Good recording and reproduction can be performed without problems such as squeaking.

Although several kinds of examples of the embodiments of the present invention have been described above, the magnetic tape and the portion A are brought into contact with each other by making the members 1a to 1d and the pad supporting portions 10a to 10d conductive in each example. Further, it is possible to suppress the occurrence of electrification of the magnetic tape due to friction, and to prevent uneven winding of the tape due to electrification of the tape, adhesion of dust to the tape, and generation of noise exerted on the magnetic head.

In each of the examples, the members 1a to 1d are shown as examples in which a fluorine-based resin is used, but it goes without saying that any material can be used as long as it satisfies the requirements of the present invention in terms of friction coefficient. Absent.

[0030]

As described above, the magnetic recording / reproducing apparatus using the pad for the magnetic recording / reproducing apparatus according to the present invention does not have a problem such as tape squeaking, a good and stable head touch is obtained, and the tape tension is applied from the outside. Since it is not necessary to stabilize the magnetic recording / reproducing apparatus, it is possible to provide an inexpensive and highly reliable magnetic recording / reproducing apparatus.

Further, in the case where the tape is constructed to have a low friction coefficient, the frictional force which is a loss when the tape is driven can be reduced, so that the tape driving force can be suppressed to be small and the power consumption is low. It is possible to provide the magnetic recording / reproducing apparatus.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining a mechanism for obtaining a head touch in a conventional magnetic recording / reproducing device.

FIG. 6 is an explanatory diagram for explaining a pad mechanism in the magnetic recording / reproducing device.

[Explanation of symbols]

1 pad 2 support 10 Pad support 21 Take-up reel 22 Supply reel 31 Capstan 32 pinch rollers 41, 42, 43, 44 Tape guide 50 magnetic head 60 magnetic tape

Claims (5)

[Claims] 1. A pressure pad for pressing a magnetic tape against a magnetic head, characterized in that a material having a small difference between a dynamic friction coefficient and a static friction coefficient is used in a portion in contact with the magnetic tape. 2. A pressure pad for pressing a magnetic tape against a magnetic head, characterized in that a material having a low friction coefficient is used in a portion contacting the magnetic tape. 3. A pressure pad for pressing a magnetic tape against a magnetic head, wherein a film-like or cloth-like portion is provided at a portion in contact with the magnetic tape.
A pressure pad comprising a sheet member having a small difference between a dynamic friction coefficient and a static friction coefficient, and an elastically deformable member being used as a main structure for supporting the sheet member. 4. A pressure pad for pressing a magnetic tape against a magnetic head, comprising: a film-like or cloth-like portion at a portion contacting with the magnetic tape,
A pressure pad, wherein a sheet member having a low coefficient of friction is arranged, and an elastically deformable member is used as a main structure for supporting the sheet member. 5. A magnetic recording / reproducing apparatus comprising the pressure pad according to claim 1, 2, 3, or 4.