JPH03259447A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a stable and enough floating amt. by introducing gas through a groove which is inclined to a rotary shaft of a rotary drum and extends to the vicinity of a head window and forming an air film out of the introduced gas between the rotary drum and a tape-like recording medium. CONSTITUTION:The rotary drum 14 to be rotated at a prescribed speed is wound with the tape-like recording medium 11 to be traveled at a prescribed speed, and a desired signal is recorded to the tape-like recording medium 11 or a signal recorded on the tape-like recording medium 11 is reproduced. In this case, the groove 30 inclined to the rotary shaft of the rotary drum 14 and extending to the vicinity of the heat window M is formed on the side surface of the rotary drum 14, and the gas around the rotary drum 14 is introduced via the groove 30, and then the air film is formed by the introduced gas between the rotary drum 14 and the tape-like recording medium 11. By this method, the stable and enough floating amt. can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a recording/reproducing device, and is particularly applicable to a recording/reproducing device such as a video tape recorder that records or reproduces a predetermined signal using a rotating drum. It is something.

B. Summary of the Invention The present invention enables a magnetic tape to be stably and sufficiently levitated in a recording/reproducing apparatus by forming oblique grooves extending to the vicinity of the head window on the side surface of a rotating drum.

C. Prior Art Conventionally, in a recording/reproducing apparatus such as a video tape recorder, a magnetic tape is wound around a rotating drum that rotates at a high speed, and the magnetic tape is run to record video signals.

For this reason, in this type of video tape recorder, an air film is formed between the rotating drum and the magnetic tape to levitate the magnetic tape by a minute amount from the rotating drum to prevent wear and scratches on the magnetic tape. being done.

That is, as shown in FIG.
A depth number [
A plurality of parallel grooves 4A, 4B, and 4C with a diameter of [μm] are formed, and an air film is formed with air flowing in from the scanning start end side of the magnetic head 5 through the parallel grooves 4A to 4C.

In addition, the side surface of the rotating drum 3 is finished to be extremely smooth, and the head window M that exposes the magnetic head 5
The magnetic tape was finished with a puff to prevent scratches on the magnetic tape.

D Problems to be Solved by the Invention However, in the air film formed by the parallel grooves 4A to 4C, there is a problem in that the flying height of the magnetic tape is insufficient near the connecting portion 8 between the fixed drum 2 and the rotating drum 3.

For this reason, in the magnetic tape, the edges of the fixed drum 2 and rotating drum 3 of the connecting portion 8 may come into contact with the edges of the head window M, and in this case, the magnetic tape will be damaged.

For this reason, in the conventional video tape recorder, if - time stop and still image playback are continued, the image quality of the playback image inevitably deteriorates.

In addition, there is a problem that the flying height of the magnetic tape becomes unstable.
In this case, the contact of the magnetic head 50 with respect to the magnetic tape changes, causing the signal level of the reproduced signal to fluctuate, or the magnetic tape to vibrate, causing fluctuations in the time axis, resulting in unevenness in the reproduced image.

As one way to solve this problem, for example,
Although it is possible to levitate the magnetic tape using the technique disclosed in Japanese Patent No. 9-110065, it is still insufficient in practice.

The present invention has been made in consideration of the above points, and aims to propose a recording/reproducing device that can obtain a stable and sufficient flying height.

8 Means for Solving the Problems In order to solve the problems, in the present invention, the tape-shaped recording medium 11 that runs at a predetermined speed is wound around the rotating drum 14 that rotates at a predetermined speed, and the tape-shaped recording medium 11 is In the recording/reproducing device 0 for recording a desired signal or reproducing the signal recorded on the tape-shaped recording medium 11,
A groove 30 is formed on the side surface of the rotary drum 14 and extends to the vicinity of the head window M so as to be inclined with respect to the rotation axis of the rotary drum 14, and gas around the rotary drum 14 is introduced through the groove 30. Then, an air film is formed between the rotating drum 14 and the tape-shaped recording medium 11.

7 Actions Gas is introduced into the groove 30 that extends to the vicinity of the head window M, which is inclined with respect to the rotation axis of the rotating drum 14, and the introduced gas forms an air film between the rotating drum 14 and the tape-shaped recording medium 11. For example, a stable and sufficient flying height can be obtained even near the head window M.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 2, 10 indicates the drive system of the video tape recorder as a whole, and the magnetic tape 11 runs at a predetermined speed.
is wound around the rotating drum 14 using the inclined guides 12 and 13.

As shown in FIG. 3, the rotating drum 14 is connected to the fixed drum 1.
5, and rotates at a predetermined speed in the direction indicated by the arrow with the drum shaft 16 as the central axis of rotation.

Further, each of the rotating drums 14 has a magnetic helad 1 at its tip.
Head bases 20 and 22 equipped with 7 and 18
They are arranged at an angular interval of 0 degrees, and the tips of the magnetic helads 17 and 18 protrude several tens [μm] from the side surface of the rotary drum 14 through a head window M provided on the side surface of the rotary drum 14. ing.

As shown in FIG. 1 when the side surface of the rotating drum 14 is expanded,
In the rotating drum 14, a plurality of grooves 30 extending obliquely from the open end side of the rotating drum (that is, the opposite side of the fixed drum 15) are formed around the entire circumference, and the grooves 30 allow the magnetic tape 11 to be stably and sufficiently It is made to float.

That is, the grooves 30 are formed on the side surface of the rotating drum 14, which has been sufficiently mirror-finished, using a photo-etching method, and the groove width is from several [μm] to several tens [μm], and the groove interval W is equal to the groove width. It is selected so that it becomes 1 to 10 times.

Further, the groove 30 extends in the direction opposite to the rotational direction of the rotary drum 14 at an angle α of approximately 30 degrees with respect to the open end side surface of the rotary drum 14, and its terminal end extends approximately 1 [■
) (position expressed in distance).

As a result, in the rotating drum 14, the conventional parallel groove 4
Instead of A to 4C, air is introduced through the grooves 30 to form an air film.

That is, the air introduced in the groove 30 forms a continuous fluid boundary layer along the groove 30, thereby causing the gap between the head window M, the fixed drum 15, and the rotating drum 14 located on the extension of the groove 30 to form a continuous fluid boundary layer. Even at E, the magnetic tape 11 can be sufficiently and stably levitated.

According to experiments, as shown by curve Ll in FIG.
In the case of parallel grooves 4A to 4C, the flying height changes to the negative side in the gap E between the fixed drum 15 and the rotating drum 14,
While the edges of the fixed drum 15 and the rotating drum 14 come into contact with the magnetic tape, in this embodiment, a flying height of several μm can be stably obtained even in the gap E, as shown by the curve L2. Understood.

Therefore, by obtaining a sufficient flying height, it is possible to effectively avoid abrasion and scratches on the magnetic tape, as well as clog of the magnetic head. Deterioration can be effectively avoided.

Furthermore, the magnetic tape can be used for a longer period of time.

Furthermore, by obtaining a stable flying height, the contact of the magnetic head against the magnetic tape can be stably maintained, and fluctuations in the signal level and time axis of the reproduced signal can be effectively avoided.

In fact, in conventional video tape recorders, when the contact between the magnetic head and the magnetic tape deteriorates, the only way to improve it is to increase the amount of protrusion of the magnetic head, which in turn ends up damaging the magnetic tape and repeating the vicious cycle. was.

However, according to this embodiment, the contact of the magnetic head against the magnetic tape can be stabilized without repeating such a vicious cycle.

In the above configuration, surrounding air is introduced between the side surface of the rotating drum 14 and the magnetic tape 11 through the groove 30 formed on the side surface of the rotating drum 14, and the introduced air reaches the groove 30 near the head window M. A continuous fluid boundary layer can be formed along the

As a result, the head window M located on the extension of the groove 30,
The magnetic tape 11 can be sufficiently and stably floated even in the gap E between the fixed drum 15 and the rotating drum 14.

According to the above configuration, by forming the groove 30 extending obliquely to the vicinity of the head window M on the side surface of the rotating drum 14, the air introduced through the groove 30 continues along the groove 30 to the vicinity of the head window M. A fluid boundary layer can be formed, and the magnetic tape 11 can be sufficiently and stably levitated.

In the above-described embodiments, the present invention is applied to a so-called upper drum rotation type magnetic recording and reproducing device in which a rotating drum is arranged on a fixed drum. However, the present invention is not limited to this. When applied to a magnetic recording and reproducing device of a so-called middle drum rotation type in which fixed drums 36 and 37 are arranged above and below a rotating drum 35 as shown in the figure, the entire structure is composed of a rotating drum 38 as shown in FIG. The present invention can be widely applied to magnetic recording and reproducing devices using a full-circumference drum rotation system.

In this case, as shown in FIG. 7, in the middle drum rotation method and the full circumference drum rotation method, the grooves 30 may be formed from above and below the rotating drum.

Further, in the above-described embodiment, the groove 30 is formed in a straight line, but the present invention is not limited to this, and the groove may be formed in a curved line if necessary.

Further, in the above-described embodiment, the groove 30 is formed all around the side surface of the rotating drum 14, but the present invention is not limited to this, and as shown in FIG. It may be formed only in the vicinity of .

Further, in the above-described embodiments, a case has been described in which the present invention is applied to a video tape recorder, but the present invention is not limited to this. It can be widely applied to

In this case, depending on the rotation speed, size, etc. of the rotating drum,
A stable and sufficient flying height can be obtained by changing the groove size, groove interval, groove inclination, and groove length to various values.

Further, the present invention is not limited to magnetic recording and reproducing devices, but can be widely applied to recording and reproducing devices using tape-shaped recording media.

In particular, when the rotational speed of the rotating drum is low as in a digital audio recorder, the flying height of the magnetic tape is extremely reduced in the conventional method using parallel grooves, and the magnetic tape becomes seriously damaged.

However, if the magnetic tape is levitated using the grooves formed diagonally in this manner, a stable and sufficient flying height can be obtained even when the rotational speed is low.

Effects of the Invention As described above, according to the present invention, the grooves extending to the vicinity of the head window are obliquely formed on the side surface of the rotating drum.
It is possible to form a continuous fluid boundary layer up to the vicinity of the head window with the gas introduced through the groove, and it is possible to obtain a recording/reproducing device that can sufficiently and stably levitate a tape-shaped recording medium.

[Brief explanation of drawings]

FIG. 1 is a developed view showing the side surface of a rotating drum according to an embodiment of the present invention, FIG. 2 is a plan view showing its overall configuration, FIG. 3 is a side view thereof, and FIG. 4 is a characteristic showing its floating characteristics. 5 and 6 are side views showing another embodiment, FIGS. 7 and 8 are developed views showing the side of a rotating drum according to another embodiment, and FIG. 9 is a conventional videotape. It is a perspective view showing a recorder. 2.15.36.37...Fixed drum, 3.1
4.35.38...Rotating drum, 4A to 4C1
30...groove, 5.17.18...magnetic head, 11...magnetic tape, M...
head window. Figure 4 H

Claims (1)

[Claims] A tape-shaped recording medium running at a predetermined speed is wound around a rotating drum rotating at a predetermined speed, and a desired signal is recorded on the tape-shaped recording medium, or a desired signal is recorded on the tape-shaped recording medium. In a recording/reproducing device for reproducing a signal transmitted from the rotary drum, a groove is formed on a side surface of the rotary drum, the groove is inclined with respect to the rotation axis of the rotary drum and extends to the vicinity of the head window, and the groove around the rotary drum is formed through the groove. A recording/reproducing apparatus characterized in that a gas is introduced, and the introduced gas forms an air film between the rotating drum and the tape-shaped recording medium.