JPS6358618A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To decrease the tape winding value to a cylinder and to attain a compact and light-weight mechanism part by using two pairs of rotary heads and dividing a piece of track for each head to perform the recording/reproducing jobs. CONSTITUTION:A rotary part of a cylinder 22 contains heads 23-26. A pair of heads 23 and 24 having the same azimuth are set opposite to another pair of heads 25 and 26 of the same azimuth with a 180 deg. space secured between them. The heads 23 and 25 or 24 and 26 are set at approximately same position within the same rotary plane. While the head 24 or 26 corresponding to the head 23 or 25 are set so as to form a level difference delta in the direction vertical to the head rotary plane. The inter-gap distance between heads 23 and 25 or heads 24 and 26 is reduced less than the track length. Then those heads 23-26 are revolved at a frequency fv and a tape 21 is driven at a speed vt. Then the high density recording/reproducing jobs are possible with no guard band.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic recording and reproducing device suitable for an 8 mm video tape recorder (hereinafter referred to as 8 mm VTR) of a PCM multi-track system.

(Prior art) In recent years, demand for higher sound quality has increased in video tape recorders, and in 8mm VTRs, video signals and
In addition to the M audio signal (monaural), a method for converting the audio signal into PCM and recording and reproducing it in stereo has been standardized.

8mm VTRs can usually record and play back video signals and PCM audio signals at the same time (or after-record PCM audio signals), but there is also a system called a PCM multi-track system that records and plays only PCM audio signals. There is. In this system, a normal video track is divided into five equal parts, and together with the conventional PCM rack, it is possible to record and reproduce six channels of PCM audio signals.

FIG. 4 shows an outline of the recording pattern of the PCM multi-track system. According to this system, one track recorded on the tape 11 is divided into six 366 pieces and recorded as tracks T1 to T6. In this case, the amount of overlap is set to 5°. Also, the center of track T4 (video track center) and tape 1
1 and the track angle θ are standardized.

Since each PCM audio signal is recorded in stereo,
Each of the tracks T1 to T6 can be independently recorded and reproduced. When recording/reproducing one track at a time, the track TI.

For T3 and T5, the tape 11 is fed in the forward direction X1 at a tape speed vt. In addition, the track T2
．． For T4 and T6, the tape 11 is sent in the forward direction X1 or the reverse direction X2 at a tape speed vt. When the tape 11 is sent in the reverse X2 direction, reverse recording and reproduction becomes possible, and continuous recording and reproduction (auto-reverse function) becomes possible without rewinding the tape 11. In addition, in FIG. 4, X3 is the head rotation direction.

In order to obtain the above-described track pattern, an 8 mm VTR with a PCM multi-track system performs recording and reproduction using the configuration shown in FIG. That is, the tape 11 has a diameter of 40 mm.
It is wound over 221Q around the mm cylinder 12. This cylinder 12 is provided with a guide (hereinafter referred to as a lead) that supports the tape 11 diagonally.

Rotating magnetic head heads 13 and 14 having different azimuth angles are arranged facing each other at a distance of 180° from the rotating portion of the cylinder 12. The heads 13 and 14 are driven to rotate at a frequency of fv/2 (fv is the field frequency). This enables high-density recording and reproduction without guard bands.

As shown in FIG. 5, the magnetic heads 13 and 14 are supported without any step in the direction perpendicular to the head rotation surface.

By the way, in recent years, video equipment and audio equipment have become smaller.

With the increasing demand for weight reduction, 8mm VT
Even the R needs to be made smaller and lighter. However, in the current 8 mm VTR, it is difficult to make the mechanical parts smaller and lighter, and this is an obstacle to promoting smaller and lighter 8 mm VTRs.

(Problems to be Solved by the Invention) As described above, 8 mm VTRs have conventionally had the problem that it is difficult to make the mechanical parts smaller and lighter, making it difficult to reduce the overall size and weight.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic recording/reproducing device configured so that its mechanical parts can be made smaller and lighter.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention comprises a pair of rotating heads having a predetermined step in a direction perpendicular to the rotating surface of the heads.
Each head pair divides one track for recording and reproduction.

(Function) According to the above configuration, since the amount of tape wrapped around the cylinder can be reduced, the size and weight of the magnetic recording/reproducing device can be reduced.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing the configuration of one embodiment, but before explaining these diagrams, first, using FIG. 3,
An overview of one embodiment will be explained. In the following explanation, this invention will be described as an 8mm VTR with a PCM multi-track system.
We will explain the case where it is applied to as a representative.

FIG. 3 shows a tape pattern of one embodiment. Note that this figure shows the tape in a stationary state.

In FIG. 3, PCM tracks T6 are recorded on the tape 21 at 36° increments (the angle is based on a cylinder having a diameter of 40 mm). Track T1~
T6 is the first track group of T1 to T3 and T4 to T6.
The recording head is divided into a second group of tracks, and the head is mounted at a distance δ in the direction perpendicular to the rotational surface of the head, so that divided recording and one-divided reproduction are performed by two heads arranged so as to have a step difference. There are two pairs of heads like this, and the azimuth of the heads is the same in each desk, but in the rough space,
are configured differently. As a result, tracks having the same azimuth on one track (tracks consisting of tracks T1 to T6) but having different azimuths between adjacent tracks can be formed in the length direction of the tape.

Note that θ0 is the track inclination angle (cylinder lead angle) when the tape 21 is stationary.

This θ0 is the same as the lead angle of the cylinder 12 in FIG.

Here, for the installation, if the angle difference δ is (D Niji cylinder diameter 40M) and the distance between the center of the track T4 and the lower end of the tape 21 is set equal to that shown in FIG. For tracks 1, 3.5, forward direction X1, track T2 . Regarding T4°T6, by sending the data in the forward direction X1 or the reverse direction X2 at a speed vt, it is possible to record and reproduce tracks T1 to T6 in the same pattern as the pattern shown in FIG.

According to such a configuration, the necessary tape winding angle is 1
13' and about half that of FIG. 5, and if the winding is approximately the same but at an angle, the cylinder diameter can be halved.

In the case of the above configuration, although the track T3 and the track T4 are discontinuous, this does not pose a problem because the recording and reproduction of the PCM audio signal is performed independently for each channel.

Now, returning to FIGS. 1 and 2, the configuration of one embodiment will be described. In the figure, 22 is a cylinder with a diameter of 20 mm around which the tape 21 is wound.

The winding angle is 226°. In the cylinder 21,
The lead that supports the tape 21 diagonally is at an angle θ with the rotating surface.
0.

The rotating portion of the cylinder 22 is provided with heads 23 to 26. Among these, heads 23 and 24 form one head pair with the same azimuth, and heads 25 and 26 form the other head pair. The two heads in each set are 180Q
They are placed facing each other and separated from each other.

Note that the head 23 or 25 and the head 24 or 2
The distance between 6 and 6 is determined by considering the dynamic balance of the cylinder.
It is not necessary to provide them 180° opposite each other.

The heads 23 and 25 or the blades 24 and 26 are arranged at approximately the same position within the same rotation plane.

On the other hand, the head 24 or 26 corresponding to the head 23 or 25 is arranged so as to have a step δ in the direction perpendicular to the head rotation surface, as shown in FIG.

The distance between the gaps between the heads 23 and 25 or the heads 24 and 26 is sufficiently small relative to the track length, so the heads that were placed opposite each other at 180° in the case of a cylinder with a diameter of 40 mm will be placed opposite each other at 180° in the case of a cylinder with a diameter of 20 mm. In this case, they are arranged 360° apart.

In the above state, by rotating the heads 23 to 26 at a frequency fv and feeding the tape 21 at a speed Vj, guard panless high-density recording and reproduction can be performed, and the resulting recording pattern is similar to that of the conventional system shown in FIG. It perfectly matches the pattern recorded by.

As detailed above, according to this embodiment, the amount of tape wrapping can be reduced to half of the conventional amount, so the cylinder diameter can be reduced to half of the conventional one, and the tape can be pulled out from the cassette. Since the amount of tape to be converted when winding the tape diagonally around the cylinder is reduced, it is possible to make the 8mm VTR smaller and lighter.

In the above description, the present invention has been applied to a PCM multi-track system, but the number of tracks may be reduced, for example, the first track group may be replaced by track T1,
The second track group may be the track T2, and recording and reproduction corresponding to a high number of bits may be performed.

[Effect of the invention] As described above, according to the present invention, it is small.

A magnetic recording/reproducing device that can be made lightweight can be provided.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the configuration of an embodiment of the present invention, FIG. 3 is a diagram also showing the tape pattern, and FIGS.
FIG. 2 is a diagram for explaining a VTR. 21...Tape, 22...Cylinder, 23-26.
...Rotating magnetic head. Applicant's agent: Patent attorney Takehiko Suzue 1.

Claims (1)

[Claims] By scanning the magnetic recording medium obliquely with a rotating magnetic head that moves relative to the magnetic recording medium,
A magnetic recording and reproducing device for recording and reproducing signals has two pairs of rotating heads arranged with a predetermined step in a direction perpendicular to the head rotation surface, and each pair of heads records one signal. A magnetic recording and reproducing device characterized in that it is configured to record and reproduce by dividing a track.