JPS62298013A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To generate no tracking shift even if a recording phase and a reproducing phase are different from each other, and to satisfactorily reproduce a signal by adjusting the height for attaching a reproducing head to a rotary drum, in accordance with a meandering state of a magnetic tape. CONSTITUTION:For instance, it is supposed that a signal S1 has been recorded in a position of height H1 from the lower end of a tape 1, by a recording head 2 in a position P1. The signal S1 is reproduced by a reproducing head 3 in a position P2. However, since the tape 1 is meandering, when the head 3 has been attached to height being equal to that of the head 2, a position of height H2 from the lower end of the tape 1 being lower than the height in which the signal S1 has been recorded is scanned as shown by a broken line, and a tracking shift is generated. Therefore, in accordance with a meandering state of the tape 1, the height for attaching the head 3 to a rotary drum is adjusted. Therefore, a scan on the signal S1 recorded in a position of the height H1 can be executed by the head 3, and the signal can be satisfactorily generated.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a rotating magnetic head device used in a helical scan type video tape recorder, etc. The present invention relates to a device comprising a recording-only head for recording signals and a reproduction-only head for reproducing signals recorded by the head.

B0 Overview of the Invention The present invention is used in a helical scan type video tape recorder, etc., and includes a recording head for recording a signal on a portion of a magnetic tape, and a playback device for reproducing the signal recorded by the head. In a rotating magnetic head device having a head, the mounting height of the reproducing head on the rotating drum is adjusted according to the meandering state of the magnetic tape, so that the recording phase and the reproducing phase are different. Despite this, tracking deviation does not occur and good signal reproduction can be performed.

BACKGROUND OF THE INVENTION Conventionally, so-called 1.5-head type Ω-wound video tape recorders have been known that adopt the SMPTE and IEC type C formats.

In addition to the main head for recording/reproducing video signals, this video tape recorder is equipped with an auxiliary head (head 0,5) for recording/reproducing the vertical synchronization signal portion. The signals are divided and recorded on the magnetic tape, and when played back, a completely continuous video signal with no missing parts can be obtained.

D1 Problems to be Solved by the Invention Incidentally, a video tape recorder has been proposed in which a digital audio signal is recorded/reproduced on a sync track in a lower area of the tape, which is used as a recording area for a vertical synchronizing signal portion. In such a videotape recorder,
Due to the time required for digital signal processing, dedicated heads are used for recording and reproduction, and in many cases there is a wall that causes the reproduction head to scan the tape in advance of the recording head. In this case, the reproducing head and the recording head are arranged on the rotating drum at a predetermined angular interval.

In other words, the recording phase and the reproduction phase are different. However, due to the influence of so-called reeds provided on the outer circumferential surface of the fixed drum to adjust the position of the tape and guide bins near the drum, the tape usually runs in a meandering manner on the outer circumferential surface of the drum. , there was a risk that tracking deviation would occur.

Therefore, the present invention was proposed in view of the above-mentioned conventional problems, and it is possible to perform good signal reproduction without causing tracking deviation even if the recording phase and the reproduction phase are different. The purpose of the present invention is to provide a rotary magnetic head device that is capable of rotating.

Means for Solving the E0 Problem In order to achieve the above-mentioned object, the rotary magnetic head device of the present invention includes a recording head for recording a signal on a part of a magnetic tape, and a recording phase control by this recording head. a rotary drum having a reproducing head that performs reproducing operations in a phase different from that of the reproducing head, a head height adjusting means for adjusting the height of the reproducing head, and a tape position that adjusts the position of the magnetic tape while it is running. and a fixed drum having regulating means on the outer circumferential surface, and the mounting height of the reproducing head on the rotating drum is adjusted according to the meandering state of the magnetic tape by the tape position regulating means of the fixed drum. It is characterized by

21 Effects According to the present invention, the mounting height of the reproducing head on the rotating drum is adjusted according to the meandering state of the magnetic tape, and the scanning locus of the reproducing head corresponds to the recording pattern of the signal recorded by the recording head. It almost matches.

G. Example G-1 Basic Principle First, the basic principle of the present invention will be explained with reference to FIG. As described above, the magnetic tape 1 normally runs in a meandering manner on the outer circumferential surface of the fixed drum due to the influence of the reed, which is a position regulating means provided on the outer circumference i of the fixed drum, the guide pin near the drum, and the like. In this FIG. 1, the tape 1 is held down at position P, and
2 and is pressed upwards. The above positions P, P2 are absolute positions that do not move as the tape 1 runs. A recording head 2 dedicated to recording and a reproducing head 3 dedicated to reproduction are arranged on a rotating drum at a predetermined angular interval, and the recording head 2 performs a recording operation on a part of the tape 1 near position P1, It is assumed that the reproducing head 3 performs a reproducing operation near position P2.

Now, for example, as shown in FIG. 1(A), position P1
Assume that a signal S is recorded by the recording head 2 at a height Hl from the bottom end of the tape 1.

This signal S, as shown in FIG.
The data is reproduced by the reproduction head 3 at the time. However,
Since the tape 1 is meandering, if the playback head 3 is installed at the same height as the recording head 2, the tape will be lower than the height at which the signal S is recorded, as shown by the broken line in the figure. 1, a position at a height H2 from the lower end of the image 1 is scanned, resulting in tracking deviation. Therefore, in the present invention, the mounting height of the reproducing head 3 on the rotating drum is adjusted according to the meandering state of the tape 1, and the signal S recorded on the reproducing head 3 at the height H1, This allows for good signal reproduction.

G-2. Configuration and Operation Next, a rotating magnetic head device according to an embodiment of the present invention will be specifically described. The rotating magnetic head device of this example is as follows:
As shown in FIG. 2, it consists of an upper drum 10 which is a rotating drum and a lower drum 20 which is a fixed drum. A lead 21 serving as a tape position regulating means is provided on the outer circumferential surface of the lower drum 20, and the position of the magnetic tape (not shown here) is adjusted while it is running. Specifically, the tape is slightly bent upward by the shoulder portion 21A. Further, the tape is slightly bent downward by guide pins 31 and 32 near the lower drum 20. This results in the tape meandering, for example as shown in FIG. Although there are varying degrees of tape meandering, such tape meandering inevitably occurs in all video tape recorders.

As shown in FIG.
Modulation) A recording head 12 for recording audio signals and a reproducing head 13 for reproducing the recorded audio signals are provided. video head 1
The recording head 1 and the recording head 12 are arranged at an angular interval of about 120° from each other, and the recording head 12 and the reproducing head 13 are arranged at an angular interval of about 90° from each other. Therefore, when the recording phase and the reproduction phase are different, the reproduction head 13 is
As will be described later, a track that is 3V (V: field period) ahead of the recording head 12 is scanned in advance. The magnetic tape 41 is wound (loaded) over substantially the entire circumference of the drum, and is guided by the guide pins 31 and 32. In addition, the above-mentioned upper drum 10 includes:
In reality, many more heads are provided in addition to the heads 11, 12, and 13 described above, but they are omitted in this embodiment to simplify the explanation.

4 and 5 show the structure around the reproducing head 13 in an enlarged manner. A reproducing head 13 (head chip) is attached to the tip of a protruding portion of a head base 14, and the head base 14 is fixed to the upper drum 10 with a set screw 16 via a height adjustment spacer 15. . The spacer 15 is fixed to the upper drum 10 by a set screw 17. Furthermore, a push screw 19 is provided in the screw hole 10A of the upper drum 10, which together with the parallel pin 18 constitutes a head height adjusting means. The above-mentioned parallel pin 18 is provided between the above-mentioned push screw 19 and herad pace 14, and by rotating the push screw 19, the head base 1
The degree of deflection of the head 13 can be changed, and the height of the head 13 can be adjusted.

The push screw 19 is finely threaded, and can be finely adjusted by, for example, about 1 μm per 1° of rotation angle. Further, the other heads 11 and 12 have a similar structure to the above, allowing fine adjustment of the mounting height. These head height adjustments can be performed using an optical microscope and a test tape, or can be performed using only an optical microscope.

FIG. 6 shows the signal recording pattern. The upper and lower regions of the magnetic tape 41 are audio tracks 42, 43 and 44 for audio signals, respectively.
It becomes. The region below the audio track 43 is a video track 45 for a video signal, and by the recording operation of the video signal by the video head 11, each video track TN, TN+1, . . . is formed with a second shadow. The area below this video trunk 45 is a control track 46 for control signals (CTL signals). Above audio track 42.43
44 and the control track 46, each signal υ is recorded by each fixed head (not shown), respectively. The area between the control track 46 and the audio trunk 44 is an audio track 47 for digital audio signals.
N,)H+1.

... are formed sequentially.

During the same rotation of the upper drum 10 (within the IV period), the video head 11 scans the video track TN, the recording head 12 scans the audio track AN, and the playback head 13 advances by 3v compared to the recording head 12. The track AN+3, which the recording head 12 scans 3v later, is scanned in advance. Here, upper drum 10
The order in which each head starts contacting the magnetic tape 41 within the same rotation of the playback head 13 is, for example,
, recording head 12, and video head 11 in this order. The reproducing head 13 is attached to the upper drum 10 at a height that depends on the meandering state of the tape 41 by a head height adjusting means (see FIGS. 4 and 5) consisting of the parallel pin 18 and the push screw 19. It has been adjusted.

During the IV period in which the video signal is recorded on the video track TN by the video head 11, the recording head 12 records a digital audio signal on the audio track AN.

However, since digital signal processing (including encoding, etc.) for recording requires 2V time, the audio signal recorded on the above track AN corresponds to the video signal 2V before, and the audio signal recorded on the above track AN corresponds to the video signal 2V before. The audio signal corresponding to the TN video signal is shown in audio track A with diagonal lines.
Recorded 2v later on N+2.

On the other hand, during reproduction, the audio signal reproduced from each audio track by the reproduction head 13 is output after a signal processing time of 1 V is required. Therefore, the audio track AN+2 in which the audio signal corresponding to the video signal of the video track TN is recorded is scanned by the playback head 13 during the period IV before the video track TN is scanned,
It is output in synchronization with the output period of the video signal of the video track TN. From the above explanation, the playback head 13
It will become clear why the recording head 12 scans a track υ further advanced by 3v.

As mentioned above, the playback head 13 is connected to the upper drum 10.
Since the installation height of the tape 41 is adjusted according to the meandering state of the tape 41, the scanning locus of the reproducing head 13 during reproduction will be the same as that of the recording head 12, even though the recording phase and the reproduction phase are different. This substantially matches the recording pattern of the audio signal recorded by the above method, and thus good signal reproduction is performed.

Note that the present invention can also be applied to a device in which the tape position regulating means are provided dispersedly on the outer peripheral surface of the fixed drum.

Effects of the Invention As is clear from the description of the embodiments described above, in the rotating magnetic head device of the present invention, the mounting height of the reproducing head on the rotating drum is adjusted according to the meandering state of the magnetic tape. Even if the recording phase and the reproduction phase are different, tracking deviation does not occur and good signal reproduction can be performed.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the basic principle of the present invention, Fig. 2 is a side view schematically showing a rotating magnetic head device according to an embodiment of the invention, and Fig. 3 is a diagram for explaining the basic principle of the present invention. FIG. 4 is an enlarged plan view showing the structure around the reproducing head, FIG. 5 is an enlarged side sectional view of the main part, and FIG. 6 is a diagram showing the signal recording pattern. 1.41... Magnetic tape 2.12... Recording head 3.13... Playback head 10... Upper drum 18... Parallel pin 19... Push screw 20... Lower drum 21. ...Lead 21A...shoulder part

Claims (1)

[Claims] A recording head for recording a signal on a part of a magnetic tape, a reproducing head that performs a reproducing operation in a phase different from the recording phase by this recording head, and adjustment of the mounting height of this reproducing head. a rotating drum having head height adjusting means for adjusting the position of the magnetic tape; and a fixed drum having tape position adjusting means on its outer circumferential surface for adjusting the position of the magnetic tape while it is running; A rotating magnetic head device characterized in that a mounting height of the reproducing head on the rotating drum is adjusted depending on a meandering state of the meandering magnetic tape.