JPH0349121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for magnetic recording and reproducing control signals for locating information signals recorded on desired tracks on a magnetic recording medium.

For example, as a method for magnetically recording and reproducing control signals for positioning audio signals recorded on audio tracks in audio magnetic recording and reproducing, a method has been proposed in which a coded control signal is recorded between audio signals on an audio track. However, in this method, if the blank part between audio signals is short, it is not possible to record a control signal in this blank part, and when rewriting the code content, the audio signals before and after it must be erased. There was a drawback that the control signal could not be rewritten. In addition, methods for recording control signals between audio tracks other than audio tracks have also been proposed, but such conventional methods require dedicated recording and playback heads for control signals, and are particularly useful for cassette tape recorders. However, it had the disadvantage that it could not be used in practice due to limitations such as head arrangement.

The present invention aims to solve such conventional drawbacks, and will be explained below using one embodiment.

In FIG. 1, 1 indicates a magnetic tape, and this magnetic tape 1 is used for audio magnetic recording and reproduction.
Use a track stereo cassette tape.

A forward audio track 2 is provided in the lower half of the magnetic tape 1, and a backward audio track 3 is provided in the upper half. Each of them consists of left channel audio tracks 2L, 3L and right channel audio tracks 2R, 3R.

Then, each audio track 2L, 2R, 3L, 3
A blank track is provided between the channels R to prevent crosstalk between the tracks. In this embodiment, each blank track between the left and right channels is used as a control track 4, 5.
Audio signal positioning control signals are recorded on the top.

Hereinafter, a detailed explanation will be given using the forward direction audio track 2.The left and right channel audio track 2
On L and 2R, audio signals 6 ₁ , 6 _{2 .} . . such as music are recorded with magnetization directions parallel to the running direction of the magnetic tape 1, and at the starting ends of each of these audio signals 6 ₁ , 6 ₂ . Each blank section 7 ₁ , 7 ₂ ... between the preceding audio signals
The control signals 8 ₁ , 8 _{2 .} . . are recorded at respective positions on the control track 4 corresponding to the audio signals 6 ₁ , 6 ₂ .

Recording and reproducing of the control signals 8 ₁ , 8 _{2 .} . . is performed using a magnetic head used for recording or reproducing the audio signals 6 ₁ , 6 ₂ .

The magnetic head 9 is one example of audio signals 6 ₁ , 6 ₂ . . .
As shown in FIGS. 2 and 3, the left channel core 10 corresponds to the left and right channel audio tracks 2L and 2R, respectively.
In each track contact portion 11L, 11R of the L and right channel core 10R, there is an operating gap 12L for reproducing the audio signals 6 ₁ , 6 ₂ . . . in a direction perpendicular to the running direction A-A of the magnetic tape 1. 12R are formed respectively, and coils 13L, 14L and 13R, 14R are wound in a balanced manner around each core 10L and 10R, respectively.

15 is a spacer forming a non-magnetic layer between the core 10L and the core 10R, and control signals 8 ₁ , 8 ₂ . . .
When recording control signals 8 ₁ , 8 ₂ . . . , it acts as an operating gap for recording. As shown in FIG. 4, in the left channel core 10L, each coil 13L, 14L is wound counterclockwise when viewed from the working gap 12L side, and one end aL,
bL are connected to each other and grounded, and their other ends cL and dL are connected to movable contacts of switches SW ₁ and SW ₂ , respectively. Each switch SW ₁ ,
One fixed contact of SW ₂ is connected to an input terminal 16 to which a control signal coded with a sinusoidal signal of, for example, 5 Hz is applied, and the other fixed contact of each switch SW ₁ and SW ₂ is connected to a differential They are connected to the − input terminal and + input terminal of the amplifier 17L, respectively. In addition, in the right channel core 10R, each coil 13R, 14R is wound clockwise when viewed from the working gap 12R side, and one end of each coil is aR, bR.
are connected to each other and grounded, and their other ends cR and dR are respectively connected to movable contacts of switches SW ₃ and SW ₄ . One fixed contact of each switch SW ₃ and SW ₄ is connected to the input terminal 16, and the other fixed contact of each switch SW ₃ and SW ₄ is connected to the differential amplifier 1.
It is connected to the + input terminal and - input terminal of 7R, respectively.

Note that 18L and 18R indicate output terminals for left and right channels, respectively.

The magnetic head 9 configured as described above switches each switch SW 1 to SW ₁ when recording the control signals 8 ₁ , 8 ₂ .
SW ₄ is connected to the illustrated embodiment. When a coded control signal to be recorded is applied from the input terminal 16 together with a required bias current, for example, the positive or negative 1 of the sine wave signal corresponding to the code "1" is applied.
Core 10 for left and right channels in response to cycles
Magnetic poles of opposite polarity are alternately and simultaneously formed on each of the track contact portions 11L and 11R of L and 10R, and as shown in FIG. In order to generate the magnetic field 19, control signals _{8 1} , _{8 2 .}

Next, the control signals 8 ₁ , 8 ₂ recorded in this way
. . ., the switches SW ₁ to _{SW 4} are connected to the side shown by the broken line, and the magnetic head 9 functions as a normal reproduction head. That is, the audio signals 6 ₁ , 6 ₂
In order to position the magnetic head 9 in a tape transport mode faster than the normal playback speed, the magnetic head 9
control signals 8 ₁ ,
Among the magnetic field components of 8 ₂ ..., audio signals 6 ₁ , 6 ₂ ...
Detect magnetic field components parallel to the magnetization direction of... The detection signal from the left channel core 10L passes through the differential amplifier 17L and is output from the output terminal 18L.
In addition, the detection signal from the right channel core 10R is taken out from the output terminal 18R through the differential amplifier 17R, and then subtracted by a required circuit to form a reproduction control signal, whose code content is readable. It will be done.

When the head position of the desired audio signal is detected in this positioning mode, the magnetic tape 1 is transported at the normal playback speed. The magnetic head 9 transmits the audio signals recorded on the left and right audio tracks 2L and 2R, respectively, with the magnetization direction parallel to the tape running direction A-A, through the working gaps 12L and 12R of the cores 10L and 10R for the left and right channels. The reproduced signal is taken out from the output terminals 18L and 18R.
In addition, in positioning mode, only the control signal component is
Further, in the normal reproduction mode, a necessary filter circuit (not shown) is provided in the reproduction system circuit so that only the audio signal component is extracted.

Also, to erase the control signals 8 ₁ , 8 _{2 . .} . , supply the required erasing current from the input terminal 16 with each switch SW ¹ to SW ₄ connected to the solid line side in the figure, as in the case of recording. This is done by

Note that the control signals recorded and played back by the method of the present invention are not limited to the positioning signals of the embodiments, but also the playback signals.
In the case of a magnetic recording/reproducing device that automatically switches between EQ, noise reduction, etc. using a coded signal recorded on a magnetic tape, such an operation switching signal may be used.

According to the present invention, the information signal recording or reproducing head can be used for recording or reproducing a control signal, and since the control signal is provided between the information tracks, its practical value is extremely high.

Furthermore, in the past, control signals were recorded in opposite phases for the left and right channels, and during playback, reproduction control signals with opposite phases were obtained from the left and right channels, thereby making it easier to distinguish between information signals and control signals. According to this method, there is an advantage that reproduction control signals having mutually opposite phases can be obtained from the left and right channels by recording only one control signal.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining one embodiment of the present invention, FIG. 3 is a diagram showing one embodiment of a magnetic head used in the present invention, and FIG. 4 is a circuit diagram used in the present invention. are shown respectively. 1...Magnetic tape, 2L, 2R, 3L, 3R...
...audio track, 6 ₁ , 6 ₂ , 6 ₃ ... audio signal,
8 ₁ , 8 ₂ , 8 ₃ ... control signals.

Claims (1)

[Scope of Claims] 1. In order to record and reproduce information signals on first and second information tracks on a magnetic tape, a first working gap is formed in a direction perpendicular to the running direction of the magnetic tape. and a second information track core, and a second information track core for forming a second working gap parallel to the running direction of the magnetic tape between the first and second information track cores. A magnetic head made of a non-magnetic material disposed between cores is used to transmit the control signal between the first and second information tracks so that its magnetization direction is perpendicular to the magnetization direction of the information signal within the same plane. A magnetic recording and reproducing method characterized in that recording is performed using the second working gap so that the following is achieved.