JPS63288492A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain an excellent simultaneous monitorings by disposing two pieces of double-azimuth heads on positions aparted with 180 deg. sandwiching the rotary shaft of a rotary drum, and executing a recording and reproducing operation at every half turn of the rotary drum by means of two pairs of a recording and reproducing head alternately at every one turn of the drum. CONSTITUTION:The double-azimuth heads are used for the recording heads AR, BR and the reproducing heads AP, BP which are positioned at 180 deg. to each other, and the winding angle of a magnetic tape around the drum is made 180 deg. to execute recording and reproduction at every half turn of the drum. Therefore, because a recording action and a reproducing action can be executed alternately with actually neglectable overlapping time, a recording signal is not superposed on a recording signal by the crosstalk. As a result, interchangeable recording patterns can be obtained with a drum whose diameter is half compared with conventional case, and at the same time, simultaneous monitorings can be executed without generating any crosstalk.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus having a so-called simultaneous monitor function, which is configured to simultaneously record and reproduce information.

[Prior Art] Fig. 3 is a plan view showing the arrangement of a rotating head attached to a rotating drum of a conventional magnetic recording/reproducing device and the winding position of a magnetic tape. Drum C (hereinafter referred to as "drum"), (2) is a magnetic tape wrapped around the outer periphery of drum (1) at a wrapping angle of 90', and AR is a magnetic tape with a positive azimuth angle attached to drum (1). AP is the recording head A.
A reproducing head having the same positive azimuth angle for reproducing the signal of the track recorded on the magnetic tape (2) at R, BR.
is a recording head having a negative azimuth angle, BP is a reproducing head having the same negative azimuth angle for reproducing the signal recorded on the magnetic tape (2) by the recording head BR, and the recording heads AR and BR are the same.

The playback head AP is mounted at a position 180 degrees apart from the rotation axis (not shown) of the drum (1), and the playback head AP is located 90 degrees from the recording head AR when viewed from the rotational direction of the drum (1).
The reproducing head BP is attached at a position 0 degrees behind the recording head BR, and the reproducing head BP is attached at a position 90 degrees behind the recording head BR.

Figure 4 is a block circuit diagram of the recording/reproducing system of this conventional example.
Figure 5 is the timing diagram of Figure 0, where (3)
is a memory in which input signal a (shown in FIG. 5(a)) is once written and read out as signal b (shown in FIG. 5(b)) with a compressed time axis.
R is recorded alternately on the magnetic tape (2). The signals recorded on this magnetic tape (2) are transmitted to the playback head AP,
Or alternately played by BP. This recording/playback operation switches every rotation (90°) of the drum (1), (recording by AR) → (playback by AP) → (BR
The process is repeated in the following order: (recording by BP) → (reproduction by BP) → (recording by AR) →. The memory (4) once writes the reproduced signal C (shown in FIG. 5(C)) and reads it out as a signal d (shown in FIG. 5(d)) whose time axis has been expanded.As a result, the reproduced signal is different from the input signal. rotating drum (
Although there is a delay of two rotation periods in step 1), the recorded signals can be output almost simultaneously as signals via the magnetic tape (2). In FIG. 5, Ao=A3 is the recording/reproducing head AR with a plus azimuth angle.

Shows the signal divisions recorded and reproduced by AP, and BO to B3 are recording and reproducing heads BR and B with negative azimuth angle.
P represents the signal division to be recorded and reproduced.

Note that the signal (b) recorded on the magnetic tape (2) includes:
It is assumed that a margin signal necessary for recording the digital signal is included, and that the time axis compression by the memory (3) is performed at a compression rate necessary for recording.

[Problems to be Solved by the Invention] Conventional magnetic recording and reproducing devices are configured as described above. For example, in order to downsize the system, a drum (
If the diameter of 1) is halved (15 mm), the track format of the signal recorded on the magnetic tape (2)° will be the same as that recorded with the conventional drum diameter (30 am) shown in Figure 3. In order to achieve this, it is necessary to make the winding angle of the magnetic tape (2) 180 degrees, as shown in FIG. In this case, the diameter of the drum (+) becomes the tsuba, so the diameter of the drum (+) becomes the tsuba.
Since the circumferential speed (1), that is, the relative speed between the rotary head and the recording (reproducing) track, decreases, the recording rate is also slightly lowered in order to make the recording wavelength the same as before. As a result, as shown in FIG. 7, the timing of recording and reproducing must be recorded and reproduced at the same time during the period of the recording track length. Generally, when recording and reproducing signals on magnetic tape using a rotating head,
Signals are transmitted between the recording/reproducing amplifier and the rotary transformer. This rotary transformer is 1
A flat coil made by winding a coil around a flat core material such as ferrite with winding grooves is installed facing the upper drum side where the rotating head is attached and the lower drum side connected to the amplifier. , which allows signals to be transmitted through an air gap. In the case of the conventional device, since four rotating heads are provided, the coils for the four heads are wound on one flat core material. For this reason, the distance between the coils cannot be maintained sufficiently, so that signal leakage between the coils, called crosstalk, occurs. Therefore, when playing back while recording, a large recording signal of several tens of milliamps is superimposed on a weak playback signal of several to four volts due to the crosstalk of the rotary transformer, resulting in the problem that an accurate playback signal cannot be obtained. .

This invention was made to solve the above problems, and even if the winding angle of the magnetic tape is 180 degrees,
It is an object of the present invention to provide a magnetic recording and reproducing device that can perform good simultaneous monitoring without deteriorating reproduced signals due to crosstalk from recorded signals.

[Means for Solving the Problems] A magnetic recording/reproducing device according to the present invention has two double azimuth heads formed integrally with two magnetic heads having different azimuth angles, which are arranged at 180 degrees ## with a rotating shaft of a rotating drum sandwiched between the two double azimuth heads. The two magnetic heads on one double azimuth head are used as recording heads, and the two magnetic heads on the other double azimuth head are used as playback heads, and recording and playback are performed each time the rotating drum rotates. Record two sets of movements.
It is characterized in that the reading head is configured to perform the reading alternately every rotation.

[Function] Since the two sets of recording and reproducing heads are provided close to each other, when recording and reproducing operations with different azimuth angles are performed alternately for each rotation of the rotating drum, the input signal can be adjusted to approximately the same level. If the time axis is compressed and recorded, and the playback signal is expanded to the original time axis, then during the overlapping period of the recording operation period and the reproduction operation period, two magnetic・The length corresponds to the rad spacing. However, since the interval between the two magnetic heads of the double azimuth head is as small as several 1100 JL, the period in which the recording operation period and the reproduction operation period overlap is short, and this overlapping period is within the period in which the margin signal is arranged. It fits, so there is no problem.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, (5) and (8) are double azimuth heads in which two magnetic heads with positive and negative azimuth angles are integrally formed, and they face the drum (1) across the rotation axis at a 180° angle. The double azimuth head (5) is used as recording heads AR and BR, and the other double azimuth head (8) is used as recording heads AR, BR and 1800 mm, respectively.
Heads at separate positions are used as playback heads AP and BP. This double azimuth head (5), (6
), the head spacing between the two magnetic heads AR and BR, AP and BP is several 11001 L, and the drum (1) of this example
(Diameter 15mm) Nora tape (2) Rolling length 15X
This is a sufficiently small value compared to πX% '423.5+s■.

FIG. 2 is a recording/reproduction timing diagram illustrating the operation of this embodiment.

In order to downsize the system, the diameter of the drum (1) in this embodiment is 15 mm, similar to the conventional one shown in FIG.
It is. When the lead angle of the drum (1) is several degrees, the recording track &L is the magnetic tape (
The angle of the winding in 2) is 180 degrees. In addition, there is a recording wavelength and drum rotation, and in order to make the recording wavelength the same as that of the conventional drum diameter (30 am) shown in Fig. 3, the drum (+
) is doubled.

The operation of this embodiment with the above parameters set will be explained below.

Magnetic tape (2) wrapped 180 degrees around the drum (1)
), a signal b (shown in FIG. 2(b)) whose time axis is approximately compressed is recorded on the magnetic tape (2) by the recording head AR for the period of common rotation of the drum (1). The recording track on which this signal has been recorded is reproduced during the next station rotation period following the recording operation of the drum (1) by the reproduction head AP installed at a position 180 degrees apart from the recording head AR, and During one rotation of (1), recording by the recording head AR and reproduction by the reproducing head AP (Fig. 2 (C))
(illustrated) is performed.

In the next one rotation period of the drum (1), recording by the recording head BR and reproduction by the reproducing head BP are similarly performed. In this case, in order to make the arrangement of the tracks recorded on the magnetic tape (2) the same in the head scanning direction, the recording signal input to the recording head B (as shown in Fig. fS2 (b))
The timing of (drum diameter x π) is determined from the timing of the signal input to the recording head AR (shown in FIG. 2(b))
×N)/(distance between recording heads AR and BR). The signals recorded by the recording heads AR and BR in this way are transferred to the reproduction head AP whose azimuth angle is the same.
, BP, recording and reproduction are alternately repeated at intervals of the rotation period of the drum (1). The thus reproduced signal C (shown in FIG. 2(C)) is converted into a continuous reproduced signal d whose time axis is extended as shown in FIG. 2(d) by the memory (4) shown in FIG. is output.

In addition, plus azimuth angle recording/reproducing heads AR, AP
To select heads BR and BP with negative azimuth angles, a signal (shown in Fig. 2 (e)) is generated by dividing the rotation detection pulse of the drum (1) by 2, and the low level of this signal is output to the recording head. Playback head AP for AR, BR, and High level.

All you have to do is select it as BP.

Note that in the above operation, there is a reproduction period by the reproduction head BP, a recording period by the recording head AR, and a reproduction period by the reproduction head A.
The reproduction period by P and the recording period by recording head BR slightly overlap, but this overlapping period is a small period corresponding to the spacing between the two magnetic heads, double azimuth head (5) and (f?). Since the signal being reproduced during this time is a margin signal unrelated to the information, no problem occurs in the time axis expansion of the reproduced signal.

[Effect of the Invention J As described above, according to the present invention, the recording heads AR, BR
The reproducing heads AP and BP are each constructed of double azimuth heads and are disposed at positions facing each other by 180 degrees, and the magnetic tape is configured to have a winding angle of 180' so that recording and reproduction are performed every rotation period of the drum's collar. Therefore, the recording operation and the reproducing operation can be performed alternately with a practically acceptable overlapping time, so that the recording signal is not superimposed on the reproducing signal due to crosstalk. As a result, it is possible to obtain a magnetic recording and reproducing apparatus that can perform simultaneous monitoring without crosstalk, while providing compatible recording patterns with a conventional drum diameter.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the relationship between the arrangement of the recording/reproducing head of a rotating drum and the winding angle of the magnetic tape according to an embodiment of the present invention, and FIG. 2 is a timing diagram for explaining the operation of this embodiment. 3 is a plan view showing the relationship between the arrangement of the recording/reproducing head of the rotating drum of a conventional magnetic recording/reproducing device and the winding angle of the m4A tape, and FIG. 4 is a circuit diagram of the conventional recording/reproducing system. , FIG. 5 is a timing diagram of this conventional example, FIG. 6 is a plan view showing the relationship between the arrangement of the recording/reproducing head of a rotary drum and the winding angle of the magnetic tape in another conventional example. It is a timing diagram of a conventional example. (1)...Rotating drum, (2)...Magnetic tape, (
5). (8)...Double azimuth head, AR, BR...
Recording head, AP, BP... playback head. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) Two double azimuth heads, which are integrally constructed of a rotating drum and two magnetic heads with different azimuth angles, each disposed 180 degrees apart from each other across the axis of rotation of the rotating drum; 1 around the rotating drum above
The magnetic tape is provided with a magnetic tape that is wound and runs at a winding angle of 80 degrees, one of the double azimuth heads is used as a recording head, and the two magnetic heads alternately record data every rotation of the rotating drum. , the other double azimuth head is used as a reproducing head, and the two magnetic heads are configured to alternately reproduce signals recorded on the magnetic tape by the recording head having the same azimuth angle before half a rotation. Device.