JPS59142702A - Magnetic recording and reproducing system - Google Patents

Abstract

PURPOSE:To perform recording and reproduction in both-way runs of a magnetic tape by dividing the recording part of the magnetic tape into two upper and lower parts, and performing the recording and reproduction on one part in the forward run of the tape and on the other part in the backward tape run. CONSTITUTION:A guide drum 1 is provided with four rotary heads 2a, 2b, 2c, and 2d at equal intervals of 90 deg., and the magnetic tape 3 is wound around the outer circumference of the guide drum 1 helically to an angle theta which is little bit larger than 180 deg.; and the magnetic tape 3 is driven in said state to run forward or backward. When the magnetic tape 3 runs forward as shown by an arrow A, each rotary head performs recording/reproducing operation at a position in the latter half TA of the circumferential contacting section of the magnetic tape 3. Electric switching operation is performed at 1/4 cycles of heat rotating period. Consequently, the four rotary heads record or reproduce one- field video signals helically at the upper half position in the running direction of the magnetic tape.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a magnetic recording and reproducing system suitable for use in a helical scan type magnetic recording and reproducing device that is capable of recording and reproducing back and forth tape with a tape cassette loaded. It is related to.

<Prior art> Recent helical scan type magnetic recording and reproducing devices have adopted a high-density recording method and have become capable of recording/reproducing for quite a long time. Time recording/playback is desired.

Problems> One possible solution is the so-called auto-reverse method, which automatically reverses the running direction of the tape when it reaches the end of the tape with the tape cassette hk loaded, and records/reproduces on different tracks as the tape reciprocates. However, in this case, it is relatively easy to achieve this when simply recording/playing audio signals using a fixed head, but since a rotating head is used when recording/playing video signals, the auto-reverse method It is not easy to adopt
Nc Purpose> The present invention has been made in view of the above points, and provides an auto-reverse type helical scan type magnetic recording/reproducing device in which video signals can be recorded/reproduced back and forth from a tape using a rotating head. This provides a magnetic recording and reproducing method.

<Examples> The present invention will be described below with reference to examples shown in the drawings. 1st
The figure shows a schematic configuration of a magnetic recording/reproducing apparatus adopting the method of the present invention.
rotating heads 2a, 2b.

2c and 2d are arranged at equal intervals of 90', and recording/
In the reproduction mode, the magnetic tape 3 is helically attached to the outer periphery of the guide drum 1 over an angle θ slightly larger than 180°, and in this state, the magnetic tape 3 is driven to run in the forward or reverse direction. be done. Furthermore, the rotating head 2a,
2c and the rotating heads 2b and 2d are formed with opposite azimuth angles, and each rotating head 2a+
2b+ 2c+ 2d are always rotated in the direction of arrow C at a constant speed.

And now, in the recording/playback mode, the magnetic tape 3 is pointing to the arrow A.
When traveling in the positive direction shown in , K is the head rotation period so that the recording/reproducing operation is performed when each rotary head 2a + 2b + 2c, 2d is at the position of the latter half TA of the circumferential section with the magnetic tape 3. As a result, the magnetic tape 3 has four rotating heads 2a+ located in the upper half of the magnetic tape running direction as shown in FIG. 2b, 2c,
2d, video signals corresponding to one field are sequentially recorded/reproduced in a helical manner.

Furthermore, here, the audio head 4 and the control head 5
Both are switchable in two stages, upper and lower, and especially when the magnetic tape 3 is driven to run squarely south, audio signals and control signals are recorded by the audio head 4 and control head 5 in the upper stage, respectively.

FIG. 2 shows the recording pattern recorded by each head when the magnetic head 130 travels in the foot direction.
a6a... is a video track, 7aU audio track, 8
a indicates a control track.

Meanwhile, the magnetic tape 3 reaches the end of the tape and is automatically reversed.
Loss 1-[When traveling in the opposite direction shown in month 3, recording is performed when each rotary head 2a, 2b, 2c, 2d is at the position of the first half TB of the circumferential section with the magnetic tape 3. Electrical switching operations are performed alternately so that regeneration takes place. As a result, as shown in FIG. 2, four rotary heads 2a, 2b, 2C12df are formed on the magnetic tape K17 at positions of 1:11 with respect to the tape running direction, thus forming a helical video track 6b, 6b...Vζ Sequential recording/playback operations are performed, and the lower row f:; ) Bow and control signals are recorded/played back to the audio track 7b and control trunk 8b, respectively.

In addition, in the embodiment 1-, there are four rotating heads 2a.

211, 2C, and 2d, and rotate these heads at a rotation period of 1/4) 21? 6.6...
On the other hand, the audio head 4 uses two switching heads, upper and lower, to record different audio signals on different audio tracks 7a and 7b K when the magnetic tape 3 is running in the forward direction and when it is running in the reverse direction. However, the recording/playback of audio signals is not limited to this method; for example, as is well known, a dedicated audio head is omitted and a rotating head is used to record the end of a helical video track. The KPCM modulated audio signal may be recorded/played intermittently.

<Effects> As described above, the magnetic recording and reproducing method of the present invention has the advantage of increasing the tape force by four tapes per kite drum in a helical scan type magnetic recording and reproducing device capable of reciprocating recording/reproducing with a loaded tape. rotating heads are arranged at equal intervals of 90 degrees, and a magnetic tape is placed around the outer circumference of the guide drum at 180 degrees.
The rotary head is switched at 1/4 of the rotation period to alternately drive the recording/reproducing operation, and when the magnetic tape is running in the forward direction and in the reverse direction.
Since the rotary heads in the circumferential sections that differ by 0° are arranged to be driven, the recording section of the magnetic tape is divided into two sections -1-down. On the other hand, recording/reproduction occurs when the tape runs in the opposite direction.

Therefore, by adopting the magnetic recording and reproducing method of the present disclosure, it becomes possible to record/reproduce back and forth on a magnetic tape using an auto-IJ hearth type magnetic recording and reproducing device, and it becomes possible to perform long-term recording/reproduction on existing tape cassettes. It will be revived or performed as a Noh in January.

[Brief explanation of the drawing]

FIG. 1 shows a magnetic recording/reproducing device 11 (
FIG. 2 shows a diagram of a recording pattern on a magnetic tape according to the Hongenmei system. 1. Kite drum, 2a, 2b, 2c+ 2d
- Rotating head, 3...magnetic tape

Claims (1)

[Claims] 1. In a helical scan type magnetic recording and reproducing device that is capable of reciprocating recording and reproducing of a tape while it is loaded in a tape cassette, four rotating spatula drivers 90 are connected to a guide drum.
The magnetic tape is arranged at equal intervals of 180° and attached to the outer periphery of the guide drum over a length of 180° or more, and the rotary head is switched at a rotation period of 174 to alternately drive the recording/reproducing operation, and the magnetic tape is The rotary head is operated in a circumferential section that differs by 90 degrees when the tape is running in the forward direction and when it is running in the reverse direction. A magnetic recording/reproduction method in which recording/reproduction is performed while the other side of the tape is running in the opposite direction.