JPH02105379A - Rotary magnetic head type recording/reproducing device - Google Patents

Abstract

PURPOSE:To surely reproduce the signals immediately after they are recorded by a preceding magnetic head without using any exclusive magnetic head for reproduction by successively switching four magnetic heads added to a rotary drum between a recording circuit and a reproducing circuit. CONSTITUTION:A rotary drum 13 contains a pair of magnetic heads R1 and R2 of plus azimuths and a magnetic heads L1 and L2 of minus azimuths with a 90 deg. space secured between both pairs. These magnetic heads form a magnetic head assembly 12 and then switched successively by a switch circuit 16 to be connected to a recording circuit 14 in a record state for each 270 deg. rotation of the assembly 12. In a reproduction state the magnetic heads corresponding to the magnetic heads connected to the circuit 14 are successively switched by the circuit 16 and connected to a reproducing circuit 15. This switching operation is carried out in the delayed timing equal to the time during which the assembly 12 turns by 180 deg..

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotating magnetic head type recording/reproducing device, such as a video tape recorder, which is equipped with a rotating magnetic head assembly and records and reproduces signals on a magnetic tape. It is related to the device.

[Conventional technology]

When recording signals on a magnetic tape using a recording/reproducing device, it is impossible to confirm whether the recording of the signals is being performed normally unless the recorded signals are reproduced. Especially when recording signals that are not reproducible,
It is necessary to reproduce and confirm the recorded signal while keeping the recording/reproducing device in the recording state, simultaneously with recording the signal.

Conventionally, for example, VTRs for professional use are equipped with a magnetic head that records signals in advance, and a magnetic head that follows only for reproduction. Then, the recorded state of the signal is changed to 'ff' by reproducing it with a subsequent magnetic head.
I was able to recognize it.

[Problem to be solved by the invention]

However, in the above-mentioned conventional rotary magnetic head type recording and reproducing apparatus, it is necessary to provide a magnetic head exclusively for reproduction in order to check the recording state of the signal. Therefore, the structure of the rotating magnetic head assembly etc. becomes complicated and the manufacturing cost becomes high.

In particular, in the case of a recording and reproducing apparatus that records and reproduces ordinary signals by winding a magnetic tape over 270 degrees around a rotating magnetic head assembly consisting of four magnetic heads attached to a rotating drum, the above-mentioned If a read-only magnetic head is provided, a total of eight magnetic heads will be attached to the rotating drum, which will make the layout of the magnetic heads difficult, increase the number of assembly steps, and reduce layer and manufacturing costs. This had the problem of being expensive.

[Means to solve the problem]

In order to solve the above-mentioned problems, a rotating magnetic head type recording/reproducing device according to the present invention provides a rotating drum having a rotating shaft inclined with respect to the running direction of the magnetic tape, with a gap larger than 2/3 of the track pitch. each having a width of 2
Each positive azimuth magnetic head and negative azimuth magnetic head are provided at 90° intervals and with alternating azimuth directions.
A rotating magnetic head assembly that records and reproduces signals on a magnetic tape wound at an angle of 70 degrees or more; and a rotating magnetic head assembly that records and reproduces signals on a magnetic tape wound over 70 degrees; While the magnetic head is connected to the recording circuit in sequence, the magnetic head is connected to the recording circuit at a timing delayed by the time required for the rotating magnetic head assembly to rotate approximately 180 degrees with respect to the switching timing at which the magnetic head is connected to the recording circuit. The magnetic head is characterized in that it is provided with a switching circuit that sequentially switches the magnetic heads provided opposite to the magnetic heads and connects them to the reproducing circuit.

[For production]

With the above configuration, as the rotating magnetic head assembly rotates, the preceding magnetic head forms a recording track on the magnetic tape and records the signal sent from the recording circuit. Here, the gap width of the magnetic head is 2/3 of the track pitch.
Therefore, the recording track is formed to have a track width equal to the gap width of the magnetic head and larger than 2/3 of the track pitch.

On the other hand, the succeeding magnetic head, which is provided opposite to the preceding magnetic head, records the recording track formed by the preceding magnetic head on the magnetic tape with a delay of approximately 180 degrees of rotation of the rotating magnetic head assembly. Pass the position.

At this time, the succeeding magnetic head passes through a position shifted by 2/3 of the track pitch in the direction of the gap width, but the width of the recording track formed by the preceding magnetic head is Since it is formed to be larger than 2/3 of the pitch, the passing range of the succeeding magnetic head reliably overlaps a part of the recording track formed by the preceding magnetic head.

On the other hand, the switching means is operated at a timing that is delayed by the time required for the rotating magnetic head assembly to rotate approximately 180 degrees with respect to the switching timing at which the preceding magnetic head is connected to the recording circuit. While passing the position of the recording track formed by the magnetic head, the following magnetic head is switched and connected to the reproducing circuit, so that the signal recorded by the preceding magnetic head is reliably reproduced immediately after recording.

Therefore, without providing a magnetic head exclusively for reproduction,
The recording state of the signal recorded by the preceding magnetic head can be checked immediately after recording.

〔Example〕

As an embodiment of the present invention, an example of a video tape recorder for recording and reproducing video signals will be described below with reference to FIGS. 1 to 8.

As shown in FIG. 1, a video tape recorder, which is a rotating magnetic head type recording/reproducing device, includes a rotating magnetic head assembly 12 for recording and reproducing video signals on a magnetic tape 11.
is provided.

This rotating magnetic head assembly 12 includes a rotating drum 13'' having a rotating shaft inclined with respect to the running direction of the magnetic tape 11.
, two positive azimuth magnetic heads R each.
1, R2, and negative azimuth magnetic head L,
R2 are provided at 90° intervals and in alternating azimuth directions, and are driven by a drive means (not shown) to rotate in the direction indicated by arrow A.

A magnetic tape 11 is mounted on the outer peripheral surface of the rotating magnetic head assembly 12.
is a wrapping angle of 270° + overlap angle α,
It is wound diagonally according to the inclination of the rotating shaft of the rotating drum I3. The magnetic tape 11 is driven by a drive means (not shown) and travels at a speed of 19.3 tnr+ in the track pitch direction while the rotating magnetic head assembly 12 rotates 270 degrees in the case of EP mode in the VHS system, for example. That is, the vehicle travels in the direction indicated by arrow B at a speed where the track pitch Tp is 19.3-.

The gap width Tg of the magnetic heads R+'Rz .L, .R2 is set to be larger than 2/3 of the track pitch Tp of the recording tracks formed on the magnetic tape 11. That is, the track pinch Tp of the recording track in the BP mode of the VH3 system is 19.3I1.
The gap width is set to Tg-30tMn with respect to m. (19,3x2/3-ζ12.9ttm〈〈30-
) Also, the magnetic heads R1, R2, Ll, -R2 are rotated every time the rotating magnetic head assembly 12 rotates 270° during signal recording.
2 are sequentially switched to connect the magnetic heads R1, R2, Ll, and R2 to the recording circuit 14.
The magnetic heads R9, R2, Ll, R2 and It is connected to a switching circuit 16 that sequentially switches the magnetic heads R8, R2, Ll, and R2 provided facing each other and connects them to the reproducing circuit 15.

In the above configuration, operations performed when recording a video signal on the magnetic tape 11 will be explained based on FIGS. 2 to 8. Here, FIGS. 2 to 8 show magnetic heads R8, R2, Ll, R based on the track pattern coordinate method.
The relationship between the position of 2 and the track pattern formed on the magnetic tape 11 is shown.

First, the rotating magnetic head assembly 12 rotates in the direction shown by the arrow A, and the magnetic head R is rotated, for example, as shown in FIG.
When it reaches the rotational position o, the magnetic heads L, -R, .
R2 are 90°, 180°, and 270°, respectively
The magnetic tape 11 is in a rotational position, and both are in contact with the magnetic tape 11.

If the recording of the video signal is started when the magnetic head R comes to the 0° rotation position, the magnetic head R7
is connected to the recording circuit 14 by a switching circuit 16 during rotation from a rotational position of 0° to a rotational position of 270°. Therefore, the magnetic tape 11 has a recording trunk TR.
I is formed and one field of video signal is recorded.

This recording track TRI has a track width Tw of 30 tm, which is equal to the gap width Tg of the magnetic head R4, and has a track width Tw of 30 tm, which is equal to the gap width Tg of the magnetic head R4. Formed diagonally.

Recording track T3. is formed and the magnetic head R+ is 27
When it reaches the 0° rotation position, as shown in Figure 3,
The magnetic head L1 comes to the rotational position Oo. Also, at this time, the magnetic heads R1, R2, Ll, and R2 are moved in the relative position with respect to the magnetic tape 11 and in the rack pitch direction due to the running of the magnetic tape Il and the inclination of the rotation axis of the rotating drum 13. It comes to a position shifted by 19.3-.

When the magnetic head L reaches the 0° rotational position, it is connected to the recording circuit 14 by the switching circuit 16 while rotating from the 0° rotational position to the 270° rotational position, similar to the magnetic head R1. . Therefore, similarly to the recording track TR3, the magnetic head L.

The track width Tw of 301 nn is equal to the gap width Tg of
recording tracks TLl are formed on the magnetic tape 11,
The field video signal is recorded.

Here, since the recording track TLI is formed at a position shifted by 19.3 trm from the recording trunk TRI, the range indicated by the symbol a in the already formed recording track TRI is overwritten and erased. Only a width range of 19.3-, which is equal to the track pitch Tp, remains as the recording track T, ll.

The recording track TLI is formed and the magnetic head L moves to 270
When it reaches the rotation position of °, as shown in Figure 4,
The magnetic head R2 comes to the 0° rotation position. Also, magnetic heads R, -R, ·L, -L.

, the magnetic head L1 is at a position further shifted by 19.3 trrh relative to the magnetic tape 11 in the track pitch direction compared to when the magnetic head L1 is at the Oo position.

Then, the magnetic head R2 rotates 270° from the 0° rotation position.
While rotating to the rotational position, the switching circuit 16 connects the recording circuit 14 to the recording track TR2, which has a track width Tw of 30 capes, similar to the recording track TLI described above.
is formed at a position shifted by 19.3 trm with respect to the recording track TLI on the magnetic tape 11. Also, at this time, similarly to the recording track TRI, the range already indicated by the symbol in the recording track TLI that has already been formed is erased, and 1 equal to the track pitch Tp is erased.
Only a width range of 9.3 ptn remains as recording track TL+.

Similarly, every time the rotating magnetic head assembly 12 rotates 270 degrees, the switching circuit 16 switches the magnetic heads L2, R1, L, . . .
4, and video signals are recorded.

Further, when a signal recorded on the magnetic tape 11 is reproduced immediately after recording to check the recording state of the signal, the following operation is performed.

For example, while the recording track T++2 is being formed,
When the magnetic head R2 reaches the 180° rotation position, that is, when the time period for the rotating magnetic head assembly 12 to rotate 180° has elapsed since the magnetic head R2 was connected to the recording circuit 14, the magnetic head R2 As shown in FIG. 5, the magnetic head R provided facing the
It has reached the 0° rotation position.

At this time, the magnetic head R1 passes through a position shifted by 2/3 of the track pitch Tp in the track pitch direction with respect to the recording track TR□ formed by the magnetic head R2. In other words, the passing range of the magnetic head R is, in the recording track TR□, track width Tw-) rack pitch TpX2/3-303-30u, 3 x 2/3 piece 1
7. Overlaps with the range of 1-.

Therefore, by switching the switching circuit 16, the magnetic head R3 is connected to the reproducing circuit 15, so that the magnetic head R2 rotates from the rotational position of 180° to the rotational position of 270°. /3 is formed, the magnetic head R1 rotates from the 0° rotation position to 9
Rotate to the 0° rotation position and move to the front 1 of recording track TR2.
The video signal of 1/3 field recorded in /3 is reproduced.

The magnetic head R2 and the magnetic head R3 are each
When the magnetic head L is rotated to the 270° rotation position and the 90° rotation position, as shown in FIG.
2 comes to the 0° rotation position. As shown in FIGS. 6 to 8, this magnetic head L2 is rotated 2 degrees from the 0° rotation position.
During the rotation to the 70° rotation position, the recording track TR is connected to the recording circuit 14 by the switching circuit 16.
Similarly to I.TLI..., a recording track TL2 is formed on the magnetic tape 11.

On the other hand, while the magnetic head L2 rotates from the Oo rotational position to the 180° rotational position while the recording track TL2 is being formed, the magnetic head R5 rotates as shown in FIGS. 6 and 7. , rotates from the 90° rotation position to the 270° rotation position, and the middle 1/3 of the recording track TR□.
Then, the video signal of the 2/3 field recorded in the last 1/3 is reproduced. Therefore, the magnetic head R2 is 1
When the magnetic head R rotates from a rotational position of 80° to a rotational position of 270°, the video signal of the 1/3 field recorded in the front 1/3 of the recording track TR2, which is reproduced by the magnetic head R, is recorded. The video signal of one field of track TR2 will be reproduced.

When the magnetic head L2 rotates to the 180° rotation position and the magnetic head R rotates to the 270° rotation position, that is, after the recording circuit 14 switches from the magnetic head R2 to the magnetic head L2, the rotating magnetic head assembly body 12 is 18
When the time for 0° rotation has elapsed, the regeneration circuit 15
However, by switching the switching circuit 16, the magnetic head R1 is switched to the magnetic head L1.

Therefore, as shown in the 8th episode, the magnetic head I-2 is
When the rear 1/3 of the recording track TL□ is formed by rotating from the 0° rotational position to the 270° rotational position and the video signal of 1/3 field is recorded, the magnetic head I5
．． is rotated from O' to a rotational position of 90', and the video signal recorded on the front 1/3 of the recording track TL2 is reproduced in the same way as when the video signal recorded on the recording track TR□ shown in FIG. 5 is reproduced. A 1/3 field video signal is reproduced.

Thereafter, similarly, the video signal recorded on the magnetic tape 11 is always reproduced with a delay of the time required for the rotating magnetic head assembly 12 to rotate 180 degrees, and the recording state of the recorded signal is
It is confirmed immediately after being recorded.

In this embodiment, a case has been described in which the track pitch Tp and the gap width Tg are 19.3 pm and 30 IJfn, respectively, but the present invention is not limited to this. It is sufficient if it is larger than /3. For example, VH3H2O
Track pitch Tp of recording track in 3P mode
Even if the gear width Tg=70 for =58 voices, the following magnetic head overlaps the range of Tg-TpX2/3#31.31M in the already formed recording track, so the following magnetic head Reproduction using a magnetic head is possible. However, if there is a restriction such as the SN ratio of the reproduced signal, the amount of overlap needs to be set to a predetermined value in accordance with the restriction.

Furthermore, the timing of switching between the recording circuit 14 and the reproducing circuit 15 by the switching circuit 16 is not limited to being delayed by exactly the time required for the rotating magnetic head assembly 12 to rotate 180 degrees, but may also be delayed due to, for example, a misalignment of H alignment in the recording track. It is also possible to delay the time by a correspondingly corrected amount of time.

〔Effect of the invention〕

The rotating magnetic head type recording/reproducing device according to the present invention has a gap width larger than 2/3 of the track pitch on a rotating drum having a rotating shaft inclined with respect to the running direction of the magnetic tape, as described in second part. Two positive azimuth magnetic heads and two negative azimuth magnetic heads are provided at 90° intervals and with alternating azimuth directions, and are wound around the outer circumferential surface by 270° or more. a rotating magnetic head assembly that records and reproduces signals on a magnetic tape; and a recording circuit that sequentially switches the four magnetic heads each time the rotating magnetic head assembly rotates 270 degrees during signal recording. On the other hand, the rotary magnetic head assembly is installed facing the magnetic head connected to the recording circuit at a timing delayed by the time required for the rotating magnetic head assembly to rotate approximately 180 degrees with respect to the switching timing for connecting the magnetic head to the recording circuit. This configuration includes a switching circuit that sequentially switches the magnetic heads and connects them to the reproducing circuit.

This eliminates the need for a dedicated magnetic head for playback.
Since the recorded signal can be played back simultaneously with the recording of the signal while the recording/playback device is kept in the recording state, the recording state of the recorded signal can be changed without increasing manufacturing costs. This has the effect of reliably preventing recording errors caused by, for example, clogging of the magnetic head.

[Brief explanation of drawings]

1 to 8 show one embodiment of the present invention, in which FIG. 1 is a block diagram showing the configuration of a rotating magnetic head type main recording/reproducing device, and FIGS. 2 to 8 are respectively , is an explanatory diagram showing the relationship between the position of a magnetic head and a track pattern formed on a magnetic tape. 11 is a magnetic tape, 12 is a rotating magnetic head assembly, 13 is a rotating drum, 14 is a recording circuit, 15 is a reproduction circuit, 16 is a switching circuit, R8 and R2 are positive azimuth magnetic heads, L and R2 are negative azimuths. This is a magnetic head.

Claims (1)

[Claims] 1. Two positive azimuth magnetic heads and two negative azimuth magnetic heads each having a gap width larger than 2/3 of the track pitch are mounted on a rotating drum having a rotation axis inclined with respect to the running direction of the magnetic tape. A rotating magnetic head assembly in which heads are arranged at 90° intervals and in alternating azimuth directions, and records and reproduces signals on a magnetic tape wound at an angle of 270° or more on the outer circumferential surface. When recording a signal, the four magnetic heads are sequentially switched and connected to the recording circuit every time the rotating magnetic head assembly rotates 270 degrees. A switching circuit is provided that sequentially switches between the magnetic head connected to the recording circuit and the magnetic head disposed opposite to the magnetic head connected to the reproducing circuit at a timing delayed by approximately 180° rotation time of the rotating magnetic head assembly. A rotating magnetic head type recording/reproducing device characterized by: