JPH0736211B2 - Rotating head of magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, R-DAT [rotary head digital audio].
tape recorder] and the like, and relates to a rotary head used in a magnetic recording / reproducing apparatus of a digital oblique scanning system.

[Conventional technology]

In the R-DAT, two magnetic heads are attached to a rotary drum at 180 ° intervals, and recording is performed on a magnetic tape by an oblique scanning method while switching these alternately.

FIG. 7 shows an outline of the R-DAT tape format.

The specifications of the R-DAT in the standard mode are as follows.

Tape width A: 3.81mm Tape speed V _T : 8.15mm / s Rotating drum diameter: 30mm Rotating drum speed N: 2000rpm Relative speed of magnetic head V _H : 3.133m / s Stationary track angle: Approx. 6 ° 22 'track Length L: 23.501 mm Track pitch P: 13.591 μm Here, each track is equally divided into 196 blocks. Therefore, the block length B per block is about 1.120 mm (≈23.501 ÷ 196). Also,
The bending amount α _H, which is the displacement distance along the longitudinal direction between the adjacent tracks, is determined by the rotational speed N of the rotating drum and the tape speed.
Calculated from V _T , rotating drum diameter and static track angle,
It will be about 0.1215 mm. Therefore, the bending amount α _H and the block length B substantially match.

Next, a conventional R-DAT recording method for satisfying the above specifications will be described with reference to FIGS.

As shown in FIG. 8, the rotary drum 11 is rotated at the number of revolutions N in total. The rotating drum 11 has two magnetic heads 12a.
・ 12b are installed at the same height at 180 ° intervals.
The tape 13 is wound around the rotary drum 11 at an angle of 90 ° and travels in the forward direction of rotation of the rotary drum 11 at the tape speed V _T. At this time, the rotary drum 11 is obliquely arranged with respect to the tape 13 by the stationary track angle. Therefore, the magnetic heads 12a · 12b will be scanned in an oblique direction on the tape 13 at a relative speed V _H.

As shown in FIGS. 9 and 10, the magnetic heads 12a and 12b are formed by laminating two magnetic material pieces 14 and 14, respectively. A gap 15 is formed at the joint between the two magnetic pieces 14, 14. Also, the gap 15
Glasses 16 and 16 made of a non-magnetic material are filled in the upper and lower portions of the so as to form a predetermined gap width.
Furthermore, the gaps 15 and 15 of the magnetic heads 12a and 12b are
Are provided with different azimuth angles of ± 20 °.

Therefore, as shown in FIG. 11, the tracks T ₁ , T ₂ , T _3, ... Based on the above specifications are sequentially formed on the tape 13.
Then, the odd-numbered tracks T ₁ , T _3, ... Are magnetic heads 12a.
, And even-numbered tracks T ₂ , T _4, ... Are alternately recorded by the magnetic head 12b. Further, there is a difference of ± 20 ° in azimuth angle between adjacent tracks T. The tracks T thus recorded are alternately reproduced by the magnetic heads 12a and 12b having the same azimuth angle.

[Problems to be Solved by the Invention]

However, in such a conventional R-DAT, each track T
_In order to form ₁ · T ₂ · T ₃ ... And perform a series of recording, it was necessary to provide two magnetic heads 12a and 12b on the rotary drum 11 at 180 ° intervals. And this magnetic head 12a ・ 12b
Installation requires extremely high precision. For example R
-Track pitch P of DAT is 13.591 μm as described above.
Is. On the other hand, VTR [video tape recorder] of the VHS system, in which two magnetic heads are also mounted on the rotating drum at 180 ° intervals and recording / playback is performed by the diagonal scanning system.
Then, it is 58μm in the standard mode and 19μ in the triple mode.
m. From this, the magnetic head 1 in the R-DAT
It can be seen that the height positions of the 2a and 12b on the rotary drum 11 must be attached with higher precision than that of the VHS type VTR which originally requires high precision.

Therefore, in the conventional rotary head of the R-DAT, extremely high precision is required for attaching the magnetic head to the rotary drum, which causes a problem of hindering the improvement of productivity.

On the other hand, in order to improve the mounting accuracy of the two magnetic heads, simply arranging both the magnetic heads 12a and 12b close to each other makes it possible to strictly adhere to the same tape format recorded by the conventional rotary head. It is not possible, and compatibility with the conventional rotary head is lost.

Therefore, according to the present invention, in the case of a device for recording / reproducing information as a digital signal such as an R-DAT, the signal is always taken into the memory and then recorded / reproduced, so that the tape format is matched. If we keep this in mind, we will pay attention to the fact that even if the timing of recording / reproducing a signal changes, it does not matter at all.By changing the timing of recording / reproducing a signal, the conventional tape format can be strictly adhered to, and both The magnetic heads are brought close to each other to improve the accuracy of attaching the magnetic heads to the rotary drum.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, a rotary head of a magnetic recording / reproducing apparatus according to the present invention uses a pair of magnetic heads having different azimuth angles, which are attached to a rotary drum, at the same time to operate a tape by an oblique scanning method. Provided in a digital magnetic recording / reproducing apparatus for sequentially forming and recording tracks in an oblique direction on the top and / or reproducing the recorded signal;
The two magnetic heads are arranged close to each other, and the distance between the gaps of the two magnetic heads is an odd multiple of the amount of bending, which is the distance along the longitudinal direction of the tracks between adjacent tracks on the tape. It is characterized in that they are set to be substantially equal to each other and that the height position deviation between the gaps of both magnetic heads is set to be substantially equal to the same odd multiple of the track pitch as described above.

[Work]

According to the above configuration, the two magnetic heads are arranged close to each other on the rotating drum, and the distance between the gaps of the two magnetic heads is along the longitudinal direction of the tracks between the adjacent tracks on the tape. Since it is set to be approximately equal to an odd multiple of the amount of deviation, which is the amount of deviation, and the deviation of the height position between the gaps of both magnetic heads is approximately equal to the same odd multiple of the track pitch, Quantity 1
When set to double, one magnetic head records a track with the first quarter rotation of the rotary drum 1, while the other magnetic head is the first track counted from the adjacent track. Then, the first magnetic head records the second track and the latter magnetic head records the third track in a quarter rotation after further recording three quarters. In the following, two tracks are simultaneously recorded for each rotation of the rotary drum 1. In other words, when recording is performed on the tape using such a rotary head, a plurality of tracks based on the same tape format as those recorded by using the rotary head provided with the conventional magnetic head at 180 ° intervals are sequentially formed. Will be done. Here, the reason why the bending amount is set to an odd multiple is that the azimuth angles of the two magnetic heads are different from each other. The magnetic head must be the first (adjacent track), third or fifth from this track.
This is because the odd-numbered tracks are scanned such as the second.

By setting the mutual relationship of the two magnetic heads in this way, the state of the track formed by recording on the tape can be achieved even if the two heads are not mounted so as to face each other as in the conventional case, but both heads are brought close to each other. Is compatible with the conventional tape format. In this case, it is possible to fix the two magnetic heads on the same head base when forming the magnetic cores, and further to integrally form the magnetic cores of the two magnetic heads. Compared with the conventional configuration in which the magnetic heads of No. 2 are mounted at 180 ° intervals by two mounting operations, the mounting error of both magnetic heads is less likely to occur, and the required mounting accuracy can be easily obtained with high accuracy. .

However, since it operates simultaneously when recording or reproducing information,
At the time of recording, it is necessary to send recording signals for two tracks to these magnetic heads at the same time, and when sequential signals such as audio signals and video signals are sent one after another, the magnetic head is Compared with the conventional rotary head mounted at 180 ° intervals, it is necessary to delay the signal to be sent to the preceding magnetic head by a time that is approximately an odd multiple of half a rotation of the rotary drum. However, the rotary head of the present invention is a digital system. Since it is provided in the magnetic recording / reproducing apparatus, this delay can be easily created by using a memory element or the like. It should be noted that it is not always necessary to create such a delay time when recording digital information having no order. Further, at the time of reproduction, signals for two tracks are simultaneously reproduced from these two magnetic heads. In this case, signal processing reverse to that of the above-mentioned recording may be performed.

Further, for example, in the case of the above-mentioned R-DAT, the seventh
As described with reference to the drawing, since the bending amount α _H and the block length B substantially match, the distance between the two magnetic heads may be set to a distance that is an odd multiple of one block. In addition, the odd multiple of the bending amount is practically set to about 1 or 3 times, so that the actual gap interval is usually less than 1 mm. When the track has an overwrite portion, the deviation amount of the original recording start portion of the signal is the bending amount.

[First Embodiment] The first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

This embodiment shows a case in which the "odd multiple" in the positional relationship between the two magnetic heads in the R-DAT rotary head is set to one. The R-DAT tape format is as described above with reference to FIG.

As shown in FIG. 1, the rotary drum 1 is rotationally driven at a rotational speed N by a rotary head driving device (not shown). This rotating drum 1 has two magnetic heads.
2a and 2b are attached adjacent to each other to form a rotary head. The tape 3 is wound around the rotary drum 1 at an angle of 90 ° and travels in the forward direction of rotation of the rotary drum 1 at a tape speed V _T by a tape feeding device (not shown).
At this time, the drum 1 is obliquely arranged with respect to the tape 3 by the static track angle. Therefore, the magnetic heads 2a · 2b will be scanned in an oblique direction on the tape 3 at a relative speed V _H.

The magnetic heads 2a and 2b are, as shown in FIG.
It is placed in close proximity. The magnetic core of the one magnetic head 2a is formed by laminating two magnetic material pieces 4, 4. A gap 5 is formed at the joint between the magnetic pieces 4, 4. In the upper and lower parts of this gap 5,
The magnetic material pieces 4 and 4 are formed so that a predetermined gap width is formed.
Is cut out, and glass 6 made of non-magnetic material is cut in this part.
6 is filled. The magnetic head 2a is configured by winding a winding wire (not shown) around the magnetic core. The other magnetic head 2b has the same structure as this magnetic head 2a.

However, the gaps 5 and 5 of the magnetic heads 2a and 2b are
Different azimuth angles of ± 20 ° are provided. The magnetic heads 2a and 2b are arranged such that the distance between the gaps 5 on the rotary drum 1 matches the block length B of one block. The block length B is about 0.120 mm, which is almost the same as the bending amount α _H on the tape format. Therefore, each magnetic head 2a
・ The facing magnetic pieces 4 and 4 in 2b are
It is composed of extremely thin magnetic material pieces so that they do not overlap. Furthermore, this magnetic head 2a
2b is provided with a shift corresponding to the track pitch P on the tape format at the height position between the gaps 5 on the rotary drum 1. This track pitch P is 1
It is 3.591 μm. From these things, each gap 5
The positional relationship between the five requires extremely high accuracy. However, this accuracy can be easily realized by fixing the magnetic cores of the magnetic heads 2a and 2b on the same head base in the process of manufacturing the magnetic head.

FIG. 2 (b) shows another embodiment of the magnetic heads 2a and 2b. In this case, the magnetic heads 2a and 2b are integrally formed by joining the facing magnetic material pieces 4 and 4 via the glass 6. It has become. The distance between the gaps 5 and the displacement of the height position are made to match the block length B and the track pitch P, respectively, as in the case of FIG. Therefore, the accuracy of the positional relationship between the gaps 5 can also be easily realized in the magnetic head manufacturing process.

Therefore, the two magnetic heads 2a and 2b may be attached to the rotary drum 1 in a state in which the positional relationship is set with high accuracy in advance, which facilitates the assembling work. When recording is performed on the tape 3 by using the rotary head configured as described above, as shown in FIG. 3, tracks T ₁ , T ₂ , T _3, ... Based on the tape format of R-DAT are sequentially formed. It
At this time, in the first quarter rotation of the rotary drum 1, the magnetic head 2a records the track T ₁ and, at the same time, the magnetic head 2b.
Records track T ₂ . Then, an additional 4 3 rotated a quarter turn after the minute, the magnetic head 2a is at the same time to record the track T _3, the magnetic head 2b records a track T _4. In the following, two tracks are simultaneously recorded for each rotation of the rotary drum 1. Similarly, in the case of reproduction, two tracks are simultaneously reproduced in this order. In this case, no guard band is formed between the tracks T, but the influence of crosstalk can be eliminated because the azimuth angles are different.

Thus, in the R-DAT of this embodiment, two tracks are simultaneously recorded by the two magnetic heads 2a and 2b. Therefore, it is necessary that the audio signal sent for recording be sent to the rotary head at the same time as the signal for the next one track is made to stand by once. However, since the R-DAT converts an audio signal into a digital signal and records it, such processing can be easily performed by using a memory element or the like.
Also in the case of reproduction, if the reverse process is performed, the original continuous audio signal can be obtained.

Since the R-DAT of this embodiment performs recording based on the tape format of the R-DAT, it is of course possible to reproduce the recorded tape 3 with the conventional R-DAT. Moreover, it goes without saying that the tape 3 recorded by the conventional R-DAT can be reproduced by the R-DAT of this embodiment.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS.

This embodiment shows a case in which the "odd multiple" in the positional relationship between the two magnetic heads in the R-DAT rotary head is tripled. The constituent members having the same functions as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, the point that the rotary drum 1 rotates at the number of revolutions N, the tape 3 is wound around the rotary drum 1 and travels in the forward direction of rotation of the rotary drum 1 at the tape speed V _T. The same as in the first embodiment. Further, the respective magnetic heads 2a and 2b configured similarly to the first embodiment are also mounted adjacent to the rotary drum 1.

However, as shown in FIG. 5, this magnetic head 2a
2b is arranged such that the distance between the gaps 5 on the rotary drum 1 matches three times the block length B of one block. Correspondingly to this, a gap corresponding to three times the track pitch P is provided at the height position between the gaps 5. The positional relationship between the gaps 5 and 5 is
By fixing each magnetic core on the same head base in the magnetic head manufacturing process, it can be easily realized with high accuracy. Therefore, these two magnetic heads 2a
The 2b can be attached to the rotary drum 1 with the positional relationship set in advance with high accuracy, so that the assembling work becomes easy.

When recording is performed on the tape 3 by using the rotary head configured as described above, tracks T ₁ , T ₂ , T _3, ... Based on the tape format of R-DAT are formed as shown in FIG. . At this time, in the first quarter rotation of the rotary drum 1, the magnetic head 2a records the track T ₁ , and at the same time, the magnetic head 2b records the third track T ₄ . And
The magnetic head 2a records the track T ₃ and at the same time, the magnetic head 2b records the third track T ₆ in the quarter rotation after the third quarter rotation. Subsequently, two tracks separated by three tracks are simultaneously recorded for each rotation of the rotary drum 1. Similarly, in the case of reproduction, two tracks separated by three tracks in this order are simultaneously reproduced. Incidentally, in such recording / reproducing, the scanning of the track T ₂ is lost. However, such a dropout has almost no effect because it is only one track at the beginning of recording and reproduction. Further, in order to eliminate such a drop, it is sufficient to scan the track T ₂ with only the magnetic head 2b in advance at the first one rotation of the rotary drum 1.

Thus, also in the R-DAT of this embodiment, two tracks are simultaneously recorded by the two magnetic heads 2a and 2b. As for the audio signal sent for recording, the signals for the preceding three tracks are once put on standby, and the signal for the next one track is sent to the rotary head simultaneously with the signal for the first track. Need to Therefore,
A memory element or the like for performing such processing requires a larger capacity than that of the first embodiment. However, in this embodiment, the distance between the gaps 5 and 5 of the magnetic heads 2a and 2b can be set to about 0.360 mm, which is three times the block length B. When the distance between the gaps 5 and 5 is wide in this way, the magnetic material pieces 4 and 4 facing each other can be made large, which is advantageous in that the magnetic heads 2a and 2b can be easily manufactured. In the case of reproduction, the reverse process is performed to obtain the original continuous audio signal.

Since the R-DAT of this embodiment is also based on the R-DAT tape format, it has the same compatibility with the conventional R-DAT as in the first embodiment.

〔The invention's effect〕

As described above, the rotary head of the magnetic recording / reproducing apparatus according to the present invention operates two sets of magnetic heads attached to the rotary drum and having different azimuth angles at the same time, and the magnetic head is slanted on the tape by the slant scanning method. Is provided in a digital magnetic recording / reproducing apparatus for sequentially forming and recording tracks in different directions and / or reproducing recorded signals. The two magnetic heads are arranged close to each other, and both magnetic heads are arranged. The distance between the head gaps is approximately equal to an odd multiple of the amount of bending, which is the distance along the longitudinal direction of the tracks between adjacent tracks on the tape, and the height position deviation between the gaps of both magnetic heads Is set to be approximately equal to the same odd multiple of the track pitch as described above.

As a result, it is possible to strictly adhere to the conventional tape format, improve the accuracy of attaching the magnetic head to the rotary drum, and improve the productivity.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention. FIG. 1 is a plan view showing the arrangement of magnetic heads on a rotary drum, and FIG. 2 (a) is a plan view of FIG. FIG. 2 (b) is a view of the magnetic head in the direction of arrow II, FIG. 2 (b) is a view of the other embodiment of the magnetic head in the direction of arrow II in FIG. 1, and FIG. 3 is a portion for showing the track pattern on the tape. It is a front view. Fourth
FIGS. 6 to 6 show a second embodiment of the present invention, FIG. 4 is a plan view showing the arrangement of magnetic heads on a rotary drum, and FIG. 5 is a magnetic head at arrow V in FIG. FIG. 6 is a partial front view showing the track pattern on the tape. FIG. 7 shows a tape format of R-DAT, FIGS. 8 to 11 show a conventional example, and FIG. 8 is a plan view showing an arrangement of magnetic heads on a rotary drum, and FIG. 8 is a view of the magnetic head taken along the arrow IX in FIG. 8, FIG. 10 is a view of the magnetic head taken along the arrow X of FIG. 1, and FIG. 11 is a partial front view showing the track pattern on the tape. is there. 1 is a rotating drum, 2a and 2b are magnetic heads, 3 is a tape, 5
Is a gap, α _H is a bending amount, B is a block length, and P is a track pitch.

Claims (1)

[Claims] 1. A set of two magnetic heads having different azimuth angles attached to a rotary drum are simultaneously operated to sequentially form diagonal tracks on a tape by an oblique scanning method for recording, and / or Alternatively, it is provided in a digital magnetic recording / reproducing apparatus for reproducing recorded signals, the two magnetic heads are arranged close to each other, and the distance between the gaps of the two magnetic heads is such that each adjacent track on the tape. Is approximately equal to an odd multiple of the amount of bending, which is the distance of displacement along the longitudinal direction of the track between them, and the displacement of the height position between the gaps of both magnetic heads is approximately equal to the same odd multiple of the track pitch. A rotary head for a magnetic recording / reproducing apparatus, characterized in that