JP2769740B2 - Magnetic recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus used for data backup of a computer or recording / reproducing of music information. The present invention relates to a magnetic recording / reproducing apparatus which can prevent crosstalk between a recording signal and a reproduction signal when performing afterwriting.

[Conventional technology]

FIG. 14 shows a rotary head device mounted on a conventional magnetic recording / reproducing device for DAT. This conventional example,
It is used for backing up data of a computer and has a verify function for performing a read-after-write operation. The diameter of the rotating drum 1 is 30mm
And the winding angle of the magnetic tape T is about 90 °.
Four magnetic heads are mounted. Of the four magnetic heads, A and B are magnetic heads for recording, and A 'and B' are magnetic heads for reproduction. FIG. 15 shows a recording signal (A) for writing with the A head and the B head and a reproduction signal (B) from the A 'head and the B' head along the time axis.

FIG. 15 shows a situation in which read-after-write is being performed. As described above, the diameter for DAT is 30 mm.
The winding angle of the magnetic tape T around the rotary drum 1 is about 90 °. Therefore, the recording signals from the recording heads A and B arranged at an arrangement interval of 180 ° are temporally intermittent as shown in FIG. 15 (A). Further, since the reproducing heads A 'and B' are provided at a phase of 90 ° with the A and B heads, the reproduced signals overlap the recording signals on the time axis as shown in FIG. 15 (B). Not intermittent. In read-after-write, it is confirmed by the reproduction signal whether or not the signal has been recorded on the tape reliably. In this rotary head device, as shown in FIG. 15, the recording signal (A) and the reproduction signal (B) do not overlap in time, so that the recording signal transmission path and the reproduction signal transmission path are
There is no crosstalk in a rotary transformer or the like, and there is no noise problem caused by simultaneous scanning of the tape by the head.

[Problems to be solved by the invention]

Recently, downsizing of a magnetic recording / reproducing device for DAT or the like has been required, and for that purpose, use of a rotating drum having a diameter smaller than 30 mm has been considered. In addition, with a device using this small-diameter rotating drum, a diameter of 30 mm
There is also a demand for compatibility with devices using conventional rotary drums. For example, when a rotating drum having a diameter of 20 mm is used, in order to be compatible with a device using a rotating drum having a diameter of 30 mm, the tape wrap angle around the drum is (90 × 3/2) = 135 °. Become. In order to maintain compatibility with the conventional device having a read-after-write function shown in FIG. 14, it is necessary to use a four-head system in which the winding angle of the magnetic tape is 135 °. In this device,
If recording of two tracks and read-after-write are completed during one rotation of the rotating drum, the head during the recording operation and the head during the reproducing operation scan the tape at the same time. For this reason, in the rotary transformer, crosstalk in which the recording signal gives noise to the transmission path of the reproduction signal occurs, and a countermeasure against the noise due to the crosstalk is required. However, in a rotary drum having a small diameter of about 20 mm, the rotary transformer inside the rotary drum also has a small diameter, so that the windings in the transformer are close to each other, and it is difficult to take measures against the crosstalk.

When four independent magnetic heads are used to realize a verify function for performing a read-after-write operation, four head windows are formed on the peripheral surface of the small-diameter drum. The number of times of sliding per unit time increases as compared with the two-head system, and tape damage increases. In addition, the tape is 13
In the case of a structure in which four independent heads are wound around at 5 °, a plurality of heads come into contact with the magnetic tape at the same time within the range of the tape winding angle, which adversely affects the contact state between the tape and the head. Will be.

The present invention has been made to solve the above-mentioned conventional problems, and can perform a read-after-write operation using a small-diameter drum, and can eliminate the problem of noise between a recording system and a reproduction system. It is still another object of the present invention to use a magnetic recording / reproducing apparatus which can minimize tape damage by minimizing the number of head windows formed in a rotary drum and prevent deterioration of a contact state between a tape and a magnetic head.

[Means for solving the problem]

A magnetic recording / reproducing apparatus according to the present invention includes a recording magnetic head Wa for scanning the same track on a magnetic tape, a reproducing magnetic head Ra for read-after-write, and a recording magnetic head Wb having a similar relationship. A magnetic head Rb is mounted on a rotating drum, and a magnetic tape 90
In the magnetic recording / reproducing device wound at an angle of ゜ 180 ° or less, the arrangement of the magnetic heads is opposite to the rotation direction of the rotating drum, in the order of Wa-Ra-Wb-Rb, and The tape is arranged in the order of Wa-Ra-Rb-Wb while the rotating drum rotates 360 ° or more while the arrangement angle of the head between Wa-Ra and between Wb-Rb is larger than the tape winding angle. The head is switched so as to perform recording / reproduction with respect to.

Alternatively, a recording magnetic head Wa for scanning the same track on a magnetic tape, a reproducing magnetic head Ra for read-after-write, and a recording magnetic head Wb and a reproducing magnetic head Rb having a similar relationship are provided on a rotating drum. In the magnetic recording / reproducing apparatus mounted, wherein the magnetic tape is wound around the rotary drum at an angle of 90 ° or more and 180 ° or less, the arrangement of the magnetic heads is opposite to the rotation direction of the rotary drum, Rb-Ra-Wb, and between Wa-Rb and Ra
The head is arranged so that the angle of the head between -Wb is larger than the tape winding angle, and recording and playback is performed on the tape in the order of Wa-Ra-Wb-Rb while the rotating drum rotates 360 ° or more. It is characterized in that the heads are switched in such a manner as to perform.

Further, in the above two means, it is preferable that a combination head in which two magnetic heads for recording and two magnetic heads for reproduction are combined in total of two magnetic heads is mounted on the rotating drum. .

[Action]

In the magnetic recording / reproducing apparatus according to the present invention, the recording / reproducing operation is performed by arranging and arranging the respective heads as described above and rotating the rotary drum by 360 ° or more. When two or more heads scan the tape at the same time, a switching operation is performed so that a recording or reproducing operation is performed by only one of the heads, and the recording operation and the reproducing operation are temporally performed by this switching operation. Avoid duplication. As a result, even if a small-diameter rotary drum is used, compatibility with a conventional rotary drum can be ensured, and crosstalk in read-after-write operation can be prevented.

Further, four magnetic heads can be used as two combination heads, whereby the head window formed on the rotating drum can be minimized, and tape damage due to sliding of the window can be minimized. Further, in this case, it is possible to prevent the two heads from simultaneously contacting the magnetic tape, and it is possible to prevent the contact state between the magnetic tape and the head from being deteriorated.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings of FIG. 1 to FIG.

FIG. 1 is a plan view showing a rotary head device used in a magnetic recording and reproducing apparatus according to a first embodiment of the present invention.

The recording heads Wa and Wb are provided on the rotating drum 10 shown in FIG.
In addition, playback heads Ra and Rb are mounted. The diameter of the rotating drum 10 is 20 mm, and the winding angle of the magnetic tape T around the drum 10 is 135 °.

Opening angle beta ₁ of the opening angle and Wb and Rb between the head Wa and Ra is required to be 135 ° or more. Also the first
In the illustrated embodiment, the heads Wa and Wb are arranged at 180 ° and R
a and Rb are also arranged at 180 °.

FIG. 2 is a plan view of a track recorded on the magnetic tape T as viewed from the recording surface side (the rotating drum side). FIG. 3 is an explanatory diagram showing a recording signal and a reproduction signal in a read-after-write operation.

The read-after-write operation is completed by the rotation of the rotary drum 10 by 720 °. First recording track a _n is effected by the recording head Wa. Recording signal at this time is Wa _n. Then the angle beta ₁ delayed start of recording heads Wa, track a _n-1 is scanned by the reproducing head Ra, reproduced signal Ra _n-1 for verification is obtained. Next, at the second rotation, the reproducing head R is delayed by an angle β ₂ (180 ° in the embodiment shown) from the start of reproduction by the reproducing head Ra.
The track b _n-1 is scanned by b, and a reproduction signal Rb _n-1 for verification is obtained. Moreover, recording of the track b _n is performed by the recording head Wb angularly beta ₃ delayed reproduction start by the reproducing head Rb. The recording signal at this time is Wb
_n . In this way, the tracks a _n and b _n
And playback of tracks a _n-1 and b _n-1 (verify)
Are completed, and the read-after-write operation is completed.

In the embodiment of FIG. 1, the opening angles of Wa and Wb and
Since the opening angles of Ra and Rb are both 180 °, β ₂ is 180 ° and β ₁ + β ₂ + β ₃ is 540 °.
opening angle of a and Wb and Ra and Rb are not necessarily 180 degrees, conditions necessary each angle beta ₁ and beta ₂ and beta ₃ is 135 ° or more.

As shown in FIG. 3, since there is no time overlap between the recording operation and the reproducing operation, it is possible to prevent crosstalk that causes noise in a transmission path of a signal during reproduction of a recording signal in a rotary transformer or the like.

4 to 6 show a further preferred embodiment corresponding to the first embodiment.

To realize the method of the embodiment of FIG. 1 as described above, each of the angle of the beta ₁ and beta ₂ and beta ₃ is required to be 135 ° or more, four satisfying this condition Of the rotating drum and the independent head of
This can be implemented by a structure that is exposed from each of the head windows. 4 to 6, the structure of the first embodiment is further preferred, and the heads Wa and Rb and Wb and Ra are combination heads, respectively. 18
They are arranged at an angle of 0 °. FIG. 4 is a perspective view showing an example of the structure of the combination head. The recording head Wa and the reproducing head Rb are installed on a common head base 15, and the head base 15 is
Fixed to 10. Similarly, the other heads Wb and Ra are installed on a common head base and fixed to the rotating drum 10.
Therefore, as shown in FIG. 6, the number of head windows formed on the peripheral surface of the rotary drum 10 can be reduced to only two locations indicated by 10a and 10b. Therefore, in a small-diameter rotary drum having a diameter of 20 mm, the number of windows sliding on the tape can be minimized, and thus tape damage can be minimized. Also in this structure,
135a wrapped around the tape, head window 10a
And 10b do not contact at the same time, so that the contact state between the head and the magnetic tape can be improved.

Further, in this combination, as shown in FIG. 6, the head cap of the recording head Wa and the reproducing head Rb
It is necessary to provide a height difference between the lower ends of the head caps and a height difference h between the lower ends of the gaps of Wb and Ra. Although the height difference h is shown in FIG. 2, the track inclination angle θ is 6 ゜ 22′59.5 ″ and the track width dimension is 13.591 μm in FIG.
m, and the opening angle α between the recording head and the reproducing head is 4.87 ° (see FIG. 5), h becomes 30.5 μm. By setting h to this value, heads Rb and Ra
_n-1 and a _n-1 can be scanned. In the adjustment of h, each head is mounted on each arm 15a and 15b of the head base 15 as shown in FIG. The h can be adjusted by pressing and displacing the arms 15a and 15b with screws.

Here, as shown in FIG. 11, by making the head track width l of the reproducing heads Rb and Ra sufficiently large, the adjustment of h becomes unnecessary. That is, the reproducing heads Rb and Ra do not affect the reproducing operation as long as the width is within two tracks. In this structure, arms 15a and 1
No adjustment work between the heads is required without forming 5b.

 FIG. 7 shows a second embodiment of the present invention.

In this embodiment, recording heads Wa and Wb are arranged on one side, and reproducing heads Ra and Rb are arranged on the same side on the other side. Also in this case, the diameter of the rotary drum 10 is 20 mm, and the opening angle between Wa and Rb and the opening angle β between Wb and Ra are 135 ° or more (the other angle conditions are β ₁ and β in the first embodiment).
_2, is the same as the β ₃ of the conditions). Also in this embodiment, recording and reproduction (read-after-write) of two tracks are completed by the rotation of the rotary drum 10 by 720 °. The recording signal and the reproduction signal at this time are as shown in FIG. After first recording head Wa is scanning the track a _n, reproducing heads Ra scans the track a _n-1. Next, the recording head Wb scans the track b _n , and then the reproducing head Rb scans the track b _n-1 to complete recording and reproduction. Also in this example, the recording signal and the reproduction signal do not overlap in time, and there is no stroke from the recording signal path to the reproduction signal path. In this embodiment, the recording heads Wa and Wb may scan the tape simultaneously. Since the recording current is larger than the reproducing current, for example, a recording signal sent to the head Wa during the recording operation gives noise to the head Wb on the non-recording side, and noise is added to the tape by the head Wb without recording. There is. Therefore, as shown in FIG. 10, it is desirable that the rotary transformer is arranged at a position farthest from the transmission path of the recording heads Wa and Wb.

In the embodiment shown in FIG. 7, a combination head can be used. As shown in FIG. 9, without providing a Wa and the lower end of the stepped gap Wb in this case, it is possible to head Wa and Wb scans the track a _n and b _n.

 FIG. 12 and FIG. 13 show a third embodiment of the present invention.

In this embodiment, the diameter of the rotating drum 20 is 15 mm. In order to maintain compatibility with the apparatus shown in FIG. 14, the tape wrap angle is 180 °. The recording head Wa and the reproducing head Rb and the heads Wb and Ra are combination heads. In this embodiment as well, as shown in FIG.
It is completed by the rotation of 720mm.

〔effect〕

As described above, according to the present invention, even when recording and reproduction (read-after-write) are performed using a small-diameter rotary drum, crosstalk between the recording system and the reproduction system does not occur. Also, by using a combination head, the number of head windows of the rotating drum can be minimized, and tape damage due to these windows can be suppressed. Further, deterioration of the contact state between the head and the tape can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a rotary head device used in the magnetic recording / reproducing apparatus of the present invention. FIG. 2 is a plan view showing the scanning state of the head from the recording surface side of the tape. Is an explanatory diagram showing a recording signal and a reproduction signal on a time axis, FIG. 4 is a perspective view when a combination head is used, FIG. 5 is a plan view showing an opening angle of the head when a combination head is used, FIG. 6 is an enlarged front view showing a combination head, FIG. 7 is a plan view showing a rotary head device according to a second embodiment of the present invention, FIG. 8 is an explanatory diagram of recording signals and reproduction signals, and FIG. FIG. 10 is an enlarged front view showing the combination head of the second embodiment, FIG. 10 is a sectional view of a rotary transformer used in the second embodiment, and FIG. 11 is another example of the combination head used in the first embodiment. Enlarged front view, twelfth FIG. 13 is a plan view showing a rotary drum according to a third embodiment of the present invention, FIG. 13 is an explanatory diagram of recording signals and reproduction signals, and FIG. 14 shows a rotary head device used in a conventional magnetic recording / reproducing apparatus. FIGS. 15 (A) and (B) are plan views, and are explanatory diagrams showing a recording signal and a reproduction signal in the conventional example on a time axis. Wa, Wb …… Recording head, Ra, Rb …… Reproducing head, 1,1
0,20 …… Rotary drum.

Claims (3)

(57) [Claims] 1. A recording magnetic head Wa for scanning the same track on a magnetic tape, a reproducing magnetic head Ra for read-after-write, and a recording magnetic head Wb and a reproducing magnetic head Rb having a similar relationship. In a magnetic recording / reproducing apparatus mounted on a rotating drum and a magnetic tape wound around the rotating drum at an angle of 90 ° or more and 180 ° or less, the arrangement of the magnetic heads is opposite to the rotating direction of the rotating drum. , Wa-Ra-Wb-Rb, and the arrangement angle of the head between Wa-Ra and between Wb-Rb is larger than the tape winding angle, and the rotating drum rotates 360 ° or more. A magnetic recording / reproducing apparatus which performs head switching so as to perform recording / reproducing on a tape in the order of Wa-Ra-Rb-Wb. 2. A recording magnetic head Wa for scanning the same track on a magnetic tape, a reproducing magnetic head Ra for read-after-write, and a recording magnetic head Wb and a reproducing magnetic head Rb having a similar relationship. In a magnetic recording / reproducing apparatus mounted on a rotating drum and a magnetic tape wound around the rotating drum at an angle of 90 ° or more and 180 ° or less, the arrangement of the magnetic heads is opposite to the rotating direction of the rotating drum. , Wa-Rb-Ra-Wb, and the arrangement angle of the head between Wa-Rb and between Ra-Wb is larger than the tape winding angle, and the rotating drum rotates 360 ° or more. A magnetic recording / reproducing apparatus which performs head switching so as to perform recording / reproducing on a tape in the order of Wa-Ra-Wb-Rb. 3. A rotating drum is provided with a combination head in which two magnetic heads for recording and two magnetic heads for reproduction are combined in total of two magnetic heads. 3. The magnetic recording and reproducing apparatus according to 2.