JPH05303728A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To stabilize a regenerative signal even when the bend of a track exists by increasing the kinds of the azimuth angle of a recording and reproducing head attached to a rotary head cylinder succeedingly and on the other hand, to controlling a head width. CONSTITUTION:A magnetic recording and reproducing device is provided with the constitution of the recording and reproducing head where the relation of n>=3, L<=tn holds when the kinds of the azimuth angle are (n) kinds, a track width is (t) and a recording and reproducing head width is L. That is, this device is constituted so that e.g. three heads 9, 10, 11 are attached to the rotary head cylinder 3 at even intervals of 120 deg. and the kinds of azimuth angle are three kinds. In such a case, when L2=3t2, the normal regenerative signal is obtained even when a recording signal is bended as a right figure in the figure or the inclination angle beta2 of the track is deviated when the deviated amt. is t2 or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable increase in the recording density of a magnetic recording / reproducing apparatus. Along with this, the track width is becoming narrower in the magnetic recording / reproducing apparatus of the helicopter scan type.

A conventional magnetic recording / reproducing apparatus will be described below. FIG. 8 is a plan view of a conventional magnetic recording / reproducing apparatus, and FIG.
FIG. 10 is an enlarged view of the main part, and FIG. 10 shows a pattern on the magnetic tape recorded by the magnetic recording / reproducing apparatus. In FIG. 8, 1 is a magnetic tape, 2 is a cassette containing the magnetic tape 1, 3 is a rotary head cylinder, and 4 and 5 are heads attached to the rotary head cylinder at intervals of 180 degrees. , 5 is an enlarged view of FIG. The heads 4 and 5 have azimuth angles α inclined in opposite directions as shown in FIG. 9, and the head width L ₁ thereof is the track width t ₁
Is slightly larger than. 6 is a post arranged to wind the magnetic tape 1 around the rotary head cylinder 3 at a predetermined angle (180 degrees). Reference numeral 7 denotes a capstan, which is configured such that the magnetic tape 1 is sandwiched between the capstan 7 and the pinch roller 8 and is rotated at a predetermined number of rotations to feed the tape at a predetermined speed.

In the magnetic recording / reproducing apparatus configured as described above, when the head 4 records one track, the magnetic tape 1 is moved by the capstan 7, and another head 5 records a new track. It Here, the track width t ₁ is determined by the speed of feeding the magnetic tape by the capstan 7 and the number of rotations of the rotary head cylinder 3. Since overwriting is performed at the time of recording, if there is a relation of L ₁ > t _{1, the} recording pattern is as shown on the left side of FIG. On this recording pattern, the head 4 moves in the direction of arrow A as shown in the figure to reproduce the recording signal. At this time, the head 4 is controlled by the pilot signal so as to move substantially in the middle of the track B. Since the track A and the track B have different azimuth angles, the track A is moved by the head 4.
The signal cannot be reproduced at the portion X overlapping with because of azimuth loss. In addition, during fast forward playback or rewind playback, the head 4
Moves on the alternate long and short dash line in FIG. At this time, since there is a relation of L ₁ > t ₁ , even if the signal is reproduced over the tracks, the signal of the track B and the signal of the adjacent track B are continuously reproduced, so that the reproduced signal is interrupted. There is no such thing.

[0005]

However, in the above-described conventional configuration, when the recording signal is bent or the track inclination angle β ₁ is deviated as shown in the right diagram of FIG. There is a problem in that the control of the pilot signal makes it impossible to follow up, and the vehicle travels even in a place deviated from the track B, so that a normal reproduction signal cannot be obtained. This tendency becomes more pronounced as the track width t ₁ becomes smaller. For example, if a narrow track width t ₁ of several μm is to be realized, the working accuracy of the rotary head cylinder 3 must be significantly improved, which is suitable for mass production. Not done. In addition, compatible factors such as compatibility reproduction and expansion / contraction of the magnetic tape due to changes in temperature and humidity can be considered as factors for the track bending or the deviation of the inclination angle β ₁ .

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a magnetic recording / reproducing apparatus capable of stably reproducing a narrow track width while maintaining the machining accuracy of a rotary head cylinder to the conventional level.

[0007]

In order to achieve this object, the magnetic recording / reproducing apparatus of the present invention has an azimuth angle of n.
When the type, the track width is t, and the recording / reproducing head width is L, the recording / reproducing head has a configuration satisfying the relationship of n ≧ 3 L ≦ tn.

[0008]

[Function] With this configuration, the magnetic tape expands and contracts due to compatibility reproduction and temperature / humidity changes, and the track bends and inclination angle β
_{Even if 1} is deviated, a stable reproduction signal can be obtained.

[0009]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a magnetic recording / reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of a main portion thereof, and FIG. 3 shows a pattern on a magnetic tape recorded by the magnetic recording / reproducing apparatus. Here, the same reference numerals are given to the same parts as those described in the above-mentioned conventional example, and the duplicated description here is omitted. Here, the difference from the conventional example of FIG. 8 is that
Three heads 9, 10 and 11 are attached to the rotary head cylinder 3 at equal intervals of 120 degrees. As shown in FIG. 2, which is an enlarged view of the heads 9, 10 and 11, the azimuth angles of these heads are shown. Means that there are three types. Also, since the number of heads is increased from 2 to 3, the angle of winding the magnetic tape 1 around the rotary head cylinder 3 can be as small as 120 degrees, and the heads are recorded on the magnetic tape in the order of 9 → 10 → 11. Or played.

Magnetic recording / reproducing apparatus configured as described above
When recorded in L₂> T₂ If there is a relation of
The recording pattern is as shown. Here, fast forward playback or rewind
During reproduction, the head 9 moves on the alternate long and short dash line. this
Time, L₂<(3-1) t₂= 2t₂ If so, use several tracks as shown by the dashed line in the figure.
When played back, the same azimuth track as head 9
It becomes smaller than the gap and the playback signal is interrupted.
I will. Therefore, the head width of the head 9 is L₂≧ (3-1) t₂= 2t₂ Need a relationship. Also, L₂= 3t₂ In that case, the recording signal may bend as shown in the right figure in FIG.
Kuwa truck inclination angle β ₂Even if there is a deviation, the deviation
Amount t₂A normal reproduction signal can be obtained if: Well
It was L₂> 3t₂ Then, even if the track shift amount is less than t, the same
I picked up the track next to Jimus, and L₂≤3t₂ A relationship is needed.

As is apparent from FIG. 10 of the conventional example, it is obvious that the conventional magnetic recording / reproducing apparatus cannot obtain a normal reproduction signal when the track is displaced by t ₁ .

As described above, according to this embodiment, the azimuth is
There are 3 types of corners, and the head width L ₂2t₂≤L₂≤3t₂ By doing so, the amount of track deviation is t₂Degree
If so, a normal reproduction signal can be obtained.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a plan view of a magnetic recording / reproducing apparatus according to the second embodiment of the present invention, and FIG. 6 shows a recording pattern on a magnetic tape recorded by the magnetic recording / reproducing apparatus. Here, the same reference numerals are given to the same parts as those described in the above-mentioned conventional example, and the duplicated description here is omitted. Here, the difference from the conventional example of FIG. 8 is that the rotary head cylinder 3 has 12, 13, 14, 1
The four heads shown by 5 are mounted in pairs of 12.13 and 14/15 at intervals of 180 degrees, and the azimuth angle of the heads is 4 as shown in FIG. 5, which is an enlarged view of the heads. It is a kind. Here, at the head 12, the tape insertion side C of the rotary head cylinder 3
When recording or reproduction is performed by rotating from the tape to the tape output side D, next, recording or reproduction is performed by the head 15. After that, recording or reproduction is performed in the order of 13, 14, 12, and 15.

Magnetic recording / reproducing apparatus configured as described above
When recorded in L₃> T₃ If there is a relationship of,
The recording pattern is as shown. Here, fast forward playback or rewind
For reproduction, the head 12 moves on the alternate long and short dash line. this
Time, L₃<(4-1) t₃= 3t₃ If so, use several tracks as shown by the dashed line in the figure.
When played back accordingly, the same azimuth tiger as head 12
The playback signal is interrupted.
End up. Therefore, the head width of the head 12 is L₃≧ (4-1) t₃= 3t₃ Need a relationship. Also, L₃= 4t₃ If so, the recording signal may bend as shown in the right figure in FIG.
Kuwa truck inclination angle β ₃Even if there is a deviation, the deviation
The amount is 1.5t₃A normal playback signal can be obtained if
It Also, L₃> 4t₃ If so, the amount of track deviation is 1.5 t₃Less than
Picked up the track next to the same azimuth, L₃≤4t₃ A relationship is needed.

As described above, according to this embodiment, the azimuth is
There are four types of corners, and the head width L ₃To 3t₃≤L₃≤4t₃ By doing so, the amount of track deviation is 1.5 t₃
A normal reproduction signal can be obtained up to a certain degree.

(Third Embodiment) A third embodiment of the present invention will be described below with reference to the drawings. FIG. 7 shows a plan view of a magnetic recording / reproducing apparatus according to the third embodiment of the present invention.
Here, components similar to those described in the second embodiment above are designated by the same reference numerals, and duplicate description thereof will be omitted. Here, the difference from the second embodiment of FIG. 4 is that
Four heads denoted by 12, 13, 14, and 15 are attached to the rotary head cylinder 3 at equal intervals of 90 degrees,
The azimuth angle and head width L ₃ of those heads are shown in FIG.
As described above, it is the same as the second embodiment. Further, the magnetic tape 1 is wound around the rotary head cylinder 3 by 90 degrees, and the head is recorded or reproduced in the order of 12 → 15 → 13 → 14. The recording pattern and the movement of the head 12 during reproduction are the same as in the second embodiment.

[0018]

As described above, according to the present invention, there are n kinds of azimuth angles, t is the track width, and L is the recording / reproducing head width.
Then, by adopting a reproducing head configuration in which the relationship of n ≧ 3 L ≦ tn is established, it is possible to realize an excellent magnetic recording / reproducing apparatus in which a stable reproduced signal can be obtained even when the track width is narrow. is there.

[Brief description of drawings]

FIG. 1 is a plan view of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of the magnetic head according to the first embodiment.

FIG. 3 is a recording pattern diagram of the magnetic recording / reproducing apparatus according to the first embodiment.

FIG. 4 is a plan view of a magnetic recording / reproducing apparatus according to the second embodiment.

FIG. 5 is an enlarged view of a main part of the second embodiment.

FIG. 6 is a recording pattern diagram of the magnetic recording / reproducing apparatus according to the second embodiment.

FIG. 7 is a plan view of a magnetic recording / reproducing apparatus according to the third embodiment.

FIG. 8 is a plan view of a conventional magnetic recording / reproducing apparatus.

FIG. 9 is an enlarged view of a main part of the magnetic recording / reproducing apparatus.

FIG. 10 is a recording pattern diagram of the magnetic recording / reproducing apparatus.

[Explanation of symbols]

 3 rotary head cylinder 9 magnetic head 10 magnetic head 11 magnetic head 12 magnetic head 13 magnetic head 14 magnetic head 15 magnetic head

Claims (2)

[Claims] 1. A magnetic tape is wound around a rotary head cylinder at a predetermined angle to perform recording or reproduction by a helicopter scan method, and a recording / reproducing head mounted on the rotary head cylinder has an azimuth recording angle. In the magnetic recording / reproducing apparatus of the type, a recording pattern of the magnetic tape is formed by a substantially linear track having an inclination of a predetermined angle with respect to a tape traveling direction having non-overlapping n kinds of azimuth angles. A magnetic recording / reproducing apparatus having a recording / reproducing head satisfying n ≧ 3 L ≦ tn, where t is the track width and L is the recording / reproducing head width. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein a winding angle θ for winding the magnetic tape around the rotary head cylinder has θ ≧ (360 / n) °.