JPH0520649A - Head device - Google Patents

Abstract

(57) [Abstract] [Purpose] In an editing and recording device mainly used for editing for broadcasting and professional use, the improvement of the head manufacturing and mounting accuracy should be minimized to balance the recording loci during recording and editing. Therefore, it is intended to improve the stability against noise and errors at edit points. [Structure] Head groups 1 and 2 composed of a plurality of heads
And a head 12 which is a reference position and is the last recording head 12 among the heads included in the predetermined head group 1
Of the head groups 2 other than the head group 1 including 2, the mounting accuracy and / or the head width accuracy of the head 22 that performs the last recording is higher than those of the other heads and is mounted on the rotating body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head device which can be used in a video / audio signal recording / reproducing apparatus such as a VTR.

[0002]

2. Description of the Related Art In recent years, in a video / audio signal recording / reproducing apparatus such as a VTR, the density has been increased, the track has been made narrower, and an azimuth angle has been provided between the heads of adjacent tracks, and a guard is provided between the recording tracks. The so-called azimuth recording, which does not have a band, is used.

A digital VTR for broadcasting which adopts such a recording system is described in "Technical Report of the Television Society of Japan VOL.11,
No.24, PP13-18, VR '87 -30 ”. According to this, in this VTR, the width of the recording head is set to be wider than the track pitch so that a guard band does not occur even if there is a head mounting error or a head width error.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a VTR for broadcasting,
The work of editing is performed by connecting a plurality of materials to create one program. What is important at the time of this editing is that noise and error do not occur at the editing point and it is stable. For this purpose, it is necessary that the recording loci before and after the editing point be as continuous as possible. Therefore, at the editing start point, the locus recorded on the base is reproduced by the head for editing and recording, and tracking control is performed so that the output envelope thereof is maximized.

However, since the width of the recording head is set wider than the track pitch in the conventional VTR, the range in which the reproduction envelope becomes maximum has a width and it is difficult to perform accurate tracking. Therefore, there is a disadvantage that an already-recorded locus and a newly-recorded locus are deviated at the edit point, and as a result, noise and errors increase. This error is particularly noticeable at the edit point when the original trajectory remains as an obstruction to the newly recorded trajectory at the same azimuth angle.

To solve this problem, the width of the recording head may be made equal to the track pitch. In this case, however, a guard band may be generated or the pitch may be shifted due to an error in the head width or mounting. .. This phenomenon is the accumulation of the mounting error and the width error for the loci recorded by the heads other than the head that is the mounting reference position.
It will be noticeable. Also, at the editing point,
Although improved, the larger the aforementioned error, the smaller the margin for errors and noise.

[0007]

In order to solve the above problems, a head device of the present invention comprises a head group composed of a plurality of heads, and a reference position is recorded last among the heads included in a predetermined head group. Among the head groups other than the head group including the means for performing the head and the head for the reference position, the mounting accuracy and / or the head width accuracy of the head that performs the last recording is set higher than the other heads to rotate the head. It has a means of attaching to the body.

[0008]

According to the present invention, the error of the deviation of the locus recorded by the last recording head among the head groups other than the head group including the head to be the reference position is recorded by another head with the above-described structure. The locus can be made equal to or close to the locus, the recording locus can be balanced, the locus shift due to editing can be minimized, and the stability can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a head device according to an embodiment of the present invention. 1A is a front view and FIG. 1B is a plan view. In FIG. 1, 1 and 2 are head groups, and 11,
Reference numerals 12, 21, 22 are heads. Further, FIG. 2 is a recording locus on a tape recorded by a recording / reproducing apparatus having such a head device. Normally, in a VTR having such a head device, the recording locus is formed obliquely with respect to the tape, but in FIG. 2, a part thereof is shown in the vertical direction for convenience. In FIG. 2, 3 to 8 are boundaries of the loci, 30 to 8
0 is a recording locus. FIG. 2 shows a state in which the locus is formed without error according to the reference value.

The operation of the head device of this embodiment constructed as described above will be described below.

The reference position for mounting the head is the head group 1.
Is set at the lower end position of the head 12 (A2). Based on this position, all the heads are mounted at a predetermined height, and the height h1 to the lower end position of the head 11 (A1) of the head group 1 and the lower end position of the head 21 (B1) of the head group 2 are set. Height h2, head 22 of head group 2 (B
The height h3 to the lower end position of 2) is determined. The width of each head 11, 12, 21, 22 is w1, w2, w3.
It is indicated by w4. When recording is performed by the rotary head device configured as described above, as shown in FIG. 2, the tape and the head run, and the locus 40 by the head 12 (A2) is formed immediately after the locus 30 by the head 11 (A1). Was
Head 21 (B1) after head group 1 has rotated 180 degrees
A locus 50 by the head 22 (B2) is formed immediately after that, and loci 70, 80 are sequentially formed. The track pitch TP at this time is determined by the tape speed, the head mounting height, and the head width.

The head group 1 and the head group 2 perform recording as a pair, and the head 12 immediately after the head 11
Since the recording is performed immediately after the head 21, the head 11
A portion of the track recorded by the head 21 and extending to the right of the track pitch over the track pitch is erased by recording by the subsequent heads 12 and 22. Therefore, the widths of the heads 11 and 21 are set to be wider than the track width for obtaining the specified track pitch. The height h1 from the lower end position of the head 12 to the lower end position of the head 11 is the loci 30,7.
0, ... Is set to a height to obtain a specified track pitch TP. The lower end position of the head 22 is set to the same height as the lower end position of the head 12 as a specified value. The lower end position of the head 21 is based on the lower end position of the head 12, and the locus 50,
Is set to a height to obtain a specified track pitch TP. At this position, the head group 1 and the head group 2 are located at 18
When mounted at 0 degrees, the default value is head 1
It is the same as the prescribed lower end position of 1. Head 12, head 2
The widths w2 and w4 of 2 are set to a specified width that is almost equal to the track pitch in order to prevent the already recorded track from being cut off at the editing end point.

However, the attachment of these heads always contains some error. Also, there is an error in the head width. For simplification of description, assuming that these attachment errors and width errors are all ± 1 μm, the left end (boundary 4) of the locus 40 is set as the reference position and the left end ( Boundary 3)
Is ± 1 μm, the right end of the trajectory 40 (boundary 5) is ± 1 μm, the left end of the trajectory 50 (boundary 5) is ± 1 μm, the left end of the trajectory 60 (boundary 6) is ± 1 μm, and the right end of the trajectory 60 (boundary 7) is ± 1 μm.
There is an error of 2 μm (in the case of normal recording, the locus 70 is recorded following the locus 60, and the left end error is ± 1 μm.
Therefore, when the error at the right end of the locus 60 becomes +1 μm or more, the head 11 overwrites and the right end error of the locus 60 becomes +1 μm / −2 μm). Here, the locus 30
When the widths of the head 11 and the head 21 are made wider than the specified value by 2 μm or more, the right end of the track and the right end of the track 50 are always overwritten by the track recorded by the next head 12 and 22, and the error is absorbed.

As is clear from the above description, the locus 60
The error at the right end is the sum of the mounting error at the lower end position of the head 22 and the width error of the head 22, which is larger than the other boundaries. Further, the error with respect to the continuity of the locus when the editing that ends at the right end of the locus 60 is larger than that at the editing at other points, and the stability at this point becomes worse.

Therefore, in the present invention, the width accuracy and / or the mounting accuracy of the head 22 is set higher than those of other heads. The head 22 is the head 12 which is the reference position.
Of the head groups 2 other than the head group 1 including, the head group performs the last recording. For example, when the width accuracy and the mounting accuracy of the head 22 are ± 0.5 μm, the trajectory 6
The error at the right end of 0 (boundary 7) is ± 1 μm, which is the same as the other boundaries. Further, if either the width accuracy or the mounting accuracy is ± 0.5 μm, the error at the right end (boundary 7) of the locus 60 is ± 1.5 μm, which is improved from the original state and is balanced in each boundary. ..

Further, the tracking at the time of editing can be performed more accurately than in the conventional example by performing the reproduction output of the head 12 having the same specified width as the track width and serving as a mounting reference.

Although the present invention has been described above with respect to a VTR, the present invention is similarly effective for a recording / reproducing apparatus such as a disc.

[0019]

As described above, according to the present invention, among the heads included in the predetermined head group (1), the reference position is set to the head (12) for the last recording, and the head group (including the head to be the reference position). Among the head groups (2) other than 1), the mounting accuracy and / or the head width accuracy of the head (22) for the last recording is higher than those of the other heads to balance the recording loci and edit It is possible to minimize the deviation of the trajectory and improve the stability.

Also, in the manufacture and mounting of the head, it is sufficient to increase the accuracy of the specific head, and the manufacture can be facilitated.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing the configuration of a head device in an embodiment of the present invention.

FIG. 2 is a schematic pattern diagram showing a recording locus on a tape recorded by a head device in the embodiment.

[Explanation of symbols]

 1, 2 head group 11, 12, 21, 22 heads 3, 4, 5, 6, 7, 8 Recording track boundary 30, 40, 50, 60, 70, 80 Recording track

Claims (1)

Claim: What is claimed is: 1. A head device for use in an apparatus for performing recording on a recording medium in units of the head group, using a rotating body having a plurality of head groups composed of a plurality of heads. When attached to the rotating body, the reference position is set to be the last recording head among the heads included in the predetermined head group, and the last recording is performed among the head groups other than the head group including the reference position head. A head device characterized in that the head mounting accuracy and / or the head width accuracy is higher than those of other heads.