JPH0443780A - magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a helical scanning type magnetic recording and reproducing apparatus that divides and records one field of video signals into an odd number of tracks.

2. Description of the Related Art Conventionally, for the purpose of recording a large amount of data in a magnetic recording/reproducing device (hereinafter referred to as VTR), a method of recording L field information on a tape using a plurality of heads has been studied. As shown in the figure, a VTR with the same configuration as VH3 has a track pitch of 1/3, an azimuth angle of θ, and -0 respectively.

Three heads l with azimuth angles of 10, -0.

The first head group 4 consists of 2.3 and the first head group 4.
A second head group 10 consisting of three heads 6, 7, and 8 arranged approximately 180 degrees apart on the drum 14 and having azimuth angles of +θ, -0, and 10, alternately every field period. If one field of information is divided into three tracks and recorded and reproduced on the magnetic tape 13, it is possible to record and reproduce three times the amount of information compared to VH3.

Problems to be Solved by the Invention However, as mentioned above, narrowing the track pitch,
When considering still playback in a configuration with an increased number of drums, the first head group 4, as shown in Figure 8, generates three heads that make up one field while the drum rotates half Because the head scans across the tracks 17, 18, 19, the head trajectory becomes the head trajectory 20.21.22, and the diagonally shaded blocks 24.25.
Only 26 will be played. Next, as shown in FIG. 9, during the next half rotation of the drum, the second head group 10 scans the head trajectory 2B, 29.30, and moves to the diagonally lined block 31.30 of the track. 32.34
．． Only 35 will be played. Therefore, during still playback, only a portion of the tracks constituting one field is played back, and since a continuous playback signal cannot be obtained, there is a problem in that noise occurs on the screen.

The present invention solves the above-mentioned problems and provides a VTR that divides one field of information into an odd number of tracks for recording and reproduction.
An object of the present invention is to provide a magnetic recording device that reproduces video signals without noise during still reproduction.

Means for Solving the Problems In order to solve the above problems, the magnetic recording/reproducing apparatus of the present invention has two head groups each having an odd number of heads with different azimuth configurations, and a two auxiliary heads configured adjacent to one head so that they have different azimuth angles and have the same head height;
It consists of a head switching circuit, a switching signal generator, and a field memory.

According to the above-described structure, during still playback, the signal is played back by one of the two auxiliary heads during a period when the heads of two groups of odd heads do not play back tracks. A switching signal generator generates a switching signal for signals reproduced from the heads of the group and two auxiliary heads, and a head switching circuit switches the signals reproduced from the head whose azimuth matches the track constituting one field, Since the reproduction is performed, reproduction signals can be obtained almost continuously, and a reproduction image without noise can be obtained.

Example Below, regarding a magnetic recording and reproducing device according to an example of the present invention,
This will be explained with reference to the drawings. FIG. 1 is a block diagram of a magnetic recording device according to an embodiment of the present invention, FIG. 2 is a diagram showing the arrangement of heads on a drum, and FIGS. 3 and 4 are diagrams showing the height of the heads. FIG. 5 and FIG. 6 are diagrams showing head trajectories during still playback by the first head group and the second head group, respectively.

In FIG. 2, the drum 14 is rotated 1800 r counterclockwise.
Rotate with p-. During recording and reproduction, the magnetic tape 13 passes through the inclined post 15, contacts the ram 13 over approximately 180 degrees, and advances to the inclined post 16, where the three heads 1, 2, .
First head group 4 consisting of 3 and 3 heads 6.7.8
The second head group 9 is arranged on the drum at intervals of approximately 180 degrees, and the first head group 4 records images of even fields on three diagonal tracks on the magnetic tape 13 every one field period. The second head group 9 records and reproduces video signals of odd fields. FIG. 3 shows the head level differences of heads 1°2.3, 6, and 7.8. head 1
and head 6, head 1 and head 7, head 3 and head 8
have the same height, and the head spacing χ1. χ2 and head height differences yl and y2 are set. Furthermore, head 1 is -θ, head 2 is +θ,
3 is -θ, 6 is +θ.

7 has an azimuth angle of -θ and 8 has an azimuth angle of +θ, and the recorded tracks have a configuration in which the azimuths of adjacent tracks are different from each other. The first auxiliary head 5 is configured to have a different azimuth angle -θ and the same head height with respect to the head 1 that scans the center track of the three tracks reproduced by the first head group 4. The head spacing χ3 is set so that the head 1 is as close as possible to the head 1.

The second auxiliary head 1O is used for reproducing 3 of the second head group 9.
The head 7, which scans the center track of the book, is configured to have a different azimuth angle +θ and the same head height, and the head spacing χ3 is set so that the head 7 is as close to the head 7 as possible. There is.

FIG. 5 is a diagram showing a head trajectory during still reproduction by the first head group 4, and FIG. 6 is a diagram showing a head trajectory during reproduction by the second head group 9. The head trajectory indicates the trajectory of the center position of the head. Track 17.1
8.19 are tracks recorded by heads 1.2.3, respectively. Tracks 17 and 19 are at 10 azimuth and track 18 is at +θ azimuth. The even field to be played is track 17.18.19
It is made up of. In Fig. 5, head trajectory 20.2
2 are head trajectories scanned by the heads 1.3 of the first head group 4 during still reproduction, and head trajectories 21 are head trajectories scanned by the head 2 and the first auxiliary head 5 during still reproduction. It is a trajectory. In FIG. 6, head trajectories 28 and 30 are the head trajectories scanned by the heads 6 and 8 of the second head group 9 during still playback, and head trajectories 29 are the head trajectories scanned by the heads 6 and 8 of the second head group 9, and the head trajectories 29 are the head trajectories of the head 7 and the second auxiliary head 10.
This is the head trajectory during still playback scanned by. During still playback, the period in which the drum makes one revolution is divided into six equal parts, and the first
Period 1, period 2, period 3, period 4, period 5, and period 6 start from the start of track scanning of the head group 4. Since the head reproduces the signals of tracks with the same azimuth, during one rotation of the drum, the block 23 below the track 19 divided into three by the first auxiliary RAD 5 is reproduced in period 1, and 2, the first head group 4 is on track 17.18
．． Block 24 in the middle of the track that divided 19 into three equal parts.
25 and 26 are respectively reproduced with rad 1°2.3, and in period 3, the block 27 on the track which divided track 17 into three is played with the first auxiliary rad 5, and in period 4, the block 27 on the track 17 is divided into three equal parts, and in period 4, the second The head group 9 divides the track 18 and 19 into three equal parts and reproduces blocks 31 and 32 below the track with the heads 6 and 7, respectively, and in period 5, the second auxiliary head 10 reproduces the track 18 into three parts.
Regenerate the equally divided middle block 33, and in period 6
Head group 9 reproduces blocks 34 and 35 on the track 17 and 18 into three equal parts using heads 7 and 8, respectively.

FIG. 1 is a block diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. As explained in FIG. 2, the first head group 4 is made up of heads 1.2.3, and the second head group 9 is made up of head groups 6.7.8. The head switching circuit 11 switches the heads 1.2.3, 6.7.8 and the first head according to the signal output from the switching signal generator 12.
Input the signals reproduced from the auxiliary RAD 5 and the second auxiliary RAD 10, and when the azimuth of the track and the head that make up one field match, the signal is switched to the A channel, B channel, and C channel. Output in 3 channels.

Regarding the above configuration, the operation of still playback of even fields will be explained. During still playback of an even field, the switching signal generator 12 generates a signal for switching the head at the timing shown in Table 1 while the drum rotates once. The head switching circuit 11 receives the signal output from the switching signal generator 12, and outputs the signal of the first auxiliary head 5 to the A, B, and C channels in period 1, and outputs the signal of the first auxiliary head 5 to the A, B, and C channels in period 2.
The signals of the heads 1, 2, and 3 of the first head group 4 are output to channels A, B, and C, respectively, and the signals of the first auxiliary head 5 are output to channels A, B, and C during period 3, In period 4, the signal of the head 6 of the second head group 9 is output to the A and B channels, the signal of the head 7 of the second head group 9 is output to the C channel, and in the period 5, the signal of the head 6 of the second head group 9 is output.
, outputs the signal of the second auxiliary head 10 to the C channel, outputs the signal of the head 7 of the second head group 9 to the A channel in period 6, and outputs the signal of the head 7 of the second head group 9 to the B and C channels. 8 signals are output. Therefore, a reproduced signal can be obtained substantially continuously during still reproduction, and a reproduced signal of an even field without noise can be obtained.

Table 1 As described above, according to the magnetic recording/reproducing apparatus of the embodiment of the present invention, during still reproduction of an even field, during one rotation of the drum, the heads 1 of the first head group 4 and the second head group 9
．． 2, 3, 6, 7.8, the first auxiliary head 5 and the second auxiliary head 10 are switched to reproduce the head that matches the azimuth of the track constituting one field, thereby eliminating noise. Still playback of even fields can be realized.

It should be noted that even in still reproduction of odd fields, which are not described, reproduction signals are obtained almost continuously, so it is clear that noise-free still reproduction can be obtained by changing the switching timing of the switching signal generator 12.

Furthermore, as shown in FIG. 4, it is also possible to configure the middle head and the auxiliary head in the same block, and the switching time delay is smaller than in the configuration shown in FIG. 3, making it easier to implement the present invention.

In addition, although we have explained the case where one field of video signal is divided into three tracks and recorded, it can also be divided into five tracks and recorded, or when it is divided into seven tracks and recorded. Even if it is attached, the effect of the present invention will not be lost in any way.

Also, although I did not describe the feeding of the tape 14,
Although the feeding of the tape 14 has not been described, it is clear that if the present invention is used when the tape is fed intermittently, intermittent slow playback can be realized.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the first
By providing the above auxiliary head and the second auxiliary head, reproduction signals can be obtained substantially continuously during still reproduction, making it possible to reproduce still images without noise in even or odd fields.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a magnetic recording device according to an embodiment of the present invention, FIG. 2 is a diagram showing the arrangement of heads on a drum, FIGS. 3 and 4 are diagrams showing the height of the heads, and FIG. FIG. 6 is a diagram showing the head trajectory during still playback by the first head group, FIG. 6 is a diagram showing the head trajectory during still playback by the second head group, FIG. FIG. 8 is a diagram showing a head trajectory during still reproduction by the first head group of the conventional example, and FIG. 9 is a diagram showing the head trajectory during still reproduction by the second head group of the conventional example. 1.2, 3.6, 7.8...Head, 4...
...First head group, 5...First auxiliary head, 9...Second head group, 10...Second auxiliary head, 11... ...Head switching circuit, 12...Switching signal generator, I3...
...Magnetic tape, I4...Drum. Name of agent: Patent attorney Shigetaka Awano (1 person)

Claims (1)

[Claims] A helical scanning magnetic recording and reproducing device configured to record and reproduce video signals on three or more odd-numbered tracks for each field so that adjacent tracks have different azimuth angles, a first head group consisting of an odd number of heads configured on the drum and recording and reproducing the tracks of the even field almost simultaneously; and a second head group consisting of an odd number of heads configured on the drum and recording and reproducing the tracks of the odd field almost simultaneously. The heads of the first head group are configured to have different azimuth angles and the same head height with respect to the head that scans the center track of the tracks constituting an even field during recording and reproduction among the heads of the first head group. a first head disposed adjacent to the first head group;
The auxiliary head is configured to have different azimuth angles and the same head height with respect to the head that scans the center track of the tracks constituting the odd field during recording and reproduction among the heads of the second head group. A second auxiliary head disposed adjacent to the second head group, a head switching circuit, and a switching signal generator, and during still playback, the switching signal generator causes the head switching circuit to switch the head. Upon receiving the head switching signal, the head switching circuit outputs a signal and outputs a signal reproduced by the head of the first head group and the signal reproduced by the head of the second head group so as to reproduce the head whose azimuth matches the track constituting one field. 1. A magnetic recording and reproducing apparatus characterized in that a signal reproduced by a head of a head group, a signal reproduced by the first auxiliary head, and a signal reproduced by the second auxiliary head are switched.