JPH04138786A - Method and device for magnetic recording and reproduction - Google Patents

Abstract

PURPOSE:To reduce the cross talk with an adjacent track by arranging signals while performing correction by means of the time axis change of a recording signal when the adjacent recording track and the arrangement of the signal are not matched in a magnetic recording and reproduction system recording and reproducing plural video signals with different signal systems. CONSTITUTION:By a switch control circuit 6, switches SW1 and SW2 selecting the output of tracks T1 to T4 memory parts is selectly controlled, and recording signals are outputted to turn time axis for T1 to be the same, to advance T2 for 0.25H, to advance T. for 0.5H, and to advance T4 for 0.75H against a reference signal time axis. Thus, the signal outputted from a memory circuit 3 is recorded on a tape by heads CH1 and CH2 through magnetic recording process after D/A conversion. Therefore, since H arrangement can be performed even in a signal of any system, the cross talk of the adjacent track at the time of recording and reproduction of a multisignal can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording and reproducing method and apparatus for recording and reproducing a plurality of video signals of different signal formats, and in particular to multi-signal recording without guard bands between recording tracks. The present invention relates to a technique for arranging signals between tracks to reduce the effects of crosstalk with adjacent tracks during playback.

[Conventional technology]

Conventionally, FM modulated video signals have been solidly recorded or overlapped onto magnetic tape in order to increase the recording density. However, if guard bands are not provided between recording tracks in this way, crosstalk from adjacent tracks will occur unless the signals are arranged between each track (hereinafter referred to as H arrangement. H means one horizontal period). comes out in a big way. Therefore, crosstalk between adjacent tracks is reduced by arranging the tracks in an H-shape or by changing the gap angle of the head in an azimuth manner.

The H arrangement is determined by the scan angle of the head, the number of rotations of the drum, and the tape feed speed. In the standard mode and long-time mode, which have the same signal system, the H arrangement is adjusted by the tape feed speed. Also, if H alignment is not possible, for example in β■, the difference between adjacent tracks will be 0.7H, so 0.5
A method called H carrier shift, that is, F for each truck.
A method is adopted in which the M carrier frequency is shifted by 1/2 of the horizontal synchronizing signal frequency to create frequency interleaving.

For example, in Japanese Patent Application Laid-Open No. 54-72623, in a color under one-sided system, when the tape pattern is not lined up in H, the head mounting angle is set to 1 for the luminance signal.
H alignment is performed with a shift of 0.5n from 80', and H alignment is performed with a delay of (2n-1)H (where n is a positive integer) every other frame for color signals.

[Invention or problem to be solved]

However, in VTRs that record and play back multiple signals with different signal formats, even if you adjust the H alignment by adjusting the tape feed speed, H alignment is very difficult and requires a specific tape feed speed and rotation speed, which is not practical. Must not be.

Furthermore, in the technique disclosed in the above-mentioned publication, since the head mounting position is shifted from 180" in order to arrange H-level luminance signals, there is a problem that it cannot support video signals of multiple signal formats. In terms of technology, with VTRs that can record and reproduce video signals of different signal formats, it has been difficult to arrange them in H array due to differences in drum rotation speed, number of scanning lines, etc.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a magnetic recording and reproducing method and apparatus that can realize H-alignment no matter what signal format video signals are recorded or reproduced. purpose.

[Means to solve the problem]

In order to achieve the above object, the magnetic recording and reproducing method according to the present invention is a magnetic recording and reproducing method for recording and reproducing a plurality of video signals of different signal formats. This method is characterized by correcting and arranging the signals by changing the time axis.

Further, a magnetic recording and reproducing device according to the present invention is a magnetic recording and reproducing device that records and reproduces a plurality of video signals of different signal formats, and includes a plurality of storage units that store signals corresponding to recording tracks, and a magnetic recording and reproducing device that records and reproduces a plurality of video signals of different signal formats. The present invention is characterized in that it includes a control means for controlling a change in the time axis of the recording signal at the writing and reading timings to each of the storage sections in order to arrange the signals.

Furthermore, the magnetic recording/reproducing apparatus configured as described above is provided with a reference signal generator that serves as a reference for changing the time axis, and simultaneously controls the signal arrangement of adjacent recording tracks based on the reference signal of this reference signal generator, and simultaneously controls the signal alignment during playback output. It is characterized by performing control.

[For production]

In the magnetic recording and reproducing method according to the present invention, a signal system,
If the signal alignment with adjacent tracks does not match due to tape feed speed, drum rotation speed, or multi-channeling, this can be corrected by changing the time axis of the signal to achieve signal alignment, thereby eliminating the effects of crosstalk with adjacent tracks. reduce

Furthermore, the magnetic recording and reproducing apparatus of the present invention includes a plurality of storage units that store signals corresponding to the recording tracks, and the control means controls the time axis change of the signal output from each storage unit. Realizes signal alignment with adjacent tracks.

moreover. In the magnetic recording/reproducing apparatus of the present invention, by performing signal arrangement control and reproduction output control simultaneously based on the reference signal of the reference signal generator that serves as a reference for changing the time axis, jitter correction can be achieved at the same time as the signal arrangement effect. It can be done.

〔Example〕

Hereinafter, embodiments according to the present invention will be described based on the drawings. In this embodiment, in a mode for recording and reproducing standard video signals such as NTSC and PAL, conventional VH
3 (registered trademark), etc., by mechanically setting the drum diameter and tape speed, and using the same mechanism, record video signals of different formats, such as HDTV. When reproducing, the signals are processed electrically to realize H arrangement.

First, a method that allows H arrangement even at arbitrary tape speeds and rotational speeds will be explained. Figure 1 (a) to (e)
shows a recording arrangement in which VH5 and high-definition signals are recorded on four tracks.

In the VHS normal mode with 525 scanning lines as shown in Figure (a), H alignment is possible if the start position is shifted by 1.5H between each track, and similarly as shown in Figure (b). In VH33x mode, only 0.5H, and the same figure (C
) When recording a high-definition signal with 1125 scanning lines as shown in (), H alignment is possible if the start position is shifted between each track by 0.75H.

On the other hand, in the example of the recording arrangement of a high-definition signal, the same figure (
As shown in d), when the start position is 0.5H, it is not possible to arrange H as shown. However, the same figure (e)
is an example in which the high-definition signals are arranged in H, and shows a state in which the signals are arranged in H even if the start position shift is 0.5H. Comparing this with (d) in the same figure, track T2 is TL
0.25H ahead of T, track T is 0.25H ahead of T
This shows that it is sufficient to carry out a method in which the track T4 is advanced by 0.25H from T4, and the track T1 is delayed by 0.75H from T4. That is, track T is the same with respect to the reference signal time axis, and track T2 is (1
, 25H, track T should be advanced by 0.5H, and track T4 should be advanced by 0.75H on the time axis of the recording signal.

Figure 2 shows a timing chart for H alignment as described above. - In the shell, there is an overlap of about 3H at the switching point of the head between each track, and for H alignment, the center of signal overlap or IH Even if the discrepancy is within this range, no problem will occur during playback.

As shown in Figure 3, the head arrangement and tape winding angle are as follows: 2 heads CH and CH2 are installed at 180'' intervals, the tape is wound 180' around the drum, and the drum is rotated at 3800 rp11. When rotated, one field of 60Hz video signal can be recorded on two tracks (one frame = four tracks).

Also, Figures 4(a) and (b) show the UNIHI VT
An example of an R video signal and a MUSE video signal is shown, both are TCI signals, and the color signals are R-Y and B-Y.
The two color difference signal components are arranged in line order. Therefore,
The signal of the adjacent track is R-Y.

By recording so that they are aligned with the B-Y components, that is, so that odd lines and even lines are aligned on adjacent tracks, the influence of crosstalk from adjacent tracks on color signals is reduced.

Next, FIG. 5 shows a specific configuration diagram of the H array control circuit in this embodiment. A signal generator 2, a memory circuit 3 that inputs and stores an input video signal via the A/D converter, a memory write control circuit 4 that sends a write pulse to the memory circuit 3, and the reference signal generator. a memory read control circuit 5 that sends a read pulse to the memory circuit 3 based on a reference signal from the memory circuit 2; a switch control circuit 6 that selects the output of the memory circuit 3; D/A converters 7 and 8 which D/A convert the output of the memory circuit 3 via switches sw and sw2 that operate as shown in FIG.
9. FM modulator which uses the output to perform FM modulation process for FM magnetic recording. It is equipped with an IO and heads CH and CI (2) that record the output on tape.

Here, the memory circuit 3 has T1 to T4 memory sections corresponding to the respective tracks T1 to T4 shown in FIG. The data is stored in each of the T1 to T4 memory sections through the control section, and reading is performed by the memory control section based on the output from the memory read control circuit 5 which outputs a read pulse for the T1 to T4 memory sections based on a reference signal. The Tl-T4 memory section outputs the output at appropriate timing. Note that the reference signal from the reference signal generator 2 is reset every frame in order to have a correlation between memory write and read.

Then, the switch control circuit 6 selects and controls the switches SW1 and SW2, which select the outputs of the T1 to T memory sections, so that the tape pattern shown in FIG. On the other hand, a recording signal is outputted in which the track TI is the same, the track T is advanced by 0.25H, the track T3 is advanced by 0.5H, and the track T4 is advanced by 0.75H. In this way, the signal output from the memory circuit 3 is D/A converted and then recorded on the tape by the heads CH and CH2 through a magnetic recording process. The reference signal from the reference signal generator 2 is also supplied to a drive system (not shown) (drum rotation, tape feeding, etc.), and during playback, the reference signal is stored in a -degree memory by a playback circuit (not shown) and then output as the reference signal. It is called based on the reference signal from the signal generator and returns to the original signal by D/A conversion.

Therefore, according to the above configuration, signals of any type can be arranged in H order, thereby reducing crosstalk between adjacent tracks when recording and reproducing multi-signals. Also, H
Since the arrangement is performed by controlling the write and read timing to the memory circuit 3, the time axis of the recording signal can be changed at any time setting, and the number of scanning lines for each signal method can be changed. It is possible to prevent defects in H alignment due to differences. Furthermore, a reference signal generator 2 that serves as a reference for changing the time axis
By performing the H arrangement control and the playback control based on the reference signal, it is possible to achieve the effect of jitter correction.

In the embodiment shown in FIG. 5, the memory circuit 3 is provided with a dedicated memory section for each track T1 to T4. It can also be used as a ride lead, and as shown in the embodiment of FIG. 6, a shared memory section for tracks T and T and tracks T2 and T4 may be provided in the memory circuit 3. For example, in the embodiment shown in FIG. 5, a memory for about one frame is required, but in the embodiment shown in FIG. 6, the memory capacity for about one field is sufficient.

In addition, in the embodiment shown in FIG. 5 described above, the input video signal is sequentially recorded on each track of the tape in the order of the line number of the scanning line, but each track signal recording arrangement shown in FIGS. 7 and 8 is As shown in the tape recording arrangement, track T1
By sequentially recording lines 1 and 2 on the first track T2 and lines 3 and 4 on the track T2, it is possible to further reduce the crosstalk of the chrominance signal and the luminance signal due to adjacent tracks.

Furthermore, in the embodiment described above, the drum rotation speed is 1800 r.
pm, 2-head configuration, and tape winding 180a, but it goes without saying that H-arrangement can be done in the same way in other ways. For example, track T has lines 1 to 4.
, In NQ, , 5 to 8 can be recorded on track T2, and in that case, there will be a difference of 4 lines between adjacent tracks.

〔Effect of the invention〕

As described above, according to the present invention, by changing the time axis of the recording signal to align signals with adjacent tracks,
Since signals of any type can be arranged in H order, crosstalk between adjacent tracks during multi-signal recording and reproduction can be reduced.

Furthermore, according to the present invention, since the H-alignment is implemented in the write and read timing control for the memory circuit having a plurality of recording units corresponding to the tracks, the time axis of the recording signal can be changed at any time setting. In addition, it is possible to prevent defects in H alignment due to differences in the number of scanning lines in each signal system.

Furthermore, the effect of jitter correction can also be achieved by performing the H alignment control and the playback control based on the reference signal from the reference signal generator 2, which serves as a reference for changing the time axis.

[Brief explanation of drawings]

Figures 1 (a) to (e) are tape recording arrangement diagrams explaining an example of H degree arrangement according to the method of the present invention, Figure 2 is a timing chart of H arrangement, and Figure 3 is a head arrangement and tape winding angle. 4(a) and 4(b) are explanatory diagrams of the UNIH1 signal and the MUSE video signal, FIG. 5 is an H array control circuit diagram illustrating the device of the present invention, and FIG. 6 is an explanatory diagram of the UNIH1 signal and the MUSE video signal. Such circuit diagrams, FIG. 7 and FIG. 8, are a signal recording arrangement diagram of each track and a tape recording arrangement diagram for explaining another embodiment. 1... A/D converter, 2... Reference signal generator, 3.
...Memory circuit, 4...Memory write control circuit, 5.
...Memory read control circuit, 6...Switch control circuit, CH, CH...Head, sw, sw2...Switch, T1 to T4...Track. Inventor Fumio Inaba

Claims (3)

[Claims] (1) In a magnetic recording and reproducing method for recording and reproducing a plurality of video signals with different signal formats, if the signal alignment does not match with the adjacent recording track, the signal alignment is corrected by changing the time axis of the recording signal. A magnetic recording and reproducing method. (2) A magnetic recording and reproducing device that records and reproduces a plurality of video signals of different signal formats is provided with a plurality of storage units that store signals corresponding to recording tracks, and each of the above-mentioned storage units is used to arrange signals with adjacent recording tracks. What is claimed is: 1. A magnetic recording and reproducing apparatus comprising: a control means for controlling a change in time axis of a recording signal at write and read timings to a section. (3) The magnetic recording and reproducing apparatus according to claim 2, further comprising a reference signal generator serving as a reference for changing the time axis, and simultaneously controlling the signal alignment of adjacent recording tracks based on the reference signal of the reference signal generator. A magnetic recording/reproducing device characterized by controlling output.