JPH041911A - Magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To attain a tracking servo operation without using any tracking-only head by reproducing a tracking pilot signal which is written into a recording track by means of an existing rotary eraser head that is not usually used in reproduction. CONSTITUTION:The rotary eraser head 18 having the track width larger by about two pitches of a recording track including a tracking pilot signal is provided on a rotary head drum 10. Simultaneously, the tracking pilot signals are stored while superposing them on the recording signals at every recording track by the record/reproduction heads 14 and 16 upon recording. Then these tracking pilot signals are detected via the head 18 at reproduction, and the tracking servo operations are carried out based on the tracking pilot signals. Thus the tracking pilot signal written into the recording track is reproduced without using any tracking-only head. Then a tracking servo operation is attained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording/reproducing method, and in particular, a magnetic recording/reproducing method in which a tape is helically scanned by a recording/reproducing head of a rotating head drum.
The present invention relates to a magnetic recording and reproducing method for recording in a tape format in which guard bands are provided between recording tracks and reproducing recorded tracks recorded in this tape format.

[Conventional technology]

The mainstream recording method for home video video signals is a high-density recording method that does not provide guard bands between video tracks, using a combination of the ``slanted Asia recording method'' and the ``color signal processing method using line correlation.'' There is.

That is, the former eliminates the crosstalk between video tracks of the FM-modulated luminance signal, and the latter eliminates the crosstalk between the video tracks of the low-frequency converted chrominance signal. This enables density recording.

On the other hand, during playback, a tracking servo is applied to prevent the head of the rotating head drum from falling off the track.
There is a pilot method used in mm VTR and the like.

In this pilot method, four types of tracking pilot signals f, f each having a constant frequency in a frequency range lower than that of the low frequency conversion color signal are used during recording.

f3f is recorded by sequentially superimposing it on a video signal etc. for each track, and if the head is out of track during playback, the pilot signal due to crosstalk from the pilot signal of the track being played back and the adjacent track to which the head approaches. Get two of the signals.

The beat signal output of these two pilot signals is set in advance to be a constant value, and the relationship with the track is also determined, so the state of track deviation is detected by this and the tracking servo is applied. ing.

[Problem to be solved by the invention]

By the way, the above-mentioned pilot method can only be applied to a recording method that records in a tape format with no or few guard bands, as described above, and when playing back a track recorded in a tape format with a wide guard band, Tracking was performed using a fixed head (control head) using a linear track at the lower edge, or a head exclusively for tracking was provided.

Note that the tape format having a guard band has the advantage that there is no crosstalk between adjacent tracks and high image quality can be realized.

The present invention has been made in view of the above circumstances, and is a magnetic recording/reproducing method that can reproduce a pilot signal for tracking written on a recording track without providing a dedicated head for tracking while providing a guard band. The purpose is to provide a method.

[Means to solve problems]

In order to achieve the above object, the present invention helically scans a tape running at a constant speed by a recording/reproducing head of a rotating head drum, and records a guard band between recording tracks containing a tracking pilot signal or a recording track that does not include a tracking pilot signal. In a magnetic self-recording and reproducing method of recording in a tape format with tracks and reproducing the recording tracks recorded in the tape format, the rotary head drum has a pitch of approximately two tracks or more of recording tracks containing a tracking pilot signal. A rotary erasing head having a track width of It is characterized by detecting a tracking pilot signal and performing tracking servo based on the tracking pilot signal.

[Effect]

According to the present invention, a rotating erasing head that erases recorded signals on a recording track prior to the recording/reproducing head during recording is used, and during playback, superimposed recording signals are written on the recording track via this rotating erasing head. A pilot signal for tracking that has been generated is regenerated, and tracking servo is performed based on the regenerated pilot signal.

The self-rotating erasing head described above is configured to have a track width of approximately two track pitches or more, so it can simultaneously reproduce two or more types of pilot signals.
Track deviation can be detected.

〔Example〕

Preferred embodiments of the magnetic recording and reproducing method according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a plan view of a rotary head drum applied to the magnetic recording and reproducing method according to the present invention, and FIGS. 2 and 3 show the relationship between each head and recording track in the recording state and the reproducing state, respectively. FIG.

As shown in these drawings, the rotary head drum 10 includes an A head 14 and a B head 16 for recording and reproducing distribution signals such as FM signals (luminance signals) and low frequency conversion color signals on a magnetic tape 12, and these heads. A rotary erasing head (hereinafter referred to as F/E head) 18 is provided prior to the A head 14 and the B head 16 for erasing the recording signal of the recording track that has already been recorded during recording. Furthermore, this F/E head 1
8 is about 1/2 track pitch from 1 to erase,
It is configured to be able to move downward.

The A head 14 and the B head 16 of the rotary head drum IO helically scan the tape 12 as shown in FIG. 2, and record recording signals on the recording track 20.
Four types of tracking pilot signals f that have a constant frequency in the frequency and numerical range lower than the low frequency conversion color signal in the recording signal
1fx fsf is sequentially written for each track.

Further, a recording method in which guard bands 22 are provided between recording tracks 20 is adopted.

On the other hand, the F/E head 18 has a track width of approximately 2 track pitches, and during recording, the A head 14 and the B head 1
6, the recorded signals recorded on each track are erased two tracks at a time.

Next, a case will be described in which a recorded signal is reproduced from a tape recorded as described above.

In this case, as shown in FIG.
/2 track pitch, and the F/E head 18 reproduces the tracking pilot signal superimposed on the recording track 2o.

When the A head 14 and the B head 16 trace the recording track 20 with high accuracy (no track deviation), the F/E head 18 straddles the three tracks, and the three tracks obtained from the three tracks are Among the different pilot signals, the levels of the pilot signals obtained from both tracks are equal.

On the other hand, when a track misalignment occurs, a level difference occurs between the pilot signals obtained from the tracks on both sides among the three types of pilot signals obtained by the F/E head 18, and as a result, the track misalignment is detected. The direction of deviation is detected.

That is, during reproduction, track deviation is detected from three types of pilot signals obtained from the F/E head 18, and tracking servo is performed based on the track deviation. In addition to the capstan servo, in which a rotary head drum is driven at a constant speed and tracking is performed by controlling the tape feed, there is also a tracking servo system in which tracking is performed by moving a head mounted on the drum.

In this embodiment, the track width of the F/E head is approximately 2 track pitches, but it is not limited to this, and may be approximately 2 track pitches or more. Also, by γ-do to F/E, 3
If more than one type of pilot signal can be detected and a pilot signal corresponding to the track deviation can be obtained, it is not necessary to move the F/E head by approximately 1/2 track pitch as in this embodiment.

〔Effect of the invention〕

As explained above, according to the magnetic recording and reproducing method according to the present invention, since the tracking pilot signal written on the recording track is reproduced using the existing rotary erasing head that is not normally used during reproduction, a guard band is provided. Even in a recording system in which a tracking pilot signal is recorded together with a recording signal in a tape format such as that shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a rotary head drum applied to the magnetic recording and reproducing method according to the present invention, and FIGS. 2 and 3 show the relationship between each head and recording track in the recording state and the reproducing state, respectively. It is a view seen from the surface side. 10... Rotating head drum, 12... Magnetic tape,
14°°°A''' head, 16...B head,
18... Rotating erase head (F/E head), 20...
- Recording track, 22...guard band.

Claims (1)

[Claims] A tape running at a constant speed is helically scanned by a recording/reproducing head of a rotating head drum, and guard bands or recording tracks not containing a tracking pilot signal are provided between recording tracks containing a tracking pilot signal. In a magnetic recording and reproducing method for recording in a tape format and reproducing recording tracks recorded in the tape format, the rotary head drum has a rotating head drum having a track width approximately two track pitches or more of a recording track containing a tracking pilot signal. An erasing head is provided, and during recording, the recording/reproducing head records a tracking pilot signal for each recording track by superimposing it on the recording signal, and during reproduction, the tracking pilot signal is detected via the rotating erasing head, and the tracking pilot signal is detected by the rotating erasing head. A magnetic recording and reproducing method characterized by performing tracking servo based on a tracking pilot signal.