JPH0273501A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten an unphotographable time at the time of consecutive recording by providing a preceding head to execute preceding recording to a normal head. CONSTITUTION:At the time of a recording mode, the same signal is transmit to both a normal head 12 and a preceding head 14 and a track formed by the head 14 immediately before the head 12 is erased by a rotary erasing head 16. Thus, the head 14 executes the same recording as the head 12 by preceding by the N tracks and the recording by the head 14 is executed between the current position of the head 12 and the position preceding by N tracks. Next, in accordance with a recording command, a preproducing mode is obtained, and when a tracking servo is obtained, it is turned to the recording mode. Thus, the recording by the head 14 is used at the interval until the tracking servo is obtained, even when a tape preroll operation is not performed, tracking does not become turbulent and the good consecutive recording without generating unrecorded parts is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device, and particularly to a magnetic recording and reproducing device that can perform good continuous shooting.

[Conventional technology]

When recording while editing one after another by interrupting VTR recording using the pause operation and starting recording again,
If you simply perform a pause operation, the next recording will start regardless of the track that has already been recorded, and the tracks will be arranged unevenly in this part, and the tracking servo will come off in this part during playback, causing the image to be distorted. arise.

In order to prevent this image from being distorted, there is a technique for editing connections known as the "backspace editing method."

In this method, when the pause button is operated, the capstan motor is reversed while the pinch roller is pressed, and the tape is rewound a certain amount (about 15 mm) to wait for the start of the next recording. When the pause mode is released, the tape is first driven in the play mode, and when the tracking servo is released, the mode is switched to the record mode and recording is resumed.

[Problem that the invention seeks to solve]

However, in the case of continuous shooting using the conventional backspace editing method, the time during which shooting cannot be performed during continuous shooting cannot be made shorter than the total time of the tape pre-roll operation time and the time required for tracking servo. - There is a problem in that even if the pause mode is canceled immediately after the pause button is operated, recording cannot be started until the above-mentioned photography disabled time has elapsed.

The present invention has been made in view of the above circumstances, and it is possible to eliminate the tape pre-roll operation, shorten the time during which shooting is not possible during splicing, and also enable good splicing without the occurrence of blank areas. The purpose of the present invention is to provide a magnetic recording/reproducing device that is possible.

Means for Solving Problem C] In order to achieve the above-mentioned object, the present invention provides advance recording with a predetermined height difference and mounting angle with respect to the first head that performs normal recording or recording/playback of the rotating head drum. a rotary erasing head that transmits the same signal to the first and second heads during recording, and erases the track formed by the second head immediately before the first head; It is characterized by the fact that the tape is not pre-rolled during a pause stop, and the recording mode is switched to when synchronized with the preceding track at the start of recording to perform continuous shooting.

[Effect]

According to the present invention, the second head is attached to the rotating drum with a predetermined height difference and attachment angle with respect to the first head, and when recording, the second head records the same as the first head. Recording is performed in advance by a predetermined number of tracks. Further, the rotary erasing head erases the track formed by the second head immediately before the east 1 head. Therefore, when you pause,
Since the final recorded image of the first head and the inter-track image are recorded in advance by a predetermined number of tracks, it is possible to omit the tape pre-roll operation at the time of pause stop.

〔Example〕

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

FIGS. 1(Δ) and 1(B) are a plan view and a front view, respectively, of a rotary head drum of a magnetic recording reproduction apparatus according to the present invention. This rotary head drum 1o is of a two-head type, and is provided with two normal heads 12.12 for performing normal recording or recording/playback, and two normal heads 12.12 for recording prior to these normal heads 12.12. A leading edge 14.14 is provided.

The rotating head drum 10 also includes a leading head 14.1.
The track formed by 4 is normally transferred to the head 12.12
A rotary eraser 16 is provided for erasing immediately before the rotation.

The preceding hen 14 is attached to the normal hen 12 with a predetermined height difference ΔH and a predetermined mounting angle Δβ so that the same recording as the normal hen 12 is recorded in advance by a predetermined number of tracks.

Next, the height difference ΔH and the mounting angle Δβ will be explained.

FIG. 2 is a conceptual diagram of a track pattern on the tape magnetic surface side recorded by the rotary head drum 10 of FIG. 1.

As shown in the figure, the preceding head' 14 is the normal head 1.
2, the height difference ΔH and the mounting angle Δβ between the normal head 2 and the preceding head 14 are calculated by the following formula, ΔH=Vt x xsin as (m
m)-(1)R/30. However, the above formula (1) and formula (
In Equation 2), vt: Tape feed speed (mm/s> D = Ni drum diameter (+no+) R Ni drum rotation speed (rpm) αS Ni drum lead angle N: Number of tracks to be preceded.

Note that the number of tracks N to be preceded is set to be at least larger than the number of tracks required for the tracking servo to rise.

Next, the operation of the magnetic recording/reproducing apparatus according to the present invention will be explained.

First, in the recording mode, the same signal is transmitted to both the normal head 12 and the leading head 14, and the rotating erase head 16 sends the leading head 14 just before the normal head 12.
The track formed by this process is erased. This results in
The leading head 14 precedes by N tracks and performs the same recording as the normal head 12, and the leading head 14 performs recording from the current position of the normal head 12 to the position N tracks ahead.

Here, when a pause stop command is applied, the tape is stopped at that position without prerolling the tape, and waits until the next recording starts.

Next, when a command to start recording is given, the tape is first driven in the playback mode, and when the tracking servo is established, the mode is switched to the record mode and the same recording as above is resumed.

As a result, in the section after the tape is driven until the tracking servo is activated, the recording by the leading radar 14 is utilized, and tracking is not disturbed during playback even without tape pre-rolling, and there are no unrecorded areas. This allows you to take continuous shots.

In addition, when applying tracking servo, use the β method or VH5
In this method, during recording, a signal indicating the rotational position of the rotating head is recorded on a coytrol track on the lower edge of the tape, and during playback, the rotation of the rotating head is controlled based on the playback control signal from the control track and the signal indicating the drum rotational position. Tracking is achieved by controlling the tape feed according to the phase. Therefore, the β method and VH5
In this method, in order to apply tracking servo without performing a tape pre-roll operation as in the present invention, it is necessary to apply a tracking servo to a normal control head that records a control signal on a control track, similar to the preceding head 14 for the normal head 12 described above. It is necessary to provide a control head for recording a preceding control signal.

Further, in a method of detecting track deviation without using a control track, for example, the LePilot method in 3 mm video, there is no need to provide the above-mentioned control head or the like. That is, in the Pyro/) method, four types of tracking pilot signals f, f2f, f, each having a constant frequency in a frequency range lower than the low frequency conversion color signal are used.
, are sequentially written for each track, and if there is a track shift during playback, two pilot signals are obtained: one from the track being played back and another from the crosstalk from the adjacent track to which the head approaches. The frequency difference between these two pilot signals is set in advance to be a constant value, and the relationship with the track is also determined, so it is possible to detect the state of track deviation and apply tracking servo. .

〔Effect of the invention〕

As explained above, according to the magnetic recording and reproducing apparatus according to the present invention, since a preceding head is provided that performs preceding recording with respect to the normal head, tracking can be performed during playback even without performing a tape pre-roll operation during pause stop. It is possible to perform a good splicing operation without disturbance and without the occurrence of a non-recorded part, and in particular, by abolishing the tape pre-roll operation, it is possible to shorten the time during which photography is not possible during splicing.

[Brief explanation of the drawing]

1(A) and (B) are a plan view and a front view, respectively, of a rotating head drum of a magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a side of the tape magnetic surface recorded by the rotating head drum of FIG. 1. FIG. 2 is a conceptual diagram of a track pattern of FIG. 10... Rotating head drum, 12... Normal head, 14... Leading head, 16... Rotating erasing head.

Claims (1)

[Claims] A second head that performs advance recording is attached to the first head that performs normal recording or recording/playback of the rotating head drum with a predetermined height difference and installation angle, and when recording, the second head is the same as the first and second heads. A rotary erasing head that transmits signals and erases the track formed by the second head immediately before the first head is installed, and when starting recording without performing a pre-roll operation of the tape at the time of pause stop,
A magnetic recording/reproducing device characterized in that a continuous recording is performed by switching to a recording mode when synchronized with a preceding track.