JPH04355294A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the decrease of track width and the discontinuity of a track phase at the time of editing and recording. CONSTITUTION:At the time of editing and recording, a signal for showing an editing mode is applied to a head position controller 11 through a mode input terminal 12. Based on a head position control signal generated by the head position controller 11, a controller 10 moves a position of magnetic heads 5 and 6 to the track width direction and sets it to a state being suitable to recording. As a result, even if editing and recording are executed, a decrease of track width and discontinuity of a track phase are not generated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus that performs highly accurate editing.

0002

2. Description of the Related Art The popularity of video signal recording devices (hereinafter referred to as VTRs) using magnetic tape as a recording medium, especially home VTRs, has been rapidly increasing in recent years. Recently, devices have become smaller and lighter, can reproduce relatively high-quality images, and are also equipped with various functions.

By the way, one of these functions is an editing function. The editing function also has various modes, and the editing function is essential regardless of whether it is a stationary type or a movie type.

[0004] Conventional editing operations will be explained below with reference to the drawings. FIG. 4 is a block diagram showing the configuration of a conventional example. In the figure, 36 is a video signal input terminal;
7 is a recording side signal processor, 38 is a switch, 39 is a rotating cylinder, 40 and 41 are magnetic heads, and magnetic head 40
and 41 are fixed on the rotating cylinder 39, and helically record signals on the magnetic tape 42. 45 is a controller, 43 is a reproduction side signal processor, and 44 is a video signal output terminal.

The video signal to be recorded is input to the video signal input terminal 3.
6 to the recording side signal processor 37. The recording side signal processor 37 processes pre-emphasis, clip, and FM.
Modulation, low frequency conversion of the carrier color signal, etc. are performed. The output of the recording side signal processor 37 is input to one input terminal of a switch 38. During recording, the switch 38 is closed to the recording side signal processor 37, and signals are supplied to the magnetic heads 40 and 41. The magnetic tape 42 is wound around a rotating cylinder 39, and the running of the magnetic tape 42 and the rotation of the rotating cylinder 39 are controlled by a controller 45.
formed on top.

During reproduction, information recorded on the magnetic tape 42 is taken out via the magnetic heads 40 and 41 and supplied to the switch 38. The controller 45 causes the magnetic heads 40 and 41 to correctly trace the magnetic tape 42.
The running of the magnetic tape 42 and the rotation of the rotary cylinder 39 are controlled respectively. During playback, the switch 38 is closed to the playback signal processor side 43, and the playback signal processor 43 performs an operation roughly opposite to that of the recording side signal processor 37, and outputs the playback signal via the video signal output terminal 44. Output. The reproduction side signal processor 43 performs FM demodulation, de-emphasis, frequency conversion of the carrier color signal, and the like.

A recording pattern on the magnetic tape 42 is shown in FIG. 5 and will be further explained. In the figure, 46 is a magnetic tape;
51-54 are magnetic heads, 55 is magnetic head width, 47-
50 is a track, 56 is a track width, 57 is a magnetic tape running direction, and 58 is a magnetic head scanning direction. Generally, the magnetic head width 55 of the magnetic heads 51 to 54 is a track width of 5
Set larger than 6. Moreover, the magnetic heads 51 and 52
indicates the position during recording, and the magnetic heads 53 and 54 indicate the positions during reproduction. During recording, the recorded track (for example, track 47) is overwritten by a part of the magnetic head 52 when forming the next track (for example, track 48), so the track 47 becomes slightly narrower than the magnetic head width 55. , the track width becomes 56. Therefore, the center of the track formed on the magnetic tape 46 is different from the center of the magnetic head.

On the other hand, during reproduction, the controller 45 operates so that the centers of the tracks 49 and 50 formed on the magnetic tape 46 coincide with the centers of the magnetic heads 53 and 54.

[0009]

[Problems to be Solved by the Invention] By the way, when editing is performed, the mode is suddenly switched from the playback state to the recording state. There are various editing modes, but to explain the editing operation in the conventional method shown above, we will use "splicing" (also called "assemble editing") as an example and explain it below with reference to Figure 6. . In FIG. 6, 46
is a magnetic tape, and 47, 48, 59, and 60 are already recorded tracks. 49, 50, 59, 61... are tracks newly recorded by "splicing", 53 and 5
4 is a magnetic head, 56 and 63 are track widths, 57 is a scanning direction of the magnetic tape 46, and 58 is a scanning direction of the magnetic head. When performing continuous shooting, the magnetic tape 46 is rewound a little and the previous signal is reproduced. As already explained, in the reproduction state, the centers of the magnetic heads 53 and 54 coincide with the centers of the tracks that have already been recorded. If a new signal is taken over from track 49, the magnetic head 53 will trace over the original track 49 in the same way as in the reproduction operation, so part of track 60 will be erased by overwriting. The track width is 63 (ordinarily, the track should extend up to the broken line).

In this way, the track 60 immediately before editing has a narrower track width than the other tracks. Furthermore, the track phase becomes discontinuous in steps with the editing point as a border. This phenomenon causes the quality of the reproduced signal to deteriorate during reproduction, and tracking control to become unstable. In particular, digital V is expected to be put into practical use in the future.
In TR, if the track width decreases too much, the limit of error correction ability will be exceeded, resulting in extreme image quality deterioration.

[0011] In view of the above-mentioned problems, the present invention has been made to
It is an object of the present invention to provide a magnetic recording/reproducing device that prevents discontinuity in track phase without reducing track width.

0012

[Means for Solving the Problems] In order to achieve this object, the present invention provides a head position controller that moves the head position in the track width direction when editing is performed so that it is at the same position as when recording. It is prepared.

[0013]

[Operation] In other words, during normal playback, the center of the magnetic head coincides with the center of the track being formed, but when recording for editing, the edge of the magnetic head aligns with the center of the original track, as in normal recording. By matching the edges, the above-mentioned discontinuity does not need to occur. As a result, even if editing is performed on a VTR, deterioration in playback image quality and inconveniences in playback tracking control can be avoided.

[0014]

[Examples] The present invention will be explained below along with examples.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 1 is a video signal input terminal, 2 is a recording side signal processor, 3 is a switch, 4 is a rotating cylinder, and 5
6 is a magnetic head, 7 is a magnetic tape, 8 is a reproduction side signal processor, 9 is a video signal output terminal, 10 is a controller, 11 is a head position controller, and 12 is a mode signal input terminal. A video signal to be recorded is applied to a recording side signal processor 2 via a video signal input terminal 1. The recording side signal processor 2 performs pre-emphasis, clipping, FM modulation, low frequency conversion of the carrier color signal, etc. Furthermore, digital VT
In R, the recording side signal processor 2 further performs high efficiency encoding, error correction encoding, formatting, digital modulation, etc. The output of the recording side signal processor 2 is input to one input terminal of the switch 3. During recording, the switch 3 is closed to the recording side signal processor 2 side, and signals are supplied to the magnetic heads 5 and 6. The magnetic heads 5 and 6 are fixed on a rotating cylinder 4 via an element (for example, a piezo element, hereinafter referred to as a piezo element) whose mechanical shape changes depending on an applied voltage, and perform helical recording on a magnetic tape 7. . The magnetic tape 7 is helically wound around the rotating cylinder 4, and the running of the magnetic tape 7 and the rotation of the rotating cylinder 4 are respectively controlled by a controller 10, and signals are recorded on the magnetic tape 7 in a predetermined recording format. is formed. During reproduction, information recorded on the magnetic tape 7 is supplied to the take-out switch 3 via the magnetic heads 5 and 6 on the rotary cylinder 4. The controller 10 controls the magnetic heads 5 and 6.
The traveling of the magnetic tape 7 and the rotation of the rotary cylinder 4 are respectively controlled so that the magnetic tape 7 is traced correctly on the magnetic tape 7. During playback, the switch 3 is closed to the playback signal processor 8 side, and the playback signal processor 8 performs an operation roughly opposite to that of the recording side signal processor 2, and outputs the playback video signal via the video signal output terminal 9. Output.

By the way, when a new signal is to be recorded on an already recorded signal portion of the magnetic tape 7 or following an already recorded portion, a mode signal indicating an editing mode is inputted to the mode signal input terminal 12. This mode signal is guided to the head position controller 11. The head position controller 11 outputs a head position signal for moving the head position in the track width direction according to the input mode signal.
The signal is applied to the piezo element on the rotating cylinder 4 via the rotary cylinder 4 to shift the position of the magnetic heads 5 and 6 in the track width direction. Hereinafter, a description will be given of "continuous shooting" with reference to FIG. 2 as an example.

In FIG. 2, 13 is a magnetic tape, 14,
Tracks 15, 16, and 17 are tracks on which signals have already been recorded on the magnetic tape 13, tracks 18, 19, 20, and 21 are tracks newly recorded by "splicing", and tracks 22 to 25.
is a magnetic head, 26 is a track width, and 27 is a magnetic tape 1.
3 is the scanning direction, and 28 is the scanning direction of the magnetic head. In the figure, for convenience of explanation, the track formation direction (that is, the scanning direction of the magnetic head) is almost perpendicular to the scanning direction of the magnetic tape, but in the case of helical scanning, it is diagonal. Needless to say.

[0018] When performing continuous shooting, use a little magnetic tape 1.
3, first play back the previous signal up to track 17 and apply tracking control. However, at this time (after track 18), a mode signal indicating continuous shooting recording is applied to the head position controller 11, which outputs a head position signal that moves the position of the magnetic head 22 in the track width direction. This head position signal is applied to the piezo element on the rotating cylinder 4 and shifts the position of the magnetic head 22 in the track width direction, so that the position is adjusted so that the magnetic head 24 has the same tracking phase relationship as the magnetic head during recording. The playback operation is executed under control. Magnetic head 23 and magnetic head 25
The same goes for the relationship with If the area after track 18 is a new recording portion, the tracks after track 18 are also formed at the same location as the original track.

FIG. 3 is a diagram showing a schematic configuration of the rotary cylinder shown in FIG. 1. As shown in FIG. In the figure, 5 and 6 are magnetic heads, 2
9 and 30 are piezo elements, 31 to 34 are piezo elements 29
and 30 are the displacement directions, and 35 is the rotation direction of the rotary cylinder 4. As already described, a mode signal indicating continuous shooting is applied to the head position controller 11, which outputs a head position signal for moving the head position in the track width direction. This head position signal is applied to the piezo elements 29 and 30 on the rotary cylinder 4 via the controller 10 to shift the position of the magnetic heads 5 and 6 in the shift directions 31 to 34 (track width direction). As a result, the position is controlled so that the tracking phase relationship is the same as that of the magnetic heads 24 and 25 during recording, such as the magnetic heads 24 and 25 in FIG. 2, and the reproduction operation is executed. Then it switches to recording mode. If the area after track 18 is a new recording portion, the tracks after track 18 are also formed at the same location as the original track. Note that the track position control described above may be performed after the editing and recording time.

[0020]

As described above, the present invention operates so that during editing, the magnetic head position is shifted in the track width direction at least after the point of switching to the recording mode, and the mode is switched to the recording mode in the same state as the recording mode. let As a result, discontinuity in track phase and decrease in track width do not occur before and after the editing point. Therefore, it is possible to eliminate deterioration in reproduced image quality and instability in tracking control.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a magnetic recording/reproducing device according to an embodiment of the present invention.

[Figure 2] Recording pattern diagram showing the recording state on the same magnetic tape

[Fig. 3] Schematic diagram showing the rotating cylinder section of this embodiment

[Figure 4
]Block diagram showing a conventional example

[Figure 5] Recording pattern diagram showing the recording state on the same magnetic tape

[Figure 6] Recording pattern diagram to explain continuous shooting

[Explanation of symbols]

1 Video signal input terminal 2 Recording side signal processor 3 Switch 4 Rotating cylinder 5, 6 Magnetic head 7 Magnetic tape 8. Playback side signal processor 9 Video signal output terminal 10 Controller 11 Head position controller 12 Mode signal input terminal 22-25 Magnetic head 29,30 Piezo element 31-34 Piezo element deviation direction 35　　　　Rotation direction of rotating cylinder

Claims (1)

[Claims] Claim 1: At the time of editing recording, the positional relationship between the center of the already recorded track and the center of the magnetic head is the same as the center of the track and the center of the magnetic head when the already recorded track was formed. A magnetic recording and reproducing apparatus comprising a head position controller that shifts the position of the magnetic head in the track width direction as much as possible to equal the positional relationship.