JPH02278553A - Method and device for magnetic recording and reproducing - Google Patents

Abstract

PURPOSE:To lighten the load of a tape and to enable one part of information to be reproduced at the time of fast forward by winding the tape around a head drum at a smaller tape wrapping angle at the time of high speed search than at the time of normal recording and reproducing. CONSTITUTION:The tape winding angle can be changed in a tape loading mechanism by properly moving a loading base 20 having its slant post 20A and guide roller 20B and a loading base 22 having its slant posts 22A and 22B, etc. At the time of high speed search, the winding angle beta is set as about 1/3 of its normal case, and then the tape 10 is half loaded to a rotary head drum 12. At the time of operation, a correcting command is outputted by a control circuit to make the tape speed about 50 times of its normal case and also the rotation of the drum 12 a normal relative speed. By this method, the load on the tape is diminished to make the tape capable of fast forwarding, and one part of the information can thus be reproduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording and reproducing method and apparatus, and particularly to magnetic recording using the so-called helical scanning method in which magnetic tape is wound diagonally around a rotating head drum to record and reproduce. The present invention relates to a reproduction method and apparatus.

[Conventional technology]

As a conventional magnetic recording/reproducing apparatus of this type, there is a video tape recorder (VTR) as shown in FIGS.

This VTR has a function of detecting the cue signal recorded on the videotape 1 using the audio control head 2 to cue the cue of the videotape 1. When performing normal recording and playback, the 5th As shown in the figure, move the loading bases 3.4 to their respective predetermined forward ends,
A video tape 1 is wound around a rotary head drum 5 at a predetermined tape winding angle and brought into contact with an audio control head 2.

On the other hand, when searching the beginning of the video tape 1, the loading bases 3 and 4 are moved to predetermined positions in the middle of tape loading, as shown in FIG. The video tape 1 is brought into contact with the audio control head 2 by setting the angle to zero or to a small value. This results in
The load on the tape can be reduced, and high-speed cueing can be achieved.

[Problem to be solved by the invention]

By the way, it would be convenient if images could be displayed when fast forwarding or rewinding to find the place you want to see, but the conventional VT
When starting the tape with R, the video tape 1 is not wound around the rotary head drum 5 accurately, so a picture cannot be displayed.

Furthermore, as is clear from the shape of the case 7), the above-mentioned VTR is a VH3 type VTR, but in a VTR that does not have a fixed head, such as an 8mm VTR,
It is not possible to start the tape at high speed like with R.

Therefore, when performing a search such as finding the beginning of an 8 mm VTR tape, the tape must be wound around a rotating head drum as in normal recording and playback, which increases the load on the tape and reduces the search speed. is limited.

That is, there is a problem in that the search speed is limited to about 7 to 9 times the tape speed during normal recording and playback.

The present invention has been made in view of the above circumstances, and when performing a high-speed search using a rotary head drum, the present invention provides a magnetic field. In a magnetic recording and reproducing method in which a magnetic tape is wound at a tape winding angle and magnetic recording and reproducing is performed on the magnetic tape via the rotating head drum, when a tape winding is smaller than the predetermined tape winding angle during a high-speed search. A magnetic tape is wound around the rotary head drum so as to have a diagonal angle, and the magnetic tape is fed at high speed, so that part of the information recorded on the magnetic tape is reproduced via the rotary head drum. It is characterized by

[Effect]

According to the present invention, during high-speed search, the magnetic tape is wound around the rotary head drum so that the tape winding angle is smaller than the tape winding angle during normal recording and reproduction. This reduces the load on the magnetic tape and enables fast forwarding of the tape.

Then, the magnetic tape is fed at high speed in the loading state with the small tape winding angle, and part of the information recorded on the magnetic tape is reproduced via the rotary head drum.

When the information reproduced in this way is only video information, it is possible to display a part of the picture in one screen, for example, the upper half, the lower half, etc., and high-speed search by picture is possible. Also, ID (identificati).

O) If it contains information, the tape can be cued using that information.

〔Example〕

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

1 and 2 are plan views respectively showing an embodiment of the mechanical part of the magnetic recording/reproducing apparatus according to the present invention, in which a 3 mm video cassette is used as the tape cassette.
It is shown regarding VTR.

First, to briefly explain the track arrangement of an 8 mm video tape, etc., as shown in Figure 4, a video tape 10 has an auxiliary track for cueing and an auxiliary trunk for audio at the top and bottom ends, respectively. Between these trunks, there is provided an area for recording and playback by means of a rotating head drum.

This area includes the area where the video signal and FM audio signal are recorded (180' in tape winding angle), and the area where the PC
It consists of an area where M audio signals are recorded (36 degrees in tape winding angle), and a 6.8H (H
: Horizontal scanning line) PCM post-recording margin and V −
A pguard area is provided, and it is also being considered to use a part of it as an ID area.

Incidentally, the auxiliary track for cueing and the auxiliary track for audio are recorded and reproduced by an optionally installed fixed head (cue head, audio head), but these are not used in a normal 3 mm VTR.

Now, 8 m+n VTR shown in Fig. 1 and Fig. 2
As shown in FIG.
) (hereinafter referred to as full loading), and as shown in FIG. 1, the tape winding angle β (ζα/3) is smaller than the tape winding angle α. It is configured so that the video tape 10 can be wound (hereinafter referred to as half loading).

That is, the tape loading mechanism includes a loading base 20 having an inclined post 2OA and a guide roller 20B.
, the loading base 22 having the inclined posts 22A and 22B, the left and right swinging pins 24, 26, the guide rollers 28, etc. are appropriately moved to form a desired tape path, and the videotape 10 is fully loaded or half loaded onto the rotating hent drum 12. Loading.

First, to explain the case of full loading from the unloading state, as shown in FIG. Form a tape path in .

Subsequently, the loading bases 20 and 22 are moved from the positions shown by the dashed-dotted lines as shown by the arrows to draw out the tape in the cassette 14 and form a tape path from the drum port to the drum outlet. Note that while the loading base 22 is moving to a predetermined full loading position, the loading base itself rotates clockwise, the inclined post 22A functions as an inclined post on the tape exit side, and the inclined post 22B functions as a guide. It is designed to take a predetermined posture so as to function as a pin.

Finally, the pinch roller 30 is pressed onto the capstan 32 to complete tape loading.

Next, a case of half loading from a full loading state will be described. As shown in FIG. 1, the loading base 22 and the guide roller 28 are moved from the positions shown by the dashed lines as shown by the arrows. At this time, while the loading base 22 is moving to a predetermined half-loading position, the loading base itself rotates counterclockwise, and the inclined post 22B functions as an inclined post on the tape exit side during half-loading.
The inclined post 22A assumes a predetermined posture so as to function as a guide pin.

The half-loading position of the loading base 22 coincides with the unloading position as shown in FIG. 2, and the loading base 22 is accurately regulated at the full-loading position and the half-loading position (unloading position). has been done.

When half-loading is performed in this way, the video tape 10 is wound around the rotating head drum 12 at a predetermined tape winding angle β, and this rotating head drum performs magnetic recording and reproduction on a part of the tape. becomes possible.

Note that the loading base 20 on the tape loading side is fully loaded.
The positions at the time of loading and half loading are the same, and as is clear from this, when /S-flow deinking, the position is approximately 1/3 of the bottom of the video tape 10, that is, the PCM area and the PCM area as shown in FIG. Magnetic recording and reproduction can be performed on a portion of the tape including the ID area.

Further, it goes without saying that the half loading is not limited to the case where the half loading is performed from the full loading state as described above, but the half loading can also be performed from the unloading state. Further, the tape guide band for making the tape follow the drum accurately is generally provided with a relief from the tape at the tape entrance/exit, but the rotary head drum 12 according to the present invention has a relief from the tape at the tape exit during half loading. An escape is provided.

Next, control of the 8 mm VTR having the above configuration will be explained.

FIG. 3 is a block diagram of the main parts of the above-mentioned 8Q VTR. In the figure, the operation buttons 40 include a high-speed search button in addition to the usual record button, playback button, fast forward button, rewind button, etc., and various modes are selected by operating these buttons.

When the recording or playback mode is commanded from the operation button 40, the system control circuit 42 controls the drive circuit 44.
The loading motor 46 is driven via the tape loading mechanism 48, thereby operating the tape loading mechanism 48 to perform full loading as described above. Similarly, when the high speed search mode is commanded from the operation button 40, the system control circuit 42 operates the tape loading mechanism 48 to perform half rope inking.

The system control 142 outputs speed commands for the rotating drum 12 and capstan 32 to the servo circuit 50 according to various modes.

That is, the servo circuit 50 has the following functions in recording and playback modes:
The rotating head drum 12 is commanded to rotate at 1800 rpm and the tape speed is 14.3 mm/sec, and the servo circuits 50 are connected to drive circuits 52 and 54, respectively.
The drum motor 56 and the capstan motor 58 are controlled to achieve the above-mentioned speed through the . Incidentally, the rotational speed of the rotary head drum 12 and the rotational speed of the capstan 32 are detected by a PG sensor (not shown), respectively.
The PG multiplied signal from the G sensor is added to the servo circuit 50 as a feed bank signal. Further, in the playback mode, a known tracking servo is applied using tracking pilot signals f1 to f recorded superimposed on the video track and the PCM trunk.

On the other hand, when the high-speed search mode is selected, the system control circuit 42 operates at a speed approximately 5 times faster than the tape speed during normal recording and playback.
While outputting the tape speed command so that it becomes 0 times,
The rotation speed of the rotating hent drum 12 is approximately 2133 rp.
Outputs a speed command of m.

That is, the relative speed between the video tape 10 and the rotary head drum 12 during normal recording and playback is 3.752 m/s, but if the tape speed is increased by 50 times, the relative speed becomes 3.051 m/s.
m/s. Therefore, the rotating hent drum 12
The rotational speed of is corrected as described above, so that the same relative speed as during normal recording and playback can be obtained. Furthermore, here,
The case where a high-speed search is performed by forward-feeding the tape has been described, but when performing a high-speed search by feeding the tape backwards, the rotation speed of the rotary head drum 120 should be set to approximately 1450 rpm.
Make it.

As mentioned above, in the high-speed search mode, the tape is fed at 50x speed in the half-loading state, and the tape ID is searched at high speed.
You can search for information such as cue information recorded in the area.

In the above embodiment, information in the ID area is searched at high speed. The lower half, upper half, etc.) may be played back. However, in this case, for example, part of the video signal is stored in a field memory or the like, pictures of each video trunk are connected, and a pseudo synchronization signal is added to form a video signal that allows high-speed picture searching.

Further, the present invention is not limited to 8 mm VTR, but VH3
It can also be applied to ゜β system VTRs, digital audio tape recorders (R-DAT), etc. Furthermore, the tape winding angle with respect to the rotating hent drum during half loading, the tape winding position, the rope ink mechanism for half loading, the tape speed during high speed search, etc. are not limited to this embodiment, and various designs are possible. .

〔Effect of the invention〕

As explained above, according to the magnetic recording and reproducing method and apparatus according to the present invention, the magnetic tape is wound around the rotating head drum so that the tape winding angle is smaller than the tape winding angle during normal recording and reproducing. Therefore, the load on the tape can be reduced, the tape speed can be increased, and high-speed searches can be performed using the rotating head drum.

[Brief explanation of drawings]

1 and 2 are plan views showing a half-rope ink state and a full loading state, respectively, of the magnetic recording and reproducing device according to the present invention, and FIG. 3 is a main block of the magnetic recording and reproducing device shown in FIG. 1. 4 are diagrams showing the track arrangement of a 3 mm video tape, and FIGS. 5 and 6 are plan views each showing an example of a conventional magnetic recording/reproducing apparatus. 10...Video tape, 12...Rotating hent drum, 14...Casseft, 20.22...Loading base, 2OA, 22A, 22B...
Inclined post, 20B, 28...guide roller,
24.26... Swing pin, 30... Pinch roller, 32... Capstan, 40... Operation button, 42... Stem control [1, 48
...Tape loading mechanism, 50...Servo circuit.

Claims (2)

[Claims] (1) A magnetic recording and reproducing method in which a magnetic tape is wound around a drum having a rotating head so as to have a predetermined tape winding angle, and magnetic recording and reproducing is performed on the magnetic tape via the rotary head, wherein the predetermined tape winding angle is set at the time of high-speed search. A magnetic tape is wound around the drum having the rotary head so that the tape winding angle is smaller than the tape winding angle of . A magnetic recording and reproducing method characterized in that reproduction is performed through a rotating head. (2) A magnetic recording and reproducing device that winds a predetermined first tape around a drum having a rotating head at a predetermined winding angle, and performs magnetic recording and reproducing on the magnetic tape via the rotating head, which performs high-speed search. winding the magnetic tape around the drum having the rotary head so as to have the first tape winding angle or a second tape winding angle smaller than the first tape winding angle, respectively; tape loading means; tape feeding means for feeding the magnetic tape at a predetermined speed; and when a high-speed search is instructed by the instruction means, the tape winding angle on the drum having the rotary head is adjusted to the second tape winding angle. controlling the tape loading means so that the magnetic tape is at an angle, controlling the tape feeding means so as to feed the magnetic tape at high speed, and playing back part of the information recorded on the magnetic tape via the rotary head. A magnetic recording and reproducing device comprising: means;