JPS6028043B2 - Magnetic recording and reproducing device for electronic editing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a rotary magnetic head device equipped with a rotary magnetic head for recording and reproducing and a rotary magnetic head for erasing, each of which scans a magnetic tape diagonally with respect to its longitudinal direction. A rotating magnetic head for erasing erases a desired part of the recording magnetization locus formed with a gap, and a rotating magnetic head for recording and reproducing transfers a new video signal or audio signal to that part. The present invention relates to an improvement of a magnetic recording/reproducing device for electronic editing, which records information signals such as the following.

First, a conventional magnetic recording/reproducing device for electronic editing will be explained.

This device has a rotating magnetic head device, and the magnetic tape is wound and guided around the magnetic tape guide drum at a winding angle of, for example, about 180 degrees, and the upper drum of the magnetic tape guide drum is the rotating drum, The lower drum is a fixed drum, and the upper drum, which is a rotating drum, has two rotating magnetic heads for recording/reproduction arranged at an interval of approximately 180 degrees, and two rotating magnetic heads for erasing arranged at an angular interval of approximately 180 degrees. The head is attached. In this case, the angle formed by the straight line connecting the two rotary magnetic heads for recording and reproducing and the straight line connecting the two rotary magnetic heads for erasing is set to a predetermined value. Furthermore, when the drum rotates in a predetermined direction about the center of the drum, two rotating magnetic heads for erasing are arranged in front of the two rotating magnetic heads for recording and reproducing. These rotary magnetic heads for recording and reproducing and rotary magnetic heads for erasing each scan the magnetic tape diagonally with respect to its longitudinal direction. Then, a desired part of the recording magnetic trace formed at a predetermined gap on the magnetic tape is erased using a rotary magnetic head for erasing, and a new one is written on that part using a rotary magnetic head for recording and reproducing. It is designed to record information signals. Next, with reference to FIG. 1, the scanning trajectories of the recording/reproducing rotary magnetic head and the erasing rotary magnetic head on the magnetic tape of the subordinate electronic editing magnetic recording/reproducing apparatus will be described.

In FIG. 1, TP is a magnetic tape, Tr and Tr' are adjacent scanning trajectories of the magnetic gaps of two rotating magnetic heads thereon, and have the same track width Wr, and Cr and Cr' are At each centerline, the spacing or pitch is P. Further, the width of the guard band, that is, the gap between the equal scanning trajectories Tr and Tr' is Wg. Te and Te' are adjacent scanning trajectories of the magnetic gaps of the two erasing rotary magnetic heads on the magnetic tape, and have the same track width We (>Wr), and their respective center lines C
e, Ce' are the center lines Cr, Cr of the scanning trajectories Tr, Tr'
′. In this case, the track width We is made to be approximately equal to the pitch P. Note that arrow a indicates the running direction of the magnetic tape TP, and arrow b
are the rotational directions of the recording and erasing rotary magnetic heads, and are in the same direction. Center lines Cr, Ce of scanning trajectories Tr, Te
match, and therefore the center line Cr of the scanning trajectories Tr' and Te'
, Ce' coincide, and there is a gap width d between the lower edge of the scanning trajectory Te of the magnetic gap of the rotating magnetic head for erasing and the upper edge of the scanning trajectory Tr' of the magnetic gap of the rotating magnetic head for recording and reproducing. do.

Examples of the dimensions of Wr, We, P, Wg, and d in FIG. 1 are Wr=125 mm, We=P=165 mm, Wg=40 mm, and d=Science=2 capes.

In such a magnetic recording and reproducing device for electronic editing, the recording scanning trajectory Tr
, T', first erase the recording magnetization trajectory of the video signal recorded in the recording scanning trajectory dimension r' with one of the rotating magnetic heads for erasing. After that, a new video signal is recorded on one of the rotating magnetic heads for recording and reproduction, and then the recorded magnetization trajectory of the video signal recorded in the recording scanning trajectory Tr is transferred to the other rotating magnetic head for erasing. The data is erased using the soldering iron, and then a new video signal is recorded using the other rotary magnetic recording/reproducing head.

However, in this case, since the interval width d between the lower edge of the erasing scanning trajectory Te and the upper edge of the recording scanning trajectory Tr' is extremely narrow, the recorded magnetization trajectory of the video signal recorded on the recording scanning trajectory r is erased. At this time, due to the relative positional deviation between the center lines Cr and Ce, the interval between them becomes smaller than the pitch P, and a part of the recording scanning trajectory and even the recorded magnetization trajectory of the newly recorded video signal are erased. As a result, there is dust in the recording scanning locus Tr' that lowers the S/N during reproduction of the newly recorded video signal. In view of the above, the present invention solves the above-mentioned drawbacks without changing the width of the gap (guard band) between adjacent recording scanning trajectories on the magnetic tape or the track width of the magnetic gap of the rotating magnetic erasing head. We would like to propose a magnetic recording and reproducing device for electronic editing in which the magnetic recording device is removed.

The present invention will be described in detail below with reference to FIGS. 2 to 4, one embodiment of the present invention.

The present invention has a rotary magnetic head device R equipped with rotary magnetic heads He, He2 for recording and reproduction and rotary magnetic heads He, He2 for erasing, each of which scans a magnetic tape TP diagonally with respect to its longitudinal direction. A desired portion of the recording magnetization locus formed at a predetermined gap on the magnetic tape TP is erased by the erasing rotary magnetic heads He, He2, and a new recording/reproducing rotary magnetic head is inserted into that portion. In a magnetic recording and reproducing device for electronic editing, which is designed to record information signals such as: The track width 9 of the magnetic gap 3 is selected to be slightly larger than that of the magnetic gap 3, and
Rotating magnetic head He for erasing on the magnetic tape TP,
, He2, the center lines Ce, Ce' of the scanning trajectories Te, Te' of the magnetic gap 4 are the center lines Cr, Cr of the scanning trajectories Tr, Tr' of the magnetic gap 3 of the rotary magnetic head for recording and reproducing.
' is slightly deviated in a direction opposite to the running direction a of the magnetic tape TP.

FIG. 2 shows the rotating magnetic head device R, and D is a magnetic tape guide drum, on which the magnetic tape is wound and guided at a winding angle of approximately 1800 degrees, for example. The upper drum of the magnetic tape guide drum D is a rotating drum, and the lower drum is a fixed drum.
Rotary magnetic heads He, He2 for recording and reproducing are arranged at an angular interval of about 80 degrees, and rotating magnetic heads He, He2 for erasing are arranged at an angular interval of approximately 180 degrees.

In this case, the angle between the straight line connecting the recording/reproducing rotary magnetic heads He, . . . 2 and the straight line connecting the erasing rotary magnetic heads He, . He2 is the same. Furthermore, when the drum rotates in the direction of arrow a about the axis 0, the rotating magnetic heads He, He2 for erasing are arranged to precede the rotating magnetic heads He, He2 for recording and reproducing, respectively. ing. Fig. 3 shows the upper drum D of the rotary magnetic head He2 for recording and reproduction, the ratio and the rotary magnetic head He2 for recording and reproduction.
A and B show the state in which it is installed. In this case, the rotating magnetic heads He, He2 for recording and reproducing and the rotating magnetic heads He, He2 for erasing are respectively attached to the base M by, for example, adhesive, and these bases M are attached to the upper drum by bolts V, respectively. It is fixed to the bottom surface of D. In addition, in this FIG. 2, the surface reference plane Lo of the upper drum D is
are drawn so that they match. FIG. 4 shows the scanning trajectories on the magnetic tape TP of the rotary magnetic head for recording and reproducing and the rotary magnetic head for erasing of the magnetic recording and reproducing apparatus for electronic editing of this embodiment, and parts corresponding to those in FIG. is attached.

Tr, Tr' are rotating magnetic heads on the magnetic tape TP,
, Day 2 are adjacent scanning trajectories of the magnetic gap 3, which have the same track width Wr, Cr and Cr' are their respective center lines, and their interval pitch is P. Also, the equivalent scanning trajectory Tr,T
The width of the guard band or gap between r' is Wg. T
e and Te' are the scanning trajectories of the magnetic gaps 4 of the erasing rotary magnetic heads He, , He2 on the magnetic tape TP, which have the same track width We (>Wr), and whose respective center lines Ce
, Ce' are the center lines Cr, Cr' of the scanning trajectories Tr, Tr'
For this reason, f(0<f<physically speaking, the running direction of the magnetic state is shifted in the opposite direction.

In this case, the track width We is roughly referred to as the pitch P. Note that the running direction a of the magnetic tape TP and the rotation direction b of the recording and erasing rotary magnetic heads are the same direction. Center line C of scanning locus I r, Te
If r and Ce are shifted by f, and therefore the center lines Cr' and Ce' of the scanning trajectory T', Te' are shifted by f, then the scanning trajectory T of the magnetic gap 4 of the erasing rotary magnetic heads He,, He2
The interval width d existing between the lower green of e and the upper green of the scanning locus Tr' of the magnetic gap 3 of the recording and reproducing rotary magnetic head 1, 2
is larger by f than in the case of FIG.

Examples of dimensions of Wr, We, P, Wg and d in Fig. 1 are: Wr=125 mm, We=P=165 mm, Wg=40''
, f: 10th grade d = Gakuju f = 3.

It is mu. By the way, the erasing rotary magnetic heads He, , He2
Since these are ahead of the recording and reproducing rotary magnetic heads 1, 2, respectively, a predetermined height is required between the centers of the respective magnetic gaps 3 and 4. Therefore, the rotary magnetic heads He, He2 for erasing and the rotary magnetic heads He, . The lead time for each ratio is t, the rotation period of the upper drum D is T, and the angle of the scanning trajectories Tr, Tr', Te, Te' with respect to the longitudinal direction of the magnetic tape? o, the leading distance is 1, and the center of the magnetic gap 4 of the erasing rotary magnetic head He,, He2 and the magnetic gap 3 of the ratio of the recording/reproducing rotary magnetic head He,, He2
The height between the center of the rotating magnetic head is m,
Let the relative velocity of He,, He2 with respect to the magnetic tape be v(=
9.53 k'sec), then t = sheep x ridge ÷ 1 = t x v m = l sinC.

becomes.

Therefore, in the case of a magnetic tape (cassette tape) with a width of 3/4 inch (1.905 mm), m=24.4 peaks.
The explanation will be given by returning to FIG. 3 again.

In FIG. 3A, the recording/reproducing rotary magnetic head 1, 2 is placed in the track of the magnetic gap 3 by & (=Wr), the center line of the track is L, and the reference plane of the center line L is ( Upper drum D
, when the height with respect to the lower surface of , is h, g, = 125 m, h, = 90 m. In addition, in FIG. 2B, the rotary magnetic head for erasing is moved in the track of the magnetic gap 4 by g2.
(=We), the height of the center line of the track with respect to the reference plane Lo is h2, the erasing rotating magnetic head He,, He2
If the height of is ○, &=165mm, h2=114.4
um, G, = 215.2 mu. In this case, in order to obtain the center axis of the erase track, the erasing rotary magnetic heads He, , He2 are
The tip is shaved off to a thickness of G2 = 50.2 mm. Therefore, the height between the track center line L of the recording/reproducing rotary magnetic head He,, Day 2 and the track center line L of the erasing rotary magnetic head He, He2, that is, the center-to-center height m is m
=24.4〆. In order to record a new video signal on the recording scanning trajectory Tr, Tr'1 with such an electronic editing magnetic recording/reproducing device, first, the recording magnetization trajectory of the video signal recorded on the recording scanning trajectory r' is changed to one side. The rotating magnetic head for erasing erases data, and then the rotating magnetic head for recording and reproducing records a new video signal, and then the video signal recorded on the recording scanning trajectory Tr is erased. The recorded green magnetization locus is erased by the other erasing rotary magnetic head, and then a new video signal is recorded by the other recording/reproducing rotary magnetic head.

In this case, the lower edge of the erase scanning trajectory Te and the recording scanning trajectory Tr
' Since the distance d from the upper green is narrower than in the case of Fig. 1, the width of the gap (guard band) between adjacent recording scanning trajectories on the magnetic tape, the rotating magnetic head for erasing. When erasing the recorded magnetization locus of the video signal recorded on the recording trajectory Tr without changing the track width of the magnetic gap, the distance between them changes to the pitch due to the relative positional deviation between the center lines Cr' and Ce. Even if it is smaller than P, the recording scanning trajectory Tr'
Even the recorded magnetization locus of the video signal newly recorded in the recording scan trace Tr' is partially erased, and the S/N during playback of the video signal newly recorded in the recorded scanning trace Tr' decreases. There's no dust. Note that the number of magnetic heads for recording/reproducing and erasing is not limited to two, but may be one or three or more, and the magnetic tape may be wound in a Q-wound or a Q-wound.

[Brief explanation of the drawing]

FIG. 1 is a pattern diagram showing a scanning locus on a magnetic tape of a conventional magnetic recording/reproducing device for electronic editing, FIG. 2 is a schematic plan view showing a rotating magnetic head device of the present invention, and FIG. FIG. 4 is a cross-sectional view of a part of the figure, and is a burn diagram showing the scanning locus on the magnetic tape of the present invention. R is a rotating magnetic head device, 2, 2 is a recording/reproducing rotating magnetic head, 3 is its magnetic gap, He,, He2 is an erasing rotating magnetic head, 4 is its magnetic gap, TP is a magnetic tape, Tr, Tr' is the scanning locus of the magnetic gap 3 of the recording/reproducing rotary magnetic head He,, He2, Cr, Cr' is its center line, Te, Te' is the erasing rotary magnetic head He,, He2
The magnetic gap Ce, Ce' is its center line. Figure 2 Figure 3 Rudder diagram Dimensions of the ship

Claims (1)

[Claims] 1. A rotary magnetic head device comprising a rotary magnetic head for recording and reproduction and a rotary magnetic head for erasing, each of which scans a magnetic tape diagonally with respect to its longitudinal direction, and is formed with a predetermined gap in the magnetic tape. A magnetic recording/reproducing device for electron concentration, wherein a desired portion of the recorded magnetization locus is erased by the rotating magnetic head for erasing, and a new information signal is recorded in that portion by the rotating magnetic head for recording/reproducing. The track width of the magnetic gap of the rotating magnetic head for erasing is selected to be slightly larger than the track width of the magnetic gap of the rotating magnetic head for recording and reproducing, and the rotating magnetic field for erasing on the magnetic tape is The center line of the scanning locus of the magnetic gap of the head is slightly offset from the center line of the scanning locus of the magnetic gap of the recording/reproducing rotary magnetic head in a direction opposite to the scanning direction of the magnetic tape. A magnetic recording and reproducing device for electronic editing.