JPS62124601A - Rotary head type recording device - Google Patents

Abstract

PURPOSE:To erase only a desired part of each track without increasing the number of rotary erasing heads, by inclining and placing a direction of a head gap of the rotary erasing head, in the longitudinal direction of a tape-shaped recording medium from the direction vertical to the trace direction. CONSTITUTION:Recording is executed by using six pieces of recording heads on the periphery of a drum. Accordingly, when one piece of flying erasing head (FEH) has been used, six tracks of one field portion are erased simultaneously. Between a video are and an audio area, a guard space B is provided, but in order to execute a high density recording, the guard space is made as narrow as possible. Therefore, a gap of the FEH is inclined in the longitudinal direction of a tape from the direction vertical to the trace direction. In this way, even if width of a rotary erasing head becomes wide, the FEH can reduce the trace distance simultaneously against the width direction of a tape-shaped recording medium, therefore, only a desired part of each track can be erased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention relates to a rotary head type recording device having a rotary recording head that diagonally traces a tape-shaped recording medium and a rotary erasing head that is wider than the recording head. It is.

[Conventional technology]

An example of this type of device is a so-called helical scan type tape recorder.

FIGS. 6(a) and (υ) are diagrams showing the positional relationship of the flying erase head with respect to the recording track in a helical scan type video tape recorder.

In FIG. 3 (8), T, , T2. T3. T4 is a recording track, A and B are rotating heads, and FEH is a flying erase head. In general, it is necessary to minimize the number of FEHs, so in a rotating two-head helical scan type VTR, as shown in the figure,
is one piece, and its track width is 2 of the recording track pitch.
Consideration is being given to setting it at least twice as high.

It's a moat, with many heads arranged in a rotating head assembly,
It is conceivable to increase the amount of recorded information per unit time by forming the same number of recording tracks as the number of heads per rotation.

For example, in a tape recorder that uses four rotating heads to form four recording tracks per rotation of the rotating head assembly, one FEH is required as shown in Figure 3(b).
As shown in the following, it is necessary to set the width of the FEH to at least four times the recording track pitch.

By the way, in this type of tape recorder, it has been considered to divide one track into a plurality of parts and record different information signals in each of the divided parts. That is, a plurality of areas extending in the longitudinal direction of the tape-shaped recording medium are used for information on each side.

For example, in FIG. 6(b), the portion marked with ■ is a video signal area, and the portion marked with A is an audio signal area.

[Problem that the invention seeks to solve]

However, in a tape recorder of the type that divides one track into a plurality of tracks as described above, re-recording cannot be performed satisfactorily if one attempts to re-record only one of the information signals. For example, when performing so-called dubbing by rewriting only the audio signal in Fig. 3(b), if you try to erase the part where the audio signal shown in a is recorded, the part where the video signal shown in will also be deleted.

As mentioned above, FEH in a conventional rotary head type recording device
There is a timing when parts where different information is recorded are traced at the same time. Therefore, it is difficult to erase only one of the above-mentioned pieces of information, and this is a serious problem especially when the guard space between the areas where each piece of information is recorded is narrow.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a rotary head type recording device that can erase only a desired portion of each track without increasing the number of rotary erasing heads. The purpose is to

[Failure to solve the problem]

In the rotary head type recording device according to the present invention, the direction of the head gap of the rotary erasing head is inclined from the direction perpendicular to the tracing direction to the longitudinal direction of the tape-shaped recording medium.

[For production]

Even if the width of the rotating erasing head becomes wider with the above configuration, the FEH can simultaneously reduce the trace distance in the width direction of the tape-shaped recording medium, making it possible to erase only the desired portion of each track. Ta.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. 1, taking as an example a VTR that digitally records video and audio signals for one field divided into six tracks.

FIG. 1 is a diagram showing the positional relationship between an FEH and a recording pattern on a tape for explaining an embodiment of the present invention, and FIG. 2 is a diagram showing a recording pattern on a tape after digital recording.

The VTR of this embodiment performs recording using six recording heads on the circumference of the drum. Therefore, when one FEH is used, six tracks corresponding to one field must be erased at the same time. The video signal for a single field is recorded on 6 tracks, and the video signal for one frame is recorded on 12 tracks. Further, one track is divided into a video area and an audio area for recording.

A guard space is provided between the video area and the audio area, but for high-density recording, it is desirable to make the guard space as narrow as possible. For this purpose, the FEH gap is tilted from the direction perpendicular to the trace direction to the longitudinal direction of the tape, and the degree to which this FEH tilt should be set will be explained with reference to FIG.

In Figure 1, t is the track width, y is the amount of deviation between adjacent tracks in the recording direction, B is the guard space width between the video track and audio track, G is the head gap width, and n is the FEH once. is the number of tracks to be erased in the trace.

Figure 1 (8) shows the case where the direction of the FEH gap does not need to be tilted with respect to the direction perpendicular to the trace direction, and the condition that does not require tilting the FEH is (n-1)y+G<B
......(1). Conversely, it is necessary to tilt the direction of the FEH gap under the condition of (n-1)y+GΣB (2).

When tilting the direction of the FEH gap, see Figure 1 (b).
As in, excitation θ= y/l (
3), the direction of the FEH gap is parallel to the longitudinal direction of the tape, and the width of the guard band space can be minimized.

Further, when the guard band space is predetermined to be G, the inclination angle of the FEH gap direction with respect to the direction perpendicular to the trace direction is as follows.

Similarly, when tilting the gap direction as described above,
As shown in Figure 1 (b), FE is attached to the rotating head assembly.
Either a method of attaching the H at an angle or a method of attaching it at an azimuth angle as shown in FIG. 1(c) may be used.

Oka, the VTR in the above example had six recording heads per cylinder and one FEH.
The present invention can be applied effectively as long as the condition that one or more recording tracks are simultaneously erased by FEH is satisfied.

〔Effect of the invention〕

As described above, this invention has the advantage that only a desired portion of each track can be erased because the direction of the head gap of the rotary erasing head is tilted from the direction perpendicular to the tracing direction to the longitudinal direction of the medium. .

Another advantage is that the number of rotating erasing heads can be minimized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the FEH and the recording track on the tape to explain an embodiment of the present invention, FIG. 2 is a diagram showing the recording pattern on the tape after digital recording, and FIG. is a diagram showing the positional relationship of FEH with respect to each recording track in helical scan type V'I'H. FEH is a rotating erasing head, and A and B are rotating recording heads.

Claims (2)

[Claims] (1) It has a rotating recording head that traces a tape-shaped recording medium diagonally, and a rotating erasing head that is wider than the rotating recording head, and the direction of the head gap of the rotating erasing head is set from the direction perpendicular to the tracing direction. A rotary head type recording device characterized in that the recording medium is arranged at an angle in the longitudinal direction of the recording medium. (2) The rotary head type recording device according to claim (1), wherein the direction of the head gap of the rotary erasing head is set at the same angle as the longitudinal direction of the recording medium.