JPS59104703A - Signal recording method on video tape - Google Patents

Abstract

PURPOSE:To record plural programs simultaneously to a single video tape by providing (n) sets of magnetic heads which form pairs in the direction of the diameter of a rotating body. CONSTITUTION:A magnetic head 4 consists of two heads 41 and 42, and the azimuth angles theta are opposite to each other for gaps 41g and 42g of the heads 41 and 42 respectively when viewed from an arrow A. A magnetic head 5 also has azimuth angles theta opposite to each other for gaps 51g and 52g of both heads 51 and 52 respectively when viewed from an arrow B. The record signals of the 1st program are recorded continuously over tracks A1, B2, A1-, while the record signals of the 2nd program are recorded continuously over tracks A2, B1, A2- respectively. An adverse azimuth is obtained between adjacent tracks since the heads 41, 42, 51 and 52 have azimuth angles opposite to each other. Thus the crosstalk disturbance can be deleted with this loss.

Description

TECHNICAL FIELD The present invention relates to a video tape recorder, and more particularly to a method for recording signals on a video tape in a magnetic head assembly.

Background technology Consumer video tape recorder (hereinafter referred to as VTR).

)'s head scanning mechanism is called a helical scanning system because the videotape is wound diagonally around a rotating head cylinder. This method depends on the number of heads.
It is classified into head type, 2 head type, 93 head type, 4 head type, and 1.5 head type. Current home VT
In R, the 2-head system is the mainstream, and all of the above-mentioned systems except the 1.5-head system have been commercialized. On the other hand, some broadcast VTRs that require high image quality have four or more heads, but generally scan in the width direction of the tape. There is no known helical scanning system with three or more heads (however, in a four-head system, there are two heads for recording and two heads for playback, for a total of four heads, so there are only two heads for recording).

Therefore, a signal recording system that allows a single magnetic head assembly to simultaneously record a plurality of programs (broadcast programs) on a single tape has not been known at all.

Purpose of the Invention Therefore, the main purpose of the present invention is to provide a new signal recording method for videotape that allows multiple programs to be recorded simultaneously on one videotape (multiple programs can be played back at the same time during playback). be.

In order to achieve the above object, the present invention provides a system for recording signals on a video tape using a magnetic head fixed to a rotating body such as a rotating drum or a rotating disk, in which magnetic heads are arranged in pairs in the diametrical direction of the rotating body. The basic feature is that a plurality of programs can be recorded on the videotape at the same time by providing #Ji (n is a natural number including 1).

However, when n = 1, each magnetic head consists of two heads arranged in the direction of the rotation axis (usually in the vertical direction) of the rotating body. Preferably, the two heads are constructed in one piece before installation to increase productivity.

The number of electric circuits corresponding to the number of programs to be recorded is required, but this is a natural premise.

A more detailed explanation will be given below based on examples.

Embodiment FIG. 1 is a basic conceptual diagram. When the recording signal of program 1 and the recording signal of program 2 are supplied to the video head 1 in parallel and at the same time, the video tape 21 is helically scanned to record these two recording signals. There are three possible contents of the two recording signals: a combination of a video signal and a video signal, a combination of a single video word and an audio signal, and a combination of an audio signal and an audio signal.

FIG. 2 shows an outline of the video head 1. 3 is an upper drum driven by a morph above a fixed drum (not shown);
Reference numeral 4-5 denotes magnetic heads which are provided on the lower side of this one drum 3 and form a pair in the diametrical direction of the upper drum. The videotape 2 is wound around the upper and lower drums in an Ω-shape as shown in the figure, and travels along the arrow.

As shown in FIG. 3(A), the magnetic head 4 consists of two heads 41 and 42 that are disposed offset from left to right in the axial direction of the rotating drum 3, that is, in the vertical direction.

When viewed from the direction of the arrow in Figure 2, these two
Gap 41g of each head 41.42, 4
2g, the azimuth angles θ are opposite to each other jl[]. The magnetic head 5 also has the same structure as the magnetic head 4, as shown in FIG. 3), and when viewed from the direction of arrow J3 in FIG. It has an azimuth angle θ.

FIG. 5 shows the tape pattern recorded on the video tape 2 by this magnetic head 4.

Area A and territory area are tracks recorded by magnetic heads 4 and 5, respectively. Track A1 is recorded by the head 41, and at the same time as recording of this track A1, the head 42
Accordingly, track A2 is recorded. On the other hand, in area B,
Track B2 is recorded by the head 51, and this track B2 is recorded by the head 51.
Track B1 is recorded by the head 52 simultaneously with the recording of track B1.

In other words, the recording signal of the first program is track A1.
．． B2. AI...is a series of songs, and the recording signal of the second program is on tracks A2, B1... A2.・
・It is a series of mountains.

As you can see from the tape pattern in Figure 5, spatula t'41
．． Since 42s, 51, and 52 have opposite azimuth angles, adjacent tracks have opposite azimuths, and this loss can eliminate crosstalk interference.

FIG. 4 shows another example of the magnetic head 4.5. A magnetic shielding material S is interposed between the upper head 41 and the lower head 42. Magnetic head 5 in FIG. 4B. has a similar structure.

In a preferred embodiment, each of these magnetic heads 4.5 is constructed in one piece. Zunawachi, head 41
・42.51.52 are created independently, but at least before attaching the magnetic heads 4 and 5 to the upper drum 3,・
Glue them together with epoxy resin, etc. to make them into a single piece. This improves productivity.

Although the above signal recording method is unique, it can be made compatible with conventional methods. That is, the sum W of the vertical lengths of the gaps 41g and 42g of the magnetic head 4
(head width W in Figures 3 and 4) compared to the conventional VH3 system.
Compatibility with any conventional system can be achieved by selecting a track width corresponding to the specified track width of the β system or the unified standard system. If the system of this embodiment is adopted, the band of the audio signal (FM) can be arbitrarily widened even if the video signal is recorded in program 1 and the mushroom voice signal is recorded in program 2, so the band of the audio signal (FM) can be arbitrarily widened. The sound quality problem of the system can be solved. This is as if from 4 signals to A to F
This change is similar to that of the M signal.

When recording an FM audio signal on a video track, it is also preferable to first set it as a PC MIg signal. Reduces noise and expands dynamic range. Note that when recording a combination of a video signal and an audio signal, it is preferable to record the audio signal in synchronization with the synchronization signal of the video signal so that the two programs can be played back synchronously. In addition, when recording a combination of video signals and the synchronizing signals have different phases, using a CCD delay circuit to match the phases will prevent noise bars from appearing during playback and provide a stable screen. Obtainable.

According to such an embodiment, it is possible to create a VTR that can record two broadcast programs at the same time. Furthermore, even when recording one program, one video word may be recorded on one track and its audio signal may be recorded on the other track. For the audio signal, either FM analog recording or FM PCM recording may be applied. Furthermore, if both tracks are used as audio channels, it is possible to realize high fidelity with a microsecond. ■Two types of video signals can be recorded simultaneously using two cameras.

For example, as in the tape pattern shown in FIG. 6, the first video signal is recorded on the track PRI.1. The second video signal is recorded on track 'f R2. Regarding audio, the audio signal corresponding to the first video signal is the conventional audio channel C.
The audio signal corresponding to the second video signal is recorded on channel c t-+2. Note that CT is a control track.

Since it is possible to record two images 1u at the same time, it can be applied to a recording device for stereoscopic television.

For example, track PRI in FIG. 6 is assumed to be a video signal from the left eye camera, and track PR2 is assumed to be a video signal from the right eye camera.

Next, a more general recording method, that is, a method in which n pairs of magnetic heads are provided in the diameter direction of the rotating drum and a plurality of programs are simultaneously recorded on one video tape will be briefly described. FIG. 7 shows a schematic diagram in the case of two sets. A plurality of programs can be recorded by selecting the head width and head mounting height of the two pairs of magnetic heads to suit the format. In this case, as shown in FIG. 8, the magnetic head can be attached to the upper drum 31 rotating above the lower drum 32 in the direction along the rotational direction of the drum as shown in FIG. There are two ways of rotating the drum as shown in (13), that is, the vertical direction (FIG. 8(b) shows the case of 3Mi).

As a method for effectively preventing crosstalk interference between adjacent tracks, for example, the two pairs of magnetic heads shown in FIG. 7 are used, and each magnetic head is mounted with one gap as shown in FIG. 8(a). At this time, a tape pattern as shown in FIG. 9 can be recorded. That is, a guard band CB is formed between track P1 (1 corresponding to program 1) and track PR2 corresponding to program 2 to prevent interference between adjacent tracks.

Note that at least one of the two pairs of magnetic heads shown in FIG.
It is also possible for each magnetic bed of the set to be a magnetic head with two gaps as shown in FIG. 3 or FIG. 4. In such a case, if n pairs of magnetic heads are installed, a maximum of 2n programs (video or audio) can be recorded.

As described above, the signal recording method of the present invention (according to which n sets of magnetic heads are arranged in the diametrical direction of a rotary body, and independent recording signals are supplied to each set of magnetic heads to record one video tape) to multiple video signals at the same time.

It is possible to record audio signals, ie, multiple programs.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the basics of the present invention; Figure 2 is a schematic diagram of the video head section of the embodiment; Figures 3 (A) and (B) are taken from the directions of arrows A and B in Figure 2; 4(A) and 4(B) are also explanatory diagrams of similar head gaps according to other examples, FIG. 5 is an explanatory diagram of the chief pattern according to the embodiment, and FIG. Figure 7 is an explanatory diagram of the tape pattern when using a stand camera.
FIG. 8 is an explanatory diagram of a magnetic head arrangement method, and FIG. 9 is a schematic diagram of a tape pattern showing an example of interference removal by a guard band. 1... Video head assembly, 2... Video tape, 3.31... Upper drum as a rotating body,
4, Death...Magnetic head, 41.42.51.52.
...Magnetic? 71', a head with independent gaps forming 4*5. Patent Applicant Sharp Corporation Agent Patent Attorney Aoyama Haga 2 people Figure 2 t3: t: At 82 Al

Claims (7)

[Claims] (1) A method in which signals are recorded helically on a video tape using a magnetic head provided on a rotating body, in which n pairs of magnetic heads are provided in the diametrical direction of the rotating body, whereby a plurality of signals are recorded on the video tape at the same time. A signal recording method on videotape that records programs. (2) At least one set of magnetic heads among the n sets of magnetic heads is composed of two heads arranged in the direction of the rotational axis of the rotating body, and the two heads are arranged at an azimuth angle of each gap. 1. A signal recording system for a videotape-1 according to claim 1, wherein two opposite tracks are provided, thereby eliminating crosstalk due to azimuth loss between adjacent tracks. (3) The @ recording method for videotape according to claim (2), wherein the two heads are constructed in one piece. (4) The sum of the lengths of the gaps in the rotational axis direction of the two heads is selected to correspond to the specified track width of the Vl-IS method, β method, or unified standard method;
This makes it compatible with each of the above-mentioned systems. (5) The head installation height and head width of the n sets of magnetic heads are selected to eliminate interference between each recording track during recording of a plurality of programs by means of a guard band. 1) One-word recording method on videotape described in section 1). (6) The video tape recording method according to any one of claims (1) to (5), wherein the Zoloclam is a video signal, an audio signal, or a combination thereof. (7) A signal recording method on a videotape of the 1:j'4 game according to claim (6), wherein the audio signal is a PCM signal.