JPS63316301A - Helical scanning type recorder - Google Patents

Abstract

PURPOSE:To simultaneously record different signals in parallel and to attain parallel reproducing by providing a helical scanning type recorder with 2-channel magnetic head means to form obliquely parallel tack strings having a recording pattern coincident with that of the recorder. CONSTITUTION:The helical scanning type recorder is provided with 1st magnetic head means HA, HA'... for forming 1st oblique track strings TA, TA'... on a magnetic tape at a prescribed pitch alternately in each field with reverse azimuth and 2nd magnetic head means HB, HB'... for forming 2nd track strings TB, TB'... so as to insert them between respective 1st oblique track strings alternately in each field with reverse azimuth. The array pitch of the 1st and 2nd track strings and the inclination angle of tracks are matched with the recording format of the known helical scanning type recorder. Consequently, parallel recording of 2 channels can be attained and an existing helical scanning type recording/reproducing machine can be used for reproducing each single channel and monitoring it.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a helical scan recording device, and in particular to a VTR that can simultaneously record different video signals on the same tape and reproduce them simultaneously or individually. It is suitable for use in

[Summary of the invention]

A second diagonal track row is formed by interpolating the first diagonal track row to enable recording of two channels of true signals on the same tape, and records the trunk pinch and track inclination angle using a well-known helical scan type recording device. It is a helical scan type recording device that has playback compatibility as well as format.

[Conventional technology]

There are cases where the same object is imaged by a video camera from different angles and two video signals are recorded and played back at the same time, and there are cases where two different images whose contents are related to each other are recorded and played back and displayed. An example of the former is when an object is imaged and recorded using two video cameras separated by a distance corresponding to the difference in left and right human visual angles, and the two played back images are combined to obtain a three-dimensional image. An example is a case where a video screen and a data screen such as a chart related to the content are simultaneously displayed.

[Problem that the invention seeks to solve]

When using a helical scan tape recorder as a video recorder, two or more pairs of rotating heads are installed to simultaneously form and record tracks for multiple channels, play back each channel simultaneously, and monitor each playback signal on multiple monitors. It is conceivable to send it to a receiver.

However, since the recording format of the tape recorded in this manner does not satisfy compatibility with commercially available VTRs, the recorded signals cannot be reproduced on commercially available VTRs.

In view of this problem, the present invention is capable of recording and reproducing at least two channels of different signals, and is
The purpose is to achieve compatibility with R without signal deterioration.

[Means for solving problems]

The helical scan type recording apparatus of the present invention includes first magnetic head means (HA, HA') for forming first diagonal track rows (TAlTa ``'--) of a predetermined pinch on a magnetic tape in reverse azimuth alternately in fields. --------・・
) and a second magnetic head means (Ha, Ha′・～・−).

The arrangement pitch and track inclination angle of the first or second track row are matched to the recording format of a known helical scan type recording device.

[Effect]

Parallel recording of two channels is possible, and one channel at a time can be reproduced and monitored using existing helical scan recorders.

〔Example〕

FIG. 1 shows the helical scan recording format of this embodiment. In this embodiment, three channels A, B, and C are recorded/
Reproduction is possible. The tracks T, , T, , TA of each field are closely arranged in this order along the longitudinal direction of the magnetic tape 1a, and the tracks T, ′, Tc ′, TA ′ of the next field are closely arranged in this order with a guard band G placed. It is arranged.

The tracks T, , T, are formed by heads of the same azimuth, and between them the trunk Tc is TA, T.

It is formed with a head of opposite azimuth. Also, the track TA to T in the next field,' is T.

The azimuth is reversed with respect to each of ~T.

FIG. 2 is a schematic plan view of the rotary head drum 2, in which rotary heads H6, HA, and H are provided in the order of rotational direction R along the drum rotation direction R, concentrated at approximately - locations on the circumferential surface of the drum. On the other hand, the field pair rotation He', HA
', Hl' are provided at positions 180° opposite to each other.

Therefore, each A-C channel can be recorded and played back almost simultaneously.

FIG. 3 is a plan view of the integrated magnetic head, and FIGS. 4A and 4B are front views showing the gap surface of the magnetic head. The head base 3 is divided into three parts in the rotational direction, and has heads Hc and HA.
, Hm are attached to the tips of each part. Head HA and H
Since 1 is used as a 2-channel pair as described later, it should be placed as close as possible so that the trunk can be traced at the same time. In the embodiment, the corner between HA and H8 on the track is approximately 4H (H: horizontal synchronization interval).

In order to enable the close arrangement of these heads HA, H, the cores 4A, 4B of each head and the pole pieces 5A, 5
The arrangement of B is reversed. If necessary, in order to reduce crosstalk between the A and B channels, a silicone resin 6 may be bridged between the heads HA and Hl, and a one-turn short ring 7 may be wound thereon.

The head H1 is used for the third channel and is mounted at a position preceding the rotation direction R.

Centered on the gap position of the head 7 head HA, the He head is ahead by about 12H in this embodiment.

The integrated heads HA' to H6', which are 180° opposed to each other, have almost the same configuration as that in Fig. 3, but the azimuth angle of the gap is in the opposite direction with respect to HA to H6, as shown in Fig. 4 A and B. ing. That is, if the azimuth angle of the gap 8 of heads H4 and H++ is +7°, the head Hc is -7°, and the heads HA', H,', and H3' are -7° and -7°, respectively.
, +7°. The width of the gap 8 corresponding to the track width is about 20μ for each head. As shown in Figure 1, in order to form tracks TA and T1 (TA' and Tll ゛) on both sides of track Tc (Tc'), each head is provided with a step in the height direction (in the axial direction of the rotating drum). It is.

During recording, a 20μ trunk T is first formed by the head H6, and then the heads HA1H1 are formed on both sides of the trunk T.
A 20μ trunk T4, TB is formed by partially overlapping the track T. For this reason, track T
, is removed by overwriting approximately 5μ on both sides, resulting in a width of lOμ.

Next, since the tape 1a advances about 60μ before the head HA ” to He ′ on the 180° opposite side hits the tape, the track TA is separated by a non-signal guard band G of about 10μ.
'~T,' are formed.

Since the azimuth of the 3-channel track arrangement is forward, reverse, forward, reverse...-----------,
Tracks with the same azimuth are not adjacent to each other, so there is little crosstalk. Also, tracks Tm, Ts, Tm', 7s that can be used as a 2-channel pair
Although the azimuths are the same, there is very little crosstalk because tracks TA and guard bands G with opposite azimuths are interposed alternately.

Note that channel C and the other channel A or B may form a two-channel pair.

FIG. 1 shows a well-known household V tape superimposed on the magnetic tape 1a.
A TR β■ format magnetic tape 1b is shown. In this format, the track TD, To ゛ is 27μ wide.
, fields are formed alternately at a pitch of 60μ. Track T on tape la.

If the tape speed and still angle are set so that the pitch and tilt angle of ~TC1TA'~TC' match the βI format, compatibility in the -force direction can be obtained. That is, if tape la is played on a βI format VTR, one of the three channels, for example, tracks Tm and Tll, will be played.
' can be played. At this time, the adjacent trunk Tc
, T, ', crosstalk interference will not occur due to the azimuth effect. Also, by adjusting the tracking knob, tracks T6, Tc' and TAlT
a′ can also be selectively reproduced.

Note that it is also possible to modify the format pattern shown in FIG. 1 to make the track widths of each channel approximately equal.

Further, close contact recording without guard band G may be performed.

FIG. 5 shows a schematic block diagram of a three-channel video recorder/player according to the embodiment, and for the sake of simplicity, only one head HA-Hc of the 180° pair is shown.

One set of channels A and H involves a color process and is also used, for example, for two-screen composite stereoscopic video.

The remaining channel C is monochrome and is used together with the other two channels for recording and reproducing three channels of RGB signals, for example.

In Fig. 5, the video of each channel (g No. V A
~V, luminance/chroma (Y/C) separation circuit 10A-C
and the separated luminance signal is sent to the luminance processing circuit 1.
After being processed (modulated) by 1A-C, the recording amplifier 12A
-C, head HA via recording/reproduction changeover switches 13A to C.
-Supplied to HC. During playback, the playback amplifier 14A-
The reproduced signal obtained through C is sent to the luminance process circuit 15A.
-C, and are derived from the buffer amplifiers 16A-C as reproduced video signals vA to ①.

Regarding channels A and B, chroma process circuits 17A and B (frequency conversion circuits) are attached to the recording system, and low-pass chroma bandpass filters 18A and B and reproduction chroma process circuits 19A and B are attached to the reproduction system.

The servo system of the head drum 2 operates based on, for example, a synchronization signal of the B channel video signal v1. The brightness signal of the B channel is given to the synchronization separation circuit 20, and based on the separated synchronization signal, the drum servo circuit 21 derives the phase error to the motor drive circuit 22, and the rotation of the head drum 2 is controlled. Further, the output of the capstan rotational frequency sensor 24 is supplied to a capstan servo circuit 25, and its speed error output is supplied to a capstan motor drive circuit 26 to control the rotation of the capstan 27. Further, during reproduction, as is well known, the phase of the drum or capstan is controlled based on the reproduction control signal.

In the above embodiment, the heads of each channel are arranged close to each other so that parallel recording and playback of each channel can be performed at the same time. Parallel recording and playback of each channel may be performed by electrically adjusting according to the phase difference of each head.

〔Effect of the invention〕

As described above, the present invention provides a two-channel magnetic head means to form a diagonally parallel track array having a recording pattern that matches the track pitch and trunk inclination angle of a known helical scan type recording device. Different signals can be simultaneously recorded and played back in parallel, and one of the channels can be played back using a well-known recorder/player.

[Brief explanation of the drawing]

Fig. 1 is a recording format diagram of a helical scan type recording device according to the present invention, Fig. 2 is a schematic plan view of a rotating head drum, Fig. 3 is a plan view of an integrated magnetic head, and Fig. 4 is an enlarged front view of the magnetic head. 5 is a block diagram of the recording/reproducing system. In addition, in the symbols used in the drawings, 1a, 1b-magnetic tape 2--1--rotating head drum 8------- ---Gap Ha = Hc ---Magnetic head HA'~Hc'---Magnetic head
・T s ””' T c '----・Trunk T
A ′～Te ′----・Track G・----
・−・−・・−・−・−・It is a gart band.

Claims (1)

[Claims] a first magnetic head means for forming first diagonal track rows with a predetermined pitch on a magnetic tape in reverse azimuth alternately in fields, and a second track row interposed in the first diagonal track rows in field alternation; The second formed with reverse azimuth
1. A helical scan type recording device, characterized in that the arrangement pitch and track inclination angle of the first or second track row are matched with the recording format of a known helical scan type recording device.