JPS6120284A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent mistake in photographing with very simple constitution by providing the third head having the same azimuth angle with that of the first head and the second head, and a judging device that judges that the first signal and the second signal are recorded. CONSTITUTION:A magnetic tape 3 is wound about 180 deg. on a rotary drum 2 to make the lower end of the magnetic tape 3 parallel to the tape guide lead of a fixed drum. Recording heads 1a, 1b are attached to the rotary drum 2 at the phase of 180 deg.. The height of the lower end of the head gap is equal and have the same azimuth angle. A head 4 for confirming record having the same azimuth with the recording heads 1a, 1b is attached to the rotary drum 2 at a phase delayed by angle phi from the recording head 1b. When a VTR goes to recording operation, the head 4 for confirming record scans simultaneously, tracks 7a, 7b recorded by the recording heads 1a, 1b, synthesized reproduced output of the two can be obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a magnetic recording/reproducing device.

Conventional configurations and their problems In recent years, the performance of video tape recorders (hereinafter abbreviated as VTRs) has rapidly improved.
The performance requirements are becoming stricter.

A conventional VTR will be explained below with reference to the drawings.

FIG. 1 is a plan view of a conventional VTR in which a magnetic tape is wound around a drum. %11L, 1b is a recording head,
2 is a rotating drum, and 3 is a magnetic tape.

The operation of the VTR configured as described above will be explained.

The magnetic tape 3 is wound around the rotating drum 2 such that the lower end of the magnetic tape 3 follows a tape guiding lead (not shown) of a fixed drum (not shown). Recording heads 11L and 1b are attached to the rotating drum 2 with a phase of 1 scf'.

When the VTR starts a recording operation, the magnetic tape 3 is fed at a constant speed of Vt by a capstan (not shown), and the rotating drum 2 is fed at a constant angular frequency f.

Rotate with. The rotating heads 1&, 1b record signals while rotating for 18d after the head starts touching the tape. The recording pattern on the magnetic tape 3 is linear, arranged at a constant track pitch P, as shown in FIG.

Track pitch P is track inclination angle θ, tape feed speed Vt, and drum rotation angular frequency f. It is determined by the following equation.

Here, when the hend gap width W of the recording heads 11L, 1b is smaller than the track pinch P, a guard band is generated between each track as shown in FIG. 2, and the azimuths of the recording heads 11L, 1b are mutually Even if they are the same, Ku-C-Stoke will not occur.

However, in the above configuration, the rotating head 1
If there are deposits such as magnetic powder on the front surface of the 1L or 1b head,
Even though recording current is flowing through the rotary heads 1a and 1b, the spacing increases and the high frequency signal cannot be recorded on the magnetic tape 3, making it impossible to know that a photographing error has occurred. Can not. Therefore, when recording images that cannot be retaken, such as during TV news coverage, there is a problem in that the user feels extremely uneasy.

OBJECTS OF THE INVENTION An object of the present invention is to provide a magnetic recording/reproducing apparatus that enables recording confirmation during recording operation.

Structure of the Invention The magnetic recording/reproducing apparatus of the present invention includes a first head having the same azimuth angle, provided on a rotating drum, and recording a first signal and a second signal separately in separate trunks; a second head having the same azimuth angle as the first head and the second head and configured to simultaneously scan both of the two tracks recorded by the first head and the second head; , comprising: a third head provided on the rotating drum; and a determining device that determines from the output envelope of the third head whether the first signal and the second signal are recorded. This makes it possible to check the recording during the recording operation.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a VTR according to an embodiment of the present invention, in which 1a and 1b are recording heads, 2 is a rotating drum, 3 is a magnetic tape, 4 is a recording confirmation head, 5 is a recording confirmation judge, 6 is a warning lamp provided inside the viewfinder (not shown).

The operation of the VTR of this embodiment configured as described above will be explained below. The magnetic tape 3 is wound around the rotating drum 2 by approximately 18 lengths so that the lower end of the magnetic tape 3 follows a tape guiding lead (not shown) of a fixed drum (not shown). The rotary drum 2 has a recording head of 1m and 1b.
are attached with a phase of 18d, the heights of the lower ends of the hend gas bars are the same, and they have the same azimuth angle. Further, a recording confirmation head 4 having the same azimuth as the recording heads 1a and 1b is attached to the rotating drum 2 at a phase delayed by an angle i from the recording head 1b.

The recording pattern on the magnetic tape 3 is linear, arranged at a constant track pitch P, as shown in FIG. The value of P is the track inclination angle θ, the tape feed speed Vt, and the drum rotation frequency f. It is given by the following equation.

Here, the head gap width W of the recording heads 1a and 1b is smaller than the trunk pitch, and as shown in FIG.
Since a guard band having a width of p-w) is generated, crosstalk between tracks does not occur during reproduction even though the azimuths of the recording heads 11L and 11) are the same.

In this embodiment, the head gap width W' of the recording confirmation head 4 is set to a value equal to (P+), and the head gap lower end height of the recording confirmation head 4 is set to a value equal to (P+). It is installed so that it is below the height of the lower end of the gap by Δh.However, Δh is expressed by equation (2).

Therefore, when the VTR starts recording, the recording confirmation head 4
As shown in FIG. 4, since the two tracks 7a and 7b recorded by the recording heads 1a and 1b are simultaneously scanned, a combined reproduction output of both can be obtained. The reproduction signal output from the recording confirmation head 4 is input to the recording confirmation determination device 6, but if magnetic powder, etc. separated from the magnetic tape 3 adheres to the front surface of either of the recording heads 11L, 1m). If so, the spacing loss increases and the high frequency signal is no longer recorded, resulting in a phenomenon in which the envelope of the reproduction output of the recording confirmation head 4 partially dips and is halved. Here, when the recording confirmation determiner 6 detects a drop or reduction in the playback output, it lights up a warning lamp 6 of a viewfinder (not shown) to give a warning to the cameraman. In the above embodiment, a warning lamp installed inside the viewfinder (not shown) was used as a warning means for not recording, but this is not limited to a lamp etc. As long as it is given, a buzzer or the like may be used.

Next, other embodiments of the present invention will be described with reference to the drawings.

FIG. 5 is a block diagram of a VTR during recording operation in another embodiment of the present invention. 1ya, 1yb.

1ca and 1cb are recording heads, 2 is a rotary drive I, 3 is a magnetic tape, 4a and 4b are recording confirmation heads, 6 is a recording confirmation judge, 6 is a view finder (not shown)
This is a warning lamp installed inside.

The operation of V and T H of this embodiment configured as described above will be explained below. The magnetic tape 3 is attached to the rotating drum 2 so that the lower end of the magnetic tape 3 is along a tape guide lead (not shown) of a fixed drum (not shown) at about 1a.
oi' is wound. The recording heads 1ya and 1yb are mounted on the rotating drum 21tc with a phase of 180°, and the heights of the lower ends of the head gaps match each other, and they have the same azimuth angle. Further, recording heads 1Ca and 1Cb are attached to the rotating drum 2 with a phase of 186, and the heights of the lower ends of the head gaps match each other, and the recording heads 1ya and 1yb are arranged at a phase of 186.
It has the same azimuth angle as . Recording head 1ya
The positional relationship between and 10a (or 1yb and 10b) is as shown in FIG. 6 when viewed from the front of the head. The head gap width Wy of the recording head 171L', 1yb is larger than the head gap width Wc of the recording head 10IL, 1cb, and the height of the lower end of the head is 17a, 1yb.
yb is lower than 10a and 1cb by Δ8, and the head gap center position is shifted by X in the circumferential direction. Video information captured by a camera (not shown) is separated into a luminance signal and a color signal, and the luminance signal is sent to the recording head 1ya,
The color signals are recorded on the magnetic tape 3 by the recording head 10a and ICb. The recording pattern on the magnetic tape 3 has a trunk pitch P as shown in FIG. 7, and X, Δs, Wy as shown in FIG.
, We produce a guard band with a constant width of 0.

Further, the rotating drum 2 has recording heads 1ya and 1yb.

It has the same azimuth angle as 10a and 10b, and (2Wc-
The recording head 17 has a head gap width of t4).
1L.

The recording confirmation head 4a is placed in a phase delayed by J from 1yb.
, 4b are attached. Therefore, the height of the lower end of the head gap of recording confirmation heads 4a and +b is equal to that of recording head 1.
ya,,1ybyoshiΔ. is set high. However, Δ. is expressed by equation (3).

Therefore, when the VTR of this embodiment is in a recording operation, the recording confirmation head 4a (or 4b) is moved to the recording head 1ya, 1ea (or 1yb, 1c) as shown in FIG.
Since the track 77° C recorded in step b) is scanned at the same time, it is possible to obtain a combined reproduction output of both. Recording confirmation head 4a.

The playback output of 4b is input to the recording confirmation determiner 5,
If the recording heads 17& and 1C& (or 1yb and 1
If magnetic powder or the like adheres to the front surface of either of the heads (0b), high frequency signals will not be recorded due to increased spacing loss, resulting in a phenomenon in which the reproduced output waveform will drop or be halved. Here, when the recording confirmation determiner 6 detects a drop or reduction in the playback output, it lights up the warning lamp 6.

In the above embodiment, the recording confirmation is performed while the VTR is in the recording operation, but it may be performed after the recording operation is completed.

Effects of the Invention As is clear from the above description, the present invention provides a first signal having the same azimuth angle, which is provided on a rotating drum, and records the first signal and second signal separately on separate tracks. The first head and the second head have the same azimuth angle, and both of the two tracks recorded by the first head and the second head are recorded at the same time. a third head provided on the rotating drum so as to scan; a determiner that determines from an output envelope of the third head whether the first signal and the second signal are recorded; Although the configuration is extremely simple, the excellent effect of preventing photographic errors can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the main parts of a conventional VTR, FIG. 2 is a diagram showing a recording pattern on a magnetic tape, FIG. 3 is a block diagram of the main parts of a magnetic recording device according to an embodiment of the present invention, and FIG. 5 is a block diagram of main parts of another embodiment, FIG. 6 is a positional relationship diagram of each head as seen from the front of the recording head, and FIG. 7 is a diagram showing the scanning state of the recording confirmation head. This figure is a diagram showing a recording pattern on a magnetic tape in another embodiment, and FIG. 8 is a diagram showing a scanning state of a recording confirmation head in another embodiment. 1a, 1b, 1ya, 1yb, 1ca, 1cb...
Recording head, 2...Rotating drum, 3...
...Magnetic tape, 4°4a, 4b... Head for recording confirmation, 6... Judgment device for recording confirmation, 6...
...Warning lamp, 'ya, 'irb, 7y. 7C... Recording track. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure jα Figure 2 Figure 6 Figure 7

Claims (2)

[Claims] (1) A rotating drum on which a magnetic tape is wound, the azimuth angle being the same, and a first
first and second heads that separately record the signal and the second signal on separate tracks, the first and second heads having the same azimuth angle, and having the same azimuth angle as the first head Second
a third drum provided on the rotating drum so as to simultaneously scan both of the two tracks recorded by the head of the rotary drum;
1. A magnetic recording and reproducing apparatus comprising: a head; and a determiner that determines from an output envelope of the third head whether the first signal and the second signal are recorded. (2) The magnetic recording and reproducing apparatus according to claim 1, further comprising warning means for issuing a warning in accordance with a determination output as a determination device.