JPS60216679A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To offer convenience for recording and reproduction by using a lengthwise direction track and a fixed head so as to record and reproduce sound separately. CONSTITUTION:A switch 24 is selected to the recording mode at normal recording and when a video signal is inputted, a luminance component is extracted by an LPF20, the component is subject to frequency modulation by an FM modulator 21 and fed to an adder 22. A chrominance signal component is fed to the adder 22 via a BPF25 and a frequency converter 26. The sound signal is subject to frequency modulation by an FM modulator 27 and fed to the adder 22. An output of the adder 22 is recorded on a tape 45 via an amplifier 23. A switch 46 is thrown to the position A at the sound after recording. The sound signal separated from the video sound synthesis signal is inputted to an adder 38 via the FM demodulator 37. An after recording sound signal is inputted also to the adder 38, where a signal from a pilot signal generator 41 is added thereto. An output of the circuit 42 is recorded at the recording exclusive track of a tape 45.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a helical scan magnetic recording device that records video and audio signals by forming diagonal tracks on a magnetic tape using a rotating magnetic head. The present invention relates to a magnetic recording device that records data on diagonal tracks.

In conventional simple VTRs that use cassettes and magnetic tapes, video signals are recorded on diagonal tracks using a rotating head, and control signals and audio signals are recorded on two longitudinal tracks provided at both ends of the magnetic tape. It is used.

An example of such a cassette helical VTR is shown in FIG. The figure shows an example of the tape beading state in the above-mentioned VTR, where 1 is a cassette, 2 is a magnetic tape, and 3 is a tape beading state.
and 4 are rotating magnetic heads arranged on a rotating head drum as shown. 9 is a capstan, 8 is a pinch roller, and 8 and 9 feed the tape 2 in the direction of arrow 10 at a constant speed. As a result, the magnetic tape 2 is wound around the surface of the head drum and runs,
The rotation in this direction forms diagonal tracks on the magnetic tape. 5 is a full-width erasing head for the tape, 6 is an erasing head for only audio tracks, and 7 is a recording/reproducing head for audio and control signals.

FIG. 2 is a schematic diagram showing an example of a pattern on a magnetic tape recorded by the VTR shown in FIG. 1, in which 12 is a control signal recording track, 13 is an audio signal recording track, and 14 is two rotation On the video track on which a video signal is recorded by the magnetic heads 3 and 4, a video signal of one line and one field is recorded using a known azimuth recording method. Also, the audio signal is recorded by the fixed head 7 on the audio track 15 formed in the longitudinal direction at the widthwise end of the tape, and at the same time, the audio signal is recorded on the control track 12 at the other end
A CTL signal for synchronizing playback is recorded.

On the other hand, in order to reduce the consumption of magnetic tape and make tape cassettes and devices smaller and lighter, the recording trajectory has been narrowed and the magnetic tape running speed has been reduced by increasing the recording density of video signals. and win. However, when the running speed of the magnetic tape is extremely low, it is difficult to secure sufficient frequency characteristics of the audio signal using a fixed head. Therefore, the composite signal of the video signal and the audio signal is A method of recording and reproducing data using a rotating magnetic head has been considered.

FIG. 3 is a curve diagram showing an example of the frequency band of a video/audio signal when a composite signal of a video signal and an audio signal is recorded by a rotating magnetic head. In the figure, 15 is a low frequency converted color signal band, 17 is an FM modulated luminance signal band, and 1
6 is an FM-modulated audio signal band. Note that this band is just an example, and other combinations may be used.

Conventionally, in such a system, a video signal and an audio signal are combined and recorded, so it has been impossible to record the audio signal separately.

The present invention uses such a rotating magnetic head to record video signals and audio signals on diagonal tracks, and the present invention provides a magnetic recording system in which a recording track for separately recording audio is provided in the longitudinal direction of the tape in order to facilitate recording and reproduction. The present invention provides a recording/playback device.

FIG. 4 is a schematic diagram showing an example of a magnetic tape pattern according to the magnetic recording device of the present invention.

In the figure, 18 is a CTL control signal recording track, and 19 is a track on which a video/audio composite signal is azimuthally recorded by a rotating magnetic head. 51 is an audio recording track.

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

FIG. 5 is a block diagram showing an embodiment of an electric circuit for normal recording/playback and audio dubbing of a VTR according to the present invention. In the figure, during normal recording, the recording/reproducing signal switching analog switch 24 is set to recording mode (Rec).When a video signal is input, a low-pass filter (LPF) 20 extracts a luminance signal. is extracted, frequency-modulated by an FM modulator 21, and added to an adder 22. Further, the color signal component of the video signal is extracted by a band pass filter (BPF) 25, converted to a low frequency by a frequency converter 26 which converts the color signal to a low frequency, and is added to an adder 22.

On the other hand, the audio signal is frequency modulated by a 7M modulator 27 and added to an adder 22.

As shown in FIG. 5, the audio frequency band 16 falls between the low frequency converted color signal 15 and the frequency modulated luminance signal 17. The output of the adder 22 is sent to the recording amplifier 23, applied to the rotating magnetic head 43 via the Rec terminal of the analog switch 24, and recorded on the video tape 45.

Further, during normal playback, the analog switch 24 is switched to the playback mode (Play), and the after-recording signal/normal playback signal switching analog switch 30 is switched to the normal playback position N. That is, the video and audio signals reproduced by the rotating magnetic head 43 pass through the analog switch 24 and are sent to the reproduction amplifier 2.
It will be communicated on a daily basis. The output of the reproduction amplifier is sent to a bypass filter (HPF) 51, LX"F 34, and BPF 56. 31 is an HPF that takes out the frequency-converted luminance component (17 in Figure 3), and this output is sent to a 7M demodulator 32. The signal is input to the frequency adder 33. 34 is an LPF that takes out the color signal component (15 in Figure 6) whose frequency has been converted to a low frequency band, and the color signal returned to its original state through the frequency demodulator 35 is added. The output of 36 is the reproduced video signal.Meanwhile, the frequency-modulated audio signal (16 in Figure 3) is input to the FM demodulator 37 through the BPF 56 and converted into an analog signal. An audio signal is output via switch 30.

In the apparatus of the above type, in this embodiment, in order to enable audio dubbing, a track dedicated to dubbing recording is provided and a fixed magnetic head 44 for dubbing is provided.

During audio dubbing recording, the dubbing recording/playback signal switching analog switch 46 is switched to dubbing position A. picture·
The audio signal separated from the audio synthesis signal is sent to the 7M demodulator 3.
7 and then input to an adder 68. On the other hand, the dubbing audio signal is also input to the adder 3B, and the mixing ratio of the pre-dubbing audio signal and the dubbing audio signal is freely changed by the addition level adjuster 59 attached to the adder 38, and the mixture is output from the adder 3B. be done.

The output of 38 is input to an adder 40, where a pilot signal is added from a pilot signal generator 41. Here, as shown in FIG. 6, the pilot signal 52 is in the voice band 5
Selected as 10H2 of 3 or less. Note that the band of this pilot signal may be set anywhere as long as it does not affect the audio signal. The function of this pilot signal will be described when reproducing the post-recording audio signal. The output of the adder 40 is input to a recording amplifier and bias adder 42, where a bias signal is added by a bias signal generator 43. The output of the circuit 42 passes through an analog switch 46,
A video tape 45 is recorded by a fixed magnetic head 44 for dubbing.
It is recorded on the upper track dedicated to dubbing recording.

After recording the audio dubbing signal, when the playback mode is set, the analog switches 24 and 26 are switched to the Play position. The output from the fixed head 44 is connected to a playback amplifier 47 through an analog switch 46.

The output of the playback amplifier 47 is the post-recording audio signal (sixth
The band pass filter (BP
F) 48 and a bandpass filter (BPF) 49 which extracts the pilot signal component (52 in FIG. 6). The output of the BPF 49 is then input to a pilot signal detector 50, and when the detector 50 detects the pilot signal, it switches the output mode switching analog switch 30 to the post-recording audio reproduction position A. and BPF 4 B
The post-recording audio signal that has passed through is outputted via an analog switch 30. When there is a pilot signal,
This is a mode in which the dubbing audio signal recorded on the dubbing dedicated track is output as reproduced audio from the audio output terminal.The output audio signal is here reproduced from the dubbing audio signal input to the adder 38 and the original recording track. The audio signal is a signal synthesized at a desired ratio.@On the other hand, when there is no pilot signal, the analog switch 30 is switched to the normal playback position 11, and the audio output terminal is a signal that is separated from the video/audio composite signal. This is a mode in which the audio signal is output as output playback audio.

FIG. 7 is a block diagram of a recording/reproducing section showing an embodiment of a simplified VTR according to the present invention. In the figure, reference numeral 55 is a cassette for storing a magnetic tape 56, and reference numerals 57 and 58 are rotating magnetic heads for recording and reproducing video/audio composite signals. The rotating magnetic head rotates at a constant speed in the direction of arrow 64. 60″h
A capstan 59 is a pinch roller, and the tape 56 is pressed against the capstan and the pinch roller 2, and the tape is fed at a constant speed in the direction of an arrow 63 by constant rotation of the capstan. 61 is a video tape erasing head; 62 is a fixed head for recording and reproducing OTL control signals;
65 is a dedicated fixed head for recording and reproducing the audio dubbing signal of this embodiment.

In addition, in the above-described embodiment, it is assumed that audio dubbing is performed as a separate recording of audio, but the present invention is not limited to this.

Further, in order to enable the audio dubbing recording to be performed again, it is possible to provide an erasing head for erasing the post-recording track in front of the fixed head 65 for dubbing the tape.

Similarly, the present invention is not limited to the above embodiments, but can be modified as appropriate within the scope of the claims.

As explained in detail above, the magnetic recording and reproducing apparatus of the present invention uses a rotating head to record and reproduce video signals and audio signals on diagonal tracks on a magnetic tape, and separately records and reproduces audio signals. This is made possible by using a longitudinal track and a fixed head, and has a great effect in improving the convenience of recording and reproducing in the above-mentioned apparatus which separately records audio.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a recording/reproducing section showing an example of a simple VTR using a conventional system, Fig. 2 is a diagram of a recording track pattern on a magnetic tape by the apparatus shown in Fig. 1, and Fig. 5 is a diagram of the apparatus shown in Fig. 1. 4 is a diagram showing a recording track pattern on a magnetic tape according to the present invention, and FIG. 5 is a circuit configuration of a VTR as an embodiment of the present invention. 6 is a frequency band curve diagram of a pilot signal and an audio signal of a longitudinal audio track in an apparatus according to an embodiment of the present invention, and FIG. 7 is a recording/reproducing section of a simple W VTR according to this embodiment. FIG. 30... Output mode switching switch 55... Cassette 56... Magnetic tape 57.58... Rotating head 59... Pinch roller 60... Capstan 61... Full width erasing head 62...・Control signal head 65...Fixed head for audio recording and playback 66...Tape running direction 64...Rotating head rotation direction

Claims (1)

[Claims] A magnetic recording device that records video and audio signals on diagonal tracks on a magnetic tape using a rotating magnetic head, and separately records audio signals on a longitudinal trunk on the magnetic tape using a fixed magnetic head.