JPS59116910A - Video tape recorder - Google Patents

Abstract

PURPOSE:To obtain the reproduced sound quality having a high grade and to provide an after-recording function to a tape recorder by making effective use of an FM sound signal processing system using recording with a rotary head and a sound signal processing circuit using recording with a stationary head. CONSTITUTION:The record of a TV signal, etc. is recorded in superposition on a sound signal on a track 13 by an FM modulating system with a rotary head. A sound title the like which is desired to be inserted therein can be recorded on a track 11 by a stationary head 14. The sound signal by recording with the rotaty head and the sound signal by recording with the stationary head are automatically changed over in the stage of reproducing the video and the sound signal. More specifically, in general, the FM sound signal is passed through an AM demodulator 17 and a change-over switch 20 and the sound signal is outputted. When the title or the like is recorded on the sound track 11, the sound signal of the AC bias record is outputted by the head 14 and a voice reproducer 16. Said signal is detected with a level detector 18 and the switch 20 is changed over by a switch controller 19, whereby the sound signal is outputted on the track 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video tape recorder configured to record audio signals on a magnetic chip using a fixed head and a rotary head, and to reproduce the recorded audio signals. It is.

Conventional Structures and Problems Generally, a video cheap recorder is constructed so that a fixed head records and reproduces audio signals on a magnetic tape, and a rotary head records and reproduces video (signals) on a magnetic tape. Therefore, as shown in Fig. 1, the trunk bag 7 on the magnetic tape of the Video Cheap Record is equipped with a linear audio track 1, a control track 2, and a video track 3 that performs rotary recording and playback.
Recording and playback of the video f signal and the audio signal is performed using the recorded track. However, in the video cheap recording described above, since the relative speed between the fixed head and the magnetic tape is not very fast, the reproduced sound quality on audio track 1 is not very good, with an S/N of 1-1' of about 40 dB. In order to improve this problem, attempts have been made to significantly improve performance by FM modulating the audio signal and recording it on a video track using a rotating head. This recording method uses FM between each carrier wave of the luminance and color signals by frequency division.
A method of inserting a carrier wave, or a rotation dedicated to audio, makes the azimuth angle of this rotating head different from that of a rotating head dedicated to video, and uses those azimuth effects to separate only the audio signal and the video signal. Possible methods include extraction methods. However, in any recording method using a rotary head, the audio signal is recorded at the same time as the video signal, so there is a problem in that after-recording in which only one audio word is rewritten is impossible.

OBJECTS OF THE INVENTION An object of the present invention is to provide a video tape recorder that can improve the quality of reproduced sound by recording and reproducing audio signals using a rotary head, and that enables smooth after-recording.

Structure of the Invention The video tape recorder of the present invention effectively utilizes an FM audio signal processing system using rotating head recording and an audio signal processing system using fixed head recording, and is capable of obtaining high quality playback sound as well as post-recording. It has a function.

DESCRIPTION OF THE EMBODIMENTS FIG. 2 shows an embodiment of the video tape recorder of the present invention. In FIG. A video track on magnetic tape,
The above audio track 11 and control track 12
On the video track 13, a fixed head records audio signals and control signals, and on the video track 13, a rotating head records video signals and FM-modulated audio signals. Here, the above video track 1
The audio signal on the top 3 is recorded by a rotating head exclusively for audio, and the video on the video track 13 is recorded over the audio signal by a rotating head exclusively for video whose azimuth angle is different from that of the rotating head exclusively for audio. recorded. In this case, the video-dedicated rotary head, the audio-dedicated rotary head, and the audio-dedicated rotary head are alternately arranged at positions different by 90 degrees within one rotary shilling. 14 is a fixed head for recording or reproducing the audio signal recorded on the audio track 11; 16 is a rotating head dedicated to audio for reproducing the audio signal recorded on the video track 13; 16 is audio from the fixed head 14; An audio regenerator 17 for amplifying the signal demodulates the FM-modulated audio signal from the audio-dedicated rotary head 15.

FM demodulator; 18 is a level detector that detects the level of the signal from the audio regenerator 16; 19 is a switch controller that controls the operation of the selector switch 2o in accordance with the signal from the level detector 18; Changeover switch 2
0 means that when there is a signal from the level detector 18, the switch controller 19 sends the signal to the audio reproducer 16.
When there is no signal from the level detector 18, the switch controller 19 outputs the audio signal from the FM demodulator 1 to the output terminal 21.
It is switched so that the audio signal from 7 is taken out to the output terminal 21. 22 outputs an audio signal to the fixed head 1 by operating an after-recording switch (not shown).
This is an audio recorder for recording on a magnetic tape f audio track at 4.

In a video tape recorder having such a configuration, an audio signal is superimposed on the video track 13 using an FM modulation method using a rotary head for recording television signals or recording camera shots. Next, when it is desired to reproduce one word of the video and the audio signal in its entirety and insert a comment, audio title, music signal, etc. using the audio signal into a necessary part, the audio signal can be recorded on the audio track 11 by the fixed head 14. This is the same as the audio dubbing mode of current fixed head audio recording video tape recorders. Then, when reproducing the video signal and the audio signal, a single word of audio recorded by the rotary head and an audio signal recorded by the fixed head recorded by the above method are automatically switched. In other words, in normal operation, FM audio signals with good audio performance are
The entire M demodulator 17 is set to the audio band, and the selector switch 20
An audio signal is output via i. Next, if comments are recorded on the audio rack 1 as necessary, the fixed head 14. The audio reproducer 16 outputs the audio signal recorded on the audio track 11, the level detector 18 detects one word, the switch controller 19 changes the changeover switch 20, and the audio signal on the audio track 11 is output. Ru.

In this way, the audio signal can be easily edited, and the original sound can be input and output from the foal without erasing the original sound on the video track 13, which is useful for audio editing of the video tape recorder. Indeed, the system is relatively simple, inexpensive, and has the advantage of allowing all editing functions to be added.

In addition, in the above-mentioned example, we explained the case where the FM-modulated audio signal 1g is recorded and played over the video signal 1g by a rotating head dedicated to audio, which is different from the rotating head dedicated to video, but there are other ways to record and play back the audio signal 1g, which is FM modulated, with the video signal 1g. It goes without saying that recording and reproducing the 100 audio signals may be performed using a full-rotation signal head in which a carrier wave for the audio signal is provided by FM modulation between the carrier waves for the luminance 1 word and the color signal.

Effects of the Invention As detailed above, according to the invention, in addition to recording and reproducing one FM-modulated audio word using the rotary head, the fixed head is configured to record and reproduce one audio word, so that after-sales service is possible. It has the advantage of being capable of recording and inking, and of being compatible with conventional systems that record and reproduce one audio word using only an identification head. In addition, since the audio signal is recorded and reproduced using the rotary head, the relative speed with respect to the magnetic tape is increased, and there is an advantage that high-quality reproduced sound quality can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a videotape diagram, and FIG. 2 is a system block diagram showing an embodiment of the inventive video cheap recorder. 11...Audio track/', 12...Control track, 13...Video 1 rack,
14--Fixed head, 15--Rotating head, 16--Audio reproducer, 17--FM
Demodulator, 18...Level detector, 19...
・Switch controller, 20...Choice switch. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Diagram

Claims (1)

[Claims] an audio signal recording/reproducing means by the identification head; an audio signal FM modulation/demodulation recording/reproducing means by the rotary head; a switching means for extracting one of the reproduced audio signals from both of these recording/reproducing means; and an audio signal by the fixed head. It is equipped with a control means for detecting the playback output from the recording and playback means and controlling the switching means, and when there is a playback output from the recording and playback means for one audio word by the fixed head, the sound signal is recorded by the fixed head. The switching means is controlled by the control means so as to extract the reproduced audio signal sound from the reproduction means and the reproduced audio signal from the audio signal FM modulation/demodulation recording/reproducing means by the rotary head when there is no reproduction output. A video tape recorder consisting of: