JPS6249792A - Video tape recorder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a video tape recorder suitable for crime prevention and monitoring purposes.

[Background of the invention]

Traditionally, video tape recorders have been used for crime prevention and surveillance, and time-lapse video recording is possible by intermittently extracting video signals one field (or frame) at a time from multiple fields (or frames) at a time. A video tape recorder called a videotape recorder is known (hereinafter referred to as a time lag VTR).

For example, in the time-lapse VTRVC disclosed in Japanese Patent Application Laid-Open No. 58-62985, each of multiple fields (
When recording video signals of one field (hereinafter referred to as time lag recording), when recording video signals continuously (hereinafter referred to as 1 normal recording) By running the magnetic tape at the same speed as the speed of 100 kHz, and stopping the magnetic tape during other periods, the inclination angle and track pitch of the tracks formed on the magnetic tape are made to be the same as in normal recording. I have to. From this K, when the magnetic tape is run at the same speed as normal recording and played back, the one-rotation magnetic head continues to playback and scan each track on the magnetic tape, and the long-time phenomenon is seen to be compressed in time. The reproduced image is free from noise bars and has good image quality.

Incidentally, such time-lapse VTRs are generally equipped with an alarm recording function that records the scene in a normal recording state when an emergency situation occurs. In other words, the Time Lage VTRK is equipped with an input terminal, generally called an alarm input terminal, into which a signal indicating that an emergency situation has occurred (hereinafter referred to as alarm input) is input, and this input terminal is connected to a switch installed on a door or the like. By connecting to the switch, the switch receives an alarm input generated when a door is opened, and even if it is in the time-lapse recording state, it will enter the alarm recording state for a predetermined period of time. This makes it possible to know in detail the emergency situation that occurred during monitoring when reproducing from the magnetic tape later.

When playing back a recorded magnetic tape with a time-lag VTR, the magnetic tape is run at the same speed as during normal recording. From this K, it is possible to sequentially know the recorded contents during the time lag recording and the recorded contents during the alarm recording, but what the user particularly wants to know about the recorded contents is the alarm-recorded portion representing an emergency situation. However, in the past, the common method was to start playback from the recording start point and search for the alarm recorded part while looking at the playback screen, which took time to detect the alarm recorded part, and normal pressure playback. There was a problem with having to monitor the screen.

On the other hand, the magnetic tape is played back while running in the forward or reverse direction. Searching for the alarm recorded portion is also performed using so-called forward rotation or reverse quick playback, but in this case, the playback time of the alarm recorded portion is as long as the above magnetic tape is run at the same speed as during normal recording. Comparison'1:.

Since it is very short, in order to avoid search omissions, you cannot take your eyes off the playback screen even for a moment, and it is necessary to quickly judge whether or not the playback screen represents the alarm recording portion. This imposes an unreasonable effort on the user. During the period in which the alarm recording portion is played back, a predetermined mark or the like is displayed on the playback screen. It has also been proposed to apply pressure to the user, which eliminates the need for user judgment;
The problem of constantly monitoring the playback screen still remains.

Furthermore, it is possible to record an index pulse at the start of the alarm flange, detect this during forward or reverse rotation quick playback, and cue each alarm recording section.This allows the user to view the playback screen. Although it is no longer necessary to constantly monitor or judge the content of reproduced images, it is necessary to provide a special circuit for this purpose, which poses the problem of complicating the configuration of the time lag VTR and increasing costs.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned problems, and to provide a time-lapse video system that allows users to quickly and reliably search for alarm recorded portions without complicating the configuration and reducing the burden on the user. Provide tape recorders.

[Summary of the invention]

Although a time-lapse VTR is provided with an audio signal recording and reproducing system, this audio signal recording and reproducing system is generally not used during time lapse recording because audio signals cannot be recorded and reproduced.

The present invention has been made by providing this audio signal recording and reproducing system, and in order to achieve the above object, the present invention records the audio signal at the same time when recording the alarm, and The present invention is characterized in that an audible sound is generated during the quick playback period of the alarm recorded portion so that when detecting the alarm recorded portion by quick playback from the recorded magnetic tape, the audio signal is also played back at the same time. .

[Embodiments of the invention]

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

FIG. 1 is a block diagram showing the main parts of an embodiment of a video tape recorder according to the present invention. 3 is an input terminal, 3 is an open/close switch, 4 is an audio signal recording circuit, 5 is an audio head, and 6 is a magnetic tape.

7 is an audio signal reproducing circuit, 8 is an open/close switch, 9 is an output terminal, and 10 is an input terminal.

First, in FIG. 1(a), during time lag recording, the magnetic tape 6 runs intermittently, for example, as in the prior art disclosed in the previous patent publication,
One field of video signals is extracted once per second from the video signals sent at a rate of 60 fields per second, and recorded on the magnetic tape 6 by a rotating magnetic head (not shown). At this time, the audio signal A may be supplied from the input terminal 1, but the open/close switch 3 is open and the audio head 5 does not record the audio signal onto the magnetic tape 6.

In such a state, if there is an alarm input indicating emergency information due to the activation of a door switch or the like (not shown),
The magnetic tape 6 runs continuously at normal speed and alarm recording is started. At the same time, the switch signal SW is supplied from the input terminal 2, and the open/close switch 3 is closed. Thereby, the audio signal input to the input terminal 1 passes through the open/close switch 3, is processed by the audio signal recording circuit 4, and then is supplied to the audio head 5 and recorded on the magnetic tape 6. After the set predetermined time has elapsed or the emergency situation is lifted, the alarm recording will switch to time-lag recording.
At the same time, the switch signal SW disappears, the open/close switch 3 is opened, and recording of the audio signal onto the magnetic tape 6 by the audio head 5 is stopped.

Moreover, alarm recording is performed every time there is an alarm input, and as shown in FIG. 2, the audio signal A is recorded on the magnetic tape 6 only in the alarm recording portion.

Next, when searching for an alarm recording portion from the recorded magnetic tape 6 by forward rotation or reverse quick playback as shown in FIG. 2, in FIG. ' is supplied, and the open/close switch 8 is closed. As the magnetic tape 6 runs, the audio head 5 scans it, but since no audio signal is recorded in the time lapse recording portion of the magnetic tape 6, no audio signal is obtained from the audio head 5.

When the rotating magnetic head (not shown) starts playing back the alarm recording portion of the magnetic tape 6;
Play. After the audio signal A is processed by the audio signal reproducing circuit 7, it passes through the on/off switch 8 and is supplied from the output terminal 9 to a voice generating means such as a speaker (not shown). This produces an audible sound.

Conventional Time Lagase VTRs are equipped with an audio signal recording and reproducing system, which makes it possible to record and reproduce audio signals. However, when searching for alarm recordings using quick playback, the audio is played back at a high pitch. In order to prevent audio playback, the open/close switch 8 is kept open to prohibit audio playback. However, in this embodiment, an audio signal is always recorded during alarm recording, and this open/close switch is opened when searching for an alarm recorded portion using quick playback. Make sure to close 8.
Detection of the alarm recording portion can be detected with an audible sound.

This eliminates the need to constantly monitor the playback screen.
The burden on the user is greatly reduced, and even if the magnetic tape is run at high speed, the audio signal is played back every time an alarm recording portion is detected, making it possible to quickly and reliably search for an alarm recording portion.

Moreover, the audio signal recording and reproducing system provided in the normal Time Laguess VTRK can be used as is.

There is no need to separately provide a special circuit system.

The audio signal recorded during alarm recording may be an output signal from a microphone attached to a surveillance video camera or the like.

However, when monitoring a quiet place such as inside a warehouse, no sound may be generated when an emergency situation occurs. In such a case, it becomes impossible to search for alarm recordings. Fig. 3 is a block diagram showing another embodiment of the present invention that solves this problem, in which 11 is an input terminal, 12 is an oscillation terminal. The circuit 13 is a changeover switch, and parts corresponding to those in FIG. 1 are given the same reference numerals and redundant explanations will be omitted.

In FIG. 3, an audio signal A output from a microphone (not shown) is input to the input terminal 11.

It is supplied to the a side of the changeover switch 13. The audio signal A' output from the oscillation circuit 12 is supplied to the b side of the changeover switch 13. The changeover switch 13 is closed to the a side when a microphone is connected to the input terminal 11, and is closed to the b side at other times. Therefore, during alarm recording, the audio signal A from the microphone or the oscillation circuit 12
can record audio signals from It goes without saying that the frequency of the audio signal output by the oscillation circuit 12 must be set so that an audible sound is produced when the audio signal is reproduced from the magnetic tape 6 by quick playback.

According to this example, in quiet places such as warehouses, it is sufficient to avoid connecting the microphone, and in cases where relatively loud sounds are occurring, such as monitoring business operations at a bank, the microphone can be connected. By connecting K, it becomes possible to search for the alarm recorded portion, and when playing back the alarm recorded portion, the audio can also be played back at the same time.

Further, when the audio signal A from the microphone is input to the input terminal 11, the changeover switch 13 is closed to the a side, and when this is not input, the switch K is closed.

It may be closed on the b side. This can be done by detecting the presence or absence of an audio signal from the microphone and controlling the changeover switch 13 based on this.

Further, as another embodiment of the video tape recorder according to the present invention, 1. Since audio signals are normally recorded in two channels, the audio signal from the microphone is recorded on one channel as necessary, and the audio signal from the microphone is recorded on the other channel. The audio signal from the oscillation circuit 1 is recorded in the channel 5 during alarm recording, and the alarm recording portion is searched using this audio signal.

Although the present invention has been described in detail above, the present invention is not limited to these embodiments (1) For example, when an alarm recording portion is detected and the audio signal is played back, the The operation of the video tape recorder can be stopped or the video tape recorder can be cued up.In these cases, the alarm recorded portion is played back by performing the playback operation. [Effects of the Invention] As explained above, 1 According to the present invention, since sound is always generated when an alarm recorded portion is played back quickly, it is possible to detect that the alarm recorded portion is being played back quickly without monitoring the playback screen. It is possible to reduce the burden on the user and quickly search all of the alarm recording parts, and there is no need to separately provide a special circuit system for such a search (therefore, it is possible to avoid complicating the configuration. Therefore, it is possible to solve the problems of the prior art described above and provide a video tape recorder with excellent functions.

[Brief explanation of drawings]

FIG. 1 is a block diagram of main parts showing an embodiment of a video tape recorder (7) according to the present invention, FIG. 2 is an explanatory diagram of a recording pattern on a magnetic tape, and FIG. 3 is a diagram showing a video tape recorder (7) according to the present invention. FIG. 2 is a block diagram of main parts showing an embodiment of the present invention. 1...Audio signal input terminal, 3...Open/close switch, 4...Audio signal recording circuit, 5...
...Audio head, 6...Magnetic head, 7...
...Audio signal reproducing circuit, 8...Opening/closing switch, 9...Audio signal output terminal, 11...
・Microphone input terminal, 12...Oscillation circuit. 13......Selector switch. Figure 1 (b) Figure 2 only Figure 3

Claims (4)

[Claims] (1) In a video tape recorder that is capable of transitioning between an intermittent recording state in which a video signal for one unit period is recorded every plural unit periods and a normal recording state in which a video signal is continuously recorded, the normal recording state a first means for recording an audio signal in the normal recording state; and a second means for detecting the reproduction of the audio signal during forward or reverse rotation quick playback; A video tape recorder characterized in that the video tape recorder is configured so that the searched parts can be searched. (2) The video tape recorder according to claim (1), wherein the audio signal is an output signal of a microphone. (3) The video tape recorder according to claim (1), wherein the first means includes a signal generation circuit, and the audio signal is an output signal of the signal generation circuit. (4) In claim (1), the first means includes an input terminal for a microphone output signal, a signal generation circuit, and an input terminal for the microphone output signal and the signal depending on the presence or absence of the microphone output signal. 1. A video tape recorder comprising a selection circuit for selecting one of the output signals of the generation circuit, the output signal of the selection circuit being the audio signal.