JPH069385B2 - Video tape recorder - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a video tape recorder suitable for crime prevention and surveillance.

[Background of the Invention]

Conventionally, as a video tape recorder used for crime prevention and surveillance, a time-lapse video capable of recording for a long time by intermittently extracting a video signal for every one field (or frame) every plural fields (or frames). A video tape recorder called a tape recorder is known (hereinafter referred to as a time-lapse VTR).

For example, in the time-lapse VTR disclosed in Japanese Patent Laid-Open No. 58-62985, a video signal of one field extracted for each of a plurality of fields (hereinafter described as a unit of field) is recorded (hereinafter, this is referred to as time-lapse). When recording the video signal, the magnetic tape is run at the same speed as when recording the video signal continuously (hereinafter referred to as normal recording), and the magnetic tape is stopped at other times to stop the magnetic field. The inclination angle and track pitch of the tracks formed on the tape are set to be the same as in the case of normal recording. As a result, when the magnetic tape is run at the same speed as in normal recording and played back, the rotary magnetic head plays back and scans each track on the magnetic tape as it is, and a long-time phenomenon appears to be time-compressed. The image will be obtained in good quality without noise bars.

By the way, such a time-lapse VTR is generally equipped with an alarm recording function for recording the scene in a normal recording state when an emergency occurs. That is, the time-lapse VTR is provided with an input terminal, which is generally called an alarm input terminal, to which a signal (hereinafter, referred to as an alarm input) indicating that an emergency has occurred is input, and this is provided on a door or the like. When the door is opened, the alarm input generated by the switch is received, and the alarm recording state is set for a predetermined period even in the time-lapse recording state. This makes it possible to know in detail the emergency that has occurred during monitoring, when reproducing from the magnetic tape later.

When playing back a magnetic tape that has been recorded with a time-lapse VTR, the magnetic tape is run at the same speed as during normal recording. Thereby, it is possible to sequentially know the recording contents at the time-lapse recording and the alarm recording at the time of alarm recording. In particular, it is the alarm-recorded portion representing an emergency that the recording contents are desired to be known. However, the conventional method is to start playback from the recording start point and search for the alarm-recorded portion while looking at the playback screen, which takes time to detect the alarm-recorded portion, and the playback screen is always available. Had to be monitored.

On the other hand, it is also possible to search the alarm recording part by so-called forward rotation or reverse reverse quick playback, which is reproduced while running the magnetic tape in the forward direction or the reverse direction, but in this case, the reproduction time of the alarm recording part is Compared to the case of running the above magnetic tape at the same speed as during normal recording and playing it, it is very short, so in order to lose search omission, you must keep your eyes on the playback screen for a moment. However, it is also necessary to make a quick decision as to whether or not the reproduction screen represents the alarm recording part, which imposes an unreasonable effort on the user. It has also been proposed that a predetermined mark or the like be displayed on the playback screen during the period in which the alarm recording part is played back, which eliminates the need for the user to make a judgment, but the playback screen is always monitored. That problem is not solved.

Furthermore, it is possible to record an index pulse at the start of alarm recording, detect it during normal rotation or reverse rotation quick playback, and find the beginning of each alarm recording part. It is not necessary to monitor or judge the content of the reproduced image, but it is necessary to specially provide a circuit for this, and there is a problem that the structure of the time-lapse VTR is complicated and the cost is increased.

[Object of the Invention]

An object of the present invention is to solve the above-mentioned problems, reduce the burden on the user without complicating the configuration, and make it possible to quickly and surely search the alarm recording portion for a time-lapse video tape. Providing a recorder.

[Outline of Invention]

An audio signal recording / reproducing system is provided in the time-lapse VTR. However, since the audio signal cannot be recorded / reproduced in time-lapse recording, this audio signal recording / reproducing system is generally not used.

The present invention was made by paying attention to the fact that this audio signal recording / reproducing system is provided. In order to achieve the above object, the present invention records an audio signal at the same time when recording an alarm. When detecting the alarm recording portion by performing quick-view playback from the existing magnetic tape, the microphone output audio signal is recorded when the microphone is connected, and the oscillator output audio signal is recorded when the microphone is not connected. The feature is that an audible sound is generated during the quick-reading period of the alarm recording portion so that the audio signal is also reproduced at the same time.

Example of Invention

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

FIG. 1 is a diagram showing a basic configuration of a video tape recorder according to the present invention, in which FIG. 1 (a) is an audio signal recording system and FIG. 1 (b).
Is an audio signal reproducing system, 1 and 2 are input terminals, 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-lapse recording,
The magnetic tape 6 runs intermittently as in the prior art disclosed in the above-mentioned patent publication, for example, once per second from a video signal sent at a rate of 60 fields per second. The video signal of one field is extracted at a ratio, and the magnetic tape 6
Recorded on. At this time, the audio signal A from the input terminal 1
However, since the opening / closing switch 3 is open, the audio signal is not recorded on the magnetic tape 6 by the audio head 5.

In such a state, if there is an alarm input indicating emergency information by operating a door switch or the like (not shown),
The magnetic tape 6 runs continuously at a 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. As a result, 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 is then supplied to the audio head 5 to be recorded on the magnetic tape 6. After the set predetermined time has passed or when the emergency is released, the alarm recording shifts to the time-lapse recording,
At the same time, the switch signal SW disappears and the open / close switch 3 opens, and recording of the audio signal on the magnetic tape 6 by the audio head 5 is stopped.

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

Next, when the alarm recording portion is searched by the forward rotation or the reverse fast reproduction from the magnetic tape 6 recorded as shown in FIG. 2, the switch signal SW is input from the input terminal 10 in FIG. 1 (b). 'Is supplied and the open / close switch 8
Closes. The audio head 5 scans the magnetic tape 6 as it travels, but no audio signal is recorded in the time-lapse recording portion of the magnetic tape 6, so an audio signal cannot be obtained from the audio head 5.

When the rotary magnetic head (not shown) starts reproducing the alarm recording portion of the magnetic tape 6, the audio head 5 outputs the audio signal A.
To play. The audio signal A is processed by the audio signal reproducing circuit 7, passes through the open / close switch 8, and is supplied from the output terminal 9 to a generating means such as a speaker (not shown). This produces an audible sound.

In the conventional time-lapse VTR, an audio signal recording / reproducing system is provided to enable recording / reproducing of an audio signal. However, when searching the alarm recording portion by quick view reproduction, the audio is reproduced as a high tone. For this reason, the open / close switch 8 is opened to prohibit the audio reproduction. However, in this embodiment, the audio signal is always recorded during the alarm recording, and the open / close switch is used during the search of the alarm recording portion by the quick view reproduction. Make sure to close 8
The detection of the alarm recording part can be detected with an audible sound.

For this reason, it is not necessary to constantly monitor the playback screen,
The burden on the user is greatly reduced, and the audio signal is reproduced every time the alarm recording portion is detected even when the magnetic tape is run at high speed, so that the alarm recording portion can be searched quickly and reliably. Moreover, since the audio signal recording / reproducing system normally provided in the time-lapse VTR can be used as it is, it is not necessary to separately provide a special circuit system.

The audio signal recorded at the time of alarm recording may be the output signal of a microphone attached to a surveillance video camera or the like.

However, when monitoring a quiet place such as a warehouse, sound may not be generated when an emergency occurs. In such a case, the alarm recording search cannot be performed. FIG. 3 is a block diagram of the essential parts showing an embodiment of the present invention in which such a problem is solved.
Reference numeral 2 is an oscillating circuit, and 13 is a change-over switch. The parts corresponding to those in FIG.

In FIG. 3, an audio signal A output from a microphone (not shown) is input to the input terminal 11, and the changeover switch 1
3 is supplied to the a side. The audio signal A ′ output from the oscillator circuit 12 is supplied to the side b of the changeover switch 13. The change-over switch 13 is closed to the side a when the microphone is connected to the input terminal 11, and is closed to the side b otherwise. Thus, at the time of alarm recording, the audio signal A from the microphone or the audio signal A'from the oscillation circuit 12 can be recorded. It goes without saying that the frequency of the audio signal A'output from the oscillating circuit 12 must be set so as to produce an audible sound when reproduced from the magnetic tape 6 by the quick reproduction.

According to this embodiment, the microphone may not be connected in a quiet place such as a warehouse, and the microphone may be used when there is a relatively sound such as when monitoring a scene of business at a bank or the like. By connecting to, it becomes possible to search for the alarm recording part, and when the alarm recording part is reproduced, the voice can be reproduced at the same time.

Alternatively, the selector switch 13 may be closed to the side a when the audio signal A from the microphone is input to the input terminal 11, and may be closed to the side b when this is not input. This can be done by detecting the presence or absence of a voice signal from the microphone and controlling the changeover switch 13 accordingly.

Further, as another embodiment of the video tape recorder according to the present invention, since the audio signal is normally recorded in two channels, the audio signal from the microphone is recorded in one channel as necessary, and the other is recorded. During the alarm recording, the audio signal from the oscillation circuit is recorded in the channel (1), and the alarm recording portion is searched by this audio signal.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, when an alarm recording portion is detected and an audio signal is reproduced, the video tape recorder is further reproduced. The operation of may be stopped, or cueing can be performed. The alarm recording portion is reproduced by performing a reproducing operation.

〔The invention's effect〕

As described above, according to the present invention, when the alarm recording part is played back at a quick view, a sound is always generated, so that the alarm recording part is played back at a quick view without monitoring the playback screen. It is possible to detect, reduce the burden on the user, and quickly search each alarm recording part without omission, and it is not necessary to separately provide a special circuit system for such a search, and the structure is complicated. In addition, it is possible to selectively record the output audio signal of the microphone and the output audio signal of the oscillator in the alarm recording part, and the output audio signal of the microphone is recorded. in case of,
Further, the contents of the alarm recording portion can be known not only by using the reproduced screen but also by the contents of the reproduced audio signal, and the contents of the scene can be grasped more accurately. It is possible to solve the problems and provide a violet tape recorder having an excellent function.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a video tape recorder according to the present invention, FIG. 2 is an explanatory diagram of a recording pattern on a magnetic tape, and FIG. 3 is a main block showing an embodiment of a video tape recorder according to the present invention. It is a figure. 1 ... Voice signal input terminal, 3 ... Open / close switch, 4 ...
Voice signal recording circuit, 5 ... Voice head, 6 ... Magnetic head, 7 ... Voice signal reproducing circuit, 8 ... Open / close switch, 9
...... Voice signal output terminal, 11 …… Microphone input terminal, 12 …… Oscillation circuit, 13 …… Change switch.

Claims (1)

[Claims] 1. A transition between an intermittent recording state in which a video signal of one unit period is recorded in a recording medium and a normal recording state in which the video signal is continuously recorded in the recording medium is made possible for every plural unit periods. In a video tape recorder, a microphone connecting means, an oscillation circuit for generating an audio signal, an output audio signal of the microphone is selected when the microphone is connected by the connecting means, and an output audio of the oscillator when the microphone is not connected Selecting means for selecting a signal; recording means for recording the audio signal selected by the selecting means on the recording medium only in the normal recording state; And a reproducing means for reproducing an audio signal, and reproduces the audio signal from a portion recorded in the normal recording state of the recording medium during the normal rotation or reverse rotation quick reproduction. Video tape recorders, characterized in that is configured to be able.