JPH11261992A - Television camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide plural past video images and sound by plural video memory cells and sound memory cells by switching the present sound and the past sound stored in the sound memory cell corresponding to the present video images and the past video images. SOLUTION: Video memory cells 9-11 store a video image once in every two fields at all times and shifts the respective stored video images from the video memory cell 9 to the video memory cell 10 and from the video memory cell 10 to the video memory cell 11 immediately before storing the next video image, that is the video image after four fields. At this time, a sound memory cell 14 stores the sound of a video period stored in the video memory cells 9-11. In this case, assuming, for instance, that external trigger signals are inputted after a present video field, a signal switching circuit 7 selects output (b) at this point of time and past video signals from present video signals are inputted to a DSP 4. Thus, they are outputted as a video output after six fields. Simultaneously, sound signals stored in the sound memory cell 14 are also outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance television camera using a video storage device and an audio storage device.

[0002]

2. Description of the Related Art As a conventional technique, a television camera having a function of switching and outputting a current image and a past image by using an image storage element has been put to practical use. Then, this television camera is applied to a security monitoring system, and a sensor for detecting the intrusion of a suspicious person is installed at the entrance of a building or the like. A security monitoring system that can obtain images before and after has been put to practical use.

[0003]

However, in this system, since only the image storage element is provided, the image immediately before the suspicious person enters can be obtained, but the corresponding audio information cannot be obtained. A television camera more suitable for surveillance work has not been put into practical use. An object of the present invention is to add a function of adding audio information corresponding to these videos to a function of switching between a current video and a past video using a video storage element that has been conventionally put into practical use and outputting the same. Another object of the present invention is to obtain a television camera more suitable for surveillance work.

[0004]

In order to achieve the above object, there is provided means for switching and outputting a currently captured image and a past image stored in an image storage element; This is a television camera having means for switching and outputting current audio corresponding to video and past audio stored in the audio storage element. Further, the present invention is a television camera having a plurality of the above-mentioned image storage elements, and having means for sequentially storing and reading out images at predetermined time intervals in these image storage elements. further,
The switching between the current video and the past video is performed by a television camera that is switched by a trigger from outside the television camera or by a key switch input installed on the television camera. The television camera may further include an audio input unit, an audio storage element,
This is a television camera provided with a / D converter, a D / A converter, an FM modulation circuit, and a sound superimposition circuit. Further, the video signal and the audio signal of the television camera are analog-converted, then the audio signal is FM-modulated and superimposed on the video signal, so that the television camera transmits the video and the audio through the same cable. It is. As a result, when the current video and the past video are switched and output, a plurality of past videos and audio corresponding to the video can be obtained, and a television camera more suitable for surveillance work can be obtained. Can be.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 denotes a solid-state imaging device that converts light into an electric signal. 2 is correlated double sampling (hereinafter, CDS) /
Automatic gain control (hereinafter AGC) circuit
Processing such as S / AGC is performed. An A / D converter 3 converts an analog video signal into a digital video signal. 4 is a digital signal processor (hereinafter, DSP)
Performs processing such as gamma correction and color correction. A D / A converter 5 converts a digital video signal into an analog signal. 6 is a microcomputer (hereinafter, microcomputer)
It controls the DSP 4, the signal switching circuit 7, and the memory drive circuit 8. Reference numeral 7 denotes a signal switching circuit for selecting a currently captured image and a past image stored in the image storage element 11. Reference numeral 8 denotes a memory drive circuit, which includes video storage elements 9 to
11 and the voice storage element 14 are controlled. Reference numerals 9 to 11 denote video storage elements such as field memories for storing video signals.
Reference numeral 12 denotes a microphone for inputting voice. An A / D converter 13 converts an analog audio signal into a digital signal. Reference numeral 14 denotes an audio storage element that stores an audio signal. Fifteen
Is a D / A converter, which converts a digital audio signal into an analog signal. Reference numeral 16 denotes an FM modulation circuit for FM-modulating an analog audio signal. Reference numeral 17 denotes a superimposing circuit that superimposes an FM-modulated audio signal on a video signal.

Hereinafter, these operations will be described. The video signal imaged by the solid-state image sensor 1 is a CDS / AGC
And the like, and the A / D converter 3 converts the analog video signal into a digital video signal. The audio signal obtained from the microphone 12 is also converted into a digital audio signal by the A / D converter 13. The DSP 4 controlled by the microcomputer 6 performs processes such as gamma correction and color correction on the output of the A / D converter 3 and branches into two paths.
One is input to the video storage element 9 and the other is input to the signal switching circuit 7. Here, when the signal switching circuit 7 selects the output “a”, the video signal currently being captured is input to the DSP 4. At this time, since the digital audio signal input to the audio storage element 14 is controlled so as to pass through the audio storage element 14, the current audio signal is input to the D / A converter 15. When the signal switching circuit 7 selects the output b, the past video signal is input to the DSP 4 by the operation of the video storage elements 9 to 11 described later. At this time, the past audio signal is input to the D / A converter 15 by the operation of the audio storage element 14 described later. The output of the signal switching circuit 7 is input to the D / A converter 5 via the DSP 4 and is converted from a digital video signal to an analog video signal. Then, the audio signal modulated by the FM modulation circuit 16 is superimposed by the superimposition circuit 17. Output from the television camera.

Hereinafter, detailed operations of the video storage elements 9 to 11 and the audio storage element 14 will be described. The video storage elements 9 to 11 and the audio storage element 14 are controlled by the memory drive circuit 8. The image storage elements 9 to 11 always store the image once every two fields, and store the next image, that is,
Immediately before storing the video after four fields, the stored video is shifted from the video storage element 9 to the video storage element 10 and from the video storage element 10 to the video storage element 11. At this time, the audio storage element 14 is
The audio of the video period stored in 11 is stored
(In this embodiment, for six fields). Here, for example, as shown in FIG. Assuming that an external trigger signal is input after 5, the signal switching circuit 7 selects the output b at this point, and a past video signal from the current video signal is input to the DSP 4. In this case, the video signals for every two fields are sequentially shifted to the video storage elements 9, 10, 11 as shown in FIG. Therefore, No. The video signal of 0 is stored in the video storage element 10 after two fields, and is stored in the video storage element 11 after four fields, and an external trigger signal is input. After six fields, it is output as a video output as shown in FIG. You. At the same time, the audio signal stored in the audio storage element 14 is also output as shown in the audio output of FIG.

FIG. 3 shows an example in which the television camera according to the present invention is applied to a security monitoring system. 18 is a television camera according to the present invention, 19 is a unit having a function of separating and outputting an audio signal and a video signal, 20 is a television monitor with an audio output, and 21 is a sensor for detecting that a suspicious person has crossed. is there. The sensor 21 is installed in advance at a building entrance or the like. When a suspicious person enters, a trigger signal is supplied from the sensor 21 to the television camera 18. By this trigger input, the television camera 18 operates as shown in FIG. 2 described above, and reproduces the video and audio before and after the intruder enters the monitor.

[0009]

According to the present invention, a plurality of past videos and sounds can be obtained by a plurality of video storage devices and audio storage devices without a storage device such as a video tape recorder or an audio tape recorder.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a timing chart of one embodiment of the present invention.

FIG. 3 is a configuration diagram showing an application example of the present invention.

[Explanation of symbols]

1: solid-state imaging device, 4: DSP, 7: signal switching circuit,
8: memory drive circuit, 9 to 11: video storage element, 1
4: voice storage element, 17: superposition circuit.

Claims (5)

[Claims] Means for switching and outputting a currently captured image and a past image stored in an image storage element;
A television camera, comprising: means for switching and outputting a current audio corresponding to the current video and a past video and a past audio stored in an audio storage element. 2. A television camera according to claim 1, further comprising a plurality of said video storage elements, and means for sequentially storing and sequentially reading video at predetermined time intervals in said video storage elements. . 3. The method according to claim 1, wherein the switching between the current image and the past image is performed by a trigger from outside the television camera or by a key switch input provided on the television camera. A television camera, characterized in that: 4. The television camera according to claim 1, further comprising an audio input unit, an audio storage element, an A / D converter, a D / A converter, an FM modulation circuit, and an audio superimposition circuit. Television camera. 5. The video signal and audio signal of the television camera according to claim 1, wherein
A television camera, wherein an audio signal is FM-modulated and superimposed on a video signal, so that the video and the audio are transmitted by the same cable.