JPH04189076A - Video camera - Google Patents

Abstract

PURPOSE:To display or record an object even when the object is moving by comparing an output logic value of a subtractor taking a difference between input and output signals of a 1 frame delay means with a prescribed value so as to control the operation of a display device or a recorder. CONSTITUTION:An image pickup device 1 picks up an object, it is converted into an electric signal and extracted. The electric signal is converted into a digital signal by an A/D converter 4 and the signal is delayed for one frame period at a 1 frame delay means F5 and converted again into an analog signal at a D/A converter 6. A subtractor 7 takes a difference between input and output signals at a delay means F5 and extracts an output logic value to detect movement of an object. Then a comparator 9 compares the logic value with a logic value of a setting value input terminal 8 and when the output logic value of a subtractor 7 is larger, a display device 2 or a recorder 3 is activated and when the output logical value is smaller, the display device 2 or the recorder 3 is not operated. Thus, even when the object is moving, display or recording is implemented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video camera for photographing a moving subject.

Conventional technology In recent years, video cameras have been widely used for various purposes.

An example of the conventional video camera mentioned above will be described below with reference to the drawings. FIG. 2 shows a block diagram of a conventional video camera.

In FIG. 2, reference numeral 1 denotes a photographing device that photographs a subject and converts it into a video signal, and is connected to a display device 2 such as a CRT, and a recording device 3 such as a VTR.

The operation of the video camera configured as described above will be explained below.

A photographic device 1 photographs a subject, converts it into an electrical signal, and extracts a video signal.The video signal is displayed in a visually recognizable form on a display device 2 or recorded on a recording device 3. This operation is performed regardless of the movement of the subject, and all images are displayed on the display device 2 or recorded on the recording device 3.

tJH that the invention seeks to solve However, with the above configuration, when you want to display or record only when the subject moves, for example, when you want to display or record only when there is an abnormality in a video camera used for crime prevention, or when you want to display or record only when there is an abnormality in a video camera used for crime prevention, When the subject is stationary, such as when photographing the moment an egg starts to snore, there is a problem in that all images, including still images, are displayed and recorded even when there is no need to display or record them. Was.

In view of the above problems, the present invention provides a video camera that displays or records only when a subject moves.

Means for Solving the Problems In order to solve the above problems, the video camera of the present invention includes an A/D converter that converts a photographed video signal into a digital signal, and a terminal connected to the output terminal of the A/D converter. a frame delay means and a D/D connected to the output terminal of the one frame delay means;
It is provided with an A converter and a subtracter that takes the difference between the input and output signals of the one frame delay means.

Operation With the above-described configuration, the present invention uses a subtracter to take the difference between the input and output signals of the one-frame delay means, that is, extracts the one-frame difference in the video signal to detect the movement of the subject, and detects the movement of the subject only when the subject moves. You can display or record, and stop displaying or recording when the subject is stationary.

Embodiment Hereinafter, a video camera according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a block V of a video camera according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a photographing device that photographs a subject and converts it into a video signal, and its output end is connected to an A/D converter 4. The output terminal of the A/D conversion B4 is a one frame delay means 5.
The output terminal of the one frame delay means 5 is connected to a D/A converter 6, and the output terminal of the D/A converter 6 is connected to the display device 2 and the recording device 3. 7 is one frame delay means 5
This is a subtracter that takes the difference between the input signal and the output signal. Reference numeral 9 denotes a comparator that compares the logical value of the set value input terminal 8 with the output logical value of the subtracter 7 and outputs a magnitude relationship, and its output terminal is connected to the display word W2 and the recording device 3.

The operation of the video camera configured as above will be explained below.

First, the photographing device 1 photographs a subject, converts it into an electrical signal, and extracts a video signal.The video signal is converted from an analog signal to a digital signal by an A/D converter 4, and the signal is delayed by one frame period. The signal is input to the one frame delay means 5.

The output signal of the 1-frame delay means 5 is converted back into an analog signal by the D/A converter 6, and then displayed on the display device 2 in a visually recognizable form or recorded on the recording device 3.

The subtracter 7 detects the movement of the subject by taking the difference between the input and output signals of the one-frame delay means 5. That is, when the image is a still image, the output logic value of the subtracter 7 is 0, and when the image is a moving image, the subtracter 7 obtains a logic value corresponding to the movement. The output logical value of the subtracter 7 is compared in magnitude with the logical value of the set value input terminal 8 by a comparator 9, and if the output logical value of the subtracter 7 is larger, the display device 2 and the recording device 3 are operated. .

Conversely, if the logical value of the set value input terminal 8 is larger, the display word y! 2 and recording device 3 are not operated.

Note that by changing the logical value of the set value input terminal 8,
It is possible to adjust how much movement of the subject the display device 2 and recording device 3 should be operated against.

As described above, according to this embodiment, the A/D converter 4 and the
1 frame delay means 5 connected to the output terminal of the /D converter 4, and D/D converter 4 connected to the output terminal of the 1 frame delay means 5
By providing the A converter 6 and the subtracter 7 that takes the difference between the input and output signals of the one-frame delay means 5, it is possible to display or record only when the subject is moving.

Effects of the Invention As described above, according to the present invention, an A/D converter that converts a photographed video signal into a digital signal, an l-frame delay means connected to an output terminal of the A/I converter, and a one-frame By providing a D/A converter connected to the output terminal of the delay means and a subtracter that takes the difference between the input and output signals of the one-frame delay means, the one-frame difference between the video signals can be extracted and the movement of the subject can be detected. , it is possible to display or record only when the subject moves, and stop displaying or recording when the subject is stationary.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a video camera according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional video camera. 1... Photographing device, 2... Display device, 3
... Recording device, 4 ... A/D converter,
5...l frame delay means, 6...D
/A converter, 7...Subtractor, 8...Set value input terminal, 9...Comparator. Name of agent: Patent attorney Akira Okaji and two others Figure 2

Claims (1)

[Scope of Claims] A photographing device that photographs a subject and converts it into a video signal; an A/D converter connected to an output terminal of the photographing device; and one frame connected to an output terminal of the A/D converter. a delay means; a D/A converter connected to an output terminal of the one-frame delay means; a subtracter that takes the difference between the input and output signals of the one-frame delay means; and a logical value output from the subtracter to a certain value. a comparator for comparison; a display device or a recording device connected to an output terminal of the D/A converter; and means for controlling whether or not the display device or the recording device operates using an output signal of the comparator. equipped with a video camera.