JP2939790B2 - Motion detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion detecting device for detecting a motion of an arbitrary portion of a display screen of an image display means, and more particularly, to a motion detecting device which can be easily attached to a monitor screen of an existing display such as various monitor devices. The present invention relates to a motion detection device that can be used.

[0002]

2. Description of the Related Art In a general image surveillance system, a video signal sent from a surveillance camera is displayed on an image display means (C).
(Hereinafter, referred to as a display such as an RT display), and the observer keeps monitoring the video.

[0003] In such an image monitoring system,
In many cases, images of various places are displayed on a large number of displays, and the burden on the observer was extremely large.

[0004] Then, it is necessary to keep watching the image on the screen for a long time, and depending on the monitoring target, there is a case where it is impossible to keep an eye on for a moment.

[0005]

In such an image monitoring system as described above, the burden on the observer is extremely large, and there is a possibility that changes occurring in a very short time may be missed.

Therefore, in such a surveillance system, if an alarm (or some kind of signal) is automatically issued when a change of a specific place on the surveillance screen occurs, a video from a surveillance camera is required. A configuration in which a signal is fetched into a frame memory and the signal value of each pixel is compared for each frame may be considered as a possibility.

However, if such a configuration is realized, an image processing apparatus using a computer or an image processor is required, so that the system is expected to be complicated. In addition, construction and wiring changes for distributing the video signal from the surveillance camera of the already operating image monitoring system to the image processing apparatus are required.

For this reason, a simple configuration
In addition, it has been desired to realize a motion detection device that can be easily attached to a display.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to be able to be easily attached to an arbitrary portion of a display screen of a display and to perform a predetermined movement within the display screen. An object of the present invention is to realize a motion detection device capable of detecting the motion.

[0010]

Means for Solving the Problems The inventor of the present application has conducted intensive studies to improve the disadvantages of the conventional image monitoring system, and as a result, has been able to easily add the existing image monitoring system without changing the device configuration. The present invention has been completed by finding out what is possible and a new configuration capable of detecting the motion of an arbitrary part expected on the display screen in advance.

That is, the present invention, which is means for solving the problem, is as described in the following (1).

(1) A first means for solving the problem is a light receiving means attached to an arbitrary portion of a display screen of an image display means for detecting a change in image display, and a light receiving means for detecting a change detected by the light receiving means. And a detection unit that outputs a detection signal in response to the detection signal, and detects a motion from a change in image display at an arbitrary part in the display screen.

The change in the image display detected by the detecting means includes, for example, luminance, density, color (hue, lightness,
(Color saturation) or various changes such as the appearance of a specific pattern.

Further, the invention described in claim 1 as the present invention, which is means for solving the problems, will be described below (2).
There is something like

(2) The invention described in claim 1 is a light receiving means attached to an arbitrary part of the display screen of the image display means for detecting a change in image display, and an image display means based on a light reception result of the light receiving means. A peak holding means for holding a peak value corresponding to a periodic change caused by the display method, and a delay for receiving a holding result of the peak holding means and outputting a delay signal delayed by two different time constants Means, comparing delayed signals of different time constants from the delay means,
Detecting means for outputting a detection signal when a difference of not less than a predetermined value occurs in each of the delay signals, and detecting a movement from a change in image display of a certain value or more at an arbitrary portion in the display screen. It is a detection device.

In this case as well, changes in the image display to be detected by the detecting means include, for example, luminance, density, color (hue,
Changes such as brightness, saturation) and various changes such as the appearance of a specific pattern.

[0017]

In a motion detecting apparatus which is a first means for solving the problem, in a state where a light receiving means is attached to an arbitrary portion of a display screen of an image display means, a luminance in an image display is determined.
A change in density, color, or the like is detected, and the detection means outputs a detection signal according to the change in image display. As a result, it is possible to detect a motion at an arbitrary part in the display screen.

In the motion detecting device according to the present invention, when the light receiving means is attached to an arbitrary portion of the display screen of the image display means, a change in luminance, density, color, etc. in the image display is detected, and a peak is detected. The holding means holds a peak value corresponding to a periodic change caused by the display method of the image display means in the light receiving result of the light receiving means, and the delay means receives the holding result of the peak holding means and receives two different time constants. Then, the detecting means compares the delayed signals with different time constants from the delay means, and outputs a detection signal when a difference of a certain value or more occurs between the delayed signals. As a result,
A motion can be detected from a change in image display at a certain level or more at an arbitrary part in the display screen.

[0019]

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

<Structure of Motion Estimation Device> FIG. 1 is a block diagram showing the structure of a motion estimation device according to one embodiment of the present invention.

In FIG. 1, a light receiver 1 is attached to an arbitrary portion of a display screen of an image display device, and detects a change in brightness, density, color, etc. of an image display corresponding to the portion by photoelectric conversion. It is for. As shown in FIG. 2, for example, the light receiver 1 includes a sensor 1a and the sensor 1a.
And a signal line 1c for supplying a light receiving signal from the sensor 1a to the outside so as to cover a certain area of the surrounding area and to block the influence of disturbance light from the surrounding area.

Here, the change in the image display detected by the light receiver 1 varies depending on the display method of the image display device. For example, a change in luminance, density, color, etc. can be considered. Further, as the change in color, a change in hue, lightness, saturation and the like can be considered. Further, when a specific pattern appears on the image display, it is conceivable to detect a change in the pattern or the presence or absence of the appearance.

If the luminance of the image display is detected as the sensor 1a, sensors such as a phototransistor, a photodiode, and a CDS can be used. To detect a change in color, a color meter or the like can be used. However, a phototransistor, photodiode, CDS, or the like having a wavelength-dependent characteristic for the color to be detected is used. It is also possible. In this case, the wavelength dependency of the sensor itself may be used, or a color filter or the like may be attached to the light receiving surface of the sensor. If you want to detect the appearance or change of a specific pattern, use OCR (Optica
l Character Reader) can be used.

Here, it is preferable that the sensor 1a has a light receiving area of about the size of a plurality of (several to several tens) scanning lines on the display screen of the image display device. If the light receiving area is too small, a malfunction may occur when the display screen fluctuates, for example, on the imaging side. Conversely, if the attended area is too wide, the resolution may be reduced. Further, for example, the sensor 1a or the light shielding plate 1b is configured to have adhesiveness or adsorption so that the light receiver 1 can be attached to a display screen (CRT tube surface or the like) of an image display device. Good to keep.

In the following embodiments, the description will be continued with the detection of luminance as a representative example.

The brightness adjusting amplifier 2 is a variable gain amplifying means for adjusting the gain by receiving the photoelectric conversion signal obtained by the light receiving device 1. The peak holding circuit 3 is a peak holding means for holding a peak value corresponding to a periodic change in image display caused by a display method of the image display device for a period of about one cycle.

If necessary, an automatic gain adjustment (AGC) may be realized by returning a part of the output of the peak holding circuit 3 to the gain adjustment terminal of the brightness adjustment amplifier 2.

The delay circuit 4 and the delay circuit 5 output peak holding values from the peak holding circuit 3 with different time constants. For example, the delay circuit 4 outputs a signal substantially following the change in the peak holding value, and the delay circuit 5 outputs a signal that changes with a delay of several fields to several tens of fields with respect to the change in the peak holding value. Have been.

The window comparator 6 includes delay means 4,
5 is a comparing and detecting means for comparing delayed signals with different time constants from No. 5 and outputting a detection signal when a difference equal to or more than a predetermined value occurs in each delayed signal. Then, an external buzzer, siren or the like is activated by a detection signal output from the window comparator 6.

<Operation of Motion Estimation Device> Next, the operation of the motion estimation device having the above configuration will be described. Here, a case where motion is detected from a change in luminance of image display will be described as an example.

Assuming that the image display device on which the light receiver 1 is mounted is a normal CRT display, scanning of an electron beam called raster scanning is performed.
In this case, the entire display screen appears to be shining uniformly, but it actually shines at the moment the electron beam hits the phosphor, and then the brightness or brightness of the color gradually decreases. It has become.

The degree of the decrease in the luminance and brightness differs depending on the afterglow characteristics of the phosphor, but when a CRT having characteristics called short afterglow or medium afterglow is used, the characteristics as shown in FIG. 3 are used. It has become. That is, the luminance of the pixel of interest emits light at a specific timing in a certain field period, and thereafter the luminance gradually decreases. Therefore, the peak value of FIG. 3 is held by the peak holding circuit 3, and a holding waveform as shown in FIG. 4 is generated. In this case, it is desirable that the retention period of the peak value is about one field period so that the change of the peak value of the next field is made effective.

For example, a circuit composed of a switch and a capacitor having the configuration shown in FIG. 5 can be used as the peak holding circuit 3. Then, a rising edge in each field is detected, and the following operation is repeated. Initialization immediately before peak: SW1 = ON, SW2 = OFF Peak charge to hold: SW1 = OFF, SW2 = ON In this manner, each switching state is repeated to perform peak hold for one field period.

The peak value of the photoelectric conversion signal is shown in FIG.
In the case of (a), the peak holding circuit 3
Are as shown in FIG. 6B. here,
The delay amount of the delay circuit 4 is set to be small, and a waveform almost following the output is output. Also, the delay circuit 5
In this case, a waveform that follows with a delay of several fields is output. By doing so, when a change occurs in the peak value of the photoelectric conversion signal, the delay circuit 4 outputs the signal shown in FIG.
A delay signal as shown by a solid line in (c) is obtained, and a delay signal as shown by a broken line in FIG. 6C is obtained from the delay circuit 5. These delay signals are input to the window comparator 6. In addition, where the broken line and the solid line coincide, both are shown by the solid line.

The two kinds of delayed signals are supplied to the light receiver 1
In the portion where the peak value of the photoelectric conversion signal changes, a portion having a different waveform occurs. That is, in the example shown in FIG. 6, there is a difference between the waveforms of the two types of delay signals between the period in which the peak value decreases and the period in which the peak value increases.
In the middle part, the two types of delay signals match.

It should be noted that the delayed signal of the delay circuit 5 can sufficiently follow a slow change such as a change in sunshine due to the movement of the sun in one day, so that there is no difference between the waveforms of the two kinds of delayed signals.

The case where the delay amount of the delay circuit is further different will be described with reference to FIG. here,
As in the case of FIG. 6, the delay amount of the delay circuit 4 is set to be small, and a waveform almost following the output is output. In addition, the delay circuit 5 outputs a waveform that follows after a delay of several tens of fields or more, and does not follow a short-term change.

In this way, when a change occurs in the peak value of the photoelectric conversion signal, the delay circuit 4 outputs the signal shown in FIG.
7C, a delay signal as shown by a solid line is obtained, and a delay signal as shown by a broken line in FIG. 7C is obtained from the delay circuit 5, and these delay signals are input to the window comparator 6. In addition, where the broken line and the solid line coincide, both are shown by the solid line.

The two kinds of delay signals are supplied to the photodetector 1
In the portion where the peak value of the photoelectric conversion signal changes, a portion having a different waveform occurs. That is, in the example shown in FIG. 7, there is a difference between the waveforms of the two types of delay signals in the period from the decrease in the peak value to the period in which the peak value returns.

It should be noted that the delayed signal of the delay circuit 5 can sufficiently follow a slow change such as a change in sunshine due to the movement of the sun in one day, so that there is no difference in waveform between the two types of delayed signals.

As the two types of delay circuits, for example,
The circuit can be relatively easily realized by the circuit including the peak detection unit 8a, the timer 8b, and the switches 8c and 8d as shown in FIG. In this case, the constant of the timer 8b is changed and the switch 8c is changed.
By changing the switching interval (ratio) between the two and the 8d to several times to several tens times, two types of delay times can be determined.

For example, the setting may be made so as not to follow the change of the sunshine but to respond to the movement of the person according to the application.

Then, the window comparator 6 receives the two types of delay signals (FIG. 6C), and as shown in FIG. 6D, a difference of a certain value or more was recognized between the two types of waveforms. In this case, a detection signal is output. That is, this is a period in which the luminance has changed (= a period in which there is movement), and a detection signal is obtained from the window comparator 6 as d1 and d2 in FIG.

In addition, the window comparator 6 receives the two kinds of delay signals (FIG. 7C), and as shown in FIG. 7D, a difference of a certain value or more was recognized between the two kinds of waveforms. In this case, a detection signal is output. That is, the period in which the luminance has changed in this way (= the period in which there is movement), and a detection signal is obtained from the window comparator 6 as d1 in FIG. 7D.

The reason for providing the difference equal to or larger than the predetermined value is to prevent malfunction due to noise components such as light reception noise. However, if it is too large, a problem occurs in that the sensitivity when detecting the motion is reduced. Also, by adjusting this difference, it is possible to set so as not to respond to a luminance change due to the movement of the cloud or various other slow movements.

As a result, a detection signal is output from the window comparator 6 when a change in luminance appears faster than a change in sunlight or the like on a portion of the display screen of the image display device where the light receiver 1 is attached.

<Uses of Motion Detector> (1) Installation Location: The motion near the entrance or cash register is monitored at a convenience store or the like.

The movement of entrances and passages is monitored at homes and offices.

It is monitored whether or not the cargo collapses in a warehouse or the like.

At a factory or the like, the occurrence of fire, explosion, etc. is monitored.

It is monitored whether an abnormality occurs in a product on a production line or the like.

It is monitored whether an unusual reaction has occurred in the chemical plant.

The appearance and change of the fish shadow in the fish finder are monitored.

The radar monitors a moving object or a fixed object.

A pattern that appears on the radar enemy / friend identification system or the like is monitored.

In each of the above cases, movement can be detected by detecting changes in luminance, density, and color. Further, in the case where the luminance and density values are the same and a color change appears, color detection is particularly effective. In the above case, it is effective to detect the appearance or change of a specific pattern. The installation location is not limited to the above example, and can be used for various similar applications.

(2) Method of using detection signal: Upon receiving the detection signal, an alarm such as a buzzer, siren, or warning light is sounded.

Upon receiving the detection signal, the display screen is recorded.

In response to the detection signal, the operation of another system is started or stopped.

In such a case, a necessary state can be instantaneously found without a human being constantly monitoring.

In addition, it is possible to prevent monitoring of a useless period without any change and video recording, thereby saving the trouble of the monitor and the tape. Further, in the case of video recording, long-time recording becomes possible, and the trouble of retrieving the tape later to find the corresponding portion can be saved.

<Motion detecting device and effect obtained by device: comparison with conventional example> According to the motion detecting device described above, the following effects can be obtained.

The light receiving section can be easily attached to the display screen of an existing display device. In this case, it can be attached particularly to a part to be monitored. Therefore, no operation such as changing the wiring of the existing monitoring system is required at all. Also, the monitoring position can be changed by changing the attachment part.

It is possible to detect a motion due to a change in image display of a desired part without using image processing using a frame memory or the like. Therefore, it can be realized at a low cost with a simple configuration.

Since it can be realized with a simple circuit configuration, for example, it can be driven by a battery. Therefore, it can be easily added to an existing system. Further, it can be attached to a monitoring system where the power supply has no margin. It is easy to remove, and it is easy to return to the previous state.

<Other Preferred Examples> In the description of each of the above embodiments, the case where a CRT display is used as a display device is assumed. However, the display device may be attached to a liquid crystal display device or a projection type display. It is also possible.

When a long afterglow type CRT is used for the CRT of the display device, other display means that does not generate flicker is used, or a slow response type light receiver 1 is used. In some cases, the luminance adjustment amplifier 2 and the peak holding circuit 3 can be omitted. The parts of the delay circuits 4 and 5 and the window comparator 6 can be replaced with various circuits capable of detecting a time change of the received light signal.

In a surveillance system in which images from a plurality of cameras are switched and displayed at regular intervals,
It can be used by devising such as holding a photoelectric conversion signal and the like at a fixed period.

In addition, an object of the present invention is to detect a movement in a display screen, and a structure in which a movement is detected based on a change in a signal (video signal) for forming a displayed image. A motion detection device is also conceivable.

[0070]

According to the motion detecting apparatus described in detail above, the light receiving means detects a change in the image display in a state where the light receiving means is attached to an arbitrary portion of the display screen of the image display means, and the detecting means detects the change in the image display. By outputting the detection signal in accordance with the change, it is possible to detect the movement at an arbitrary part in the display screen. Therefore, a motion detection device that can be easily attached to any part of the display screen of the display and that can detect a motion in the display screen can be realized.

Further, when the light receiving means is attached to an arbitrary portion of the display screen of the image display means, a change in the image display is detected, and the peak holding means detects the change in the light reception result due to the display method of the image display means. The delay means receives the holding result of the peak holding means, outputs a delayed signal delayed by two different time constants, and the detection means outputs the delayed signal from the delay means. By comparing delayed signals having different time constants and outputting a detection signal when a difference of a predetermined value or more occurs in each of the delayed signals, it is possible to detect a movement from a predetermined or more change in an arbitrary portion in the display screen. Therefore, a motion detection device that can be easily attached to any part of the display screen of the display and that can detect a motion in the display screen can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration example of a motion detection device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a configuration example of a light receiver of the motion detection device according to one embodiment of the present invention.

FIG. 3 is a waveform chart showing a waveform of an output of a light receiver in one embodiment of the present invention.

FIG. 4 is a waveform diagram showing a waveform when the output of the light receiver is held at a peak in one embodiment of the present invention.

FIG. 5 is a configuration diagram showing a configuration of a peak holding circuit used in one embodiment of the present invention.

FIG. 6 is a waveform chart showing waveforms at various parts in one embodiment of the present invention.

FIG. 7 is a waveform chart showing another example of a waveform at each unit in one embodiment of the present invention.

FIG. 8 is a configuration diagram showing a configuration of a delay circuit used in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiver 2 Brightness adjustment amplifier 3 Peak holding circuit 4, 5 Delay circuit 6 Window comparator 7 Display screen screen

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 7/18 G08B 13/196

Claims (1)

(57) [Claims] 1. A light receiving means attached to an arbitrary portion of a display screen of an image display means for detecting a change in image display,
The display method of the image display means in the light reception result of the light receiving means
Holds peak values according to periodic changes caused by the law
Receiving a peak holding unit and a holding result of the peak holding unit;
Output a delayed signal delayed by two different time constants.
And a different time constant from the delay means.
Comparing the delayed signals, each delay signal has a certain difference or more
Display means for outputting a detection signal when the
A motion detection device for detecting a motion from a change of an image display at a given portion or more within a predetermined range.