JPH0965325A - Image monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the image monitor in which an image confirmation is executed efficiently at a remote host terminal equipment by storing a valid image signal. SOLUTION: An external sensor 4 is provided in the vicinity of a monitor point being an object of state grasp and a frame control section 15 replying a fault signal (e) from an external sensor is provided and when it is discriminated that the possibility of fault occurrence is high, an image signal is stored at a short time interval and when it is discriminated that the possibility of fault occurrence is low, the image signal is stored at a long time interval to vary time resolution with respect to a stored frame number of a memory section 12a being a limit of the image monitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives image data of each monitoring point from a plurality of monitoring terminals via a telephone line,
The present invention relates to an image monitoring apparatus equipped with a host terminal (center machine) for displaying an image in a remote center, and in particular, when the monitoring point is normal, image signals are accumulated at long time intervals to effectively use the memory unit, and when an abnormality occurs, an external sensor is used. The present invention relates to an image monitoring device capable of accumulating image signals at short time intervals in response to a change in an abnormal signal from the device and reliably monitoring an image when an abnormality occurs.

[0002]

2. Description of the Related Art Conventionally, for example, JP-A-2-2477.
No. 86, JP-A-3-48997, JP-A-7-67098, etc., data compression is performed on still images of monitoring points obtained by a plurality of monitoring terminals, and 1
An image monitoring device in which frames are periodically transmitted to a host terminal via a telephone line and an image is displayed on the host terminal on the center side is well known and has been adopted in various fields.

FIG. 5 is a block diagram showing a schematic configuration of a conventional image monitoring apparatus. In the figure, 1 is a monitoring terminal that transmits an image signal (still image) of a monitored area as image data, 2 is a host terminal that receives and displays image data from the monitoring terminal 1, and 3 is the monitoring terminal 1 and host It is an exchange that connects to the terminal 2 via a telephone line g.

Image data obtained by imaging a surveillance area or a surveillance point is transmitted from the surveillance terminal 1 to a remote host terminal 2 via a telephone line g and an exchange 3, and the host terminal 2 receives the surveillance terminal 1 from the surveillance terminal 1. Based on the transmitted image data, the monitor area is displayed as an image on a monitor TV (described later). Here, one monitoring terminal 1 and one host terminal 2 are shown for simplification, but a plurality of monitoring terminals 1 are installed corresponding to a plurality of monitoring points, and the host terminal 2 is different from the monitoring terminal 1 from the monitoring terminal 1. It is installed in any remote center.

The monitoring terminal 1 includes an image pickup device 11 for picking up a still image of the surveillance area as an image signal a for each frame,
A memory unit 12 for sequentially storing and accumulating image data a from the image pickup apparatus 11, and an image compression unit 13 for compressing image data b sequentially read from the memory unit 12 at a predetermined compression rate to obtain image data c. And a communication unit 14 for transmitting the compressed image data c to the host terminal 2 via the telephone line g and the telephone exchange 3.

The memory section 12 stores a predetermined number of image signals a for one frame sequentially output from the image pickup device 11, and at the time of storing the predetermined number of image signals a, the oldest image signal is selected. The image signals a that are eliminated and newly captured are sequentially updated.

The host terminal 2 serving as a center machine receives the image data c from the monitor terminal 1 via the telephone line g and the exchange 3, and the image data input via the communication section 24. An image decompression unit 21 that decompresses h and temporarily stores it as an image signal i, a display control unit 22 that converts the decompressed image signal i into a video signal j, and an image of the video signal j output from the display control unit 22. A monitor TV 23 for displaying is provided.

Next, the operation of the conventional image monitoring apparatus shown in FIG. 5 will be described. First, the image signal a of the monitoring area output from the image pickup device 11 at a constant time interval for each frame is digitally converted in the memory unit 12 and sequentially stored. At this time, when the image signal a of a predetermined number of frames is stored, the memory unit 12 sequentially updates and stores the old image signal to the new image signal a.

Subsequently, the image signal b read from the memory section 12 is compressed by the image compression section 13 at a predetermined compression rate to become image data c in order to increase the information transmission speed to the host terminal 2. Compressed image data c
Is modulated into image data for the telephone line g in the communication unit 14 and transmitted to the communication unit 24 in the host terminal 2 via the telephone line g and the exchange 3. The modulated image data received by the communication unit 24 is demodulated into the image data h before modulation, and then input to the image expansion unit 21.

The image data h (compressed data) after demodulation is
The image expansion unit 21 expands the image signal i according to the compression ratio, and the display control unit 22 converts the image signal i into a video signal j. Lastly, the monitor TV 23 reproduces the image signal converted into the video signal j on the TV screen to allow the monitor to monitor the monitor area on the TV.

In this way, the host terminal 2 receives the image data h for each frame sent in time series from the image decompression unit 2
1, the image signal j is expanded, and the display control unit 22 edits the image signal j into a displayable format and displays the image signal j on the monitor TV 23. As a result, the still image captured at a constant cycle is displayed on the monitor TV at a constant cycle.

However, in the monitoring terminal 1, if the image signal a is continuously stored in the memory section 12 at a short fixed time interval, the image signal a may hardly change when the monitoring area is normal. However, the storage capacity (the number of frames) of the memory unit 12 is exceeded in a short period of time. Therefore, the memory unit 12 cannot be effectively used,
Further, on the host terminal 2, almost the same image with little change is unnecessarily updated and displayed.

On the contrary, in the monitoring terminal 1, if the image signal a is continuously stored in the memory section 12 at long constant time intervals,
When an abnormality occurs in the monitored area, the required frame of the image signal a cannot be stored in the memory unit 12 even though the image signal a is in a state of abrupt change. Therefore, similarly to the above, the memory unit 12 cannot be effectively used, and the host terminal 2 cannot display a sudden change image when an abnormality occurs.

[0014]

As described above, since the conventional image monitoring apparatus stores the image signal a in the memory unit 12 in the monitoring terminal 1 at a constant time interval, the memory unit 12 stores the image signal a. The number of image frames that can be stored on the monitoring terminal 1 side is limited depending on the capacity.

Therefore, when the monitoring terminal 1 captures the image signal a at a short fixed time interval, the allowable number of frames of the memory unit 12 is reached in a short time, and the period during which the image signal a can be stored becomes short, Since the communication time through the telephone line g is relatively long, the time required for transmission is longer than the time required for imaging, and there is a problem that image data cannot be transmitted to the host terminal 2 side.

When the monitoring terminal 1 captures the image signal a at a long fixed time interval, the image signal a can be stored in the memory section 12 for a long period of time, but an abnormality occurs at the monitoring point. In addition, there is a high possibility that necessary images are thinned out, and there is a problem in that it is impossible to permanently obtain an image when an abnormality occurs.

On the side of the host terminal 2 for displaying an image, for example, when confirming an image when an abnormality occurs, a work of selecting a target image from a group of images including a large number of meaningless same images in a normal state. Is always needed,
There is a problem that a great amount of dead time is required for searching.

The present invention has been made in order to solve the above problems, and changes the time interval for fetching an image signal into the memory unit according to the presence / absence of an abnormality, and if there is no abnormality, a long time is taken. By capturing images at intervals and, if there is an abnormality, capturing images at short intervals, effective use of the memory unit on the monitoring terminal side is realized, and the image search time on the host terminal side is shortened for searching. It is an object to obtain an image monitoring device with improved efficiency.

[0019]

An image monitoring apparatus according to claim 1 of the present invention includes a plurality of monitoring terminals for transmitting image data corresponding to an image signal for each frame via a telephone line, and the monitoring terminals. A monitoring terminal that is remotely located and that displays an image based on image data received via a telephone line, and the monitoring terminal captures a monitoring point and outputs an image signal for each frame. Means, a memory unit for storing a predetermined number of image signals, and a memory unit for sequentially updating the old image signal to a new image signal when the predetermined number of image signals are stored, and an image sequentially read from the memory unit. The host terminal has an image compression unit that compresses a signal at a predetermined compression ratio and outputs the image data as image data, and a first communication unit that transmits the image data via a telephone line.
A second communication unit that receives image data transmitted from the first communication unit via a telephone line, and an image decompression unit that decompresses the received image data at a predetermined decompression rate and temporarily stores it as an image signal. And an image display device having an image display means for displaying an image based on an image signal sequentially output from the image decompression unit, the abnormality signal is output to the monitoring terminal when an abnormal state near the monitoring point is detected. The monitoring terminal includes a frame control unit that sets a small time interval of the image signal stored in the memory unit in response to the abnormal signal.

According to a second aspect of the present invention, in the image monitoring apparatus according to the first aspect, the memory section outputs a frame count signal to the frame control section each time an image signal is input from the image pickup means, The control unit outputs a frame control signal obtained by dividing the frame count signal in response to the presence / absence of the abnormal signal to the memory unit to instruct the image signal stored in the memory unit, and when the abnormal signal is not input, A frame control signal obtained by dividing the frame count signal by a relatively large dividing ratio M is used to thin out the image signals output from the image pickup means to store one frame for every M frames in the memory unit, and an abnormal signal is input. Sometimes, a frame control signal obtained by dividing the frame count signal by a division ratio N smaller than the division ratio M is used to record one frame of every N frames of the image signal. Together is stored in the part, it is intended to stop the recording of the image signal to the memory unit after a preset period of time.

According to a third aspect of the present invention, in the image monitoring apparatus according to the first aspect, the frame control section outputs the image pickup control signals having different cycles to the image pickup means in response to the presence / absence of the abnormal signal to cause an abnormality. When no signal is input, the image signal output from the image capturing unit is thinned out and stored in the memory unit by the image capturing control signal corresponding to the synchronization signal at each relatively long constant time interval T1, and when the abnormal signal is input, The image signal is stored in the memory unit by the image pickup control signal corresponding to the synchronization signal at each constant time interval T2 shorter than the constant time interval T1, and the recording of the image signal in the memory unit is stopped after a predetermined constant time. It is a thing.

According to a fourth aspect of the present invention, in the image monitoring apparatus according to any one of the first to third aspects, the first communication section transmits from the second communication section via a telephone line. The image data is transmitted to the second communication unit when the request signal is input.

The image monitoring apparatus according to a fifth aspect of the present invention is the image monitoring apparatus according to any one of the first to third aspects, in which the frame control section, when an abnormal signal is input,
By outputting a transmission control signal to the first communication unit, the first communication unit is automatically called and image data is transmitted to the second communication unit.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a schematic configuration of Embodiment 1 of the present invention. In FIG.
2a corresponds to the monitoring terminal 1 and the memory unit 12, respectively, and is 2, 3, 11, 13, 14, 21 to 24, and a to.
c and g to j are the same as described above. here,
Detailed description of the same or corresponding parts as in FIG. 5 will be omitted.

In FIG. 1, reference numeral 4 denotes an external sensor installed near the monitoring point, which outputs an abnormal signal e to the monitoring terminal 1A when an abnormal state at the monitoring point is detected. Reference numeral 15 denotes a frame control unit provided in the monitoring terminal 1A, which sets a small time interval of the image signal a stored in the memory unit 12a in response to the abnormal signal e.

In this case, the memory section 12a has the image pickup means 1
Each time the image signal a from 1 is input, the frame controller 15
In response to the abnormal signal e from the external sensor 4, the frame control unit 15 outputs the frame count signal n to the image sensor 11 and selects whether to store the image signal a from the imaging device 11 in units of frames. The frame control signal d for the above is output to the memory section 12a.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described. When the abnormal signal e is input from the external sensor 4, the frame control unit 15 in the monitoring terminal 1A divides the frame count signal n from the memory unit 12a by a small division ratio and outputs the frame control signal d. . As a result, the number of times of thinning out the image signal a for each frame obtained from the imaging device 11 is reduced, and the memory unit 12a
The writing process of the image signal a is performed at very short time intervals.

At this time, the memory section 12a has the image pickup means 1
Each time the image signal a from 1 is input, the frame controller 15
To the memory unit 12a, the frame control unit 15 outputs a frame control signal d to the memory unit 12a by dividing the frame count signal n in response to the presence or absence of the abnormal signal e. The image signal a stored in 12a is designated.

That is, when the abnormal signal e is not input, the frame controller 15 thins out a large amount of the image signal a by the frame control signal d obtained by dividing the frame count signal n by a relatively large dividing ratio M, One frame for every M frames is stored in the memory unit 12a. When the abnormal signal e is input, the frame control signal d obtained by dividing the frame count signal n by the division ratio N smaller than the division ratio M is used.
As a result, one frame of every N frames of the image signal a is stored in the memory unit 12a, and recording of the image signal a in the memory unit 12a is stopped after a preset fixed time.

Further, when there is a transmission request signal from the communication section 24 on the host terminal 2 side via the telephone line g and the exchange 3, the communication section 14 responds to the transmission request signal and responds to the memory section 1
The image signal b read from 2a is image-compressed by the image compression unit 13, and the compressed image data c is transmitted to the host terminal 2. The host terminal 2 may include, for example, an information collecting unit associated with the monitoring point or another external sensor (not shown) in order to output the transmission request signal at an appropriate timing.

Since the image pickup device 11 is of the internal synchronization type, the image signal a is output at a constant cycle, so the frame count signal n from the memory section 12a is output at a constant cycle. Specifically, the frame control signal d from 1 is switched as follows.

For example, assuming that the frequency division ratio used in the frame controller 15 is M = 100 and N = 1, for the frame count signal n (for example, 100) corresponding to each image signal a sequentially output, In the normal state, 99 frames of the 100-frame image signal a are thinned out and 1 / M
By the frame control signal d indicating (= 1/100), the image signal a of only one frame that remains without being thinned is accumulated in the memory unit 12a.

On the other hand, when an abnormality occurs, the frame control signal d indicating 1 / N (= 1) causes all of the 100-frame image signal a to be accumulated in the memory section 12a. In this way, by changing the division ratio of the frame count signal n from M to N (<M) in accordance with the abnormal signal e,
Since the number of frames accumulated in the memory unit 12a in a unit time is larger than that in the normal time, the number of writing of the image signal a to the memory unit 12a can be increased.

Here, M = 100 and N = 1 are set as an example of the division ratio for dividing the frame count signal n.
It goes without saying that the division ratio can be set arbitrarily. After that, as described above, the frame control signal d is stopped after a predetermined time, and the recording of the image signal a in the memory unit 12a is stopped. As a result, the image signal a at the time of occurrence of abnormality is
It is ensured in the memory unit 12a without being updated.

Image signal a stored in the memory section 12a
When a transmission request signal from the host terminal 2 is generated, the image data is read out as the image signal b and becomes the image data c compressed by the image compression section 13, and the host terminal is transmitted from the communication section 14 via the telephone line g and the exchange 3. 2 is transmitted. The host terminal 2 communicates with the communication unit 2 via the telephone line g and the exchange 3.
The image data h received by No. 4 is expanded to the original image signal i by the image expansion unit 21 and displayed on the monitor TV 23 as the video signal j via the display control unit 22.

Embodiment 2 In the first embodiment, the image data c is transmitted from the monitoring terminal 1A side to the host terminal 2 side in response to the transmission request signal from the host terminal 2. However, the monitoring terminal side automatically transmits the image data c. You may make a call. The second embodiment of the present invention in which the transmission of the image data c is automatically called on the monitoring terminal side will be described below with reference to the drawings.

FIG. 2 is a block diagram showing a schematic configuration of the second embodiment of the present invention, which is 1B, 14b and 15b.
Correspond to the monitoring terminal 1A, the communication unit 14 and the frame control unit 15, respectively, and are 2 to 4, 11, 12a and 1
3 and 21 to 24 are the same as described above. Here, the same or corresponding portions as those in FIG. 1 are designated by the same reference numerals, and the detailed description thereof will be omitted.

In FIG. 2, the frame control unit 15b in the monitoring terminal 1B has a function of switching the accumulation interval of the image signal a in the memory unit 12a by the frame control signal d according to the abnormal signal e, and after a fixed time. It has a function of outputting a transmission control signal f and automatically calling the communication unit 14b to transmit the image data c.

Next, the operation of the second embodiment of the present invention shown in FIG. 2 will be described. In this case, when the abnormal signal e is input, the frame control unit 15b, as described above,
The frequency division ratio of the frame count signal n is reduced to output the frame control signal d, the number of times the image signal a is thinned out is reduced, and images are written in the memory section 12a at short intervals.

After that, the frame control section 15b stops the frame control signal d after a fixed time to stop recording the image signal a in the memory section 12a, and further outputs a transmission control signal f after a fixed time for communication. The unit 14b is called, the image signal b from the memory unit 12a is compressed by the image compression unit 13, and is transmitted as image data c to the host terminal 2.

That is, the image signal a stored in the memory section 12a is read out as the image signal b when the telephone line g is connected, and the image data c compressed by the image compression section 13 is transmitted from the communication section 14b to the telephone line g. It is transmitted to the host terminal 2 through the exchange 3. Hereinafter, in the host terminal 2, the received image data h is expanded into the image signal i by the image expansion unit 21, and is displayed on the monitor TV 23 via the display control unit 22.

Embodiment 3. In the first embodiment, the image pickup apparatus 11 is of the internal synchronization type and the image signal a is selectively stored in the memory section 12a by the frame control signal d from the frame control section 15. As the synchronization type, the frame amount of the image signal a to be stored in the memory unit per unit time may be changed by controlling the image pickup apparatus with a synchronization signal (image pickup control signal) with different intervals.

FIG. 3 is a block diagram showing a schematic configuration of the third embodiment of the present invention in which the image pickup control signal for the image pickup device is switched, and 1C, 11c, 12c and 1C.
Reference numeral 5c corresponds to the monitoring terminal 1A, the imaging device 11, the memory unit 12a, and the frame control unit 15, respectively.
~ 4, 13, 14 and 21-24 are the same as described above. Here, the same or corresponding portions as those in FIG. 1 are designated by the same reference numerals, and the detailed description thereof will be omitted.

In FIG. 3, the image pickup device 11c is capable of external synchronization, and the memory unit 12c is a frame control unit 15.
By the frame control signal d from c, the image signal a is accumulated in synchronization with the image signal a output from the imaging device 11c. In addition, the frame control unit 15c in the monitoring terminal 1C sets the output interval of the imaging control signal k, which is the synchronization signal, from K seconds to L (<K) seconds after the abnormal signal e from the external sensor 4 is input. It is supposed to change every time. The output interval L (second) is not limited to an integer and may be set to a fraction.

Next, the operation of the third embodiment of the present invention shown in FIG. 3 will be described. In this case, when the abnormal signal e is input, the frame controller 15c receives the image pickup device 11c.
To the frame count signal n of the image signal a output from the image pickup apparatus 11c.
The output interval (not shown here) is shortened.

For example, the frame controller 15c outputs the image pickup control signal k corresponding to one frame in response to the abnormal signal e, causes the image pickup device 11c to output the image signal a for one frame, and outputs the image pickup control signal. By shortening the repetition interval of k from every K seconds to every L seconds, the amount of the image signal a stored in the memory unit 12c in a unit of frame per unit time is increased.

As a result, similarly to the above, the memory unit 12
The writing process of the image signal a is performed at a short time interval with respect to c. After that, the frame control unit 15c stops the recording of the image signal a in the memory unit 12c by stopping the imaging control signal k after a predetermined time after receiving the abnormal signal e.

Further, the communication unit 14 in the monitoring terminal 1C responds to the transmission request signal from the host terminal 2 in response to the memory unit 1
The image signal b from 2c is compressed by the image compression unit 13, and the compressed image data c is transmitted to the host terminal 2.
Thereafter, the required image signal a is displayed on the monitor TV 23 in the host terminal 2 in the same manner as described above.

Fourth Embodiment In the third embodiment, the image data c is transmitted from the monitoring terminal 1C side to the host terminal 2 side in response to the transmission request signal from the host terminal 2, but in the second embodiment described above. As described above, the monitoring terminal may automatically make a call.

FIG. 4 is a block diagram showing a schematic configuration of the fourth embodiment of the present invention in which the transmission of the image data c is automatically called on the monitoring terminal side. 1D and 15d are the monitoring terminals 1C and 1D, respectively. Corresponding to the frame controller 15c, 2 to 4, 11c, 12c, 13, 14b and 21 to 24 are the same as those described above. Here, parts that are the same as or correspond to those in FIG. 2 or FIG. 3 are assigned the same reference numerals and detailed explanations thereof are omitted.

In FIG. 4, the frame control unit 15b in the monitoring terminal 1D has a function of switching the accumulation interval of the image signal a in the memory unit 12a by the image pickup control signal k according to the abnormal signal e, and after a fixed time. It has a function of outputting a transmission control signal f and automatically calling the communication unit 14b to transmit the image data c.

Next, the operation of the fourth embodiment of the present invention shown in FIG. 4 will be described. In this case, when the abnormal signal e is input, the frame control unit 15d, similar to the above,
The output interval of the imaging control signal k is shortened to shorten the frame output interval of the image signal a output from the imaging device 11c,
Images are written in the memory section 12c at short intervals.

Thereafter, the frame control section 15d stops the image pickup control signal k after a fixed time to stop recording the image signal a in the memory section 12c, and further outputs the transmission control signal f after a fixed time for communication. The part 14b is called. As a result, the image signal b read from the memory unit 12c
Is compressed by the image compression unit 13 and transmitted as image data c to the host terminal 2.

The image signal a stored in the memory section 12c is compressed by the image compression section 13 as an image signal b from the memory section 12c by the output of the transmission control signal f from the frame control section 15d after a preset time. The compressed image data c is transmitted from the communication unit 14b to the host terminal 2 through the telephone line g and the exchange 3.

[0055]

As described above, according to the present invention, in response to the abnormal signal from the external sensor, the image signal is accumulated at a short time interval when it is determined that the possibility of the abnormal occurrence is high, When it is judged that the abnormal signal is not generated and the possibility of the abnormal occurrence is low, the image signal is accumulated at a long time interval and the time resolution is changed with respect to the number of storage frames limited by the image monitoring device. Therefore, the effective image signal can be stored and the image confirmation work on the host terminal side can be efficiently performed.

Further, according to the present invention, since the communication section is automatically called to transmit the image data when an abnormality occurs, the image confirmation work on the host terminal side can be efficiently carried out. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a third embodiment of the present invention.

FIG. 4 is a block diagram showing a schematic configuration of a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a conventional image monitoring device.

[Explanation of symbols]

1A, 1B, 1C, 1D monitoring terminal, 2 host terminal,
3 exchanges, 4 external sensors, 11 and 11c imaging device, 12a and 12c memory section, 13 image compression section, 1
4, 14b, 24 Communication unit, 15, 15b, 15c, 1
5d frame control unit, 21 image decompression unit, 22 display control unit, 23 monitor TV (image display means), a, b,
i image signal, c, h image data, d frame control signal, e abnormal signal, f transmission control signal, g telephone line,
k imaging control signal, n frame counting signal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04Q 9/00 311 H04Q 9/00 311H

Claims (5)

[Claims] 1. A plurality of monitoring terminals for transmitting image data corresponding to an image signal for each frame via a telephone line, and a plurality of monitoring terminals remotely arranged in relation to the monitoring terminals and received via the telephone line. A monitoring terminal that displays an image based on the image data; the monitoring terminal stores an image signal of a predetermined number of frames and an image capturing unit that captures an image of a monitoring point and outputs an image signal of each frame. With
A memory unit that sequentially updates an old image signal to a new image signal when the image signals of the predetermined number of frames are stored; and an image obtained by compressing the image signals sequentially read from the memory unit at a predetermined compression rate. An image compression unit that outputs as data, and a first communication unit that transmits the image data via the telephone line, the host terminal transmits from the first communication unit via the telephone line. A second communication unit that receives the received image data, an image decompression unit that decompresses the received image data at a predetermined decompression rate and temporarily stores the decompressed image data as an image signal, and the image decompression unit sequentially outputs the image data. In an image monitoring apparatus having an image display unit for displaying an image based on an image signal, an external sensor that outputs an abnormal signal to the monitoring terminal when an abnormal state near the monitoring point is detected. The image monitoring apparatus includes a frame control unit that sets a small time interval of the image signal stored in the memory unit in response to the abnormal signal. 2. The memory section outputs a frame count signal to the frame control section each time an image signal is input from the imaging means, and the frame control section responds to the presence or absence of the abnormal signal by the frame control section. By outputting a frame control signal obtained by dividing the frame count signal to the memory unit, the image signal stored in the memory unit is instructed. When the abnormal signal is not input, the frame count signal is divided by a relatively large amount. By the frame control signal divided by the frequency ratio M, the image signal output from the image pickup means is thinned out to store one frame for every M frames in the memory unit, and when the abnormal signal is input, the frame counting is performed. A frame control signal obtained by dividing the signal with a frequency division ratio N smaller than the frequency division ratio M converts one frame of every N frames of the image signal. Together is stored in the serial memory, the image monitoring apparatus according to claim 1, characterized in that stopping the recording of the image signal to the memory unit after a certain preset time. 3. The frame control unit outputs image pickup control signals having different cycles to the image pickup means in response to the presence or absence of the abnormal signal, and when the abnormal signal is not input, at a relatively long constant time interval T1. The image signal output from the image pickup unit is thinned out by the image pickup control signal corresponding to the synchronization signal of No. 1 and stored in the memory unit. When the abnormal signal is input, a fixed time interval shorter than the fixed time interval T1. It is characterized in that the image signal is stored in the memory section by an imaging control signal corresponding to a synchronization signal for each T2, and the recording of the image signal in the memory section is stopped after a preset fixed time. The image monitoring device according to Item 1. 4. The first communication unit transmits the image data to the second communication unit when a transmission request signal is input from the second communication unit via the telephone line. The image monitoring apparatus according to any one of claims 1 to 3, characterized in that. 5. The frame control unit automatically calls the first communication unit by outputting a transmission control signal to the first communication unit when the abnormal signal is input. The image monitoring device according to any one of claims 1 to 3, wherein the image data is transmitted to the second communication unit.