JPH11146386A - Video changeover device and video changeover installation using the video changeover device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a video image changeover device to select a plurality of cameras sequentially using an identical video cable. SOLUTION: A 1st video input means 1 receives an external video signal C1, which is outputted from a 1st video output means 2, a switching timing means 3 generates a switching timing signal (a) based on video switching timing information set in advance by a setting means 4 and the video signal C1, a changeover means 5 switches a video signal C2 received by a 2nd video input means 6 and the video signal C1 received by the 1st video input means 1 and the switched video image is outputted from a 2nd video output means 7. With the above constitution, the video signal C1 or C2 is selected in a preset optional timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video switching device used in a monitoring system for sequentially switching video images of a plurality of cameras and recording the video in a video recording device, and more particularly to connecting a plurality of cameras to one video cable. The present invention relates to a video switching device sometimes used.

[0002]

2. Description of the Related Art Conventionally, in a monitoring system in which images from a plurality of cameras are connected to an image switching device, the image output of the cameras is sequentially switched by the image switching device, and the images are recorded in an image recording device, the number of images is the same as the number of cameras Cable is connected to the video switching device. When synchronizing the cameras, cables for the number of cameras transmitting the signals for synchronizing are connected.

When a plurality of cameras are connected on the same video cable, a controller for controlling the video timing of each camera is connected to each camera by a control cable for transmitting a control signal, and each camera is connected to the controller. The video output is turned on / off according to the control from.

[0004]

However, in the above-mentioned conventional monitoring system for connecting video cables from each camera to a video switching device, video cables for the number of cameras are required, and synchronization of each camera is required. In the case of synchronization, there is a problem that cables for the number of cameras to be synchronized are required. Also, most conventional video switching devices have eight or sixteen camera inputs, which makes it difficult to cope with a small number of camera monitoring systems or additional cameras.

A monitoring system for connecting a plurality of cameras on the same video cable requires a controller for controlling the video timing of each camera and a control cable for transmitting the control signal. There is also a problem that a control function for turning on / off the video output is required in accordance with the control from the user.

According to the present invention, in a video switching device used in such a monitoring system, a plurality of cameras can be sequentially switched on the same video cable. The purpose is to be able to easily cope with this.

[0007]

In the video switching apparatus according to the present invention, a first video input means for inputting an external video signal and a first video output means for outputting the video signal input by the first video input means. Video output means; setting means for setting video switching timing information; and a switching timing signal formed based on video switching timing information preset by the setting means and a video signal input by the first video input means. Switching timing means; second video input means for inputting an external video signal; and a switching timing signal for converting the video signal input by the second video input means and the video signal input by the first video input means. And a second video output means for outputting the switched video signal.

According to the present invention, a plurality of cameras can be sequentially switched on the same video cable, and a video switching device which can easily cope with a monitoring system of a small number of cameras and an increase in the number of cameras can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there is provided a first video input means for inputting a video signal from the outside, and a first video input means for outputting a video signal input by the first video input means. (1) video output means, setting means for setting video switching timing information, and forming a switching timing signal based on video switching timing information preset by the setting means and a video signal inputted by the first video input means Switching timing means, a second video input means for inputting an external video signal, and the switching timing between the video signal input by the second video input means and the video signal input by the first video input means. A switching means for switching according to a signal, and a second video output means for outputting the switched video signal, wherein the first video The input means receives an external video signal, the input video signal is output from the first video output means, and the switching timing means outputs video switching timing information preset in the setting means and the first video input signal. A switching timing signal is formed based on the video signal input by the means, and the switching means, in accordance with the switching timing signal, switches the video signal input by the second video input means and the video input by the first video input means. Signal and the switched video is output from the second video output means.

According to a second aspect of the present invention, there is provided an image input means for inputting an external image signal, write timing information of a camera number to be written in the image for identifying the image, and the number of images to be identified. Setting means, timing means for forming a camera number writing timing signal based on information preset by the setting means and a video signal input by the video input means, and a video signal input by the video input means. Write camera numbers up to the video number in sequence according to the timing signal.
D writing means, and video output means for outputting a video signal in which the camera number is written, wherein the video input means inputs a video signal from outside, Forms a camera number write timing signal based on the camera number write timing information set in advance in the setting means, the number of cameras, and the video signal input by the video input means, and the ID write means generates the camera number write timing signal. Has a function of writing a camera number to a video signal input by the video input means, and the video output means outputs a video in which the camera number is written.

According to a third aspect of the present invention, there is provided a first video input means for inputting an external video signal, a first video output means for outputting a video signal input by the first video input means, Setting means for setting the camera number of the camera number written in the video signal to identify the camera number, and reading the camera number written in the video signal input by the first video input means ID reading means, switching timing means for forming a switching timing signal based on a camera number preset by the setting means, and a camera number read by the ID reading means, and an external video signal. Second video input means; and a video signal input by the second video input means and a video signal input by the first video input means. Switching means for switching by a video signal, and second video output means for outputting the switched video signal. The first video input means receives an external video signal, The first video output means outputs a video signal input by the first video input means, and a camera number to be recognized preset by the setting means and an input by the first video input means read by the ID reading means. The switching timing means forms a switching timing signal on the basis of the camera number written in the converted video signal, and the switching means uses the switching timing signal to output the video signal input by the second video input means and the first video input signal. The second video output means has an effect of outputting the switched video signal by switching with the video signal input by the means.

According to a fourth aspect of the present invention, when a plurality of cameras are connected on the same video cable, the video switching device according to the second aspect is connected to the first camera, and the second and subsequent cameras are connected. Item 3. The image switching device according to Item 3, wherein the image signals from the first camera 1, the second camera, and the second and subsequent cameras connected on the same image cable are transmitted. This has the effect of being sequentially switched and output in accordance with the write timing information.

According to a fifth aspect of the present invention, there is provided a first video input means for inputting an external video signal, a first video output means for outputting a video signal input by the first video input means, Setting means for setting the write timing information of the camera number to be written in the video signal for identifying and the number of videos required to be identified, and the number of the camera number of the camera number written in the video signal, ID reading means for reading the camera number written in the video signal input by the first video input means, switching based on information preset by the setting means, and the camera number read by the ID reading means Switching timing means for forming a timing signal and a camera number writing timing signal, and second video input means for inputting an external video signal An ID writing unit that writes a camera number based on the camera number writing timing signal into a video signal input by the second video input unit, and a camera number written into the video signal input by the second video input unit Switching means for switching the video signal and the video signal input by the first video input means by the switching timing signal; and second video output means for outputting the video signal switched by the switching means. The first video input means receives an external video signal, and the first video output means outputs the first video signal.
A video signal input by the video input means, a camera number write timing preset by the setting means, a camera number recognized as the number of videos, and an ID.
The switching timing means forms a switching timing signal based on the camera number written in the video signal input by the first video input means and read out by the reading means, and the second video input means generates an external timing signal. The video signal is input, and the switching timing means writes the camera number based on the camera number to be recognized and the camera number writing timing information set in the setting means, the number of videos, and the video signal input by the second video input means. A timing signal is formed, the ID writing means writes the camera number in accordance with the camera number writing timing signal into the video signal input by the video input means, and the switching means further outputs the video signal output from the ID writing means and the first video. Switching the video signal input by the input means with the switching timing signal; Image output means has the effect of outputting the switching video signals.

According to a sixth aspect of the present invention, there is provided a video signal input by a first video input means instead of the first video output means according to the first or second or third or fifth aspect. And a synchronizing signal outputting means for outputting a synchronizing signal based on the synchronizing signal. The synchronizing signal has an effect of synchronizing each video signal.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a video switching apparatus according to Embodiment 1 of the present invention.

The video switching device 10 according to the present embodiment includes a first video input means 1 for inputting a video signal C1 from the outside,
A first video output unit 2 for outputting a video signal C1 input by the first video input unit 1, a setting unit 4 for setting video switching timing information in advance, and video switching timing information preset by the setting unit 4. Switching timing means 3 for forming a switching timing signal a based on the video signal C1 input by the first video input means 1, second video input means 6 for inputting an external video signal C2, and second video input Switching means 5 for switching the video signal C2 inputted by the means 6 and the video signal C1 inputted by the first video input means 1 in accordance with the switching timing signal a, and a second video output for outputting the switched video signal V Means 7
And

FIG. 2 is a circuit diagram of the second embodiment of the present invention.
FIG. 3 is a timing chart showing the operation of the two cameras. In FIG. 2, a camera 1 is connected to a first video input unit 1 and a camera 2 is connected to a first video output unit 2.
And the second video input means 6. The video signal C1 of the first video output means 2 is connected to an external synchronization input of the camera 2 for synchronization, and the video signals of the camera 1 and the camera 2 are synchronized. The camera here is an external synchronization compatible camera.

In FIG. 3, C1 is a video signal from the camera 1, C2 is a video signal from the camera 2, and one square
Indicates an image of one field. In the setting means 4, 60 fields are preset as video switching timing information, and the switching timing signal a from the switching timing means 3 is set.
Is a high level / low level (H /
L). The video signal V is switched between the video signals C1 and C2 every 60 fields.

The operation of the video switching apparatus according to the first embodiment configured as described above will be described with reference to FIGS.
First, the video signal C1 from the camera 1 is input to the first video input means 1, and is output from the first video output means 2 to the external synchronization input of the camera 2. Then, the video signals of the camera 1 and the camera 2 are synchronized.

Further, based on the video switching timing information previously set in 60 fields by the setting means 4 and the video signal C1 inputted by the first video input means 1, the switching timing means 3 sets H / H every 60 fields. An L-controlled switching timing signal a is output.

The switching means 5 outputs a video signal C2 inputted by the second video input means 6 connected to the camera 2.
And the video signal C1 input by the first video input means 1 is switched according to the switching timing signal a. The switched video signal V is a video signal C every 60 fields.
1 and C2, and output from the second video output means 7.

Here, an example in which the video switching timing information is set to 60 fields by the setting means 4 is used, but an arbitrary number of fields can be selected. Further, the number of horizontal scanning lines can be selected instead of the field unit, and the switching timing signal a 'switched within the field (FIG. 3)
In this case, the video signals C1 and C2 can be switched within one screen (video V ′ in FIG. 3). Further, by connecting a plurality of video switching devices 10 to one video cable and connecting a corresponding camera to these video switching devices 10,
The video signals C1 and C2 of the video V can be switched to video signals of a newly connected camera.

By providing the video switching device 10 as described above, it is possible to provide a surveillance system for sequentially switching a plurality of cameras connected on the same video cable. Further, it is possible to provide a surveillance system with a small number of cameras and a surveillance system that can easily cope with the addition of cameras. (Embodiments 2 and 3) FIG. 4 is a block diagram of a video switching apparatus according to Embodiment 2 of the present invention.

Video switching device 20 according to the second embodiment
Is a video input means 26 for inputting a video signal A from outside.
Setting means 24 for setting write timing information of a camera number to be written in an image for identifying an image and the number of images required to be identified (the number of cameras connected to the same cable); A timing number 23 for forming a camera number writing timing signal a1 based on the above information and the video signal A input by the video input means 26; An ID writing unit 261 for writing a number and a video output unit 27 for outputting a video signal V1 in which the camera number is written are provided.

FIG. 5 is a configuration diagram of the video switching device 30 according to the third embodiment of the present invention. The video switching device 30 according to the third embodiment includes a video signal Vk-1
(K is a camera number of 2 or more) and a first video output means 32 for outputting a video signal Vk-1 input by the first video input means 31.
Setting means 34 for setting the camera number of the camera number written in the video for identifying the video, and the video signal Vk-1 input by the first video input means 31 To read the camera number
A reading means 311; a camera number k to be identified which is set in advance by the setting means 34;
A switching timing means 33 for forming a switching timing signal b based on the camera number read at 1, a second video input means 36 for inputting an external video signal B, and an input by the second video input means 36 Switching means 35 for switching between the input video signal B and the video signal Vk-1 input by the first video input means 31 by the switching timing signal b;
And second video output means 37 for outputting the switched video signal Vk.

FIG. 6 is a connection diagram of n cameras using the second and third embodiments of the present invention, and FIG. 7 is a timing chart showing the operation. 6, the camera 1 is connected to the video input means 26 of the video switching device 20, and the camera 2 is connected to the second video input means 36 of the video switching device 30. The video signal V1 of the first video output means 32 is connected to the external synchronization input of the camera 2 for synchronization,
The video of the camera 1 and the video of the camera 2 are synchronized. Similarly, the n-th camera n is connected on the same video cable by the video switching device 30. The camera here is an external synchronization compatible camera.

In the setting means 24 of the video switching device 20 connected to the camera 1, one field is set in advance as camera number writing timing information, and n is set as the number of videos (the number of cameras) that need to be identified. I do. The setting means 3 of the video switching device 30 connected to the camera 2
4 is set as the camera number k to be recognized (k = 2), and the setting means 34 of the video switching device 30 connected to the camera n is set as the camera number k to be recognized as the n-th camera (k = 2).
It is assumed that n) is set.

In FIG. 7, A is a video signal from the camera 1, B is a video signal from the camera 2, N is a video signal from the camera n, and one square indicates a one-field video. The video signal V1 is a video signal when one field is set as the camera number writing timing and n is set as the number of cameras in the setting means 24 of the video switching device 20 as described above. It is output from the video output means 27. The video signal V1 is obtained by writing a camera number to the video signal A of the camera 1, and camera numbers 1 to n are written for each field, and this is repeated for every n fields. The video in which the camera numbers 1, 2, and n are written in the video signal A are A1, A2,.
, An.

The switching timing signal b is a switching signal output from the switching timing means 33 of the video switching device 30 connected to the camera 2, and is the second camera number k recognized by the setting means 34 of the video switching device 30. Since (k = 2) is set, the camera number of the video signal V1 becomes high level (H) for every second field. Here, the switching timing signal switches only the video portion excluding the portion where the camera number is written.

The video signal V2 is the same as the video signal B of the camera 2 for each H field of the switching timing signal b.
Is switched to. Similarly, the field corresponding to the camera number is switched to each camera video, and the switching timing signal n is a switching timing signal output from the switching timing means 33 of the video switching device 30 to which the camera n is connected. The number k becomes H for every n-th field. Then, as for the video signal Vn, the video signal Vn-1 is switched to the video signal N of the camera n every H field of the switching timing signal n.

The present embodiment 2 configured as described above
3 will be described with reference to FIGS. First, the video signal A from the camera 1 is transmitted to the video switching device 2
0 is input to the video input means 26, and the setting means 24 of the video switching device 20 sets one field as the camera number writing timing information and n cameras as the number of cameras in advance. Information for writing the camera numbers 1 to n is sent to the ID writing unit 261. The ID writing unit 261 sequentially writes the camera numbers 1 to n in the video signal A input by the video input unit 26. Then, the written video signal V1 is output from the video output means 27.

Therefore, the video signal V1 is obtained by writing the camera number to the video signal A of the camera 1, and
.. N are written every field, and this is repeated every n fields. That is, the video signals A1, A2,
..., An are repeated.

Next, the video signal V1 is input to the first video input means 31 of the video switching device 30, and the first video output means 3
2 is a video signal V input by the first video input means 31
1 is output to the external synchronization input of the camera 2. Then, the video signals of the camera 1 and the camera 2 are synchronized. The camera number k as the identification number set in advance in the setting unit 34 and the video signal V read by the ID reading unit 311 and input by the first video input unit 31.
On the basis of the camera number written in 1, the switch timing signal 33 is generated in the switch timing means 33 in which only the field with the camera number of the second field has a high level (H).

The video signal B of the camera 2 is input to the second video input means 36. Then, the switching unit 35 converts the video signal V1 input by the first video input unit 31 into the video signal B of the camera 2 for each H field of the switching timing signal b.
Switch to. The second video output means 37 outputs the switched video signal V2. That is, the video signal V2
Are images A1, B2,..., An. here,
The field of the video signal A2 is switched to the video signal B, but only the video portion is switched, and the camera number portion is not switched.
That is, it is assumed that the image can be switched to the image B2.

Similarly, the field corresponding to the camera number k set by the setting means 34 is switched to the video signal of each camera. And the n-th camera n
, The switching timing signal n output from the switching timing means 33 becomes H for each field of the camera number k, and the video signal Vn becomes a camera for each H field of the switching timing signal n. The video signal N is switched to n.

Here, an example in which one field is set as the camera number writing timing in the setting means 24 and n cameras are set as the number of cameras is used. However, any number of fields and any number of cameras can be selected. .

As described above, the video switching device 2 is provided for each camera.
By providing 0 and 30, it is possible to provide a monitoring system that sequentially switches n cameras connected on the same video cable. Further, it is possible to provide a surveillance system with a small number of cameras and a surveillance system that can easily cope with the addition of cameras. (Embodiment 4) FIG. 8 is a block diagram of a video switching apparatus according to Embodiment 4 of the present invention.

The video switching device 40 according to the fourth embodiment includes first video input means 41 for inputting an external video signal Vk-1 (k is a camera number of 2 or more), and first video input means. The first video output means 42 for outputting the video signal Vk-1 inputted by 41, the write timing information of the camera number to be written in the video for identifying the video, and the number of videos to be identified (connected to the same cable Setting means 44 for setting the camera number of the camera number) and the camera number of the camera number written in the video signal
And the video signal V input by the first video input means 41
The switching timing signal b and the camera number are read out based on the ID reading means 411 for reading out the camera number written in k-1 and the camera information read out by the ID reading means 411 and the information previously set by the setting means 44. Switching timing means 43 for forming a number writing timing signal c, second video input means 46 for inputting an external video signal B, and the camera number writing timing for the video signal B input by the second video input means 46 ID writing means 4 for writing camera number k based on signal c
61, a video signal B2 in which the camera number is written in the video signal B input by the second video input means 46, and a video signal Vk-1 input by the first video input means 41 by the switching timing signal b. Switching means 45 for switching
And the video signal Vk switched by the switching means 45
And second video output means 47 for outputting FIG. 9 is a connection diagram of n cameras according to Embodiment 4 of the present invention, and FIG. 10 is a timing chart showing the operation.

In FIG. 9, the camera 1 is a video switching device 4
The camera 2 is connected to the second video input means 46 of the video switching device 40. Further, the first video output means 42 is connected to the external synchronization input of the camera 2 for synchronization, and the video of the camera 1 and the video of the camera 2 are synchronized. Similarly, up to the n-th camera n are connected on the same video cable by the video switching device 40. The camera here is an external synchronization compatible camera.

In the setting means 44 of the video switching device 40 connected to the camera 1, the number 1 is set as the camera number to be identified, n is set as the number of videos (number of cameras) to be identified, and one field is set as write timing information. The setting means 44 of the video switching device 40 connected to the camera 2 includes:
No. 2 is set as the camera number k to be identified, n is set as the number of cameras, and one field is set as the write timing information. In the setting means 44 of the video switching device 40 connected to the camera n, n is set as the camera number k to be identified. It is assumed that it is.

In FIG. 10, A is a video signal from the camera 1, B is a video signal from the camera 2, N is a video signal from the camera n, and one square indicates a one-field video.

The video signal V1 is a video obtained by setting the camera number 1 in advance in the setting means 44 of the video switching device 40, and is output from the second video output means 47 of the video switching device 40. . The video signal V1 is obtained by writing the camera number 1 in the video signal A of the camera 1. The video signal V1 is supplied to the first video input unit 41 of the camera 2.
Is input to

The switching timing signal b is a switching signal output from the switching timing means 43 of the video switching device 40 connected to the camera 2, leaving one field of the previous camera number, and (n-1) ｛= nk (= 2) +1} high level (H) between fields. And the video signal V
2 is switched to the video signal B2 of the camera 2 every H field of the switching timing signal b.

Similarly, the field of the previous camera number is left, and the remaining fields are switched to the respective camera images. The switching timing signal n is a switching signal output from the switching timing means 43 of the video switching device 40 to which the camera n is connected, and the n-th field of the camera number has a high level (H).

The operation of the video switching apparatus according to the present embodiment configured as described above will be described with reference to FIGS. First, the video signal A from the camera 1 is input to the second video input means 46 of the video switching device 40, and the setting means 44 of the video switching device 40 preliminarily sets the first camera number as the camera number, Since n is set as the (number of units) and one field is set as the write timing information, information for writing the camera number 1 for each field is sent from the switching timing unit 43 to the ID writing unit 461. The ID writing unit 261 is a second video input unit 4
6, the camera number 1 is written in the input video signal A. Then, the written video signal V1 is output from the second video output means 47. That is, the video signal V1
Is a video signal A of the camera 1 in which the camera number 1 is written.

Next, the video signal V1 is input to the first video input means 41 of the video switching device 40, and the first video output means 4
2 is output to the external synchronization input of the camera 2. And
The video signals of camera 1 and camera 2 are synchronized.

The camera number 2, camera number n, and write timing information 1 field preset in the setting means 44 and read by the ID reading means 411
On the basis of the camera number written in the video signal V1 input by the first video input means 41, the camera number is the first 1
The switching timing means 33 generates a switching timing signal b in which only the field has a low level (L) and the (n-1) field has a high level (H).

The video signal B of the camera 2 is input to the second video input means 46. The switching timing unit 43 is inputted by the first video input unit 41 read out by the camera number 2, the camera number n, the camera number writing timing information 1 field, and the ID reading unit 411 set in the setting unit 44 in advance. The camera number writing timing signal c is formed based on the camera number written in the video signal V1.

The ID writing means 461 writes the camera number 2 in the video signal B input by the second video input means 46 according to the timing signal c. Switching means 45
Is the video signal B output from the ID writing unit 461.
2 and the video signal V input by the first video input means 41
1 is switched by the switching timing signal b. The second video output means 47 outputs the switched video signal V2.

Similarly, the image of the lower camera number in the upstream is left for one field, and the remaining fields are switched to the next camera image. Then, in the video switching device 40 connected to the n-th camera n, the switching timing signal n output from the switching timing means 43
The low level (L) until the (n-1) th is at a high level (H) for only the remaining one field, and the video Vn is switched to the switching signal n
Is switched to the image N of the camera n every H field.

Here, an example in which one field is set as the camera number writing timing information and n is set as the number of cameras in the setting means 44, but any number of fields and any number of cameras can be selected.

As described above, the video switching device 4 is provided for each camera.
By providing 0, it is possible to provide a monitoring system that sequentially switches n cameras connected on the same video cable. Further, it is possible to provide a surveillance system with a small number of cameras and a surveillance system that can easily cope with the addition of cameras.

Further, when an image from a camera having a small camera number is not inputted to the first image input means 41, the switching timing signal b is always kept at H and only the image inputted by the second image input means 46 is outputted. By outputting the video signal from the second video output means 47, even if a failure occurs in the video cable, the operation of the video switching device 40 connected after the failure can be guaranteed.

Although the first to fourth embodiments have been described with respect to an example in which the camera is constituted by an analog video camera, the present invention can be similarly applied to a case where video is transmitted by another digital communication system.

In the first to fourth embodiments, the first video output means outputs a video signal from a camera having a small camera number to the camera to synchronize the video output.
Instead of the first video output means, there is provided a synchronization output means for forming a synchronization signal on the basis of the video signal input by the first video input means, and the synchronization output means outputs a video signal from the first video output means. Instead, a synchronization signal may be output.

Although an external synchronization compatible camera has been described as an example here, almost the same effects can be obtained in cameras other than the external synchronization compatible camera, except for the image disturbance of the image switching unit. In this case, no synchronous output means is required.

Further, by making the camera number to be written in the video shown in the first to fourth embodiments the same as the camera number used for the conventional switcher or the like, compatibility with the conventional monitoring system can be maintained. .

[0058]

As described above, according to the present invention, by providing a video switching device for each camera, it is possible to provide a monitoring system for sequentially switching a plurality of cameras connected on the same video cable. it can. Further, the advantageous effect of providing a monitoring system with a small number of cameras and a monitoring system that can easily cope with the addition of cameras can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video switching device according to Embodiment 1 of the present invention.

FIG. 2 is a connection diagram of the video switching device according to the first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing timings of the video and the switching signal in FIGS. 1 and 2;

FIG. 4 is a block diagram of a video switching device according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a video switching device according to a third embodiment of the present invention.

FIG. 6 is a connection diagram of a video switching device according to Embodiments 2 and 3 of the present invention.

FIG. 7 is a characteristic diagram showing timings of a video and a switching signal in FIGS. 4 to 7;

FIG. 8 is a block diagram of a video switching device according to a fourth embodiment of the present invention.

FIG. 9 is a connection diagram of a video switching device according to a fourth embodiment of the present invention.

FIG. 10 is a characteristic diagram showing timings of the video and the switching signal in FIGS. 8 and 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st video input means 2 1st video output means 3 switching timing means 4 setting means 5 switching means 6 2nd video input means 7 2nd video output means 10, 20, 30, 40 video switching device 23 switching timing means 24 setting Means 26 Video input means 261 ID writing means 27 Video output means 31 First video input means 311 ID reading means 32 First video output means 33 Switching timing means 34 Setting means 35 Switching means 36 Second video input means 37 Second video output Means 41 First video input means 411 ID reading means 42 First video output means 43 Switching timing means 44 Setting means 45 Switching means 46 Second video input means 461 ID writing means 47 Second video output means

Claims (6)

[Claims] 1. A first video input means for inputting a video signal from the outside, a first video output means for outputting a video signal input by the first video input means, and a setting for setting video switching timing information Means for generating a switching timing signal based on video switching timing information preset by the setting means and a video signal input by the first video input means; and inputting an external video signal. A second video input unit; a video signal input by the second video input unit;
A video switching device comprising: switching means for switching a video signal input by a video input means in accordance with the switching timing signal; and second video output means for outputting the switched video signal. 2. A video input unit for inputting a video signal from the outside, a setting unit for setting writing timing information of a camera number to be written on a video for identifying a video and a number of videos to be identified, and the setting unit Timing means for forming a camera number writing timing signal on the basis of the information set in advance and the video signal input by the video input means; and the video signal input by the video input means in accordance with the timing signal. A video switching device comprising: ID writing means for writing a camera number up to the number of videos; and video output means for outputting a video signal in which the camera number is written. 3. A first video input means for inputting an external video signal, a first video output means for outputting a video signal input by the first video input means, and a video signal for identifying a video. Setting means for setting which camera number of the camera number written to the camera is to be identified; ID reading means for reading the camera number written in the video signal input by the first video input means; Switching timing means for forming a switching timing signal based on a camera number preset by the means and the camera number read by the ID reading means; a second video input means for inputting an external video signal; The video signal input by the second video input means and the video signal input by the first video input means are switched by the switching timing signal. A video switching device comprising: switching means for switching; and second video output means for outputting the switched video signal. 4. The video switching device according to claim 3, wherein when a plurality of cameras are connected on the same video cable, the video switching device according to claim 2 is connected to the first camera, and the video switching device according to claim 3 is connected after the second camera. Video switching equipment, characterized by connecting 5. A first video input means for inputting a video signal from outside, a first video output means for outputting a video signal input by the first video input means, and a video signal for identifying a video. Setting means for setting the write timing information of the camera number to be written to the camera, the number of videos to be identified, and the camera number of the camera number written in the video signal, and inputting by the first video input means ID reading means for reading a camera number written in the input video signal; information preset by the setting means;
Switching timing means for forming a switching timing signal and a camera number writing timing signal based on the camera number read by the reading means, a second video input means for inputting an external video signal, and the second video input means ID writing means for writing a camera number based on the camera number writing timing signal into a video signal input by the first and second video input means; and a video signal having a camera number written into the video signal input by the second video input means; Switching means for switching the video signal input by the input means according to the switching timing signal; and a second means for outputting the video signal switched by the switching means.
An image switching device, comprising: an image output unit. 6. The apparatus according to claim 1, further comprising a synchronous output unit for outputting a synchronous signal based on a video signal input by the first video input unit, instead of the first video output unit. The video switching device according to claim 2, 3, or 5.