JPH08265737A - Automatic video signal switching device - Google Patents

Abstract

PURPOSE: To easily change a switching order/time in a device for switching signals from plural video signal sources by a matrix switch and outputting them. CONSTITUTION: Video signals from the plural video signal sources 4 are switched by the matrix switch of a video unit 1, corresponding characters are superimposed in a character unit 2 and they are outputted from an output terminal 6 to a monitor or the like. When a power source is turned on, the data of the switching order/time or the like of the storage part 9 of a computer system 3 are read in a control part 11, sent out to the respective units by an input/ output part 12 and stored in a memory. By the automatic changeover specification of a console 7, they are discriminated in a discrimination part 8, control signals are sent through the control part 11 to the respective units and the switching operation of the video signals is started based on the data read from the respective memories. In the case of changing the switching order/time or the like, updating data are inputted from an input part 10 and the data of the storage part are rewritten.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic video signal switching device, and more particularly to a device for automatically switching a video signal from a surveillance camera or the like and a character signal displayed in the video.

[0002]

2. Description of the Related Art A plurality of video signal sources, for example, superposed character signals respectively corresponding to video signals from a surveillance camera,
Some devices that perform switching in a required order and a required time interval and sequentially display on a single monitor or a plurality of monitors use a hardware method of switching an analog switch by driving a relay. In this case, it is necessary to design each system according to the installation conditions of the device.
In addition, when changing a design once, it is often necessary to redesign from scratch, which is a problem of labor and time.

[0003]

SUMMARY OF THE INVENTION In view of the above, the present invention has been made in view of the above-mentioned points, in which a signal obtained by superimposing characters corresponding to each video signal on a video signal from a plurality of video signal sources is required in a required order and at a required time interval. In the case of switching and outputting with, the data such as the switching order of video signals and the switching time interval are stored in the storage medium, and when the change becomes necessary, the data of the storage medium can be rewritten. It is to be able to easily cope with a difference in installation conditions or a change in a short time.

[0004]

In order to solve the above-mentioned problems, the present invention inputs video signals from a plurality of video signal sources having the same vertical synchronization into a video unit and automatically switches from a console. A timer that counts the required clock in the case of switching in a required sequence and time interval based on the data read from the storage unit, inputting to the character unit and superimposing the character corresponding to each video signal and outputting. And a microcomputer for controlling the switching of the video signal, etc., the count-up number of the timer subtracts the required number from the number of vertical synchronization signals corresponding to the switching time interval of the video signal, the vertical synchronization frequency and the timer. The signal is output from the timer when the number divided by the product of the count-up time of
(EN) An automatic video signal switching device which switches a video unit and a character unit after a required number of vertical synchronizing signals is output from a signal output of a timer.

[0005]

With the above construction, in the video signal automatic switching device according to the present invention, data such as the video signal switching order and the switching time interval are stored in the storage section. The data in the memory is read when the power of the device is turned on,
Sent to the video unit and character unit, each M
It is stored in the memory unit via the PU. When the automatic switching operation is performed on the console of the computer device, a control signal for automatic switching is sent to the video unit and the character unit based on this signal, and a plurality of video signals input to the video unit are ordered in the required order. , The signal is input to the character unit, and the characters corresponding to the respective signals are superimposed and output. The data in the storage unit is rewritten with new data input by a required operation.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an automatic video signal switching device according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of essential parts of an embodiment of an automatic video signal switching device according to the present invention. In the figure, 1 is a video unit and 2 is a character unit. A computer device 3 controls the video unit 1 and the character unit 2. Reference numeral 4 is a video signal from a plurality of video signal sources, 5 is a video signal switched in the video unit 1, and 6 is a video signal in which characters are superimposed in the character unit 2. An operation console 7 is used for inputting automatic switching designation of video signals. A discriminating unit 8 discriminates a signal for specifying automatic switching of video signals by the console 7. A storage unit 9 stores control data for the switching order and switching interval of video signals. An input unit 10 is used to input data when rewriting the data in the storage unit 9. A control unit 11 controls the video unit 1 and the character unit 2 based on the signal from the determination unit 8. An input / output unit 12 serially converts the data from the control unit 11 and outputs it to a video unit or the like, and converts the serial data from the video unit or the like into parallel data and inputs it to the control unit 11.

FIG. 2A is a block diagram of a main part of an example of the video unit 1. Reference numeral 21 in the figure is a matrix switch, for example, for switching 8 inputs to 8 outputs.
Based on the signal from the (microprocessor unit) 25, a plurality of video signals from the video signal source 4 are switched in a required order and at a required time interval, and output from a plurality of output terminals 5. Reference numeral 22 is a two-contact switch, which is used when switching to a video signal from a terminal provided for expansion input. An input / output unit 23 inputs / outputs control data from / to the input / output unit 12. Reference numeral 24 denotes a memory unit, which automatically inputs data from the storage unit 9 sent from the computer apparatus 3 when the apparatus is turned on and inputs the data from the input / output unit 23 through the MPU 25 to record the data. MP
U25 controls the matrix switch 21 and the selector 27 based on the data read from the memory section 24. A vertical sync separation circuit 26 separates the vertical sync signal (hereinafter abbreviated as VD) of each video signal output from the matrix switch 21. The selector 27 switches VD from the vertical sync separation circuit 26 based on the signal from the MPU 25, and M
Input to the external interrupt terminal of PU25.

FIG. 2B is a block diagram of an essential part of an example of the character unit 2. Reference numeral 31 in the figure denotes an on-screen driver, which superimposes a character on the video signal input from the video unit 1 through the terminal 5 based on data from a CGROM (character data for character generation read-only memory) and outputs it. To do. An input / output unit 33 inputs the control data from the input / output unit 12. Reference numeral 34 denotes a memory unit, which automatically inputs data from the storage unit 9 sent from the computer apparatus 3 when the apparatus is turned on and inputs the data from the input / output unit 33 through the MPU 36 to record the data. A vertical sync separation circuit 35 separates VD of the video signal input from the terminal 5. The MPU 36 controls the on-screen driver 31 based on the control data from the input / output unit 33.

Next, the operation of the video signal automatic switching apparatus according to the present invention will be described with reference to the time chart shown in FIG.
This device, for example, outputs video signals output from surveillance television cameras installed at a plurality of locations in an appropriate order.
It is a monitoring device that switches at appropriate intervals, superimposes a character or the like representing a signal source generated corresponding to each camera, and displays it on a single monitor or a plurality of monitors. The storage unit 9 stores data for controlling the switching order and switching time intervals of the plurality of video signal sources 4, and the number of the video signal sources is increased or decreased.
When increasing or decreasing the number of video signal outputs (monitors, etc.), changing the switching order of video signal sources, changing the output destination of the switched video signals, or changing the switching time interval, update data from the input unit 10 Is input and the data in the storage unit 9 is rewritten via the control unit 11. The data in the storage unit 9 is read out via the control unit 11 when the device is turned on, transferred to the video unit 1 and the character unit 2 via the input / output unit 12, and stored in the respective memory unit 24 and memory unit 34. To be done.

An instruction for automatic switching of monitoring images is input from the console 7. The signal from the operator console 7 is discriminated by the discriminating unit 8 via the control unit 11, and based on this discrimination, the control unit 11 via the input / output unit 12 causes the image unit 1 and the character unit 2 to pass through.
A video signal switching preparation command is sequentially sent to. Control unit 11
The switching preparation instruction from the input / output unit 23 of the video unit 1
Input to the MPU 25 and the input / output unit 33 of the character unit 2 to the MPU 36, and return response signals to the control unit 11. Based on the response from each unit, control unit 11
Sends a switching command to the video unit 1, which is the parent unit. When there are one video unit and one character unit as shown in FIG. 1, for example, the video unit 1 is a parent unit and the character unit 2 is a child unit that is cascaded to the parent unit 1.

The MPU 25 of the video unit 1 monitors the VD switched and input by the selector 27 from the vertical sync separation circuit 26 in response to this switching command, and the MPU 25 at the first VD.
The timer of 25 is reset (), and the timer reset command is sent to the character unit 2 to reset the timer of the MPU 36. Then, the MPU 25 monitors the VD from the vertical sync separation circuit 26, the second VD transfers the data read from the memory section 24 to the matrix switch 21, and the video signal at the required switching order and switching time interval. Source 4
To switch a plurality of video signals. The video signals are switched, for example, so that the same video signals are simultaneously output to all terminals 5, or different video signals are output to each terminal 5 in the same order. Alternatively, a video signal from a specific signal source may be output to a specific terminal 5, and a plurality of video signals may be sequentially switched and output to another terminal 5. After this switching, the timer of the MPU 25 or the register for counting the count-up number of the timer is cleared to start counting the count-up number.

On the other hand, the MPU 36 of the character unit 2 receives the on-screen driver in response to the timer reset command.
Stop the characters that had been superimposed on 31 until CGROM
Address output to 32 is performed, and this is finished by the second VD so that characters can be switched at the second VD. Then, the second VD from the vertical sync separation circuit 35 outputs a control signal to the on-screen driver 31, superimposes a character on the video signal from the terminal 5, and outputs it. The reason why the second VD is switched after the timer is reset is that it takes time to send the address of the CGROM 32. If the timing of the switching command does not match VD, the character generation is not completed by the next VD. This is to prevent the output of a video signal in which characters are not superimposed.
Therefore, the MPUs 24 and 36 reset the timer each time the video signal is switched and perform control such that the video signal is switched by the second VD or characters are superimposed. Then, after switching, MP as well as MPU25 of video unit 1
The U36 timer or the register that counts the count-up number of the timer is cleared and the count-up number is started.

After the second cycle, when the count-up number of the timer or the timer after clearing the register matches the number recorded in the memory unit 24 or the memory unit 34, the MPU 25 and the character unit of the video unit 1 The second MPU 36 monitors the VD from the vertical sync separation unit 26 or the vertical sync separation unit 35, respectively, and the second VD switches the video unit 1 and the character unit 2 in the same manner as the first time described above. Then, after this switching, the registers are cleared and the counting of the count-up number is started. The reason for clearing the register is to make a correction so that a slight shift in the timer between the units is integrated and a shift in the switching timing does not occur between the units.

Each of the registers subtracts 2 from the number of VDs (60 in NTSC) corresponding to a video signal switching time interval (for example, 1 second) (subtracts the waiting for two VDs described above), and outputs VDs. The frequency (about 60 Hz) and the count-up time of the timer (for example, about 2 ms) are divided by the product. When the switching time interval is lengthened, the switching can be performed in multiples of the above switching time interval. When the switching time interval is set to be n times the switching time interval, the unit switching time interval of the video signal (the above-mentioned “1
Seconds) etc. is multiplied by n, 2 is subtracted, and VD
Count the number divided by the product of the frequency and the count-up time of the timer. The count-up time of the timer is sufficiently short with respect to the video signal switching time interval. For example, if the switching time interval is 1 second,
The count-up time is 2 milliseconds. In addition, when the timer is reset after the second round, there may be a time lag between the units due to this timer reset. Therefore, when the timer count-up time is 2 milliseconds, the count-up count is 4 The number added with is counted by the register.

[0015]

As described above, according to the video signal automatic switching apparatus of the present invention, the video signals from a plurality of video signal sources, for example, surveillance cameras, are stored in the storage unit in the order and time. The characters are switched at intervals, the characters indicating the video signal source, etc. are superimposed and output, and then input to a monitor or the like. The switching order or switching time of the video signals can be changed by rewriting the data in the storage unit.
It is possible to easily respond to a difference in installation conditions or a change in installation conditions in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts of an embodiment of an automatic video signal switching device according to the present invention.

FIG. 2 is a partial block diagram of an embodiment of a video signal automatic switching device according to the present invention, in which (a) is a main part of a video unit;
(B) is the main part of the character unit.

FIG. 3 is a time chart for explaining the operation of the video signal automatic switching device according to the present invention.

[Explanation of symbols]

 1 video unit 2 character unit 3 computer device 4 video signal source (plural) 6 video signal output (plural) 7 console 8 discriminating unit 9 storage unit 10 input unit 11 control unit 12 input / output unit

Claims (7)

[Claims] 1. A sequence and time required based on data read from a storage unit by inputting video signals from a plurality of video signal sources having the same vertical synchronization to a video unit and instructing automatic switching from a console. In the case of switching at intervals, inputting to the character unit and superimposing and outputting the characters corresponding to each video signal, a timer for counting the required clock and a microcomputer for controlling the switching of the video signal, etc. are provided. , When the count-up number of the timer becomes the number obtained by subtracting the required number from the number of vertical sync signals corresponding to the video signal switching time interval and dividing by the product of the vertical sync frequency and the count-up time of the timer The signal is output from the timer, and the microcomputer outputs the signal from the timer to the video unit and the sentence after the required number of vertical synchronization signals. Automatic video signal switching device that switches the character unit. 2. The count-up number of the timer is multiplied by the number of vertical sync signals corresponding to the unit switching time interval of the video signal by n, and the required number is subtracted to obtain the vertical sync frequency and the count-up time of the timer. 2. A signal is output from a timer when the number is divided by the product, and the microcomputer switches the video unit and the character unit after the required number of vertical synchronizing signals has been output from the signal output from the timer. Automatic video signal switching device. 3. A register for counting the count-up of the timer is provided, and the count-up number of the timer counted by the register subtracts a required number from the number of vertical synchronization signals corresponding to the switching time interval of the video signal, or The number of vertical sync signals corresponding to the unit switching time interval of the video signal is multiplied by n and the required number is subtracted, and when the numbers are divided by the product of the vertical sync frequency and the count-up time of the timer, the signal from the register 2. The automatic video signal switching device according to claim 1, wherein the video signal is switched by the microcomputer after the required number of vertical synchronizing signals from the signal output of the register. 4. The video signal automatic switching device according to claim 1, wherein the timer or the register is cleared after switching the video signal. 5. An input unit for inputting a video signal switching order or a video signal switching time interval is provided, and the data of the video signal switching order or the video signal switching time interval in the storage unit is converted into data from the input unit. The video signal automatic switching device according to claim 1, claim 2, claim 3, or claim 4, which is adapted to be rewritten. 6. The video unit includes a first memory section for storing data output from the microcomputer, and a plurality of video signals from the video signal source based on the data read from the first memory section. A matrix switch for switching to a single output destination or a plurality of output destinations and a first vertical separation signal for separating a vertical synchronizing signal of each video signal from the matrix switch
A synchronization separation circuit, a selector for switching the vertical synchronization signal from the first synchronization separation circuit based on the data from the first memory section, and a timer are provided, and the timer is operated by the vertical synchronization signal input by switching the selector. The first MPU configured to reset and control switching of the matrix switch with a required count number, and to send a signal for resetting the timer to the character unit or the like. The video signal automatic switching device according to claim 4 or 5. 7. The character unit separates a second memory unit that stores data output from the microcomputer, a CGROM that stores character data, and a vertical synchronization signal of a video signal input from the video unit. The second sync separation unit and the signal from the second sync separation unit are synchronized with each other, and based on the data read from the second memory unit, the video signal input from the video unit is based on the data read from the CGROM. And an on-screen driver for superimposing characters, and a second MPU having a timer, resetting the timer by a signal of a reset instruction from the first MPU, and controlling the character superimposition of the on-screen driver by a required count number. 7. The automatic video signal switching device according to claim 6, which is configured.