JPH04233492A - Electronic apparatus - Google Patents

Abstract

PURPOSE:To facilitate the setting of time when a plurality of electronic apparatuses each equipped with a timepiece are connected. CONSTITUTION:One specified electronic apparatus 100 is operated as master while other electronic apparatuses 200, 300 and 400 are operated as slave and time is set with the master 100. Here, time information set is transmitted to the slave sides 200, 300 and 400 to set the time of timepieces on the slave sides 200, 300 and 400 same as that of the timepiece of the master 100.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment, and more particularly to electronic equipment suitable for application to a switching device for a surveillance video camera.

0002

[Prior Art] Conventionally, when video cameras for surveillance are installed at multiple locations, it is conceivable to provide as many monitor receivers as there are video cameras, and have each monitor receiver receive the image of each monitoring location. As the number of places to be monitored increases, the number of monitor receivers as well as video cameras increases, resulting in the inconvenience that the configuration of the monitoring system becomes complicated. In addition, when recording video signals captured by a surveillance video camera on a video tape recorder (VTR) instead of a monitor receiver, similarly, as the number of places to be monitored increases, the number of VTRs increases. This has the disadvantage of complicating the configuration of the monitoring system.

For this reason, a video signal switching device for surveillance cameras has been put into practical use that switches video signals supplied from surveillance video cameras installed at multiple locations and selectively supplies them to one monitor receiver. .

[0004] This video signal switching device for surveillance cameras is one in which video signals supplied from, for example, a plurality of connected surveillance video cameras are sequentially switched at predetermined intervals and supplied to a single monitor receiver. It is. By using this video signal switching device, supervisors can monitor all locations simply by viewing the video displayed on one monitor receiver, making it easy to configure the surveillance system. At the same time, the supervisor can easily perform monitoring. Furthermore, even when a video signal obtained by a surveillance video camera is recorded on a VTR, by using this video signal switching device, the video signal can be efficiently recorded on a single VTR.

[0005]

[Problems to be Solved by the Invention] However, with this type of video signal switching device for surveillance cameras, there is a limit to the number of video cameras that can be connected with one switching device.For example, one switching device can connect eight video cameras. However, if more than eight video cameras are to be used for monitoring, it is necessary to use two or more switching devices. In this case, there are switching devices that can display the current time, but if multiple switching devices that can display this time are connected, the display time of each switching device must be set to the same time. However, setting the same time for each switching device is time consuming and inconvenient. That is, since the time is set for each device, for example, it is necessary to set the time of one switching device and then set the time of the second and third devices to match the set time. There is,
It was time consuming and difficult to set the exact same time to the second.

SUMMARY OF THE INVENTION An object of the present invention is to easily set the time of a plurality of electronic devices such as video signal switching devices with a simple configuration.

[0007]

[Means for Solving the Problems] The present invention provides an electronic device with a built-in clock device, in which when a plurality of electronic devices are connected, one predetermined electronic device (100) is used as a master, and other electronic devices (100) are connected as a master. 200, 300...) as a slave, and when the master electronic device (100) sets the time of the clock device, the set time information is transmitted to the slave electronic device (200, 300...). The time of the clock device provided in the slave electronic device (200, 300, . . . ) is set to the same time as the clock device of the master electronic device (100).

[0008]

[Operation] By doing this, when you set the current time on the clock when multiple electronic devices are connected, you only need to set the time on the master electronic device, and the slave electronic device will automatically However, the time is set and the time on the built-in clock devices of all connected electronic devices becomes the same.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In this example, the present invention is applied to a switching device for a surveillance video camera.

FIG. 1 is a diagram showing the overall configuration of the video signal switching device of this example. This video signal switching device is used for switching the output video of a surveillance video camera, and 1 in the figure is the video signal switching device. A central control unit (CPU) having a microcomputer configuration that controls each circuit of the central control unit 1 is shown.
Under the control of , the changeover switch 2 for video signal changeover is performed. In addition, 11, 12, 13...19 in the figure are the first
- Indicates a ninth video input terminal, and each input terminal 11
, 12, 13, . . . 19 are terminals to which video signals captured and output by a monitoring video camera are supplied. In this case, a maximum of eight video cameras are connected to the first to eighth input terminals 11 to 18, and other video signal switching devices, television tuners, etc. are connected to the ninth input terminal 19.

[0011] Then, video signals obtained from each video camera or the like to the video input terminals 11, 12, 13, . The video signal from the camera (or other video signal switching device, etc.) is output. In this case, the switching based on the control of the central controller 1 can be performed in an automatic switching mode in which the switching is automatically performed sequentially at a predetermined cycle, a manual switching mode in which switching is performed in response to manual operation, or by inputting an alarm signal, etc., which will be described later. It has a forced switching mode.

In this case, in this example, the central control device 1
When the switching is performed under the control of the input terminals 11 to 19, the switching is performed within the vertical blanking period of the video signals obtained at the input terminals 11 to 19. That is, when it becomes necessary to switch the input video, the central control device 1 waits until the supplied video signal enters the vertical blanking period, and then outputs the switching signal. Note that the vertical blanking periods of the video signals obtained at each of the input terminals 11 to 19 are aligned with the same timing, as will be described later.

The video signal selected by the changeover switch 2 is supplied to an output terminal 4 via a superimpose circuit 3. By connecting a monitor receiver or a VTR to this output terminal 4, it is possible to display an image of the monitored place on the monitor receiver or to display an image of the monitored place on the VTR.

Reference numeral 5 in the figure indicates a character generation circuit, and this character generation circuit 5 is equipped with a memory (not shown) for storing character data such as characters and symbols, and the stored character data is transmitted to a central control unit. 1 and supplies it to the superimpose circuit 3. Then, the character data supplied to the superimpose circuit 3 is superimposed on the video signal supplied from the changeover switch 2, and the video signal with this character superimposed is output to the output terminal 4.
supply to. This superimposed character data includes numbers indicating the selected camera number, date and time, characters indicating the setting status of various operation modes, and the like. That is, when switching the input video signal normally, characters indicating the selected camera number, date and time are superimposed on the output video signal, and characters are displayed on the corner of the screen of the monitor receiver connected to the switching device. Display the selected camera number and current date and time. Furthermore, when various operating modes are being set, a character indicating the setting status of the mode being set is superimposed, and the setting status is displayed on the screen of the monitor receiver connected to the switching device.

Further, in the figure, 20 indicates an input selection switch, and 30 indicates an active switch. Each of the switches 20 and 30 is composed of eight switches, numbered 1 to 8, corresponding to the eight video cameras connected to the video input terminals 11 to 18, and is configured on the front panel of this video signal switching device. The control unit 1 is arranged so that operation commands for the respective switches are supplied to the central control unit 1. In this case, each of the switches 20 and 30 can be individually turned on under the control of the central control device 1.

The input selection switch 20 can specify the video camera (input terminal) selected by the changeover switch 2, and can also specify the currently selected video by the above-mentioned lighting function under the control of the central control device 1. Turn on the switch number corresponding to the camera. Further, the active switch 30 is capable of instructing a video camera to be selected in an automatic switching mode to be described later, and lights up a switch numbered corresponding to the selected video camera under the control of the central controller 1.

Further, reference numeral 6 in the figure indicates a setting switch, and this setting switch 6 is composed of a plurality of keys, etc., and the operation command of each key is supplied to the central control unit 1. There are some that are arranged on the front panel together with 30, and others that are composed of dip switches and the like and are arranged on the back. In this case, various modes controlled by the central controller 1 can be set by operating each key. When making these settings, the settings can be confirmed by displaying them on the screen of a monitor receiver connected to the video signal switching device. That is, when setting various modes, etc., the character data from the character generation circuit 5 is superimposed in the superimpose circuit 3, so that characters and numbers indicating the setting state etc. are added to the video signal output from the output terminal 4. Contains information such as.

The central control unit 1 also includes a memory device 7.
is connected. This memory device 7 is composed of a ROM 7a from which only pre-stored data is read, and a RAM 7b from which the stored data can be rewritten.The ROM 7a is replaceable, and the RAM 7b is used as a backup to prevent loss of stored data. A power source (not shown) is provided.

Furthermore, a clock device 8 is connected to the central control device 1, and current time data counted by the clock device 8 is supplied to the central control device 1 and the memory device 7. In this case, based on the current time data supplied to the central controller 1, the superimpose circuit 3 superimposes numerical character data indicating the date and time on the output video signal. Also, when executing a so-called timer operation that changes the operating state (switching state) depending on time, the central controller 1 controls the predetermined timer operation based on the current time data supplied to the central controller 1. will be held. Furthermore, the current time data supplied to the memory device 7 is
The RAM 7b is configured to be able to store information according to instructions from the central control device 1. That is, some data (
For example, when storing data related to the supply of an alarm signal (to be described later), it is possible to also store data on the time at which this data was stored.

This clock device 8 is configured so that the current time can be set by operating a predetermined setting switch 6 arranged on the front panel. That is, by operating a predetermined setting switch 6 arranged on the front panel, the operating mode of this video signal switching device is set to time setting mode, and the set time is displayed on the screen of a monitor receiver connected to the video signal switching device. After that, the operator adjusts the time to an accurate time by operating a predetermined setting switch 6 while viewing the display on this screen.

In this example, when this time setting work is performed and this video signal switching device is operating as a master, which will be described later, the central control device 1 will be able to communicate with other video signal switching devices, which will be described later. Bus line 1a, 1 for connection
The time setting information is transmitted to all slaves via the time setting information. That is, data to be corrected is transmitted to all slaves at the time set as a command.

Furthermore, when this video signal switching device operates as a slave (described later), when time setting information is transmitted from another device to the central control device 1, the clock is set at the time indicated by this information. The current time of the device 8 is adjusted.

In the figure, 41, 42, 43...48 indicate first to eighth alarm input terminals, and these alarm input terminals 41 to 48 are connected to the first to eighth video input terminals 11 to 48.
It is compatible with 8 video cameras connected to 18, and an alarm signal is supplied from a sensor (infrared sensor, etc.) installed at the monitoring location of each video camera.
Alarm signals obtained at the input terminals 41 to 48 are supplied to the central control device 1. When this alarm signal is supplied to the central control device 1, the changeover switch 2 selects and outputs the video signal from the video camera corresponding to the number of the supplied terminal, and also outputs the video signal from the video camera corresponding to the terminal number supplied with the alarm signal. The number and time data are stored in the RAM 7b. Further, an alarm circuit 9 is connected to the central control device 1, and this alarm circuit 9 is composed of a speaker and a warning lamp, and depending on the set operation mode, when an alarm signal is supplied, a warning sound is emitted from the speaker. The output is output and the warning lamp flashes. A mode in which the warning sound is output and the warning lamp flashes for a preset time (10 seconds, 30 seconds, 1 minute, etc.) and a mode in which it continues until the alarm is canceled are provided.

The video signal switching device of this example also has a timer function. That is, by setting the time and various setting conditions by operating the setting switch 6 and storing the set contents in the RAM 7b, when the time counted by the clock device 8 reaches the set time, the central control device 1 It operates according to the settings set by the control. For example, this timer function allows you to change the location to be monitored during the day and at night.

Furthermore, the central control device 1 of this embodiment has control data bus lines 1a and 1b for communicating control data with other video signal switching devices and computer devices. Control data is communicated with the device connected to the connection terminal 1b.

Now, to explain the case where a plurality of video signal switching devices are connected using these bus lines 1a and 1b, using these bus lines 1a and 1b,
The respective video signal switching devices are connected in cascade as shown in FIG. That is, in FIG. 2, 100, 200, 300,
Reference numeral 400 indicates first, second, third, and fourth video signal switching devices, and these four video signal switching devices 100 to 400 have the configuration shown in FIG. 1 and are the same.

Then, by operating a predetermined key (or a switch such as a dip switch) constituting the setting switch 6 of the first video signal switching device 100, the first video signal switching device 100 is set as the master switching device. Set.

[0028] Then, the video signal switching devices 100, 200
, 300 are connected to the connection terminals of the bus lines 1b of the video signal switching devices 200, 300, and 400. And each video signal switching device 1
Eight video cameras 101-108, 201-208 are connected to the first to eighth video input terminals 11-18 of 00-400.
, 301-308, 401-408, total 32
Connect a video camera. In this case, each of the video cameras 101 to 408 is supplied with a synchronization signal from the synchronization signal generator 52, and this synchronization signal causes the video cameras 101 to 408 to capture images at the same timing. Make the synchronization signals have the same timing. Note that this synchronizing signal generator 52 also includes a power supply circuit, and the synchronizing signal generator 52 also supplies the power required by each of the video cameras 101 to 408.

The video signals obtained at the output terminals 4 of the first, second, third, and fourth video signal switching devices 100, 200, 300, and 400 are transferred to monitor receivers 51a and 51b.
, 51c, 51d. Or monitor receiver 5
A VTR (not shown) is connected in place of 1a to 51d.

Note that the example shown in FIG. 2 shows the maximum number of video cameras connected (32 cameras); in reality, the number of video cameras connected is 32 or less depending on the monitoring location, etc. Decide on the number of cameras.

When a plurality of video signal switching devices 100 to 400 are connected in this manner, by operating the setting switch 6 described above, the first video signal switching device 100 connected to the monitor receiver 51a is switched to the master video signal. The other video signal switching devices 200 to 400 are the master video signal switching device 1 via the bus lines 1a and 1b.
When a command is sent from 00, it automatically operates as a slave video signal switching device. That is, the central control device 1 of each video signal switching device is set to operate as a slave video signal switching device when a command related to switching, etc. is transmitted from another device via the bus line 1a or 1b. be. When the master and slave are set in this manner, various operations of the slave video signal switching devices 200 to 400 can be controlled by the central control device 1 of the master video signal switching device 100. That is, all the video signal switching devices 100 are controlled by the central control device 1 of the master video signal switching device 100.
The switching of video signals at 400 to 400 can be performed in conjunction with each other. By switching in conjunction with each other in this way, for example, when operating in an automatic switching mode in which images from each video camera are automatically switched sequentially at predetermined intervals, all monitor receivers 51a to 51
The video switching timings in d will now match.

Furthermore, when the time of the clock device 8 is set in the master video signal switching device 100, the bus line 1 is transmitted from the central controller 1 of the master video signal switching device 100.
Video signal switching device 2 of all slaves via a and 1b
This time setting information is transmitted as a command to 00, 300, and 400, and the video signal switching device 200 of each slave
, 300, and 400 are also configured to set the same time. That is, as shown in the flowchart of FIG. 4, when the predetermined setting switch 6 of the master video signal switching device 100 is operated to set the current time, the central control device 1 of the video signal switching device 100 The time of the clock device 8 of the video signal switching device 100 is set to a predetermined time under control based on the operation of the setting switch 6. At this time, all the slave video signal switching devices 200 and 300 are simultaneously connected via the bus lines 1a and 1b.
, 400 also transmits data regarding the set time as a command. When each slave video signal switching device 200 to 400 side receives this command, the clock device 8 is set to the time indicated by the command under the control of the respective central control device 1. The times set for each in this way are displayed on the screens of the monitor receivers 51a to 51d connected to the respective video signal switching devices 100 to 400, for example, to confirm that the same time has been set for all. can be confirmed.

Therefore, when the connections are made as shown in FIG. 2, the time setting is only required once by operating the setting switch 6 of the master video signal switching device 100, and from then on all the video signal switching devices 100 to 400 are connected in the same manner. It will have time data of . In addition, by setting this time at a predetermined period (for example, once every few days), each video signal switching device 100 to
The error in the time counted by the clock device 8 of 400 is corrected.

Here, this master video signal switching device 1
00 and the slave video signal switching devices 200 to 400 via the bus lines 1a and 1b. Communication between the video signal switching devices is as shown in FIG. Master video signal switching device 100 within one vertical period (1V) corresponding to one field period of the video signals supplied from 101 to 408.
A period a in which a command is transmitted from the second video signal switching device 200 to the second video signal switching device 200, a period b in which a response is sent from the second video signal switching device 200 to the master video signal switching device 100, and a period b in which a command is transmitted from the second video signal switching device 200 to the master video signal switching device 100. A period c during which a command is transmitted from the signal switching device 100 to the third video signal switching device 300, and a period d during which a response is sent from the third video signal switching device 300 to the master video signal switching device 100. ,
a period e during which commands are transmitted from the master video signal switching device 100 to the fourth video signal switching device 400;
A period f is set during which a response is made from the fourth video signal switching device 400 to the master video signal switching device 100. By communicating in this way between the master video signal switching device 100 and each of the slave video signal switching devices 200 to 400, mutual communication is performed between the master and all slaves within one vertical period. be exposed. Therefore, the transmission of commands from the master video signal switching device 100 to each slave video signal switching device 200 to 400 is completed within one vertical period. If there are responses b, d, and f to the command transmission in all periods as described above, it is determined that three slaves are connected on the master video signal switching device 100 side. Note that the command transmissions or responses a to f in each period include address data of the destination.

As described above, according to the video signal switching device of this example, a plurality of video signal switching devices can be operated in conjunction with each other. In this case, by simply setting the current time on one video signal switching device, the time set on the other three video signal switching devices will be the same; There is no need to set the current time to the current time, and control such as accurate switching can be performed using the same time.

In the above embodiment, a video camera for monitoring is connected to all the video input terminals 11 to 19, but other video signal sources may be connected to the video input terminals. Further, in the above-mentioned embodiment, the switching device is used for a surveillance video camera, but it goes without saying that the present invention can be similarly applied to various electronic devices that need to be linked with a clock device.

[0037]

According to the present invention, when a plurality of electronic devices each having a clock device are connected, it is only necessary to set the time using one predetermined electronic device. The clock devices of all electronic devices count the same time, allowing for accurate control in terms of time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a connection diagram showing a usage state of an embodiment of the present invention.

FIG. 3 is a timing diagram for explaining one embodiment of the present invention.

FIG. 4 is a flowchart diagram for explaining one embodiment of the present invention.

[Explanation of symbols]

1 Central control device 2 Changeover switch 3 Superimpose circuit 4 Output terminal 5 Character generation circuit 6 Setting switch 7 Memory device 7a ROM 7b RAM 8 Clock device 9 Alarm circuit 11-19 Video input terminal 20 Input selection switch 30 Active switch 41- 48 Alarm input terminals 51a-51b Monitor receiver 52 Synchronous generator 100, 200, 300, 400 Video signal switching device 101-108, 201-208, 301-308, 4
01-408 Video camera

Claims (1)

[Claims] Claim 1: In an electronic device with a built-in clock device, when a plurality of electronic devices are connected, one predetermined electronic device is operated as a master, the other electronic devices are operated as slaves, and the electronic device of the master is operated as a master. When the time of the clock device is set in the device, the set time information is transmitted to the slave electronic device, and the time of the clock device of the slave electronic device is transmitted to the clock device of the master electronic device. electronic devices that are set to the same time as the