JPH04234291A - Electronic equipment - Google Patents

Abstract

PURPOSE:To operate equipment satisfactorily when a main program is changed by transferring a proper identification code stored in a ROM to a RAM when unmatch between the code of the ROM and an identification code stored in the RAM is obtained. CONSTITUTION:When a power source is applied to a video signal switching device, a CPU 1 reads the identification code stored in the ROM 7a of a memory device and that stored in the RAM 7b, and judges whether or not match between them can be obtained. When the match is obtained between them, a switching operation is performed based on data stored in the ROM 7a and the RAM 7b as it is. Also, when unmatch is obtained between both identification codes, the data stored in the RAM 7b is erased once, and after that, the identification code in the ROM 7b is transferred again to the RAM 7b, then, it is stored. Thereby, it is possible to modify the equipment by exchanging the ROM in which the main program is stored.

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] Incidentally, not only this video signal switching device but also many types of electronic equipment have operations controlled by a built-in microcomputer. In this case, various operations are performed according to a main program stored in a memory connected to the microcomputer. On the other hand, in such electronic devices, various improvements are often made to the products as appropriate. In the case of equipment whose operation is controlled by a microcomputer, this improvement may be accomplished by changing only the main program.

However, if only the main program is changed, there is a risk that other circuits within the device will be instructed to operate in a manner that is inconsistent with the set operation. There was no guarantee that it would happen.

[0007] An object of the present invention is to enable equipment to operate satisfactorily when the main program is changed and improved.

[0008]

[Means for Solving the Problems] As shown in FIG. 1, for example, the present invention provides that a read-only memory (7a) in which a main program is written is replaceable, and that In an electronic device equipped with a writable memory (7b), a unique identification code is stored in the read-only memory (7a), and this identification code is used as an identification code stored in the writable memory (7b). When the code does not match, the memory that can be written to (7b
) is erased, and the identification code stored in the read-only memory (7a) is transferred to the writable memory (7b).

[0009]

[Operation] By doing this, when the main program of an electronic device is changed by replacing the read-only memory, various data stored in the writable memory are used to operate according to the previous main program. The data stored in this writable memory will not interfere when the main program is changed.

0010

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 a 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. That is, a ROM 7a, which will be described later as a memory connected to the central control device 1, stores in advance a program for executing switching, etc., and when various commands such as key operations are supplied, switching is performed based on this program. Switch 2 is used to perform switching, etc. In addition, 11 in the figure
, 12, 13...19 indicate first to ninth video input terminals, and each of the input terminals 11, 12, 13...19 is supplied with video signals captured and output by a surveillance video camera, etc. This is the terminal for In this case, a maximum of eight video cameras are connected to the first to eighth input terminals 11 to 18, and the ninth
Other video signal switching devices, television tuners, etc. are connected to the input terminal 19 of.

[0012] The video signals obtained from the video cameras and 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 switching is performed under the control of each input terminal 11 to 19
The switching is performed within the vertical blanking period of the video signal obtained. That is, the central control device 1
When it becomes necessary to switch input video, a switching signal is output after waiting for the supplied video signal to enter a vertical blanking period. 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.

Further, 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 the 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 can instruct the video camera to be selected in the automatic switching mode, and lights up the switch numbered corresponding to the selected video camera under the control of the central control device 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. In this case, the read-only ROM 7a stores a main program necessary for the central controller 1 to control various operations.

In this example, the installed ROM
A unique identification code is stored in 7a. This identification code is assigned based on the creation date and time of the program stored in the ROM 7a. A storage area for this identification code is also set in the RAM 7b, and the identification code in the ROM 7a is transferred to the RAM 7b and stored at a predetermined time. That is, as shown in the flowchart of FIG. 2, when the power of this video signal switching device is turned on, the identification code stored in the ROM 7a and the RAM 7b are
The central controller 1 reads out the identification code stored in the
Determine whether or not both identification codes match. When both identification codes match, ROM7a and R
The switching operation is executed based on the data stored in AM7b. If the two identification codes do not match, the data stored in RAM 7b is erased and a new R
The identification code of OM7a is transferred to RAM7b and stored.

In this way, ROM7a and RAM7b
By always making the identification codes match, the data stored in the RAM 7b is always erased when the ROM 7a is replaced. Therefore, the data stored in RAM 7b when operating with the program stored in the previously installed ROM 7a will not remain when the ROM 7a is replaced, and the data stored in the RAM 7b will not remain when the program is operated with the program stored in the new ROM 7a. When it is set, it is always in the initial state. Further, even when the backup power supply voltage drops and the data stored in the RAM 7b is destroyed, the data stored in the RAM 7b is completely erased and the identification code is stored again.

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.

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.

According to the video signal switching device of this example configured as described above, video signals supplied from a plurality of monitoring video cameras, etc. to each of the video input terminals 11 to 19 are switched according to the set mode. By switching under the control of the central control device 1, the video signal is output from the output terminal 4, and the video signal obtained at the output terminal 4 is supplied to a monitor receiver or VTR.
Multiple locations can be monitored efficiently. in this case,
When the ROM 7a constituting the memory device 7 is replaced, the data stored in the RAM 7b is always erased, so when the main program is changed to add new functions to the video signal switching device, etc. to RAM
The memory data in 7b is erased and becomes the initial state, and the RAM
The data stored in the ROM 7b does not interfere with the execution of a new program, and there is no need for the operator who replaced the ROM 7a to manually perform a reset operation. Therefore, this video signal switching device can be easily improved. This R
Examples of ways to improve the video signal switching device by changing the main program by replacing the OM7a include adding new functions that can be realized by the timer operation described above, or linking multiple video signal switching devices. Various methods can be considered, such as making it possible to operate the system, and improvements can be made as appropriate according to the user's requests. In addition, the backup power supply voltage decreases and the RAM7
Similarly, when the memory data of b is destroyed, the RA
Since the data stored in the M7b is completely erased and the identification code is stored again, by performing this operation it is also possible to detect an abnormality in the backup power supply.

In the above embodiment, a monitoring video camera is connected to each video input terminal, but other video signal sources may be connected to this video input terminal. 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 in which various operations are controlled by a microcomputer.

[0028]

[Effects of the Invention] According to the present invention, when the main program of an electronic device is changed by replacing the read-only memory, various data stored in the writable memory are automatically erased and returned to the initial state. This will cause the program to perform operations that correspond to the new program. Therefore, it is possible to easily improve the device by replacing the read-only memory in which the main program is stored.

[Brief explanation of the drawing]

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

FIG. 2 is a flowchart diagram for explaining one embodiment of the present invention.

[Explanation of symbols]

1 Central control device 2 Selector 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 terminal

Claims (1)

[Claims] Claim 1. An electronic device in which a read-only memory into which a main program is written is replaceable and also includes a writable memory separate from the read-only memory, wherein a read-only memory unique to the read-only memory is provided. storing an identification code, and when the identification code does not match the identification code stored in the writable memory, erasing the data stored in the writable memory and storing it in the read-only memory; An electronic device configured to transfer the identified identification code to the above-mentioned writable memory.