JP3739983B2 - Multi-screen display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-screen display device that can display a large screen image by combining a plurality of display units to form a multi-screen, and in particular, can easily determine a failure.
[0002]
[Prior art]
In recent years, multi-screen display devices in which a plurality of display units are combined vertically and horizontally have become widespread as devices for displaying large-screen images. As each of the display units described above, a projection display device configured using a CRT or a liquid crystal is generally used, and is often used in presentations at exhibitions, concert venues, television studios, and the like.
[0003]
In such a conventional multi-screen display device, by using a digital interface, a communication cable from an external data processor is connected only to the first display unit, and the other display units are connected from the previous stage to the next stage through the interface. If information and video are transmitted to each other, there is no need to connect an external communication cable to each display unit, and a neat multi-screen display device with few cables can be configured. However, if one display unit fails, no signal is transmitted to the subsequent display units, and these subsequent display units are operatively equivalent to the failure, and the entire screen of the multi-screen display device is displayed. The failure was conspicuous.
[0004]
In addition, in a large-scale multi-screen display device such as 100 screens, in order to determine whether it is normal or faulty, it can be confirmed by changing the wiring of the digital interface except for the faulty display unit, or a system using the digital interface It was difficult to identify the faulty display unit.
[0005]
[Problems to be solved by the invention]
In such a conventional multi-screen display device, when one display unit fails, no signal is transmitted to the subsequent display units, and these subsequent display units are in an operationally equivalent state to the failure. Thus, the failure of the entire screen of the multi-screen display device was conspicuous. In addition, in a large multi-screen display device, it is difficult to identify a defective display unit.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-screen display device that eliminates the above-mentioned problems and makes the failure inconspicuous over the entire screen when the display unit fails, and allows the failed display unit to be easily identified. And
[0007]
[Means for Solving the Problems]
The multi-screen display device according to claim 1 of the present invention is a multi-screen display device that forms a single large screen by combining a plurality of display units, and the multi-screen display device includes the plurality of display units. And a plurality of display units connected in series via a communication cable, and a connection means that enables transmission and reception of signals from the preceding unit to the succeeding unit, and provided for each of the display units. Power supply circuit that supplies power supply voltage and each display unit, which controls each of its own display units and performs information transfer processing with other display units. If an error signal is detected, an error signal is sent to the display unit at the rear stage and the error signal is sent from the front stage unit. When receiving a is characterized by comprising a control circuit for switching the screen state of its own display unit by transmitting the error signal to the subsequent display unit.
[0008]
According to the present invention, only the failed display unit is stopped by such a configuration, and the display unit subsequent to the failed display unit only switches the screen state. In addition to making it inconspicuous, the failed display unit can be easily identified.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 is a block diagram showing an internal configuration of each display unit constituting the multi-screen display device, and FIG. 2 is an overall block diagram of the multi-screen display device, particularly showing a connection relation of each display unit. is there.
[0011]
First, the overall configuration of the present invention will be described with reference to FIG.
[0012]
2, the multi-screen display device 10 has a plurality (9 in this embodiment) of display units 1, 2, 3,... In this case, display units 1, 2, and 3 are arranged in order from the left in the first column, display units 4, 5, and 6 are arranged in sequence from the right in the second column, and left in the third column. The display units 7, 8, and 9 are arranged in order, and one large screen is formed by nine screens.
[0013]
In addition, the display units 1 to 9 are provided with digital interfaces 11, 12, 13,... 19 for electrically connecting the display units, and the communication cables 21, 22, 23... 28 are connected. Each of the digital interfaces 11 to 19 has a first terminal (IN) and a second terminal (OUT). The second terminal (OUT) of the previous display unit and the second display unit of the next display unit. 1 terminal (IN) is coupled by communication cables 21-28. (Hereinafter, the first terminal will be called the IN terminal and the second terminal will be called the OUT terminal.)
In the embodiment of the present invention, the first display unit 1 constitutes a master unit, and controls the other display units 2 to 9 connected thereafter. For this reason, the digital interface 11 of the first display unit 1 has an IN terminal connected to an external data processor via the cable 20. A control signal such as a digital video signal from an external data processor and the number of each unit (number indicating the number of units) is supplied to the IN terminal of the first display unit 1. The digital interface 11 has an OUT terminal connected to the IN terminal of the second stage digital interface 12 by a cable 21.
[0014]
Thereafter, the cables 22 to 28 are connected so as to connect the OUT terminal of the digital interface located in the previous stage and the IN terminal of the next digital interface. Note that nothing is connected to the OUT terminal of the digital interface 19 of the display unit 9 in the final stage. Thus, the display units 1 to 9 are connected in series.
[0015]
Next, the internal configuration of each display unit will be described with reference to FIG.
[0016]
FIG. 1 shows the display unit 1 of the first stage (master) and the display unit 2 of the second stage as representatives, but the other display units 3 to 9 have the same configuration as the display unit 2, and the first stage The display unit 1 is controlled.
[0017]
The display unit 1 includes a control circuit 31, a digital multimedia engine (hereinafter referred to as a DME engine) 32, a fan control circuit 33, a power supply circuit 34, a video circuit 35, and a digital circuit 36. The digital interface 11 is further provided. The OUT terminal of the digital interface 11 is connected to the IN terminal of the digital interface 12 via the communication cable 21. The communication cables 21, 22,... Can perform bi-directional communication, for example, control by RS232C protocol. A signal can be input and output to the OUT terminal or the IN terminal of the digital interface. The display unit 1 is also supplied with analog video signals such as video input and RGB input.
[0018]
The control circuit 31 is composed of a microcomputer, is supplied with a digital video signal and a control signal from the IN terminal of the digital interface 11, monitors the supplied control signal, controls its own display unit 1, and performs other displays. Control units 2-9.
[0019]
The control circuit 31 controls the DME engine 32, the fan control circuit 33, the power supply circuit 34, the video circuit 35, and the digital circuit 36. The DME engine 32 performs scanning line conversion and the like on various input video signals (the above-mentioned digital video signal and analog video signal) based on the control of the control circuit 31 to switch the screen display contents. The fan control circuit 33 performs fan motor drive control for cooling the inside of the display unit 1 based on the control of the control circuit 31. Based on the control of the control circuit 31, the power supply circuit 34 turns on / off the supply of power to the video display means and each circuit in the display unit 1. Under the control of the control circuit 31, the video circuit 35 performs switching selection of video signals to be displayed on the screen among various input video signals. The digital circuit 36 supplies the built-in test pattern read control circuit 31 based on the control of the control circuit 31.
[0020]
In addition, the control circuit 31 transmits a digital video signal and a control signal from the IN terminal of the digital interface 11 from the OUT terminal to the display unit at the subsequent stage. Further, when the control circuit 31 detects a failure of its own display unit, the control circuit 31 transmits an error signal (for example, a voltage of 5 V) from the OUT terminal of the digital interface 11 to the subsequent display unit and stops the power supply circuit 34. Put it in a state.
[0021]
The display units 2, 3,... 9 are configured in the same manner as the display unit 1. Taking the display unit 2 as an example, the display unit 2 includes a control circuit 41, a DME engine 42, a fan control circuit 43, a power supply circuit 44, a video circuit 45, and a digital circuit 46, and further includes the digital circuit 46. An interface 12 is provided. The IN terminal of the digital interface 12 is connected to the OUT terminal of the digital interface 11 via the communication cable 21, and the OUT terminal of the digital interface 12 is connected to the next digital interface 13 (see FIG. 2) via the communication cable 22. Connected to IN terminal.
[0022]
When receiving an error signal from the preceding unit, the control circuit 41 transmits this error signal to the subsequent display unit and switches the screen state of the video display means.
[0023]
These circuits 41, 42, 43, 44, 45, 46 are the same as the circuits 31, 32, 33, 34, 35, 36 of the display unit 1, and each display unit can be used alone. ing.
[0024]
Next, the operation of the embodiment of the multi-screen display device of the present invention having such a configuration will be described with reference to the flowchart of FIG.
[0025]
First, in the initial setting (step S1), when each display unit is used as a multi-screen display device, the power of each display unit 1 to 9 is turned on. Thereby, the microcomputers of the control circuits 31, 41.
[0026]
As a result, the main loop is entered, and the control circuit 31 (41) sends and receives signals to the DME engine 32 (42), the fan control circuit 33 (43), and the power supply circuit 34 (44) in steps S2, S3, and S4. And periodically check whether the DME engine operation, the fan operation, and the power supply circuit operation are normal.
[0027]
If an abnormality is detected in at least one of steps S2, S3, and S4, the process proceeds to the display unit failure state processing routine in steps S5 and S6, and the control circuit 31 (41) controls the digital interface in step S5. An error signal (H = 5V) is output to the OUT side of the power supply, and in step S6, the power supply other than the power supply of the microcomputer (display unit power supply) is turned off to enter the standby state, and the process proceeds to step S9.
[0028]
When all of the DME engine 42, the fan control circuit 43, and the power supply circuit 44 are normal in steps S2, S3, and S4, the control circuit 41 is supplied from the display unit connected in the previous stage in step S7. When an error signal is checked and an error signal is detected here (when a failure occurs in a display unit in front of its own display unit), the process of step S8 is performed and no error signal is detected. In this case, the process proceeds to step S9.
[0029]
In step S8, the control circuit 41 controls the digital circuit 46 to freeze the screen, controls the digital circuit 46 to display the built-in test pattern, and controls the video circuit 45 to control the IN terminal of the digital interface 12. Any one of the processes for switching to a video signal other than (such as an analog video signal) is performed, and the process proceeds to step S9.
[0030]
In step S9, the control circuit 41 performs other normal processing and returns to step S2.
[0031]
By such processing, in the present embodiment, only the failed display unit is stopped in step S6, and the display unit connected upstream of the failed display unit performs normal display, and the display unit connected to the downstream of the failed display unit. The connected display unit performs a process of switching the screen state in step S8.
[0032]
Thereby, in this embodiment, when a display unit fails, the failure is not noticeable on the entire screen, the failed display unit can be easily identified, and the failed display unit can be replaced quickly. Thereby, for example, even when the display unit breaks down during the presentation, it is possible to avoid a situation in which the screen does not become dark and the entire system cannot be used.
[0033]
In the embodiment of FIG. 2, the case where nine display units are used has been described. However, the number of display units may be four, twelve, sixteen, etc., and is limited to the embodiment. It is not a thing.
[0034]
【The invention's effect】
In the present invention, when a display unit fails, the failure is not noticeable on the entire screen, the failed display unit can be easily identified, and the failed display unit can be replaced quickly.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a display unit constituting a multi-screen display device of the present invention;
FIG. 2 is a block diagram of a multi-screen display device using a plurality of display units of FIG.
FIG. 3 is a flowchart for explaining the operation of the embodiment of the invention shown in FIG. 1;
[Explanation of symbols]
1-9 Display unit 11-19 Digital interface 21-28 Communication cable 31, 41 Control circuit 32, 42 DME engine 33, 43 Fan control circuit 34, 44 Power supply circuit 35, 45 Video circuit 36, 46 Digital circuit

Claims (4)

A multi-screen display device that constitutes one large screen by combining a plurality of display units, the multi-screen display device comprising:
The plurality of display units;
The plurality of display units are connected in series via a communication cable, and connection means that enables transmission and reception of signals from the preceding unit to the succeeding unit;
A power supply circuit that is provided in each display unit and supplies a power supply voltage for operation to each display unit;
Each of the display units is provided with various controls of its own display unit, and performs information exchange processing with other display units. When a failure of its own display unit is detected, an error signal is displayed. Is transmitted to the subsequent display unit, and when an error signal is received from the previous unit, a control circuit that transmits this error signal to the subsequent display unit and switches the screen state of its own display unit;
A multi-screen display device comprising: 2. The multi-screen display device according to claim 1, wherein when the error signal is received from the preceding unit, the control means switches the screen state by freezing the screen. 2. The multi-screen display device according to claim 1, wherein when the error signal is received from the preceding unit, the control means switches the screen state by switching the input of the video signal to be displayed on the screen. 2. The multi-screen display device according to claim 1, wherein when the error signal is received from the preceding unit, the control means switches the screen state by displaying a built-in test pattern on the screen.

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