Road information display device, control device, and road information display system

Abstract

To provide a road information display device, a control device and a road information display system for displaying road information for reducing standby power when no display is performed to a road user.SOLUTION: In a road information display system 1, a road information display device 100 is equipped with: a display unit 20; a switching unit 30; and a control device 10. The display unit comprises: a power supply for control 21 which drives a control circuit 25 for controlling a drive circuit 23 for displaying road information on a display 24 having a light emitting device 241; and a power supply for display 22 which outputs power to the light emitting device. The switching unit connects or disconnects an external power supply and the display unit. The control device comprises a first signal generation unit which makes the switching unit 30 into a first state, starts the power supply for display while starting the power supply for control, and generates a signal for displaying the display object when an external instruction signal for displaying the display object on the display is received, and makes the switching unit 30 into a second state when the external instruction signal is not received.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to, for example, a road information display device, a control device, and a road information display system that display road information for road users. [Background Art]

[0002] For example, Patent Document 1 discloses a display device including: a first display unit that performs display to call attention of road users; a second display unit that displays sign information indicating warning or regulation; a third display unit that displays character information such as guidance or instructions; a display control unit that controls each display mode and the content of display information in each of the first to third display units (display units) according to instruction content input from an external display content instruction unit; and a power supply unit that supplies a predetermined power supply voltage to the display unit and the display control unit. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 3220379 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] However, in the case of Patent Document 1, there is a problem that power is supplied to the display device and power is consumed even when it is not necessary to call attention of road users.

[0005] In view of the above circumstances, an object of the present invention is to provide an information display device, a control device, and a road information display system that can reduce power consumption when no display is provided to road users and can shorten the time taken until road information is displayed. [Means for Solving the Problems]

[0006] To achieve the above objective, a road information display device according to one embodiment of the present invention comprises a display unit, a switching unit, and a control device. The display unit includes a display unit having a light-emitting element that displays road information, a display power supply that supplies power to the light-emitting element, a drive circuit connected between the light-emitting element and the display power supply, a control circuit that outputs a drive signal to the drive circuit to cause the display unit to display the road information, and a control power supply that supplies power to the control circuit. The switching unit has a first state in which the external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply. The control device has a signal generation unit that, when it receives an external instruction signal from an external source to display an object as road information on the display unit, sets the switching unit to a first state, activates the display power supply while the control power supply is activated, generates a signal to the control circuit to display the display object, and sets the switching unit to a second state when it has not received an external instruction signal.

[0007] In the above-described road information display device, when the signal generation unit receives the external instruction signal, it sets the switching unit to the first state and starts the display power supply while the control power supply is running. When the external instruction signal is not received, the switching unit is set to the second state. This reduces standby power (power consumption) by disconnecting the electrical connection between the external power supply and the display unit when no display object is to be displayed on the display unit, and shortens the time until the display object is displayed.

[0008] The control device may further include a thermometer for measuring the outside temperature. In that case, the control device further includes a determination unit that determines whether predetermined conditions for displaying temperature information based on the detection result of the thermometer are met, and the signal generation unit communicates with the temperature measuring device, and when it has not received the external instruction signal and the determination unit determines that the predetermined conditions are met, it sets the switching unit to the first state and displays the temperature information on the display unit.

[0009] When the signal generation unit has not received the above-mentioned external instruction signal, and the determination unit has determined that the above-mentioned outside temperature is below a predetermined temperature, the switching unit may be set to the first state and the above-mentioned temperature information may be displayed on the display unit.

[0010] The signal generation unit may cause the display unit to display at least one of the following as a display object: a display object related to weather information, a display object related to road surface information, a display object related to traffic information, or a display object related to disaster prevention information.

[0011] To achieve the above objective, a control device according to one embodiment of the present invention comprises a signal generation unit. The control device is a control device that controls a display unit having a display unit having a light-emitting element that displays road information, a display power supply that supplies power to the light-emitting element, a drive circuit connected between the light-emitting element and the display power supply, a control circuit that outputs a drive signal to the drive circuit to cause the display unit to display the road information, and a control power supply that supplies power to the control circuit, and a switching unit having a first state in which an external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply. When an external instruction signal is received from an external source to display an object as road information on the display unit, the switching unit is set to the first state, the display power supply is started while the control power supply is running, and a signal is generated in the control circuit to display the display object. When no external instruction signal is received, the switching unit is set to the second state.

[0012] To achieve the above objective, a road information display system according to one embodiment of the present invention comprises a display unit, an external indicator device, a switching unit, and a control device. The display unit includes a display unit having a light-emitting element that displays road information, a display power supply that supplies power to the light-emitting element, a drive circuit connected between the light-emitting element and the display power supply, a control circuit that outputs a drive signal to the drive circuit to cause the display unit to display the road information, and a control power supply that supplies power to the control circuit. The above-mentioned external instruction device has an external signal generation unit that generates an external instruction signal that causes the display unit to display a display object as the above-mentioned road information. The switching unit has a first state in which the external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply. The control device is configured to set the switching unit to a first state when it receives an external instruction signal from the external instruction device, to activate the display power supply while the control power supply is activated, and to generate a signal to the control circuit to display the display object, and to set the switching unit to a second state when it does not receive an external instruction signal. [Effects of the Invention]

[0013] As described above, according to the present invention, power consumption when not displaying information to road users can be reduced, and the time required to display road information can be shortened. [Brief explanation of the drawing]

[0014] [Figure 1] It is a block diagram of the road information display system according to the first embodiment of the present invention. [Figure 2] It is a block diagram of the display unit according to the first embodiment. [Figure 3] It is a flowchart of the road information display system according to the first embodiment. [Figure 4] It is a flowchart of display response time of the road information display system according to the first embodiment. [Figure 5] It is a block diagram of the road information display system according to Modification 1. [Figure 6] It is a block diagram of the road information display system according to the second embodiment of the present invention. [Figure 7] It is a first flowchart of the road information display system according to the second embodiment. [Figure 8] It is a second flowchart of the road information display system according to the second embodiment. [Figure 9] It is a flowchart relating to display response time of a conventional road information display system. MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of road information display 1 according to the first embodiment of the present invention, and FIG. 2 is a block diagram of the display unit according to the first embodiment.

[0016] <First Embodiment> As shown in Figure 1, the road information display system 1 is a system that displays information to users of expressways or general roads, and comprises a road information display device 100 and an external indicator device 40. The road information display device 100 is supported by a support column provided on the roadside and has a control device 10, a display unit 20 (display section 24), and a switching section 30. The term "user" here refers to, for example, a driver of a vehicle (car, motorcycle, etc.), but is not limited to this, and may also refer to, for example, a pedestrian or a person sitting in the passenger seat.

[0017] (external indicating device) The external indicator device 40 has an external signal generation unit 41 that outputs an external instruction signal to the control device 10 (described later) to display an object on the display unit 20 (display section 24), which will be described later. The external indicator device 40 is connected to the control device 10 by wire or wireless. The external indicator device 40 is installed in a road management office or the like that issues commands to the control device 10 to display on the display section 20.

[0018] Specifically, the external instruction signal mentioned above refers to a signal transmitted by the external instruction device 40 to the control device 10 regarding information about a display object to be displayed on the display unit 24. The signal generation unit 13, described later, generates a first display signal from the first storage unit 14 based on the external instruction signal. Here, generating an external instruction signal for the external instruction device 40 includes not only generating the signal but also outputting the generated signal to the control device 10.

[0019] Here, display objects refer to images, and examples include, but are not limited to, objects related to weather information, road surface information, traffic information, and disaster prevention information. Each will be explained with specific examples. Examples of weather information objects include text warning of snowfall and a picture of a snowman. Examples of road surface information objects include text warning of freezing and a picture of a slipping car. Examples of traffic information objects include text warning of congestion 10 kilometers ahead and a picture of congestion. Examples of disaster prevention information objects include text warning of earthquakes and a picture representing earthquake tremors.

[0020] The display unit 24 may display the information across the entire unit, or only on a portion of it (for example, the upper half or the lower half). It may also blink, rather than remaining constantly lit. Furthermore, the display may be fixed in place, or it may be displayed in a way that makes it appear as if the display object is moving. Of course, this applies not only to the display object but also to the temperature information described later.

[0021] The timing at which the external instruction device 40 generates the above-mentioned external instruction signal is when it becomes necessary to display the above-mentioned display object on the display unit 24. The road management office decides whether or not to generate the above-mentioned external instruction signal based on, for example, weather information and traffic information obtained from an external source.

[0022] For example, if there is a traffic jam 10 kilometers ahead, it is necessary to display a traffic jam indicator object on the display unit 24, and therefore an external instruction signal containing information about the aforementioned indicator object is generated. When the traffic jam is cleared, and it is no longer necessary to display the traffic jam indicator object on the display unit 24, the generation of the external instruction signal is stopped.

[0023] When the external signal generation unit 41 does not want to display the display object on the display unit 24, it is not limited to stopping the generation of the external instruction signal as described above, but may also generate a separate signal that prevents the display object from being displayed on the display unit 24.

[0024] (Switching section) The switching unit 30 is configured to connect to an external power supply and the display unit 20. In this embodiment, the switching unit 30 is controlled by an SSR (Solid State Relay). The SSR is, for example, a photocoupler.

[0025] The switching unit 30 has a first state in which it connects the external power supply to the display unit 20 (drive power supply circuit 21 and display power supply circuit 22), and a second state in which it disconnects the external power supply from the display unit 20. In other words, the switching unit 30 electrically connects the external power supply (for example, commercial power supply AC200V) and the display unit 20 by receiving a connection signal, which will be described later. When a connection signal is not received, the external power supply and the display unit 20 are electrically isolated.

[0026] (Control device) The control device 10 is connected to the external instruction device 40 by wire or wireless, and is composed of a CPU (Central Processing Unit) and the like, and includes a receiving unit 11, a display determination unit 12, a first signal generation unit 13, and a first storage unit 14.

[0027] The receiving unit 11 receives the external instruction signal output from the external instruction device 40.

[0028] The display determination unit 12 determines whether or not an external instruction signal has been acquired.

[0029] The first signal generation unit 13 generates a signal that causes the display unit 20 to display predetermined information based on the determination result of the display determination unit 12. Specifically, when the display determination unit 12 determines that it has received an external instruction signal, the first signal generation unit 13 generates a first display signal (generated based on display object information corresponding to the external instruction signal stored in the first storage unit 14) that causes the display object to be displayed on the display unit 24 as road information, and a connection signal that puts the display unit 20 into a first state where the external power supply and the display unit 20 are connected by the switching unit 30. When the display determination unit 12 determines that it has not received an external instruction signal, the first signal generation unit 13 does not generate the first display signal or the connection signal. Not generating the connection signal means that the external power supply and the display unit 20 are electrically isolated (a second state where the external power supply and the display unit 20 are disconnected). Furthermore, when the first signal generation unit 13 generates the first display signal, it includes not only generating the first display signal but also outputting the generated first display signal to the display device 10 via wired or wireless connection.

[0030] The first display signal includes a control signal output to the control circuit 25 (described later), a first output signal output to the control power supply 21 (described later), and a second output signal output to the display power supply circuit 22.

[0031] The control signal is a signal output to the control circuit 25, which drives the drive circuit 23 (driving means turning each pixel (light-emitting element 241) on or off using the switching elements of the drive circuit 23). In other words, the control circuit 25 drives the drive circuit 23 based on this signal. The first output signal is a signal output to the control power supply 21, which outputs power to drive the control circuit 25. In other words, the control power supply 21 outputs power to the control circuit 25 based on this signal. The second output signal is a signal output to the display power supply 22, which outputs power to the light-emitting elements 241. In other words, the display power supply 22 outputs power to the drive circuit 23 based on this signal.

[0032] As will be explained in more detail later, the first signal generation unit 13 first generates the control signal and the first output signal from the first display signal. Next, it generates the second output signal.

[0033] The first storage unit 14 stores programs for driving the control device 10, image information of display objects based on external instruction signals for generating the first display signal, and the like.

[0034] (Display unit) The display unit 20 includes a control power supply 21, a display power supply 22, a drive circuit 23, a display unit 24, and a control circuit 25. Power is supplied to each device of the display unit 20 from an external power supply. As mentioned above, the external power supply is, for example, a commercial power supply of AC 200V. In this embodiment, the display unit 20 is an HLM type display unit supported by a support column provided on the roadside and installed at a height of several meters to about 10 meters above the ground, but it is of course not limited to this.

[0035] The drive circuit 23 is connected between the light-emitting element 241 and the display power supply 22 and is a circuit having a switching element (such as a transistor) that turns each pixel (light-emitting element 241) on or off. The control circuit 25 and the display power supply 22 turn on the light-emitting element 241 according to the display object. In other words, the drive circuit 23 turns on or off the light-emitting element 241 by the control circuit 25 and the display power supply 22, and displays the desired display object on the display unit 24.

[0036] The control power supply 21 is a circuit connected to an external power supply and driven by an electrical signal, and includes a first power acquisition unit 211 and a first power generation unit 212. The drive power supply circuit 21 is, for example, a constant voltage circuit.

[0037] The first acquisition unit 211 acquires the first output signal from the first display signals.

[0038] When the first power generation unit 212 acquires the first output signal, it outputs the power necessary to drive the control circuit 25 to the control circuit 25.

[0039] The first power generation unit 212 is, for example, a constant voltage circuit that generates power to drive the drive circuit 23 based on the first output signal.

[0040] The control circuit 25 is connected to an external power supply and includes a third acquisition unit 251 and a second signal generation unit 252. The control circuit 25 is an integrated circuit, for example, an FPGA (Field Programmable Gate Array). The control circuit 25 outputs a drive signal to the drive circuit 23 to display road information on the display unit 24.

[0041] The third acquisition unit 251 acquires control signals.

[0042] The second signal generation unit 252 initializes the drive circuit 23 based on the acquired control signal until a predetermined time has elapsed since the acquisition of the control signal, and then generates a drive signal to drive the drive circuit 23 after the predetermined time has elapsed. The driving of the drive circuit 23 differs depending on the display object displayed by the display unit 24, and the control circuit 25 applies the necessary power to light up the light-emitting element 241 that is to be lit according to the display object. Here, the predetermined time is 800ms, but is not limited to this, and can be any time after the initialization of the drive circuit 23, which will be described later, has been performed.

[0043] Initialization of the drive circuit 23 means, for example, that even if power (power from the display power supply 22 described later) is supplied to the drive circuit 23, the light-emitting element 241 does not light up (the drive circuit 23 is in an open state).

[0044] In other words, the control circuit 25 initializes the drive circuit 23 from the time the control signal is acquired until the predetermined time has elapsed, and after the predetermined time has elapsed, the initialization is released. Releasing the initialization here means driving the switching element of the drive circuit 23 corresponding to the pixel (light-emitting element 241) that you want to light up to light up.

[0045] The display power supply 22 is a circuit connected to an external power supply and driven by an electrical signal, and includes a second power acquisition unit 221 and a second power generation unit 222. The display power supply 22 is a circuit for outputting (supplying) power to the light-emitting element 241, and the power output differs depending on the color (red, blue, green) that the light-emitting element 241 emits (i.e., multiple display power supplies 22 are provided depending on the number and color of the light-emitting elements 241). For example, 3.2V is output to the red LED, and 4.2V to the blue and green LEDs. The display power supply circuit 22 is, for example, a constant voltage circuit.

[0046] The second acquisition unit 221 acquires the second output signal from the first display signal.

[0047] When the second power generation unit 222 acquires the second output signal, it generates the power necessary to drive the light-emitting element 241 from power supplied from an external power source.

[0048] Here, the second output signal is output to the display power supply 22 after the control signal and the first output signal have been output. This is because if the first output signal were output first, the display unit 24 might display the display object that was displayed last time (that is, before the drive circuit 23 is initialized, the drive circuit 23 may be in a driving state based on the display object that was displayed last time). The second output signal is output, for example, between the time the drive signal is output and the control circuit 25 is started, and the display power supply circuit 22 is started. The control power supply circuit 21 is started, for example, between the time the control power supply circuit 21 acquires the control signal and the time the control circuit 25 generates the drive signal to drive the drive circuit 23. The display power supply 22 is started, for example, between the time the display power supply 22 acquires the second output signal and the time the circuit outputs power to the light-emitting element 241.

[0049] Furthermore, the power supplies used for the control power supply 21 and the display power supply 22 may be the same or different.

[0050] The drive circuit 23 is controlled by the control circuit 25 to cause the light-emitting element 241 (described later) to emit light based on the power supplied from the first power generation unit 212 at a predetermined timing. The predetermined timing is any time after the drive circuit 23 has been initialized by the control circuit 25 (for example, 800 ms after the second output signal is generated).

[0051] The display unit 24 is a panel having multiple light-emitting elements 241, with the light-emitting elements 241 arranged according to the pixels of the panel. In this embodiment, the light-emitting elements 241 are LEDs (Light Emission Diodes). However, the light source for display on the display unit 24 is not limited to LEDs; an incandescent light bulb may also be used. The color of the light emitted by the light-emitting elements 241 is not particularly limited, but for example, it could be red or orange.

[0052] Next, the operation of the road information display system 1 in this embodiment will be described. Figure 3 is a flowchart of the road information display system 1 in this embodiment.

[0053] First, the display determination unit 12 determines whether the receiving unit 11 has received an external instruction signal (step 101).

[0054] Next, if the first signal generation unit 13 determines that the display determination unit 12 has received an external instruction signal, it generates a connection signal to connect the external power supply and the display unit 20 (step 102).

[0055] Next, if the first signal generation unit 13 determines that the display determination unit 12 has received an external instruction signal, it generates a first display signal to display a display object on the display unit 24 (step 103).

[0056] Next, based on the first display signal, the display unit 20 causes the display object to be displayed on the display section 24 (step 104).

[0057] On the other hand, if the first signal generation unit 13 determines that the display determination unit 12 has not received an external instruction signal, it does not generate a connection signal (i.e., the external power supply and the display unit 20 remain electrically isolated) (step 105).

[0058] From the above, when the control device 10 is not receiving an external instruction signal from the external instruction device 40, the power generated when the external power supply and the display unit 20 are electrically isolated can reduce the power (standby power) generated when they are electrically connected.

[0059] In other words, conventionally, the external power supply and the display unit 20 were always electrically connected, which resulted in standby power consumption. However, by providing the switching unit 30, power is supplied only when display is needed. This reduces standby power consumption when the display is not on (for example, in the conventional case, the standby power consumption is 114VA, but in this embodiment, it is 0VA because they are electrically isolated).

[0060] Figure 4 is a flowchart showing the display response time of the road information display system in the first embodiment, and Figure 9 is a flowchart showing the display response time of a conventional road information display system.

[0061] First, let's explain the conventional display response time. The display response time is the time from when the external instruction signal is output from the external instruction device 40 to the control device 10 until the display unit 24 lights up. In addition, in conventional road information display systems, standby power is output to the control power supply 21 and the display power supply 22 by an external power supply (the external power supply and the display unit 20 are always electrically connected).

[0062] First, upon receiving an external instruction signal, a first output signal is output to the control power supply 21, turning on the power supply of the control power supply 21, and the power necessary to drive the control circuit 25 is generated (output, supplied) by the first power generation unit 212 (step 201A). At this time, the time from outputting the first output signal until the drive power supply 21 turns on is approximately 40 ms.

[0063] Furthermore, upon receiving an external instruction signal, a control signal is output to the control circuit 25, and the drive circuit 23 is initialized until the predetermined time has elapsed.

[0064] Next, a second output signal is output to the display power supply 22, and the power to the display power supply 22 is turned on (step 202A). At this time, the waiting time from step 201A to step 202A is approximately 1000ms. This waiting time is the time required to turn on the power to the display power supply 22 after the power to the control power supply 21 has been turned on (or the time until the control circuit 25 outputs a drive signal to initialize the drive circuit 23), and is to prevent the power to the display power supply 22 from being turned on prematurely.

[0065] Next, the control circuit 25 generates a control signal to drive the drive circuit 23 (step 203A). Here, the time from step 202A to step 203A is approximately 1000ms.

[0066] Next, the drive circuit 23 is driven by the control circuit 25 to display an object on the display unit 24 based on the power output to the light-emitting element 241 (step 204A). Here, the time from step 203A to step 204A is approximately 500ms, during which time the light-emitting element 241 emits light and the display object is displayed.

[0067] In summary, the total display response time until the conventional display object is displayed is 2.54 seconds.

[0068] In contrast, the display response time of this embodiment will be described (see Figure 4).

[0069] First, upon receiving an external instruction signal, the first signal generation unit 13 generates a connection signal, a control signal, and a first output signal. The control signals are output to the switching unit 30, connecting the external power supply and the display unit. The first output signal is output to the control power supply 21, turning on the power to the control power supply 21. A control signal is output to the control circuit 25, initializing the drive circuit 23 for a predetermined time. After the predetermined time has elapsed, a control signal is generated (output) to drive (light up) the drive circuit 23 (step 201). At this time, the time from outputting the connection signal and the control signal until the control circuit 25 initializes the drive circuit 23 is approximately 350ms. This is longer than the conventional 40ms because the connection is made from a state where the external power supply and the display unit 20 were electrically isolated by the switching unit 30.

[0070] Next, a second output signal is output to the display power supply 22, turning on the power to the display power supply 22 (step 202). At this time, the first signal generation unit 13 generates the second output signal between the time it outputs the first output signal to the drive power supply 21 and the time it generates the control signal that the control circuit 25 initializes. This prevents erroneous display (flickering) on ​​the display unit 24. Furthermore, this differs from the conventional flow in that the control power supply 21 and the display power supply 22 are started in parallel.

[0071] Next, the control circuit 25 generates (outputs) a control signal to drive the drive circuit 23 (step 203). Here, the time from step 202 to step 203 is approximately 800ms. This waiting time is the time required for the drive circuit 23 to initialize.

[0072] Next, the display object is displayed on the display unit 24 based on the power output to the light-emitting element 241 by the display power supply 22 and the control circuit 25 (step 204). Here, the time from step 203 to step 204 is approximately 500ms, during which time the light-emitting element 241 emits light and the display object is displayed.

[0073] In summary, the total display response time until the display object is displayed in this embodiment is 1.65 seconds. In other words, in this embodiment, the display response time can be shortened by starting the control power supply 21 and the display power supply 22 in parallel. This reduces standby power consumption and allows the display object to be displayed in a shorter time than conventional display response times. By shortening the display response time, road information can be presented quickly to road users.

[0074] <Example 1> Next, a modification 1 of the present invention will be described. Figure 5 is a block diagram of the road information display system 1A according to modification 1. Hereinafter, the configurations that differ from the first embodiment will be mainly described, and the same reference numerals will be used for the same components as in the first embodiment, and their descriptions will be omitted or simplified.

[0075] In this modified example 1, the control device 10A of the road information display device 100A has a fault detection unit 15 and a transmission unit 16, and the display unit 20A has a fault detection circuit 26, which is different from the first embodiment.

[0076] In this embodiment, the fault detection circuit 25 performs fault detection to determine whether there is a fault in the control power supply 21 and the display power supply 22. The fault detection circuit 25 is connected to the control power supply 21 and the display power supply 22. If the control power supply 21 and the display power supply 22 are normal, the fault detection circuit 25 generates a fault signal (the first display signal is not input) at a predetermined interval until the first display signal is output to the display unit 20A. Once the first display signal is output to the display unit 20A, the generation of the fault signal is stopped.

[0077] However, if there is an abnormality in at least one of the control power supply circuit 21 and the display power supply 22, the fault detection circuit 25 will not stop generating the fault signal when the first display signal is output to the display unit 20A, and the fault signal will be generated.

[0078] In this embodiment, the fault detection circuit 25 is a photocoupler, but it is sufficient if it is configured such that a fault signal is generated when the first indicator signal is not input, and the generation of the fault signal is stopped when the first indicator signal is input.

[0079] The fault detection unit 15 determines whether a fault signal has been generated when it is outputting the first display signal. In other words, as described above, if there are no faults in the control power supply 21 and the display power supply 22, when the first display signal is output to the display unit 20A, the generation of a fault signal is stopped, so it is not determined that a fault signal has been generated, and the system is determined to be normal.

[0080] However, as described above, if there is a malfunction in at least one of the control power supply 21 and the display power supply 22, when the first display signal is output to the display unit 20A, the generation of the fault signal is not stopped and the fault signal is generated. For this reason, the fault determination unit 15 determines that a fault signal has been generated while the first display signal is being output, and therefore determines that there is a malfunction.

[0081] The transmission unit 16 of the control device 10A transmits the determination result determined by the fault determination unit 15 to the external instruction device 40.

[0082] Therefore, if there is a malfunction in the display unit 20, that information can be transmitted to the external instruction device 40. This allows the road management office to be notified immediately if a malfunction occurs, and the situation where the display unit 20A is not displaying the correct information can be quickly rectified.

[0083] Furthermore, the fault detection circuit 25 may be configured separately from the control power supply 21 and the display power supply 22, or it may be incorporated into each of the control power supply 21 and the display power supply 22. This makes it easier to determine which one is malfunctioning.

[0084] Furthermore, if the fault detection unit 14 determines that there is an abnormality, the first signal generation unit 13 may be prevented from generating a connection signal to the switching unit 30. This makes it possible to more quickly prevent the display object from being displayed on the display unit 24 when there is a fault in the display unit 20, thereby preventing the presentation of incorrect information to the user.

[0085] <Second Embodiment> Next, a second embodiment of the present invention will be described. Figure 6 is a block diagram of the road information display system 1B in the second embodiment. The main points to be described will be the configurations that differ from the first embodiment, and the descriptions of configurations that are the same as in the first embodiment will be omitted or simplified.

[0086] This embodiment differs from the first embodiment in that the road information display system 1B further includes a temperature measuring device 50.

[0087] In this embodiment, the temperature measuring device 50 includes a thermometer 51, a temperature information generation unit 52, and a second storage unit 53.

[0088] The thermometer 51 measures (detects) the outside temperature. The thermometer 51 is installed, for example, on the back side or around the display unit 20 as seen by road users, but is not limited to this, and may be installed on a support column supporting the information display device 100, etc. In this embodiment, the thermometer 51 measures the outside temperature and utilizes the fact that the resistance value of a platinum resistance thermometer changes in proportion to the temperature, but is of course not limited to this.

[0089] The temperature information generation unit 52 generates a temperature signal for outputting the resistance value of the platinum resistance thermometer to the control device 10. The temperature signal includes the above-mentioned ambient temperature information. Here, generating a temperature signal by the temperature information generation unit 52 includes not only generating the temperature signal but also outputting the generated temperature signal to the control device 10.

[0090] The temperature measuring device 50 and the control device 10 communicate by wire or wireless. The temperature information generation unit 52 outputs a temperature signal to the control device 10 at a predetermined interval. The predetermined interval is, for example, once every 0.1 seconds, once every second, once every minute, or once every hour, but is not limited to these.

[0091] The second memory unit 53 stores programs for converting resistance values ​​into temperature signals, etc.

[0092] Of course, the configuration is not limited to the above, and the ambient temperature detected by the thermometer 51 may be transmitted to the control device 10 without being converted into a temperature signal by the temperature information generation unit 52.

[0093] When the receiving unit 11 of the control device 10 receives a temperature signal including temperature information, the display determination unit 12 (determination unit) determines whether the predetermined conditions for displaying the temperature information are met.

[0094] Here, the specified condition is, for example, whether the measured ambient temperature is below a specified temperature, but is not limited to this; it may also be above the specified temperature. The specified temperature is, for example, 5°C, but is not limited to this.

[0095] The first signal generation unit 13 then generates a connection signal and a second display signal that causes the display unit 24 to display temperature information based on the thermometer's detection result (the temperature information corresponding to the thermometer's detection result stored in the first storage unit 14). This signal is generated when the first signal generation unit 13 has not received an external instruction signal and the display determination unit 12 has determined that the above predetermined conditions have been met.

[0096] Next, the operation of the road information display system 1B in this embodiment will be described. Figure 7 is the first flowchart of the road information display system 1B in the second embodiment, and Figure 87 is the second flowchart of the road information display system 1B in the second embodiment.

[0097] Here, steps 101A to 104A are the same as steps 101 to 104 in the first embodiment, so their explanation is omitted.

[0098] In other words, steps 105A to 109A will be explained (see Figure 8). In step 105A, the display determination unit 12 determines whether a predetermined condition for displaying temperature information on the display unit 24 has been met (for example, the outside temperature is 5°C or lower).

[0099] If the display determination unit 12 determines that a predetermined condition has been met (YES), the first signal generation unit 13 generates a connection signal (step 106A).

[0100] If the display determination unit 12 determines that a predetermined condition has been met (YES), the first signal generation unit 13 generates a second display signal (step 107A).

[0101] Next, based on the second display signal, the display unit 20 displays the temperature information on the display unit 24 (step 108A).

[0102] On the other hand, if the display determination unit 12 determines that the predetermined conditions are not met, the first signal generation unit 13 does not generate a connection signal (i.e., the external power supply and the display unit 20 remain electrically isolated) (step 109A).

[0103] This allows the display unit 24 to display temperature information even when it has not received an external instruction signal to display a display object (for example, when the road is not frozen but the temperature is below 5°C and caution is needed). Furthermore, since the system determines whether or not to display temperature information based on predetermined conditions and displays it only when necessary, power consumption can be reduced.

[0104] <Other variations> Next, other modifications of the present invention will be described. The descriptions will primarily focus on configurations different from the first embodiment, while descriptions of configurations similar to the first embodiment will be omitted or simplified.

[0105] This modified version differs from the first embodiment in that the road information display system 1 is further equipped with a road temperature gauge (not shown) and a moisture detection device (not shown).

[0106] The road temperature sensor is installed facing the road around the display unit 20 or on the support pole mentioned above. The road temperature sensor is, for example, an infrared non-contact thermometer that measures the road temperature without contact, but it is not limited to this, and may also be an embedded road temperature sensor.

[0107] A moisture detection device detects the condition of the road surface by shining light onto the road and analyzing the amount of reflected light. In other words, if we use a dry road as a baseline, when the road (road surface) is wet, the light shining on it is more likely to be specularly reflected than when the road is dry. Therefore, the amount of light received decreases. Also, if there is snow on the road, the degree of diffuse reflection of light due to the snow is greater than when the road is dry, so the amount of light received increases compared to when the road is dry.

[0108] The outputs of the road temperature sensor and moisture detection device described above may be configured to be transmitted to the external display device 50. This allows users to more accurately understand the road conditions they are using.

[0109] Furthermore, in addition to the road temperature gauge and moisture detection device described above, an anemometer and wind direction meter may also be installed and configured to transmit their outputs to the external display device 50. This allows real-time information, such as sudden gusts of wind, to be presented to the user.

[0110] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made. Furthermore, the configurations of each embodiment and its modified form may be combined. [Explanation of Symbols]

[0111] 1…Road information display system 10...Control device 11... Receiver 12...Display judgment section 13…First signal generation unit 14...First memory section 20…Display Unit 21...Control power supply 22…Display power supply 23…Drive circuit 24...Display section 25...Control circuits 30... Switching section 40…External instruction device 50…Temperature measuring device 100...Information display device

Claims

1. A display unit comprising: a display unit having a light-emitting element for displaying road information; a display power supply for supplying power to the light-emitting element; a drive circuit connected between the light-emitting element and the display power supply; a control circuit that outputs a drive signal to the drive circuit for displaying the road information on the display unit; and a control power supply for supplying power to the control circuit. A switching unit having a first state in which an external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply, A control device having a signal generation unit configured to set the switching unit to a first state when an external instruction signal is received from an external source to display a display object as road information on the display unit, to activate the display power supply while the control power supply is activated, and to generate a signal to the control circuit to display the display object, and to set the switching unit to a second state when the external instruction signal is not received. A road information display device equipped with the following.

2. A road information display device according to claim 1, The temperature measuring device further comprises a thermometer that detects the outside temperature, The control device further includes a determination unit that determines whether predetermined conditions for displaying temperature information based on the detection result of the thermometer are met, The signal generation unit communicates with the temperature measuring device, and when it has not received the external instruction signal, and the determination unit determines that the predetermined conditions have been met, it sets the switching unit to the first state and displays the temperature information on the display unit. Road information display device.

3. A road information display device according to claim 2, When the signal generation unit has not received the external instruction signal and the determination unit has determined that the outside temperature is below a predetermined temperature, the switching unit sets the switching unit to the first state and displays the temperature information on the display unit. Road information display device.

4. A road information display device according to claim 1, The signal generation unit causes the display unit to display at least one of the following as a display object: a display object related to weather information, a display object related to road surface information, a display object related to traffic information, and a display object related to disaster prevention information. Road information display device.

5. A control device for controlling a display unit having a display unit having a light-emitting element that displays road information, a display power supply that supplies power to the light-emitting element, a drive circuit connected between the light-emitting element and the display power supply, a control circuit that outputs a drive signal to the drive circuit to cause the display unit to display the road information, and a control power supply that supplies power to the control circuit, and a switching unit having a first state in which an external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply, A signal generation unit having a signal generation unit configured to set the switching unit to a first state when an external instruction signal is received from an external source to display a display object as road information on the display unit, to activate the display power supply while the control power supply is activated, and to generate a signal to the control circuit to display the display object, and to set the switching unit to a second state when no external instruction signal is received. A control device equipped with the following.

6. A display unit comprising: a display unit having a light-emitting element for displaying road information; a display power supply for supplying power to the light-emitting element; a drive circuit connected between the light-emitting element and the display power supply; a control circuit that outputs a drive signal to the drive circuit for displaying the road information on the display unit; and a control power supply for supplying power to the control circuit. An external indicator device having an external signal generation unit that generates an external indicator signal to display the road information on the display unit, A switching unit having a first state in which an external power supply is connected to the control power supply and the display power supply, and a second state in which the external power supply is disconnected from the control power supply and the display power supply, A control device having a signal generation unit configured to set the switching unit to a first state when an external instruction signal is received from an external source to display a display object as road information on the display unit, to activate the display power supply while the control power supply is activated, and to generate a signal to the control circuit to display the display object, and to set the switching unit to a second state when the external instruction signal is not received. A road information display system equipped with the following features.

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