JP2004268675A - Electronic license plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption of an electronic license plate. <P>SOLUTION: This electronic license plate is provided with a plurality of memories 14a and 14b including at least the memory 14a storing vehicle specification information, a communication part 12 capable of communicating with an external device, a control part 13 for controlling reading or writing of information in the memories 14a and 14b based on access requests to the memories 14a and 14b received by the communication part 12 from the external device, and a power supply control part 17 capable of switching power supply from an external power source 16 and power supply from a primary battery 15. The control part 13 permits the access requests to the memory 14a storing vehicle specification information and does not permit the access request to the other memory 14b, when power supply from the external power source 16 is not performed in the power supply control part 17. <P>COPYRIGHT: (C)2004,JPO&amp;NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic license plate.
[0002]
[Prior art]
At present, it is being studied to attach an electronic license plate (smart plate) to a vehicle for the purpose of vehicle registration management, traffic volume management, and the like. The electronic license plate records information such as vehicle specification information and a vehicle number (number) on an IC chip on the license plate. The electronic license plate has a communication function, and is configured to be able to read data by an external device (roadside machine) installed along a road or the like.
[0003]
[Problems to be solved by the invention]
This electronic license plate is supposed to be supplied with power from a built-in battery (primary battery), so that the battery capacity is limited and the power consumption is severe. On the other hand, various applications (services) using information stored in the electronic license plate using the communication function of the electronic license plate are being studied. In order to realize such an application, it is not enough to supply power only from the built-in battery, and it is necessary to supply power to the electronic license plate from an external power supply such as a vehicle ACC power supply.
[0004]
However, due to the configuration of the vehicle, it is not always possible to supply an electric power source from the ACC power supply to the electronic license plate in all vehicles such as a case where an electronic license plate is attached to an existing vehicle or a low-cost vehicle. Further, even when power is supplied from the ACC power supply to the electronic license plate, it is conceivable that power is supplied from the vehicle battery when the ACC is turned off. In this case as well, it is necessary to reduce power consumption.
[0005]
In view of the above, an object of the present invention is to reduce the power consumption of an electronic license plate.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided an electronic license plate mounted on a vehicle, wherein a plurality of storage means (14a, 14b) storing at least vehicle specification information; A communication unit (12) capable of communicating with the storage unit (14a, 14b) based on an access request to the storage unit (14a, 14b) received from the external device by the communication unit (12), or A control unit (13) for controlling the writing of information, a primary battery (15) for supplying power to the control unit (13) and the like, a power supply from the primary battery (15), and a comparison with the primary battery (15) A power supply control unit (17) that can switch between power supply from an external power supply (16) capable of supplying power for a long time, and a control unit (13). When the power supply from (16) is not performed, an access request from an external device to the storage means (14a) storing the vehicle specification information is permitted, and an external request to the other storage means (14b) is made. An access request from a device is not permitted.
[0007]
As described above, when power is not supplied from the external power supply (16), only an access request to the storage means (14a) storing the vehicle specification information having the higher priority is accepted, and other storage is performed. By limiting the access request to the means (14b), the number of accesses to the storage means (14) and the number of data transmissions can be reduced. This makes it possible to reduce the power consumption of the electronic license plate.
[0008]
Further, as in the second aspect of the present invention, the ACC power supply of the vehicle can be used as the external power supply.
[0009]
In addition, the code | symbol in the parenthesis of each said means shows the correspondence with the concrete means described in embodiment mentioned later.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0011]
FIG. 1 shows the configuration of the electronic license plate 10. The electronic license plate 10 records information such as vehicle specification information and a vehicle number (number) on an IC chip on a license plate attached to the front and rear of the vehicle. The license plate is a plate-like member on which an automobile registration number is described.
[0012]
As shown in FIG. 1, the electronic license plate 10 includes a communication unit 12, a control unit 13, a memory 14, an internal battery 15, an external power supply 16, and a power control unit 17. The communication unit 12 transmits and receives signals to and from an external device (not shown) via the antenna 11. The control unit 13 controls data transmission / reception in the transmission unit 12 and also controls data read / write to the memory 14.
[0013]
The external device is installed, for example, along a road or in a facility that uses information stored in the electronic license plate 10, and has a communication function capable of communicating with the electronic license plate 10. The external device makes an access request to the memory 14 to the electronic license plate 10. The access request to the memory 14 includes a request to read data stored in the memory 14 and a request to write data to the memory 14.
[0014]
The memory 14 is storage means for storing various data, and includes a plurality of memories of different types. The memory 14 of the present embodiment includes a public memory 14a and a private memory 14b. When power is not supplied from an external power supply 16 to be described later, the public memory 14a and the private memory 14b are set to have different priorities when accessed from an external device. In this embodiment, the public memory 14a has a higher priority.
[0015]
The public memory 14a stores vehicle specification information described in the automobile inspection certificate, and can only read data. The private memory 14b is a memory area in which information other than the vehicle specification information is stored, and can read and write data. The private memory 14b can be used for various purposes.
[0016]
In the private memory 14b, a memory area that can be used in private facilities is prepared. Private facilities include gas stations, vehicle repair shops, and shops. For example, when the gas station gives a service point to the vehicle user according to the refueling amount, the service point of the gas station can be recorded in the private memory 14b.
[0017]
The electronic license plate 10 of the present embodiment includes a plurality of power supplies 15 and 16 of different types for supplying power to the control unit 13 and the like. In the present embodiment, an internal battery 15 and an external power supply 16 are used as the power supplies 15 and 16. Switching of power supply from the internal battery 15 and the external power supply 16 is controlled by the power supply control unit 17.
[0018]
The internal battery 15 is a power supply built in the electronic license plate 10, and a primary battery is used. As the external power supply 16, a vehicle ACC power supply that is supplied when the ignition key is set to the “ACC” position is used. When the ACC power is not supplied at the time of stopping or the like, a vehicle battery (secondary battery) is used as the external power supply 16 instead of the vehicle ACC power. If power cannot be supplied from the external power supply 16, power is supplied from the internal battery 15 to the control unit 13 and the like. The case where power cannot be supplied from the external power supply 16 is, for example, a case where the electronic license plate 10 is attached to a low-cost vehicle or an existing vehicle, and there is a case where the external power supply 16 is not connected.
[0019]
Next, the flow of processing of the electronic license plate 10 in response to a memory access request from an external device will be described with reference to FIG. The following processing is started by receiving a memory access request from an external device.
[0020]
First, it is determined whether the type of the memory 14 requested to be accessed from the external device is the public memory 14a (S10). As a result, if the type of the memory 14 requested to be accessed by the external device is the public memory 14a, the contents of the public memory 14a are read (S11), and the data read to the external device via the transmission unit 12 is read. It transmits (S12).
[0021]
On the other hand, if the type of the memory 14 requested to be accessed by the external device is not the public memory 14a, that is, if the type of the memory 14 is a private memory, it is determined whether or not power is supplied from the external power supply 16 (S13). As a result, when the power is supplied from the external power supply 16, that is, when the power is supplied from the vehicle ACC power supply or the vehicle battery, the contents of the private memory 14b are read (S14), and the external device is transmitted via the transmission unit 12. The read data is transmitted to (S15).
[0022]
On the other hand, when power is not supplied from the external power supply 16, that is, when power is supplied from the internal battery 15, access to the private memory 14b is restricted. Specifically, the access request to the private memory 14b from the external device is not permitted, and no processing is performed.
[0023]
As described above, when the power supply from the external power supply 16 is not performed, only the access request to the public memory 14a having a high priority is accepted, and the access request to the private memory 14b is restricted, so that the memory 14 and the number of data transmissions can be reduced, and the power consumption of the electronic license plate 10 can be reduced.
[0024]
(Other embodiments)
In the above steps S13 to S15, the access to the private memory 14b is permitted even when the power is supplied from the vehicle battery. However, if a frequent access request from an external device is assumed while the vehicle is stopped. In this case, the remaining battery power is reduced more than necessary. Therefore, even when power is supplied from the vehicle battery, access to the private memory 14b may not be permitted. Alternatively, means for monitoring the remaining amount of the battery of the vehicle may be provided so that access to the private memory 14b is restricted when the remaining amount of the battery falls below a predetermined value.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an electronic license plate of the embodiment.
FIG. 2 is a flowchart showing a flow of processing of an electronic license plate in response to a memory access request from an external device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electronic license plate, 11 ... Antenna, 12 ... Communication part, 13 ... Control part, 14 ... Memory (storage means), 14a ... Public memory, 14b ... Private memory, 15 ... Internal battery, 16 ... External power supply, 17 ... Power control unit.

Claims (2)

An electronic license plate mounted on a vehicle,
A plurality of storage means (14a, 14b) storing at least vehicle specification information;
A communication unit (12) capable of communicating with an external device;
A control unit (13) that controls reading of information or writing of information in the storage unit (14a, 14b) based on an access request to the storage unit (14a, 14b) received by the communication unit (12) from the external device. )When,
A primary battery (15) for supplying power to the control unit (13) and the like;
A power control unit (17) that can switch between a power supply from the primary battery (15) and a power supply from an external power supply (16) that can supply power for a longer time than the primary battery (15); With
When the power supply from the external power supply (16) is not performed by the power supply control unit (17), the control unit (13) stores the vehicle specification information in the storage unit (14a). An electronic license plate which permits an access request from the external device to the external device and does not permit an access request to the other storage means (14b) from the external device. The electronic license plate according to claim 1, wherein an ACC power supply of the vehicle is used as the external power supply.

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