JP2010042777A - Antitheft device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular security system capable of easily imparting a similar security function to a vehicle having no security system such as an immobilizer. <P>SOLUTION: A vehicular antitheft device comprises an authenticating means 40 for authenticating a user having an authenticated means 20 based on identification information transmitted from the authenticated means 20 having inherent identification information stored, and a current limiting means 60 which is provided between a storage battery 12 and a load 14 and limits the current supplied from the storage battery 12 based on the authentication results with the authenticating means 40. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a security system, and more particularly to a security system for a vehicle.

  In recent years, anti-theft devices called immobilizers have attracted attention as security systems for vehicles. An immobilizer electronically collates a unique ID code stored in an electronic chip embedded in a dedicated key carried by a car user with the ID code on the vehicle side, and only when both ID codes match The engine is allowed to start.

In a vehicle equipped with an immobilizer, the engine cannot be started unless the ID code matches even if the door is opened using a key or the like to start the engine. Further, the ID of the dedicated key is encrypted, and the number of combinations is enormous, so that it is almost impossible to duplicate. For this reason, the immobilizer is a security system that is extremely effective even for a combination key or a directly connected wire. In recent years, an increasing number of vehicles are equipped with an immobilizer as standard.
JP 08-1333016 A JP 2003-216994 A

  However, although the number of vehicles equipped with immobilizers is increasing, the ratio of the total number of vehicles is still small. In a vehicle not equipped with an immobilizer, even if there is no key, the engine can be started by directly connecting the harness near the key cylinder, and the vehicle can be stolen. Many other anti-theft devices such as handle locks and anti-theft alarm devices are on the market, but the number of vehicle theft itself has not decreased.

  The objective of this invention is providing the security system for vehicles which can provide the same security function easily also to the vehicle which is not equipped with the security system like an immobilizer.

  The object is an anti-theft device for vehicles, an authentication means for authenticating a user possessing the authenticated means based on the identification information transmitted from the authenticated means storing unique identification information, and a storage battery It is achieved by an anti-theft device comprising current limiting means provided between the load and a load and limiting current supplied from the storage battery based on an authentication result by the authentication means.

  In the above antitheft device, the current limiting means does not limit the current supplied from the storage battery when authentication by the authentication means is obtained, and when authentication by the authentication means is not obtained, You may make it restrict | limit the electric current supplied from a storage battery to less than the electric current value required for engine starting.

  In the above antitheft device, the current limiting means may include a switch controlled based on an authentication result by the authentication means, and a current limiting circuit connected in parallel to the switch. Good.

  In the above antitheft device, the authentication means may receive the authentication information from the authenticated means wirelessly.

  In the above antitheft device, the authentication means may receive the authentication information from the authenticated means by wire.

  In the antitheft device, the authentication unit may be installed in a vehicle compartment, and the current limiting unit may be installed in an engine room.

  Further, the above object is provided between an authentication means for authenticating a user possessing the authenticated means based on identification information transmitted from the authenticated means storing unique identification information, and a power source and a load. The present invention is also achieved by a security system comprising current limiting means for limiting a current supplied from the power source based on an authentication result by the authentication means.

  According to the present invention, since the current required for starting the engine is supplied only when authentication is obtained between the authenticated means and the authenticating means, the engine can be started even by using a technique such as a key lock or direct wiring connection. Can not do it. Thereby, the antitheft effect of the vehicle can be enhanced.

[First Embodiment]
An antitheft device according to a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram showing the overall configuration of the anti-theft device according to this embodiment, FIG. 2 is a schematic diagram showing the structure of the body unit of the anti-theft device according to this embodiment, and FIG. 3 is the host of the anti-theft device according to this embodiment. FIG. 4 is a schematic diagram showing the structure of the relay unit of the antitheft device according to the present embodiment. FIGS. 5 and 6 are schematic diagrams showing an application example of the antitheft device according to the present embodiment. .

  First, the overall configuration of the antitheft device according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the antitheft device 10 according to this embodiment includes a body unit (authenticated means) 20, a host unit (authenticating means) 40, and a relay unit (current limiting means) 60. .

  The body unit 20 is carried by a user of the vehicle and used when driving the vehicle. In the body unit 20, a unique authentication code (identification information) is recorded.

  The host unit 40 is installed in the vehicle main body, authenticates the authentication code of the body unit 20, and controls the relay unit 60 based on the authentication result. The host unit 40 and the body unit 20 can be connected to each other. The connection between the body unit 20 and the host unit 40 may be wireless or wired. In the present embodiment, a case of connecting wirelessly will be described. A case of connecting by wire will be described in a second embodiment to be described later.

  The relay unit 60 controls the electrical connection state between the storage battery 12 and the load 14 based on a control signal transmitted from the host unit 40. The relay unit 60 is connected to the host unit 40, the storage battery 12 and the load 14. The storage battery 12 is a main power source supplied to the vehicle, for example, a lead storage battery. The load 14 is all vehicle power feeding loads including a starter current that requires a large current.

  Next, each part of the antitheft device according to the present embodiment will be specifically described with reference to FIGS.

  As shown in FIG. 2, the body unit 20 includes a radio signal transmission / reception device 22 that transmits and receives radio signals to and from the host unit 40. The wireless signal transmission / reception device 22 is a wireless transmission / reception circuit including an antenna. The radio signal transmitting / receiving apparatus 22 is connected to a received signal power converting apparatus 24 that converts the received signal received by the radio signal transmitting / receiving apparatus 22 into power. Connected to the received signal power converter 24 is a power storage device 26 that stores the power converted by the received signal power converter 24.

  The radio signal transmitter / receiver 22 is also connected to a received signal demodulator 28 that demodulates the signal received by the radio signal transmitter / receiver 22. The received signal demodulator 28 is connected to an RFID (Radio Frequency Identification) microchip core 30 for processing the signal demodulated by the received signal demodulator. The RFID microchip core 30 is also connected to a transmission signal modulation device 32 that modulates a signal output from the RFID microchip core 30. The RFID microchip core 30 stores the management of the radio signal transmission / reception device 22, the power storage device 26, the reception signal demodulation device 28, and the transmission signal modulation device 32, the authentication ID code, and the stored power utilization transmission control procedure. A radio signal transmitting / receiving device 22 is connected to the transmission signal modulating device 32.

  A reception signal demodulation device 28, an RFID microchip core 30, and a transmission signal modulation device 32 are connected to the power storage device 26. Drive power is supplied from the power storage device 26 to the reception signal demodulator 28, the RFID microchip core 30, and the transmission signal modulator 32.

  As shown in FIG. 3, the host unit 40 includes a body unit presence / absence detection device 50 that detects the presence / absence of the body unit 20. The body unit presence / absence detection device 50 is connected to a transmission unit power management device 52 that manages the power supplied to the transmission unit based on a signal from the body unit presence / absence detection device 50.

  The host unit 40 also includes a wireless signal transmission / reception device 42 that transmits and receives wireless signals to and from the body unit 20. The wireless signal transmission / reception device 42 is a wireless transmission / reception circuit including an antenna. A reception signal demodulator 44 that demodulates a signal received by the radio signal transmitter / receiver 42 is connected to the radio signal transmitter / receiver 42. The reception signal demodulator 44 is connected to a microcomputer 46 that processes the signal demodulated by the reception signal demodulator 44. The microcomputer 46 is connected to a transmission signal modulation device 48 that modulates a signal output from the microcomputer 46. The microcomputer 46 stores management / authentication / relay unit 60 state control procedures for the transmission unit power management device 52, the radio signal transmission / reception device 42, the reception signal demodulation device 44, and the transmission signal modulation device 48. The microcomputer 46 outputs a state control signal for controlling the relay unit 60. A radio signal transmitting / receiving device 42 is connected to the transmission signal modulating device 48. The radio signal transmission / reception device 42, the reception signal demodulation device 44, and the transmission signal modulation device 48 are connected to a transmission / reception unit power management device 52.

  As shown in FIG. 4, the relay unit 60 is provided between the positive terminal of the vehicle storage battery 12 and the load 14 of the vehicle. Between the input terminal 62 on the storage battery 12 side and the output terminal 64 on the load side, a current limiting circuit 66 and a switch 68 are connected in parallel. The switch 68 is connected to a switch drive circuit 70 that drives the switch 68 based on a state control signal output from the microcomputer 46 of the host unit 40.

  The switch 68 is a switch with a state holding function, and for example, a latch type relay can be applied. The switch drive circuit 70 turns on and off the relay contacts of the switch 68. The turning on / off of the relay contacts can be controlled by magnetic force by applying a driving current. Since the magnetic circuit is an inductive load when viewed from the host unit 40 to be driven, it is desirable to provide a back electromotive force absorption diode when the current is stopped.

  Next, the operation of the antitheft device according to the present embodiment will be described with reference to FIGS.

  In a state where the vehicle is not used (standby state), the switch 68 of the relay unit 60 is in an open state (open state). In this state, the electric connection path between the input terminal 62 and the output terminal 64 is only the current limiting circuit 66 (see FIG. 4).

  The current limiting circuit 66 is a circuit that limits the supply of a certain current or more to the load. As the current limiting circuit 66, for example, a resettable fuse can be applied. The lower limit value of the limit current is at least a current value that can ensure at least power required in a standby state (eg, remote control door lock, hazard lamp, burglar alarm device, standby power for the antitheft device according to this embodiment). To do. The upper limit value of the limit current is less than the current value (about 1 A to several A) required when starting the engine. The current limit value is not particularly limited, and can be set to about ˜100 mA, for example.

  By setting the current limit value of the current limit circuit 66 as described above, it is possible to inhibit the start of the engine while supplying necessary power during standby. Therefore, even if the thief tries to start the engine with a key or a directly connected wire, the engine cannot be started.

  A vehicle user carries the body unit 20. The body unit 20 is not particularly limited, but is a non-contact IC card, for example. Here, a non-contact IC card will be described as an example.

  After boarding the vehicle, the user sets a non-contact IC card as the body unit 20 in an IC card reader installed in the vehicle. The IC card reader corresponds to at least the wireless signal transmission / reception device 42 and the body unit presence / absence detection device 50 in the host unit 40 of the antitheft device 10 according to the present embodiment.

  When the non-contact IC card (body unit 20) is set in the IC card reader, the body unit presence / absence detection device 50 recognizes the presence of the body unit 20 and activates the transmission / reception power management device 52. The transmission / reception power management device 52 supplies power to the wireless signal transmission / reception device 42, the reception signal demodulation device 44, and the transmission signal modulation device 48 in the standby power saving state so that transmission / reception with the body unit 20 is possible. The power supply to the host unit 40 is performed from the storage battery 12. Since a large current is not necessary for driving the host unit 40, the power supplied via the current limiting circuit 66 is sufficient.

  The host unit 40 transmits a wake-up message toward the body unit 20. The wake-up message is encoded and modulated from the format sent from the microcomputer 46 by the transmission signal modulation device 48 and transmitted via the wireless signal transmission / reception device 42.

  The wake-up message transmitted from the host unit 40 is received by the radio signal transmission / reception device 22 of the body unit 20 and sent to the reception signal power conversion device 24. The received signal power conversion device 24 converts the preamble portion (synchronization signal portion) of the wake-up message into power and supplies power to the power storage device 26. The power storage device 26 is a power storage device such as an electric double layer capacitor.

  The received signal demodulator 28, the RFID microchip core 30, and the transmission signal modulator 32 are activated by the power stored in the power storage device 26. The RFID microchip core 30 stores the management of the reception signal demodulator 28 and the transmission signal modulator 32, the authentication ID code, and the stored power use transmission control procedure, and executes control according to the program.

  As a result, the wakeup message received by the radio signal transmitting / receiving device 22 is demodulated / decoded into a format that can be read by the RFID microchip core 30 by the received signal demodulating device 28, and sent to the RFID microchip core 30.

  The RFID microchip core 30 that has received the wake-up message outputs a transmission signal including authentication code information recorded in the RFID microchip core 30 to the transmission signal modulation device 32. The transmission signal modulation device 32 encodes and modulates the signal sent from the RFID microchip core 30 and sends it to the radio signal transmission / reception device 22. The wireless signal transmission / reception device 22 wirelessly transmits a transmission signal including information on the authentication code of the body unit 20 to the wireless signal transmission / reception device 42 of the host unit 40.

  The microcomputer 46 of the host unit 40 stores management / authentication / relay unit 60 state control procedures of the radio signal transmitting / receiving device 42, the received signal demodulating device 44 and the transmitting signal modulating device 48, and the control is performed according to the program. Execute.

  The wireless signal transmission / reception device 42 receives a signal transmitted from the wireless signal transmission / reception device 22 of the body unit 20. The received signal is sent to the received signal demodulator 44 and demodulated and decoded into a format that can be read by the microcomputer 46. The demodulated / decoded received signal is input from the received signal demodulator 44 to the microcomputer 46.

  The microcomputer 46 stores a target code that permits authentication. The microcomputer 46 collates the authentication code of the body unit 20 included in the signal output from the received signal demodulator 44 with the authentication object code stored in the microcomputer 46.

  The microcomputer 46 outputs a state control signal corresponding to the verification result between the authentication code of the body unit 20 and the authentication target code stored in the microcomputer 46 to the relay unit 60.

  If the authentication code of the body unit 20 does not match the authentication object code stored in the microcomputer 46, the microcomputer 46 opens the switch 68 for the switch drive circuit 70 of the relay unit 60. Control signal for output. In this state, the electric connection path between the input terminal 62 and the output terminal 64 is only the current limiting circuit 66, and the engine cannot be started.

  On the other hand, when the authentication code of the body unit 20 matches the authentication object code stored in the microcomputer 46, the microcomputer 46 closes the switch 68 with respect to the switch drive circuit 70 of the relay unit 60. A control signal for outputting is output.

  When the switch 68 is closed, the electrical connection path between the input terminal 62 and the output terminal 64 becomes the current limiting circuit 66 and the closed switch 68. As a result, the current limitation between the input terminal 62 and the output terminal 64 is eliminated, and a current necessary for starting the engine is allowed. Thereby, the engine can be started.

  When the user stops the engine and leaves the vehicle, the body unit 20 is moved away from the host unit 40. When the host unit 40 senses the absence of the body unit 20 by the body unit presence / absence detection device 50, the microcomputer 46 controls the switch drive circuit 70 of the relay unit 60 to open the switch 68. Is output. Thus, the antitheft device according to the present embodiment returns to the standby state.

  5 and 6 are schematic views showing application examples of the antitheft device according to the present embodiment.

  As shown in FIG. 5, the input terminal 62 of the relay unit 60 is connected to the positive terminal of the storage battery 12. A battery cable that is normally connected directly to the positive terminal of the storage battery 12 is connected to the output terminal 64 of the relay unit 60. The host unit 40 and the relay unit 60 can be connected by a harness 80. The host unit 40 can be connected with an LED 82 or the like that notifies that the authentication code of the body unit 20 matches.

  As shown in FIG. 6, the relay unit 60 can be connected to the storage battery 12 and installed in the engine room 90. Installing the relay unit 60 in the engine room 90 is extremely effective in preventing theft.

  That is, by installing the relay unit 60 in the engine room 90, the presence of this system can be made inconspicuous. As a result, even if a thief enters the passenger compartment 92 with a key or the like to deal with the inside of the passenger compartment 92, the engine cannot be started.

  In the unlikely event that the harness 80 connecting the host unit 40 and the relay unit 60 is disconnected or short-circuited, the relay unit 60 starts the engine to maintain the previous control state. It is not possible.

  Even if this system is noticed, it is necessary to open the engine room 90 in order to remove the relay unit 60, and it takes a considerable time to start the engine. This has the effect of giving up the thief.

  The host unit 40 can be installed at an arbitrary location in the passenger compartment 92. Considering the convenience of the driver, it is desirable to install the host unit 40 in the vicinity of the driver's seat. The LED 82 can be installed on a location that is easy to see from the driver, for example, on the dashboard 94.

  As shown in FIGS. 5 and 6, the host unit 40 and the relay unit 60 of the anti-theft device according to the present embodiment can be easily installed later without significantly remodeling the equipment of the vehicle. Therefore, it can be easily attached to a vehicle not equipped with a security system such as an immobilizer, and security can be improved.

  As described above, according to the present embodiment, the current necessary for starting the engine is supplied only when the authentication is obtained between the body unit and the host unit. Even if is used, the engine cannot be started. Thereby, the antitheft effect of the vehicle can be enhanced.

[Second Embodiment]
An antitheft device according to a second embodiment of the present invention will be described with reference to FIGS. The same components as those of the antitheft device according to the first embodiment shown in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  7 is a schematic diagram showing the structure of the body unit of the anti-theft device according to this embodiment, FIG. 8 is a schematic diagram showing the structure of the host unit of the anti-theft device according to this embodiment, and FIG. 9 is an anti-theft device according to this embodiment. It is the schematic which shows the example of application.

  The anti-theft device according to the present embodiment is the same as the anti-theft device according to the first embodiment, except that the body unit and the host unit are connected by wire. That is, the overall configuration of the antitheft device 10 according to this embodiment is the same as that of the antitheft device according to the first embodiment shown in FIG. The relay unit is the same as the relay unit 60 of the antitheft device according to the first embodiment.

  First, the body unit 20 and the host unit 40 of the antitheft device according to the present embodiment will be specifically described with reference to FIGS.

  As shown in FIG. 7, the body unit 20 includes an electrical signal / power connection device 34 for transmitting / receiving electrical signals to / from the host unit 40 and supplying power from the host unit 40. A transmission / reception unit power management device 36 is connected to the electrical signal / power connection device 34.

  The electrical signal / power connection device 34 is also connected to a reception signal demodulation device 28 that demodulates the signal received by the electrical signal / power connection device 34. Connected to the received signal demodulator 28 is a microchip core 38 for processing the signal demodulated by the received signal demodulator. The microchip core 38 is also connected to a transmission signal modulation device 32 that modulates a signal output from the microchip core 38. The microchip core 38 stores the procedures of the electrical signal / power connection device 34, the transmission / reception unit power management device 36, the reception signal demodulation device 28, the transmission signal modulation device 32, the authentication ID code, and the transmission power utilization transmission control. ing. An electrical signal / power connection device 34 is connected to the transmission signal modulation device 32.

  The transmission / reception unit power management device 36 is connected to the reception signal demodulation device 28, the microchip core 38, and the transmission signal modulation device 32. The reception signal demodulator 28, the microchip core 38, and the transmission signal modulator 32 are supplied with driving power from the transceiver power management device 36.

  As shown in FIG. 8, the host unit 40 includes a body unit presence / absence detection device 50 that detects the presence / absence of the body unit 20. The body unit presence / absence detection device 50 is connected to a transmission unit power management device 52 that manages the power supplied to the transmission unit based on a signal from the body unit presence / absence detection device 50.

  The host unit 40 also includes an electrical signal / power connection device 54 for transmitting / receiving electrical signals to / from the body unit 20 and supplying power to the body unit 20. The electrical signal / power connection device 54 is connected to a reception signal demodulation device 44 that demodulates the signal received by the electrical signal / power connection device 54. The reception signal demodulator 44 is connected to a microcomputer 46 that processes the signal demodulated by the reception signal demodulator 44. The microcomputer 46 is connected to a transmission signal modulation device 48 that modulates a signal output from the microcomputer 46. The microcomputer 46 stores management / authentication / relay unit 60 state control procedures for the transmission unit power management device 52, the electrical signal / power connection device 54, the reception signal demodulation device 44, and the transmission signal modulation device 48. The microcomputer 46 outputs a state control signal for controlling the relay unit 60. An electrical signal / power connection device 54 is connected to the transmission signal modulation device 48. The electrical signal / power connection device 54, the reception signal demodulation device 44, and the transmission signal modulation device 48 are connected to the transmission / reception unit power management device 52.

  Next, the operation of the antitheft device according to the present embodiment will be described with reference to FIGS. 1, 4, 7 and 8.

  In a state where the vehicle is not used (standby state), the switch 68 of the relay unit 60 is in an open state (open state). In this state, the electric connection path between the input terminal 62 and the output terminal 64 is only the current limiting circuit 66 (see FIG. 4).

  The current limiting circuit 66 is a circuit that limits the supply of a certain current or more to the load. The lower limit value of the limit current is set to be equal to or greater than a current value that can secure at least power required in the standby state (for example, remote control door lock, theft alarm device, standby power for the antitheft device according to the present embodiment). The upper limit value of the limit current is less than the current value (about 1 A to several A) required when starting the engine. By setting the current limit value of the current limit circuit 66 as described above, it is possible to inhibit the start of the engine while supplying necessary power during standby.

  A vehicle user carries the body unit 20. The body unit 20 is not particularly limited, but is a contact IC card, for example. Here, a contact IC card will be described as an example.

  After getting on the vehicle, the user sets the contact type IC card as the body unit 20 in the IC card reader installed in the vehicle. The IC card reader corresponds to at least the electric signal / power connection device 54 and the body unit presence / absence detection device 50 in the host unit 40 of the antitheft device 10 according to the present embodiment.

  When the contact IC card (body unit 20) is set in the IC card reader, the body unit presence / absence detection device 50 recognizes the presence of the body unit 20 and activates the transmission / reception power management device 52. The transmission / reception power management device 52 supplies power to the electric signal / power connection device 54, the reception signal demodulation device 44, and the transmission signal modulation device 48 in the standby power saving state so that transmission / reception with the body unit 20 is possible. .

  The host unit 40 transmits a wake-up message toward the body unit 20. The wake-up message is encoded and modulated from the format sent from the microcomputer 46 by the transmission signal modulation device 48 and is output to the body unit 20 via the electric signal / power connection device 54.

  The body unit 20 activates the electrical signal / power connection device 34, the reception signal demodulation device 28, the microchip core 38, and the transmission signal modulation device 32 by the transmission / reception unit power management device 36. The microchip core 38 stores the management of the reception signal demodulator 28 and the transmission signal modulator 32, the authentication ID code, and the stored power utilization transmission control procedure, and executes control according to the program.

  The wake-up message output from the host unit 40 is input to the electrical signal / power connection device 34 of the body unit 20. Then, the received signal demodulator 28 demodulates and decodes the data into a format that can be read by the microchip core 38, and sends it to the microchip core 38.

  The microchip core 38 that has received the wake-up message outputs a transmission signal including information on the authentication code recorded in the microchip core 38 to the transmission signal modulation device 32. The transmission signal modulation device 32 encodes and modulates the signal sent from the microchip core 38 and outputs it to the host unit 40 via the electric signal / power connection device 34.

  The microcomputer 46 of the host unit 40 stores management / authentication / relay unit 60 state control procedures for the electric signal / power connection device 54, the reception signal demodulation device 44 and the transmission signal modulation device 48, and according to the program. Execute control.

  The electrical signal / power connection device 54 receives the signal output from the body unit 20. The received signal is sent to the received signal demodulator 44 and demodulated and decoded into a format that can be read by the microcomputer 46. The demodulated / decoded received signal is input from the received signal demodulator 44 to the microcomputer 46.

  The microcomputer 46 stores a target code that permits authentication. The microcomputer 46 collates the authentication code of the body unit 20 included in the signal output from the received signal demodulator 44 with the authentication object code stored in the microcomputer 46.

  The microcomputer 46 outputs a state control signal corresponding to the verification result between the authentication code of the body unit 20 and the authentication target code stored in the microcomputer 46 to the relay unit 60.

  If the authentication code of the body unit 20 does not match the authentication object code stored in the microcomputer 46, the microcomputer 46 opens the switch 68 for the switch drive circuit 70 of the relay unit 60. Control signal for output. In this state, the electric connection path between the input terminal 62 and the output terminal 64 is only the current limiting circuit 66, and the engine cannot be started.

  On the other hand, when the authentication code of the body unit 20 matches the authentication object code stored in the microcomputer 46, the microcomputer 46 closes the switch 68 with respect to the switch drive circuit 70 of the relay unit 60. A control signal for outputting is output.

  When the switch 68 is closed, the electrical connection path between the input terminal 62 and the output terminal 64 becomes the current limiting circuit 66 and the closed switch 68. As a result, the current limitation between the input terminal 62 and the output terminal 64 is eliminated, and a current necessary for starting the engine is allowed. Thereby, the engine can be started.

  When the user stops the engine and leaves the vehicle, the body unit 20 is moved away from the host unit 40. When the host unit 40 senses the absence of the body unit 20 by the body unit presence / absence detection device 50, the microcomputer 46 controls the switch drive circuit 70 of the relay unit 60 to open the switch 68. Is output. Thus, the antitheft device according to the present embodiment returns to the standby state.

  FIG. 9 is a schematic view showing an application example of the antitheft device according to the present embodiment.

  As shown in FIG. 9, the input terminal 62 of the relay unit 60 is connected to the positive terminal of the storage battery 12. A battery cable that is normally connected directly to the positive terminal of the storage battery 12 is connected to the output terminal 64 of the relay unit 60. The host unit 40 and the relay unit 60 can be connected by a harness 80. The host unit 40 can be connected with an LED 82 or the like that notifies that the authentication code of the body unit 20 matches.

  Also in the case of the antitheft device according to the present embodiment, as shown in FIG. 6, the relay unit 60 can be connected to the storage battery 12 and installed in the engine room 90. Installing the relay unit 60 in the engine room 90 is extremely effective in preventing theft.

  That is, by installing the relay unit 60 in the engine room 90, the presence of this system can be made inconspicuous. As a result, even if a thief enters the passenger compartment 92 with a key or the like to deal with the inside of the passenger compartment 92, the engine cannot be started.

  In the unlikely event that the harness 80 connecting the host unit 40 and the relay unit 60 is disconnected or short-circuited, the relay unit 60 starts the engine to maintain the previous control state. It is not possible.

  Even if a theft notices this system, it is necessary to open the engine room 90 in order to remove the relay unit 60, and it takes a considerable time to start the engine. This has the effect of giving up the thief.

  The host unit 40 can be installed at an arbitrary location in the passenger compartment 92. Considering the convenience of the driver, it is desirable to install the host unit 40 in the vicinity of the driver's seat. The LED 82 can be installed on a location that is easy to see from the driver, for example, on the dashboard 94.

  The host unit 40 and the relay unit 60 of the antitheft device according to the present embodiment can be easily installed later without significantly modifying the equipment of the vehicle. Therefore, it can be easily attached to a vehicle not equipped with a security system such as an immobilizer, and security can be improved.

  As described above, according to the present embodiment, the current necessary for starting the engine is supplied only when the authentication is obtained between the body unit and the host unit. Even if is used, the engine cannot be started. Thereby, the antitheft effect of the vehicle can be enhanced.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications can be made.

  For example, in the above embodiment, the body unit is a non-contact type or contact type IC card, but the body unit is not limited to the IC card. The form of the body unit is not particularly limited as long as it has a function of recording the authentication code and reading the information from the outside. For example, a body unit may be embedded in a key like a transponder of an immobilizer, or a body unit may be embedded in a key holder.

  In the first embodiment, passive RFID is used as the body unit 20, but active RFID may be used.

  Moreover, although the case where the authentication system using an IC card was utilized was shown in the said embodiment, the authentication system applicable to the security system of this invention is not limited to this. Any authentication system having an authentication means for authenticating a user possessing the authenticated means based on the identification information transmitted from the authenticated means storing the unique identification information can be applied to the security system of the present invention. it can.

  In addition, the internal configurations of the body unit 20, the host unit 40, and the relay unit 60 described in the above embodiment are merely examples, and are not limited thereto. Modifications and changes can be made as necessary.

  Moreover, although the example which utilized the security system of this invention for the vehicle antitheft device was shown in the said embodiment, the application which can apply the security system of this invention is limited to the antitheft device for vehicles. is not.

  For example, a device that determines some “permitted / prohibited” state based on a current from the power supply side is regarded as a load, and the current system is restricted to be held in a prohibited state by restricting current power supply. It can be used as a security system against locks and picking.

FIG. 1 is a schematic diagram showing the overall configuration of an antitheft device according to a first embodiment of the present invention. FIG. 2 is a schematic view showing the structure of the body unit of the antitheft device according to the first embodiment of the present invention. FIG. 3 is a schematic diagram showing the structure of the host unit of the anti-theft device according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing the structure of the relay unit of the antitheft device according to the first embodiment of the present invention. FIG. 5 is a schematic diagram (part 1) showing an application example of the anti-theft device according to the first embodiment of the present invention. FIG. 6 is a schematic diagram (part 2) illustrating an application example of the antitheft device according to the first embodiment of the present invention. FIG. 7 is a schematic view showing the structure of the body unit of the anti-theft device according to the second embodiment of the present invention. FIG. 8 is a schematic view showing the structure of the host unit of the anti-theft device according to the second embodiment of the present invention. FIG. 9 is a schematic diagram showing an application example of the anti-theft device according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Anti-theft device 12 ... Storage battery 14 ... Load 20 ... Body unit 22 ... Radio signal transmission / reception device 24 ... Reception signal power converter 26 ... Power storage device 28 ... Reception signal demodulation device 30 ... RFID microchip core 32 ... Transmission signal modulation Device 34 ... Electric signal / power connection device 36 ... Transmission / reception unit power management device 38 ... Microchip core 40 ... Host unit 42 ... Radio signal transmission / reception device 44 ... Reception signal demodulation device 46 ... Microcomputer 48 ... Transmission signal modulation device 50 ... Body Unit presence / absence detection device 52 ... transmission unit power management device 54 ... electric signal / power connection device 60 ... relay unit 62 ... input terminal 64 ... output terminal 66 ... current limiting circuit 68 ... switch 70 ... switch drive circuit 80 ... harness 82 ... LED
90 ... engine room 92 ... vehicle compartment 94 ... dashboard

Claims (7)

An anti-theft device for a vehicle,
Authentication means for authenticating a user possessing the authenticated means based on the identification information transmitted from the authenticated means in which unique identification information is stored;
An antitheft device, comprising: a current limiting unit that is provided between the storage battery and a load and limits a current supplied from the storage battery based on an authentication result by the authentication unit. The anti-theft device according to claim 1,
The current limiting means does not limit the current supplied from the storage battery when the authentication by the authentication means is obtained, and the current supplied from the storage battery when the authentication by the authentication means is not obtained. An anti-theft device characterized in that the current is limited to less than the current value required for starting. The antitheft device according to claim 1 or 2,
The anti-theft device, wherein the current limiting unit includes a switch controlled based on an authentication result by the authentication unit, and a current limiting circuit connected in parallel to the switch. The antitheft device according to any one of claims 1 to 3,
The anti-theft device, wherein the authentication means receives the authentication information wirelessly from the authenticated means. The antitheft device according to any one of claims 1 to 3,
The anti-theft device, wherein the authentication means receives the authentication information from the authenticated means by wire. The antitheft device according to any one of claims 1 to 5,
The authentication means is installed in a passenger compartment,
The anti-theft device, wherein the current limiting means is installed in an engine room. Authentication means for authenticating a user possessing the authenticated means based on the identification information transmitted from the authenticated means in which unique identification information is stored;
A security system, comprising: a current limiting unit that is provided between a power source and a load and limits a current supplied from the power source based on an authentication result by the authentication unit.

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