JP4008141B2 - Regular ID code reading method and anti-theft device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for reading a specific ID code from a plurality of transponders in which ID codes are individually set, and an antitheft device using the method.
[0002]
[Prior art]
This type of conventional apparatus will be described below with reference to FIGS.
That is, the key cylinder 51 is formed with a hole 53 into which the tip 52a of the key 52 is inserted, and the key cylinder 51 is provided with an annular rotor case 54. The rotor case 54 has a cylindrical rotor. 55 is rotatably mounted.
[0003]
The rotor 55 is formed with a key insertion port 56 communicating with the hole 53 of the key cylinder 51. An annular core 57 is disposed in the rotor case 54 on the outer periphery of the rotor 55, and a part of the annular core 57 is exposed on the entrance side of the key insertion port 56. As shown in FIG. 7, vehicle-side coils 58 and 59 are wound around the annular core 57 in the same direction, and an induction magnetic field is generated in a direction perpendicular to the key rotation axis XX of the key 52.
[0004]
On the other hand, the grip 52b of the key 52 is provided with a shaft-shaped core 60 that forms a magnetic circuit with the annular core 57, and the shaft-shaped core 60 is magnetically coupled to the vehicle side coils 58 and 59. A side coil 61 is wound. The key-side coil 61 is connected to a series resonance circuit K1 including a capacitor C1 and a coil L1, and the series resonance circuit K2 including a capacitor C2 and a coil L2 is connected in parallel to the series resonance circuit K1.
[0005]
Next, the operation will be described.
Now, when the key 52 is inserted from the key insertion port 56 of the key cylinder 51, a frequency signal for ID code detection is supplied from the controller side (not shown) to the vehicle side coils 58 and 59. This signal is a sine wave signal and changes from a low frequency to a high frequency within a predetermined range. The key side coil 61 receives the frequency signal for detecting the ID code via the annular core 57 and the shaft-shaped core 60, and the frequency of the received signal is the resonance frequency f1, f2 of any of the series resonance circuits K1, K2. , The current flowing through the key side coil 61 increases.
[0006]
Then, the resonance frequencies f1 and f2 due to the current increase are detected by the vehicle side coils 58 and 59, and the controller reads the ID code set in the key 52 based on the detected resonance frequencies f1 and f2, and the ID code and Then, it is determined whether or not the vehicle-side registered ID code stored in the ROM (not shown) of the controller matches, and the engine can be started only by outputting a signal for permitting engine start. To do.
[0007]
8 and 9 are different from the above-described conventional example, and the vehicle-side coil 71 is configured by winding a coil wire in a circular groove on the outer peripheral surface of a cylindrical bobbin 72 for a predetermined number of turns. In addition, both end portions 71a and 71b of the vehicle side coil 71 are connected to the vehicle side electric circuit via lead wires 73a and 73b in a terminal portion 72a integrally formed with the cylindrical bobbin 72.
[0008]
The terminal portion 72a is parallel to the cylinder axis, that is, the key rotation axis XX by inserting the cylindrical bobbin 72 into the key cylinder 74 as shown in FIG. To be extended. The cylindrical bobbin 72 is attached to engage with the outer periphery of the key cylinder 74 on the key insertion port 74a side. Therefore, the induction magnetic field generated from the vehicle side coil 71 is generated in parallel with the key rotation axis XX.
[0009]
[Problems to be solved by the invention]
However, in the antitheft device as described above, as shown in FIG. 10, after the keys 52, 75, and 76 are inserted into the key insertion ports 56 and 74a, the vehicle side coil 71 and the transponder 75a are electromagnetically coupled to supply power. The induction magnetic field generated from the vehicle side coil 71 fed from the circuit 78 is generated in parallel with the key rotation axis XX and in the vicinity of the vehicle side coil 71.
[0010]
Therefore, for example, when a plurality of keys 75 and 76 are attached to the key holder 77 as shown in FIG. 10, the key cylinder 74 is not attached horizontally but is attached obliquely as shown in the figure. The key-side coils 75 b and 76 b built in the keys 75 and 76 are easily located in the induction magnetic field generated from the vehicle-side coil 71, and these key-side coils 75 b and 76 b are connected to the vehicle-side coil 71. It becomes easy to be mutually electromagnetically coupled.
[0011]
As a result, when the ID code request signal stored in the memory 80 is transmitted to the vehicle side coil 71, the vehicle side coil 71 is transmitted from the transponders 75a and 76a of these keys 75 and 76, respectively. The ID code is received at the same time, and the ID code information receiving / decoding circuit 79 has a problem that the ID code is confused and cannot be decoded. The ID code information reception decoding circuit 79 outputs an engine start signal for permitting engine start when the received ID code matches the registered ID code.
[0012]
Accordingly, an object of the present invention is to enable quick or reliable verification even when a plurality of keys are attached to a key holder.
[0013]
[Means for Solving the Problems]
The transponder ID code reading method of the first invention is a transponder ID code reading method for transmitting a password request signal and an ID code request signal from a controller unit to a plurality of transponders and reading the password and ID code from the specific transponder. The ID code request signal is transmitted to the plurality of transponders, and if the ID code returned from the transponder cannot be read correctly by the controller unit, the password request signal is transmitted and the ID code returned thereto is transmitted. Is a method of reading.
[0014]
The anti-theft device of the second invention is a transponder in which a password and an ID code are individually set, a control unit that transmits an ID code request signal to the transponder and reads an ID code transmitted from the specific transponder; In the anti-theft device, the control unit first transmits an ID code request signal to the transponder, and determines whether the transponder is genuine based on an ID code returned from the transponder. If it cannot be determined, the device transmits a password request signal, reads the ID code returned to the password request signal, and makes a determination.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
Embodiment 1 FIG.
In FIG. 1, the same or equivalent components as those shown in FIG. 10 are denoted by the same reference numerals, detailed description thereof is omitted, and different parts, that is, an ID code information receiving / decoding circuit 79 ′ and a power feeding circuit are provided. The program processing portion 78 'will be described below based on the flowcharts shown in FIGS. As shown in FIG. 4, the memory 80 stores, for example, passwords and ID codes of five types of keys (key 1, key 2, key 3, key 4, key 5).
That is,
(1) The password for key 1 is A and the ID code is abcde
(2) Key 2 password is B, ID code is bcdef
(3) The password for key 3 is C, and the ID code is cdefg
(4) The key 4 password is D and the ID code is defgh
(5) The password for key 5 is E, and the ID code is efghhi
Is set and stored.
[0016]
1 is turned on, the program processing portion of the vehicle-side electric circuit proceeds from step 100 to step 110 as shown in FIG. Is inserted into the key insertion port 74a of the key cylinder 74 and waits for detection that a key switch (not shown) is turned on.
[0017]
In step 110, when it is detected that the key switch is turned on at time T1 (corresponding to the key SW in FIG. 2), the process proceeds to step 120. By outputting a frequency signal for exciting the side coil 71, electromagnetic waves having a constant frequency are supplied to the vehicle side coil 71, and an induction magnetic field is generated from the vehicle side coil 71. As a result, the transponder 75a (or 76a) is charged for Tb time.
[0018]
When Tb time elapses and charging is completed, the process proceeds to the next step 130, and during the next Tc time, an ID code request signal is output to the vehicle side coil 71, and the ID code request is sent from the vehicle coil 71. An induced magnetic field indicating a signal is generated. For this purpose, the ID request signal is read from the memory 80, and an induced magnetic field corresponding to the ID code request signal is output from the vehicle side coil 71. Thereafter, the process proceeds to step 140. In step 130, the key 1 password request signal “A” is not output.
[0019]
In step 140, the ID code information receiving / decoding circuit 79 ′ receives the ID code returned from the transponder 75a (or 76a) (during the time Td in FIG. 2), proceeds to step 150, and the received result is the transponder. When only the ID code indicating, for example, the ID code “abcde” of the key 1 from one of 75a (or 76a) is returned, the ID code can be read without confusion at normal times. Therefore, the process proceeds to step 160. If the read ID code is checked against the registered regular ID code and is verified as a regular ID code, the process proceeds to step 170, and the main main program, for example, engine start control When the program is activated and completes, it proceeds to step 180 and ends. If it is determined in step 160 that the code is not a regular ID code, the process returns to step 110 and the above steps are repeated again. That is, the second reading starts. This repetition is performed up to three times, for example, and is not performed thereafter.
[0020]
In step 150, if both transponders 75a and 76a return the signal indicating the ID code “abcde” of key 1 and the ID code “bcdef” of key 2 at the same time, the ID codes are confused. Since it is determined that it cannot be decoded, the process proceeds to step 190, and the second reading step in FIG. 2 is entered.
[0021]
That is, in step 190, as in step 120, an induction magnetic field is generated from the vehicle-side coil 71 for Tb time, and the transponder 75a (or 76a) is charged.
[0022]
After that, the routine proceeds to step 200, and during the next time Tf, in order to generate an induction magnetic field corresponding to a signal indicating the password “A” of the key 1 stored in the head address of the memory 80, for example, from the vehicle side coil 71. First, the memory 80 is instructed to output the password “A” of the key 1, and the process proceeds to step 210.
[0023]
In step 210, the ID code returned from the transponder 75a (or 76a) during the time Td is received. In the next step 220, it is determined whether or not the received ID code is authentic. If it is not verified that is correct, the process returns to step 190, and the process up to key 5 in FIG. 4 is executed in order until the regular ID code is verified. In FIG. 2, the time Te is a blank section for distinguishing the first reading, the second reading, the second reading, the third reading, and the like.
[0024]
【The invention's effect】
According to the first invention, it is possible to obtain a method capable of reliably reading an ID code in a short time even when a plurality of keys are attached to the key holder and carried.
According to the second aspect of the present invention, the ID code can be collated in a short time and reliably even when the key is inserted into the cylinder with a plurality of keys attached to the key holder, and the operability can be improved.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of an antitheft device according to the present invention.
FIG. 2 is a timing chart for explaining the operation of what is shown in FIG.
FIG. 3 is a flowchart for explaining the operation of what is shown in FIG. 1;
4 is a diagram for explaining a password and an ID code stored in a memory 80 in FIGS. 1 and 5. FIG.
FIG. 5 is a front view showing a key insertion slot of a key cylinder.
FIG. 6 is a longitudinal sectional view showing a first conventional vehicle key device.
7 is a perspective view showing a vehicle coil in the vehicle key device in FIG. 6. FIG.
FIG. 8 is a front view showing a vehicle side coil in a second conventional vehicle key device.
9 is a side view showing a vehicle side coil in FIG. 8. FIG.
FIG. 10 is a side view showing a key insertion state with respect to the key cylinder.
[Explanation of symbols]
51, 74 Key cylinder 71 Vehicle side coil 75a, 76a Transponder 75b, 76b Key side coil 78, 78 'Feeding circuit 79, 79' ID code information reception decoding circuit 80 Memory

Claims (2)

An ID of a transponder that transmits an ID code request signal from a control unit to a plurality of transponders each having a unique password and ID code, and reads an ID code returned from the transponder that has received the ID code request signal. In the code reading method,
When the ID code request signal is first transmitted to the transponder, and the ID code returned from the transponder that received the ID code request signal cannot be read correctly by the control unit, a specific password is transmitted next time and the password is included. A transponder ID code reading method, comprising: reading an ID code returned from a transponder. A transponder in which a unique password and ID code are set, an ID code request signal is transmitted to the transponder, an ID code returned from the transponder that has received the ID code request signal is read, and the read ID code In a theft prevention device comprising a control unit that determines whether or not the ID matches a regular registration ID code and controls the driving of the actuator,
The control unit first transmits an ID code request signal to the transponder, and determines whether or not the ID code returned from the transponder that received the ID code request signal matches the registered ID code. The anti-theft device is characterized in that, next time, a specific password is transmitted, an ID code returned from a transponder having the password is read, and it is determined whether or not it matches the registered ID code.

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