JPH0476175A - Keyless entry system - Google Patents

Abstract

PURPOSE:To improve an antitheft function yet more by applying a specified process to a fixed signal transmitted from a keyless entry receiver on the basis of a random signal, and adding an alteration to it. CONSTITUTION:In response to a first signal consisting of a fixed signal A transmitted out of a keyless entry transceiver 2, a second signal consisting of a random signal B is generated out of a body side transceiver 3. Next, a specified process is added to the second signal transmitted from the body side transceiver 3 and a third signal C is generated at the keyless entry transceiver 2. In succession, whether the third signal C transmitted from the keyless entry transceiver 2 is a normal signal or not is judged at the body side transceiver 3. When it is judged to be the normal one, a door locking mechanism is operated by a door lock control means.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a keyless entry device for locking or unlocking the doors of an automobile by remote control from outside the vehicle.

(Prior Art) Generally, a key cylinder device is attached to the door of an automobile, and the door is usually locked or unlocked by inserting a key into the key insertion slot of the key cylinder device and rotating the key. However, with this method of locking and unlocking, there is a problem that it is troublesome to operate, for example when you have a lot of luggage in your hand or when operating in a dark place. There is a problem that the key cylinder device may be forced open by inserting the key cylinder device. Therefore, as described in, for example, Japanese Unexamined Patent Publication No. 63-31847, a keyless entry device has been proposed in which doors are locked and unlocked by remote control using signals. This keyless entry device is
Normally, as described in the above publication, a signal consisting of a multi-bit key code is transmitted from a remote control key (transmitter) outside the vehicle to a receiver installed on the vehicle body. It is configured to determine whether the received key code is legitimate, and if so, to automatically lock or unlock the door.

(Problem to be Solved by the Invention) However, in conventional keyless entry devices, since the signal transmitted from the transmitter to the receiver is a fixed key code signal, the signal may be decoded. The problem is that theft is inevitable.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a keyless entry device with improved anti-theft performance.

(Means for Solving the Problems) The present invention improves theft prevention by exchanging signals between a keyless entry transmitter/receiver and a vehicle body side transmitter/receiver, and making predetermined changes to the signals in the process of transmitting and receiving the signals. Its composition is as follows. That is, the keyless entry device according to the present invention is a keyless entry device consisting of a combination of a keyless entry transmitter/receiver and a vehicle body side transmitter/receiver, and is provided in the vehicle body side transmitter/receiver and transmits data from the keyless entry transmitter/receiver. a first signal processing means for generating a second signal in response to the first signal transmitted from the vehicle; a second signal processing means for generating the added third signal; and a determining means for determining that the second signal, which is not transmitted from the keyless entry transmitter/receiver and is provided in the vehicle body side transceiver, is a regular signal. and door lock control means for operating the door lock mechanism when the third signal is determined by the determination means to be a regular signal.

(Function) When the first signal is transmitted from the keyless entry transceiver to the vehicle transceiver, the vehicle transceiver uses a first signal processing means to generate a random signal, etc., according to the first signal. This signal is then sent to the keyless entry transceiver. Next, in the keyless entry transceiver, a second signal processing means generates a third signal by subjecting the second signal to predetermined processing, and transmits this signal to the vehicle body transceiver. Then, in the vehicle transceiver, the determination means determines whether the third signal is a regular signal, and if it is a regular signal, locks or unlocks the door.

(Example) Fig. 1 is a system explanatory diagram of a keyless entry device according to an embodiment of the present invention, Fig. 2 is a perspective view of a key in the same embodiment, and Fig. 3 is a system configuration diagram of the vehicle body side transceiver. ,
FIG. 4 is a system configuration diagram of the keyless entry transmitter/receiver.

In this embodiment, only the door is unlocked by remote control, and the keyless entry device is
It is composed of a keyless entry transmitter/receiver 2 provided integrally with the engine key l, and a vehicle body side transmitter/receiver 3. Of these, the control unit 4 of the vehicle side transceiver 3 is provided with a random number generation section 7 connected to a clock section 6 of a clock 5 provided in the vehicle interior, and the random number generation section 7 is provided with a code change section 8. is connected, and this code change section 8
is connected to the transmitting antenna 9 and has a memory lO
, and is connected to a receiving antenna 12 via a code identification section 11. Further, the code changing unit 8 is connected to a battery power source (10B), and the code identifying unit 11 is connected to the door auto-lock mechanism I3. Note that the clock section 6 of the timepiece 5 is connected to a battery power source (10B), and the display section 14 is also connected to this.

On the other hand, the keyless entry transceiver 2 is provided with an entry switch 15, a code transmission circuit 16 is connected to the entry switch 15, and a power source battery 17. Code change section 18. A transmitting antenna 19 is connected. Further, a receiving antenna 20 is connected to the code changing section 18 . Note that in FIG. 2, reference numeral 21 is a terminal for connecting to the control unit 4 when rewriting the code.

The operation of the keyless entry device of this embodiment will be described below with reference to FIGS. 1, 3, and 4.

First, when the entry switch 15 of the keyless entry transceiver 2 (key side) is pressed, the code transmission circuit 1
A fixed signal (A) consisting of a predetermined key code is transmitted from 6 to the vehicle body side transceiver 3 via the transmitting antenna 19.

In the vehicle side transceiver 3, after receiving the fixed signal (A) with the receiving antenna 12, it is sent to the code identification section 11, and the code identification section 11 checks whether the above signal matches the key code stored in the memory IO. If the two are different, the following processing is not performed. On the other hand, if the two match, a random signal (B) is generated in the code changing unit 8 using a random number generated by the random number generating unit 7 based on the clock signal from the clock unit 6, and the random signal (B) is It is sent back to the keyless entry transceiver 2 via the transmitting antenna 9.

In the keyless entry transceiver 2 , the random signal (B) is received by the receiving antenna 20 and then sent to the code changing section 18 . The code changing unit 18 performs signal conversion based on the random signal (B) using the formula C=Bx3+l to obtain a signal (C), and transmits this signal (C) via the code generating circuit 16. The signal is again transmitted from the transmitting antenna I9 to the vehicle transceiver 3.

On the other hand, at the same time as the random signal (B) is generated, the code changing section 8 of the vehicle side transceiver 3 generates a signal using the same calculation formula (C=BXa+1) as the code changing section 18 in the keyless entry transceiver 2. A conversion is performed and the conversion result is stored in memory IO. Then, when the signal (C) from the keyless entry transceiver 2 is sent to the code identification unit 11 via the receiving antenna 12, this signal (C) and the above signal stored in the memory IO are compared. Then, it is determined whether the two match. If they match, a signal is sent to the door auto-lock mechanism 13, and the door is unlocked.

As described above, in this embodiment, the fixed signal transmitted from the keyless entry transceiver is changed in a predetermined manner based on the random signal, so even if this fixed signal is decoded, the door will still be unlocked. never gets locked,
A keyless entry device with improved anti-theft performance can be obtained.

Note that the present invention can also be implemented in such a way that both locking and unlocking of the door are performed by remote control.

(Effects of the Invention) The present invention is configured as described above, and the signal can be changed in a predetermined manner during the signal transmission/reception process of the keyless entry device, so that the anti-theft performance can be further improved.

[Brief explanation of drawings]

FIG. 1 is a system explanatory diagram of a keyless entry device according to an embodiment of the present invention, FIG. 2 is a perspective view of a key in the same embodiment, and FIG. 3 is a system configuration diagram of a transceiver on the vehicle body side.
FIG. 4 is a system configuration diagram of the keyless entry transmitter/receiver. 2; Transmitter/receiver for keyless entry; 3; Vehicle body side transceiver; 4; Control unit; 7: Random number generator; 8:
Code changing section, (1) Code identifying section, 13 Niorode lock mechanism, 16: Code transmitting circuit, 18: Code changing section.

Claims (1)

[Claims] (1) A keyless entry device consisting of a combination of a keyless entry transceiver and a vehicle-side transceiver, which is provided in the vehicle-side transceiver and responds to a first signal transmitted from the keyless entry transceiver. a first signal processing means for generating a second signal using the keyless entry transceiver, and generating a third signal by performing predetermined processing on the second signal provided in the keyless entry transceiver and transmitted from the vehicle body side transceiver. a second signal processing means for determining that the third signal provided in the vehicle-side transceiver and transmitted from the keyless entry transceiver is a regular signal; A keyless entry device comprising a door lock control means for operating a door lock mechanism when the third signal is determined to be a regular signal.