JPH07127317A - Keyless entry device - Google Patents

Abstract

PURPOSE:To prevent the displacement of a transmission code and a reception code, and to improve reliability by installing a device advancing the reception code until the reception code coincides with the transmission code on a receiver receiving key code signals different at every time and conducting release. CONSTITUTION:Key code signals consisting of fixed codes set at every automobile and rolling codes different at every time are transmitted from a transmitter 1, the signals are received by a receiver 2, and an actuator 3 is driven and release is performed when the signals coincide with a code stored in a memory 22. When a code advancing more than the codes of the receiver is transmitted at that time, the codes of the receiver are advanced until the codes of the receiver agree with transmission codes. The conformed codes are stored previously in the memory 22 as the next reference codes. When there is no response due to the displacement of the transmission codes and the reception codes, the key code signals are transmitted again and conformed within a fixed time. Accordingly, the displacement of the codes is corrected, and normal operation is enabled while malfeasant release can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyless entry device for transmitting a predetermined key code signal from a transmitter to perform a response operation such as unlocking.

[0002]

2. Description of the Related Art A keyless entry device of this type is designed to perform a response operation such as unlocking when a transmission code sent from a transmitter and a reception code on the receiver side match. As a countermeasure against unauthorized use by a remote controller or the like, there is also an apparatus in which the transmission code is changed for each transmission and the reception code on the receiving side is sequentially switched correspondingly. This device is a one-way communication method that does not have a transmission function from the receiving side to the transmitting side, and the key code signal is switched by a certain calculation formula, for example, and the calculation formula should be different for each device. Gives a specific combination of transmitter and receiver with the same formula.

In such a device, for example, if the transmitter is operated alone when the receiver cannot receive the transmission code, only the transmission code of the transmitter advances to the next key code signal, and the transmission code and the reception code are separated from each other. It may shift. For this reason, it is necessary for the receiver side to be equipped so that it can respond to a plurality of key code signals within a certain range. There was a problem of lowering.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object thereof is to improve the reliability of the device by limiting the number of key code signals that enable a response operation to one. It is a thing.

[0005]

In order to achieve the above object, according to the present invention, when a transmission code which is ahead of the reception code is transmitted, the transmission code and the reception code corresponding to the transmission code are transmitted next time. The received code of the receiver is advanced to the code that matches.

In this case, when the transmission code is input to the receiver, the reception code of this time is obtained based on the reception code of the previous time, the reception code of this time is compared with the transmission code, and the reception code of this time is compared with the next time. When the input transmission code and the current reception code do not match, record the code that matches the current input transmission code as the next reference reception code. A receiver can be configured.

Further, when the transmission code is input to the receiver, the reception code recorded for reference is compared with the transmission code and the reception code advanced by 1 from the reception code recorded for reference is next. If the input transmission code and the reference reception code do not match, the code advanced by 1 from the transmission code input this time is set as the next reception code for the reference. The receiver can be configured to record.

[0008]

By advancing the reception code of the receiver to a code that coincides with the transmission code next time, the deviation between the transmission code and the reception code is corrected and normal operation can be performed next time.

[0009]

EXAMPLE Next, one example shown in the figure will be described. FIG. 1 is a schematic block diagram, and FIG. 2 is a configuration diagram of a key code signal.

In FIG. 1, 1 is a transmitter, 2 is a receiver,
Reference numeral 3 is an actuator of a receiving-side device that is a target of control by this device, such as a vehicle door lock device. The transmitter 1 includes a microcomputer 11 and a memory 1.
2, signal output circuit 13, transmission unit 14, transmission switch 15
And the like, and the receiver 2 includes a microcomputer 21, a memory 22, a receiver 23, and a signal input circuit 2.
4, a drive circuit 25 and the like are provided.

The memories 12 and 22 are non-volatile and store the same calculation formulas used for switching the key code signal.
A new rolling code is calculated every time when is operated, and a key code signal including the new rolling code is transmitted from the transmitter 14 as a transmission code. In the receiver 2, when the transmission code is received by the reception unit 23, a rolling code that is compared with the rolling code of the transmission code is calculated by the above formula, and when the transmission code and the reception code match, a drive signal is output from the microcomputer 21. Is output,
The actuator 3 is driven by the drive circuit 25, and a response operation such as unlocking is performed. The transmission unit 14 and the reception unit 23 are configured to transmit and receive signals by infrared rays or ultrasonic waves, for example.

The key code signal used in this apparatus is composed of a fixed code A and a rolling code B which changes every transmission as shown in FIG. The fixed code A is a code fixed for each specific combination of the transmitter and the receiver. For example, if this keyless entry device is for locking and unlocking a car door, it is set for each car and the signal of another car is set. It is designed not to respond to. In this specification, a signal transmitted from the transmitter 1 is referred to as a transmission code, and a signal used in the receiver 2 for comparison with the transmission code is referred to as a reception code. As a general term for these, a key code signal or simply Uses code terminology.

Next, the operation will be described with reference to FIG. This Figure 3
The flowchart of (1) shows the procedure on the receiver side in the embodiment corresponding to claim 2.

First, when the transmission code transmitted from the transmitter 1 is input to the receiver 2, steps S1 to S
The routine proceeds to step 2, where it is determined whether or not the fixed codes match. If they do not match, the procedure returns to step S1. If they match, the procedure proceeds to step S3. In this step S3, it is determined whether or not the rolling code included in the transmission code is an unused one. If it is already used, the process returns to step S1. If it is not used, the process proceeds to step S4.

Step S4 is a step of calculating the reception code used for comparison with the transmission code by using the above calculation formula. In this embodiment, the rolling code used for the previous comparison is recorded in the work area as a reference, and the rolling code in the next order, that is, the rolling code used this time is obtained from the previous rolling code. Then, the obtained rolling code is compared with the rolling code of the input transmission code in step S5. If they match, the process proceeds to step S6, the actuator 3 is driven, and a predetermined response operation is performed.

Since the rolling code of the transmission code input this time is used as a reference for the next operation, this code is moved to the work area in step S7 to prepare for the next operation. After that, the process returns to step S1. This is the step S until the next transmission code is input.
When 1 is repeated and there is an input, the operations in and after step S2 are restarted.

The above is the operation in the normal case where the transmission code and the reception code match, but if there is a deviation between the transmission code and the reception code, steps S5 to S
Go to 8. Here, the rolling code used last time is once recorded in the memory area, and the rolling code of the transmission code input this time is moved to the work area as in step S7, which causes a deviation between the transmission code and the reception code. Is fixed. At the same time, the timer built in the microcomputer 21 is started and step S9
Proceed to.

The above-mentioned timer is set to a relatively short value, for example, about 3 seconds, and if the transmission code is input to the receiver 2 within this time, the process proceeds to step S2. In this case, the rolling code of the transmission code sent from the transmitter 1 is
It is one more advanced than the rolling code used last time and moved to the work area in step S8, and this time matches the code obtained in step S4. Therefore, the procedure can proceed from step S5 to S6, and even if it cannot respond to the first transmission due to the gap between the transmission code and the reception code, it can be transmitted again within the set time of the timer. The response operation will be performed without any trouble.

If the fixed code coincides with the transmitter 1 which is not a legitimate one, or if the fixed code matches due to illegal use by a learning remote controller or the like, the process can proceed to step S4. However, since the rolling code of the transmission code is different, steps S5 to S6 are performed.
Cannot be reached and no response action is taken.

If the process proceeds from step S5 to step S8 and is not transmitted within the set time, the timer expires and the process proceeds to step S10, where the previous rolling code recorded in the memory area in step S8 is used as a reference. It is moved to the work area again for use. For this reason, since the transmission code and the reception code return to the initial state in which they are misaligned, in the case of the regular transmitter 1, the response operation can be performed by performing the above-described two consecutive transmission operations again. However, in other cases, the response operation cannot be performed.

As described above, since the number of key code signals that can be responded to is limited to one, it is extremely unlikely that a response operation can be performed by an operation other than the proper owner of the transmitter 1. Moreover, according to this embodiment, when there is no response due to the difference between the transmission code and the reception code, it is necessary to retransmit within a predetermined time, and a response operation can be performed by a transmission operation by a person who does not know this. The probability of becoming lower becomes even lower, and high reliability is obtained.

In the above embodiment, the switching to the reception code used for comparison with the transmission code is performed after the transmission code is received. It is also possible to proceed to the next code and directly compare it with the reception code when the transmission code is input. This corresponds to claim 3, and FIG. 4 shows the procedure on the receiver side in the embodiment. In this case, the handling of the reference code is slightly different, and the procedure is basically the same as that shown in FIG. 3, and a device that responds only to the case of a legitimate transmitter and does not respond to other cases can be obtained.

Explaining the parts different from FIG. 3, step S15 corresponds to step S5 of FIG. 3, and here, the rolling code recorded as the reference is the same as the rolling code of the input transmission code. Directly contrasted. Step S14 is step S4
Which is inserted after step S6,
A rolling code that is one step ahead of the input transmission code is calculated, and this is calculated in step S1 corresponding to step S7.
Put it in the work area for reference at step 7. Further, step S18 corresponds to step S8, in which the reference code used in step S15 is temporarily recorded in the memory area, and the rolling code which is advanced by 1 from the transmission code input this time is used as in the case of step S17. It is moved to the area and the deviation between the transmitted code and the received code is corrected.

[0024]

As is apparent from the above description, according to the present invention, the transmission code is changed for each transmission, and when the transmission code and the reception code match, a predetermined response operation is performed on the receiver side. In the keyless entry device, when a transmission code that is ahead of the reception code is transmitted, the reception code of the receiver is advanced to the next code corresponding to the transmission code until the transmission code and the reception code match. Is.

Therefore, the number of key code signals capable of responding is limited to one, and there is a possibility that the responding operation may be performed between a transmitter and a receiver having different combinations or by an operation of an unauthorized user by a learning remote controller or the like. Extremely low,
Moreover, even if the transmitter and the receiver are operated independently and the transmission code and the reception code are misaligned, the misalignment between the legitimate transmitter and the receiver can be easily corrected to perform the response operation without any trouble. Therefore, it is possible to obtain a highly reliable and easy-to-use device.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a key code signal in the embodiment.

FIG. 3 is a flowchart showing a control procedure of the embodiment.

FIG. 4 is a flowchart showing a control procedure of another embodiment.

[Explanation of symbols]

 1 Transmitter 2 Receiver 3 Actuator 11,21 Microcomputer 12,22 Memory 14 Transmitter 15 Transmitter Switch 23 Receiver 25 Drive Circuit

Claims (3)

[Claims] 1. A transmitter comprising a transmitter for transmitting a different transmission code for each transmission, and a receiver for switching the reception code for each reception in a predetermined order in response to a change of the transmission code in the transmitter. In a keyless entry device that compares the codes and makes a predetermined response operation on the receiver side when the two match, if a transmission code that is ahead of the reception code is transmitted, respond to that transmission code. A keyless entry device, characterized in that it is configured so that the reception code of the receiver is advanced to the code where the transmission code and the reception code match next time. 2. When the transmission code is input to the receiver,
This reception code is calculated based on the previous reception code, this reception code is compared with the transmission code, this reception code is recorded for the next reference, and the input transmission code and this time are recorded. 2. The keyless entry device according to claim 1, wherein if the received code of No. 1 does not match, the code that matches the transmitted code input this time is recorded as the received code for the next reference. 3. When the transmission code is input to the receiver,
The received code recorded for reference is compared with the transmitted code, and the received code that is one step ahead of the recorded received reference code is recorded for the next reference, and the inputted transmitted code 2. The keyless entry device according to claim 1, wherein when the reference reception code does not match with the reference reception code, a code which is advanced by one from the transmission code input this time is recorded as the next reception code for the reference.