JP2824021B2 - Remote control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control device comprising a transmitter and a receiver, and more particularly to a remote control device effective for preventing unauthorized operation.

[0002]

2. Description of the Related Art Conventionally, remote control devices for performing remote control using radio waves or infrared rays have been widely used.
For example, it is also used as a substitute for a key for lock control of a door of an automobile. In particular, in the case of such a use method, in order to prevent a malfunction by another remote control device, an identification code for specifying the remote control device is added to a transmission signal of the remote control device, and this identification code is used. Remote control devices that prevent remote control from being performed if they do not match are widely used. However, even in such a remote control device, there is a possibility that the remote control device can be misused by anyone other than a legitimate user by intercepting and storing the transmission signal and transmitting the same signal later.

For this reason, there has been proposed a code-variable remote control device for transmitting a control signal, an identification code, and the like by sequentially changing the transmission for each transmission. In this method, it is necessary to register decoding data for decoding a control signal, an identification code, and the like in each of the transmitter and the receiver. For example, when changing the identification codes in a predetermined order, it is necessary to register the order of the identification codes transmitted from the transmitter (registered in the transmitter) on the receiver side.

As a method of this, there is a method of mounting a memory (ROM) in which decoding data is written in advance in a receiver. Further, there is a method in which a transmitter and a receiver are provided with a write mode, decoding data is transmitted from the transmitter, and the decoding data is received by the receiver and registered in a memory (for example, an EEPROM) of the receiver.

[0005]

However, in the former method of mounting the memory, when the transmitter is broken, damaged, or lost, the memory on the receiver must be replaced with a memory corresponding to a new transmitter. Therefore, in the case where a function that can be operated by a plurality of transmitters is added, the number of memories increases, and a problem in mounting (area, circuit pattern, connector, etc.) occurs.

[0006] In the latter case, although the number of transmissions is small, unencrypted decrypted data is transmitted, and if it is intercepted, the security of the remote control device is reduced. An object of the present invention is to solve such a problem and to provide a remote control device having high maintainability and high security.

[0007]

In order to achieve the above object, the present invention provides a control signal transmitting section for transmitting control data for controlling the operation of a controlled device, and a control signal transmitting section for decoding the control signal. A transmitter having a decryption signal transmitting unit for transmitting decryption data, and receiving and storing signal decryption data from the transmitter, receiving the control data from the transmitter, and storing the decryption data based on the stored decryption data. In a remote control device including a receiver that decodes control data and controls the operation of a controlled device, a transmission output is increased when transmitting control data to the transmitter, and a transmission output is decreased when transmitting decoded data. A transmission output control unit is provided.

[0008]

According to the present invention, when the control data is transmitted to the receiver, the transmission output increases when the control data is transmitted, and when the decoding data is transmitted, the transmission output decreases. It becomes longer and the distance of the decrypted data becomes shorter. Therefore, the possibility that the decrypted data can be intercepted can be reduced without reducing the range in which the controlled device can be controlled.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention, and shows a remote control device for controlling a door lock of an automobile. Reference numeral 1 denotes a transmitter of the remote control device, which operates the transmission switch 7 to transmit control data or decoding data stored in the memory 3 from the antenna 2.

Reference numeral 3 denotes a memory which includes data for specifying the transmitter 1 and data for operating the door lock device, and is necessary for decrypting the encrypted control data and the encrypted control data. The decryption data and the program of the microcomputer 4 are stored. Reference numeral 4 denotes a microcomputer, which controls peripheral devices according to the operated switch.

Reference numeral 5 denotes a transmission circuit, the operation of which is controlled by a control signal from the microcomputer 4, and further modulates a carrier with control data and decoding data input from the microcomputer 4 and transmits the modulated signal as a radio wave from the antenna 2. . Reference numeral 6 denotes a mode switch, and the microcomputer 4 changes the mode from the normal mode to the write mode for a predetermined time after the mode switch 6 is operated.

Reference numeral 7 denotes a transmission switch. When the transmission switch is operated, the microcomputer 4 outputs data to be transmitted to the transmission circuit 5 in accordance with the mode of the transmission switch.
Control the output level of the Specifically, when the transmission switch 7 is operated in the normal mode, the encrypted control data for controlling the door lock is transmitted at high power, and when the transmission switch is operated in the writing mode, the encryption control data is transmitted. Decryption data for decrypting the converted control data is transmitted at low power.

Next, reference numeral 10 denotes a receiver of the remote control device, which receives the radio wave transmitted from the transmitter 1 and controls the controlled device 15. Reference numeral 11 denotes an antenna for receiving a radio wave from the transmitter 1. A receiving circuit 12 demodulates and amplifies a radio wave from the transmitter 1 received by the antenna 11 and outputs it to the microcomputer 13.

Reference numeral 13 denotes a microcomputer which controls a door lock device 15 which is a controlled device via an interface 14 in accordance with an output signal from the receiving circuit 12. Specifically, the microcomputer 13 writes the decoded data into the memory 16 if the output signal from the receiving circuit 12 is the decoded data, and writes the decoded data into the memory 16 if the output signal from the receiving circuit 12 is the control data. The control data is decoded using the written decoding data, and it is determined whether or not the control data is valid.
Control 5 is performed, for example, door lock opening control.

Reference numeral 16 denotes a memory in which decoding data transmitted from the transmitter 1, programs of the microcomputer 13, and the like are stored. Further, the door lock device 15 controls the lock (lock) of the door of the automobile, and the remote control device (the receiver 1).
The door lock is opened and closed according to the control signal from 0).
FIG. 2 is a diagram showing a communicable area of the remote control device.

Since the control data of the remote control device has a high transmission output, it is possible to communicate even when the transmitter 1 and the receiver 10 are relatively far apart (within ab), and the communicable area is wide. On the other hand, the decryption data has a low transmission output,
Transmitter 1 and receiver 10 are relatively close (within ac)
Otherwise, communication is not possible and the communicable area is small.
Therefore, the range in which the decrypted data can be intercepted is also narrowed, and the security of the remote control device can be improved. Since the communicable range of the control data is not narrowed, the operability is not reduced as long as the regular transmitter 1 is used.

Next, the operation method will be described. When controlling the door lock device 15, the transmission switch 7 is operated within the controllable area. Then, the control data is transmitted from the transmitter 1 at a relatively high output, and the receiver 10 receives the control data and controls the door lock device 15. When writing the decrypted data, the mode switch 6 is operated in the area where the decrypted data can be transmitted (near the receiver b), and then the transmission switch 7 is operated within a predetermined time. Then, the decoding data is transmitted from the transmitter 1 with a low output, and the receiver 1
0 receives the decrypted data and the decrypted data is written to the memory 16.

Next, the processing performed by the microcomputer 4 of the transmitter 1 will be described with reference to the flowchart of FIG. Microcomputer 4
Starts processing when power is supplied (when a battery is connected). In step S1, it is determined whether or not the transmission switch 7 has been operated. If the transmission switch 7 has been operated, the process proceeds to step S2, and if not, the determination in step S1 is repeated.

In step S2, it is determined whether or not the mode is the write mode. If the mode is the write mode, the process proceeds to step S3. If not, the process proceeds to step S4. Note that the writing mode is set only for a certain period of time (for example, 5 seconds) after the mode switch 6 is operated, and is released after a certain period of time elapses (returns to the normal mode). Is realized by an interrupt process triggered by.

In step S3, the transmission circuit 5 is controlled so that the transmission output is set to a predetermined low output, and decoding data for decoding the control data is output to the transmission circuit 5, and the decoding data is transmitted from the transmission circuit 5. Then, the process ends (return to step S1). In step S4, the control data is encrypted based on the decrypted data, and the process proceeds to step S5.
Then, in step S5, the transmission circuit 5 is controlled so that the transmission output becomes high, the encrypted control data is output to the transmission circuit 5, and the control data is transmitted from the transmission circuit 5 to end the processing (step S5). Return to step S1).

Next, the processing performed by the microcomputer 13 of the receiver 10 will be described with reference to the flowchart of FIG. The microcomputer 13 on the receiver side also starts processing when power is supplied (when a battery is connected). In step S11, it is determined whether or not data has been received. If data has been received, the process proceeds to step S12.
Is repeated.

This determination can be made based on whether any data is being output from the receiving circuit 12. Step S1
In step 2, the data is decoded, and the routine goes to step S13. In step S13, it is determined whether or not the decrypted data is data from the legitimate transmitter 1. If the data is from the legitimate transmitter 1, the process proceeds to step S14. If not, the process returns to step S11.

In step S14, it is determined whether or not the data is control data. If the data is control data, the flow advances to step S15 to output a signal for controlling the door lock device 15 to the door lock device 15, and the process ends. Return to If it is determined in step S14 that the data is not control data, that is, if it is determined that the data is decrypted data, the process proceeds to step S16, where the decrypted data stored in the memory 16 is rewritten. Return.

Next, an example of the decryption data and the control data will be described. For example, the transmitter 1 changes the control data and transmits the data each time the transmission switch 7 is operated once. The change rule of the control data is stored in the memory 3 as decryption data, and the transmitter 1 changes the control data to be transmitted according to the decryption data.

The receiver 10 receives the decrypted data from the transmitter 1 in advance and stores the decrypted data in the memory 16, and every time the control data from the authorized transmitter 1 is received, the received control data is The comparison data is updated to determine whether the data is from the authorized transmitter 1 or not. For example, it is assumed that data indicating that control data is changed in the order of A, B, and C is stored as decryption data (in the case of a paired regular transmitter 1 and receiver 10, the same decryption data is stored. ing). When the transmission switch 7 is operated, the transmitter 1 transmits A as control data for the first time according to the decoding data, and transmits the next control data to B as control data.
Set as If the received control data is A in accordance with the decryption data, the receiver 10 processes the control data as the control data from the authorized transmitter 1, and then transmits the control data to be determined as the control data from the authorized transmitter 1 to B Set as Thereafter, this process is continued, and the control data transmitted by the transmitter 1 and the control data determined by the receiver 10 as normal control data change synchronously.

It should be noted that the decryption data includes, together with the data for decryption, an identification code having a relatively large number of digits which is set in common for the transmitter 1 and the receiver 10 which form a regular pair. The device 10 rewrites the decrypted data written in the memory 16 when the identification code included in the decrypted data matches its own identification code. Note that the encryption method is not limited to the above method, and various methods can be used.

As described in detail above, according to the remote control device of the present embodiment, control data is transmitted at a high output, and decryption data for decrypting the control data is transmitted at a low output. Thus, the possibility that the decrypted data is intercepted is reduced, and the security of the remote control device is increased. or,
Since the control data is transmitted at a high output, the controllable area is not narrowed, and both the operability and the security of the remote control device can be achieved.

[0028]

As described above, according to the present invention, when the control data is sent to the receiver, the transmission output becomes high, and when the decoding data is sent, the transmission output becomes low. It becomes longer and the distance of the decrypted data becomes shorter. Therefore, the possibility that the decrypted data can be intercepted can be reduced without narrowing the controllable range of the controlled device, so that the maintainability is high and the security is high.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a communicable area of a transmitter.

FIG. 3 is a flowchart showing a microcomputer operation of the transmitter.

FIG. 4 is a flowchart showing a microcomputer operation of the receiver.

[Explanation of symbols]

 1 ... Transmitter 2 ... Antenna 3 ... Memory 4 ... Microcomputer

Claims (1)

(57) [Claims] A transmitter having a control signal sending unit for sending control data for controlling operation of a controlled device; and a decoding signal sending unit for sending decoding data for decoding the control signal; A receiver that receives and stores signal decoding data from the transmitter, receives the control data from the transmitter, decodes the control data based on the stored decoding data, and controls the operation of the controlled device. A remote control device comprising: a transmitter provided with a transmission output control unit configured to increase a transmission output when transmitting control data and to reduce a transmission output when transmitting decoding data.