JP2000054707A - Keyless entry system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a keyless entry system which enables avoidance of a change in a distance for locking or unlocking vehicle doors even when the strength of a surrounding electric field changes by a constitution wherein a vehicle-borne machine detects the state of the surrounding electric field and makes a locking or unlocking threshold value small when this state of the electric field is faulty (bad) and which enables consequently elimination of a feeling of disorder of a driver and also execution of a locking or unlocking operation at a correct distance for ensuring both crime preventing properties and convenience, in regard to a keyless entry system equipped at least with a unidirectional communication function. SOLUTION: In a keyless entry system free of a switch operation wherein a vehicle-borne machine 1 locks or unlocks vehicle doors according to the strength of a reception electric field of a transmission signal from a portable machine 2, the vehicle-borne machine 1 detects the state of a surrounding electric field and also makes a locking or unlocking threshold value small when the detected state of the electric field is faulty.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyless switchless operation in which a vehicle-mounted device locks or unlocks a vehicle door via a door-lock actuator by a received electric field strength of a transmission signal (radio signal) from a portable device. Regarding the entry system.

[0002]

2. Description of the Related Art Conventionally, as a keyless entry system without a switch operation, there are, for example, the devices described in JP-A-6-58029 and JP-A-9-303021. That is, the former disclosed in Japanese Patent Application Laid-Open No. 6-58029 includes a portable device carried by an occupant or an operator, an in-vehicle device and a lock unit mounted on a vehicle, and the portable device opens a door of the vehicle. An unlock signal for unlocking is always transmitted at a predetermined cycle, and the vehicle-mounted device transmits an unlock signal when the unlock signal from the portable device is received at a predetermined electric field strength or higher at every predetermined period. Is a one-way communication type device configured to output a locking operation signal when the electric field strength is equal to or less than a predetermined electric field strength.

In the latter Japanese Patent Application Laid-Open No. 9-303021, an in-vehicle device driven by using a power supply of an in-vehicle battery is provided, and a portable device receives a request signal constantly transmitted from the in-vehicle device. When the mobile device creates and transmits a transmission signal, and the transmission signal is received by the on-board device,
The in-vehicle device is of a two-way communication type configured to unlock or lock the door keylessly via a door lock actuator in accordance with the strength of a predetermined electric field strength of the received transmission signal.

However, in any of these conventional devices, the transmission period and transmission intensity of a transmission signal transmitted and output from a portable device or the transmission period and transmission intensity of a request signal transmitted and output from a vehicle-mounted device are uniform. The distance of locking and unlocking the vehicle door is greatly affected by the surrounding electric field conditions, and the occupants feel uncomfortable and lock at an appropriate position (distance from the vehicle) that balances security and convenience. There is a problem that the unlock operation becomes difficult.

For example, when the electric field strength around a construction site or the like is strong and the electric field condition is poor, the unlocking operation cannot be performed unless the vehicle is closer to the vehicle than the original position. There has been a problem that the locking and unlocking distance is greatly affected by the electric field condition.

[0006]

SUMMARY OF THE INVENTION According to a first aspect of the present invention, in a keyless entry system having at least a one-way communication function, a vehicle-mounted device detects a surrounding electric field state (electric field strength state). By reducing the lock / unlock threshold value (for example, the judgment level) when the electric field condition is defective (poor), the distance for locking and unlocking the vehicle door even when the surrounding electric field intensity changes is reduced. It is an object of the present invention to provide a keyless entry system that does not change, can eliminate an occupant's uncomfortable feeling, and can perform locking and unlocking operations at an accurate distance that achieves both security and convenience. .

According to a second aspect of the present invention, in a keyless entry system having at least a one-way communication function, a portable device detects a surrounding electric field state, and when the electric field state is defective, the transmission intensity of a transmission signal is reduced. By increasing the distance, the distance for locking and unlocking the vehicle door does not change even when the surrounding electric field strength changes, so that the occupants can feel uncomfortable, and both security and convenience can be achieved. It is an object of the present invention to provide a keyless entry system capable of performing locking and unlocking operations at a precise and accurate distance.

According to a third aspect of the present invention, in a keyless entry system having at least a one-way communication function, a portable device detects a surrounding electric field state, and determines a transmission cycle of a transmission signal when the electric field state is defective. By shortening,
Even if the surrounding electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that it is possible to eliminate the occupant's uncomfortable feeling and at an accurate distance that balances security and convenience It is an object of the present invention to provide a keyless entry system that enables locking and unlocking operations.

According to a fourth aspect of the present invention, there is provided a keyless entry system having a two-way communication function.
The portable device detects the surrounding electric field condition and increases the transmission strength of the transmission signal when the electric field condition is poor, so that the distance to lock and unlock the vehicle door changes even if the surrounding electric field strength changes. It is an object of the present invention to provide a keyless entry system which can eliminate an uncomfortable feeling of an occupant, and can perform locking and unlocking operations at an accurate distance to achieve both security and convenience.

According to a fifth aspect of the present invention, in a keyless entry system having a two-way communication function,
The on-board unit detects the surrounding electric field state and transmits information on the electric field state to the portable unit as a request signal, so that the portable unit side does not need a means for detecting the electric field state,
It is an object of the present invention to provide a keyless entry system capable of improving portability of a portable device and performing appropriate control based on electric field state information in a request signal received by the portable device.

According to a sixth aspect of the present invention, in addition to the object of the fourth aspect of the invention, when the electric field state detected by the portable device is defective, the transmission intensity of the transmission signal is increased and the transmission period is reduced. By shortening the distance, even if the strength of the surrounding electric field deteriorates, the distance for locking and unlocking the vehicle door does not change at all, so that the occupant's uncomfortable feeling can be further improved, and security and convenience are improved. It is an object of the present invention to provide a keyless entry system capable of performing a reliable locking and unlocking operation at an accurate distance such that both are satisfied.

[0012] The invention according to claim 7 of the present invention, in addition to the object of the invention described in claim 2, 3, 4 or 6, is adapted to be used in a case where the surrounding electric field strength is extremely large and communication becomes impossible. An object of the present invention is to provide a keyless entry system capable of eliminating unnecessary power consumption under a communication disabled condition by stopping transmission of a transmission signal from a device.

According to an eighth aspect of the present invention, in a keyless entry system having a two-way communication function,
The on-board unit detects the surrounding electric field condition and shortens the transmission cycle of the request signal when the electric field condition is defective, so that the distance to lock and unlock the vehicle door changes even if the surrounding electric field intensity changes. It is an object of the present invention to provide a keyless entry system which can eliminate an uncomfortable feeling of an occupant, and can perform locking and unlocking operations at an accurate distance to achieve both security and convenience.

According to a ninth aspect of the present invention, in a keyless entry system having a two-way communication function,
The on-board unit detects the surrounding electric field condition and increases the transmission intensity of the request signal when the electric field condition is poor, so that the distance to lock and unlock the vehicle door changes even if the surrounding electric field intensity changes. It is an object of the present invention to provide a keyless entry system which can eliminate an uncomfortable feeling of an occupant, and can perform locking and unlocking operations at an accurate distance to achieve both security and convenience.

According to a tenth aspect of the present invention, in a keyless entry system having at least a one-way communication function, an on-vehicle device detects a surrounding electric field state, and a reception cycle (when the on-vehicle device detects By shortening the reception cycle for receiving the transmission signal), the distance for locking and unlocking the vehicle door does not change even if the surrounding electric field strength changes, and the occupant can feel uncomfortable. It is an object of the present invention to provide a keyless entry system capable of performing locking and unlocking operations at an accurate distance that achieves both security and convenience.

According to an eleventh aspect of the present invention, in the keyless entry system having a two-way communication function, when the electric field condition is poor, the portable device increases the number of transmissions of the transmission signal, so that the surrounding electric field intensity is reduced. Even if it changes, the distance to lock and unlock the vehicle door does not change,
It is an object of the present invention to provide a keyless entry system that can eliminate an uncomfortable feeling of an occupant and can perform locking and unlocking operations at an accurate distance to achieve both security and convenience.

According to a twelfth aspect of the present invention, in a keyless entry system having at least a one-way communication function, a means for detecting an electric field state is provided on the portable device side, and the electric field state is detected in a transmission signal by this detecting means. The electric field strength information is transmitted and transmitted, and on the in-vehicle device side, the control content is made variable based on the electric field intensity information in the transmission signal, so that the electric field state is detected by a single detection means on the portable device side It is another object of the present invention to provide a keyless entry system capable of performing appropriate lock and unlock control.

[0018]

According to a first aspect of the present invention, there is provided a keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door by using a received electric field strength of a transmission signal from a portable device. The on-vehicle device is a keyless entry system that detects a surrounding electric field state and reduces a lock or unlock threshold value when the detected electric field state is defective.

According to a second aspect of the present invention, there is provided a keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door according to a received electric field strength of a transmission signal from the portable device, and the switch-less operation is performed. Is a keyless entry system that detects a surrounding electric field state and increases the transmission intensity of a transmission signal when the detected electric field state is defective.

According to a third aspect of the present invention, there is provided a keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door based on a received electric field intensity of a transmission signal from the mobile device, without a switch operation. Is a keyless entry system that detects a surrounding electric field state and shortens a transmission cycle of a transmission signal when the detected electric field state is defective.

According to a fourth aspect of the present invention, there is provided an on-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, and a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation in which the on-vehicle device locks or unlocks the vehicle door by the on-vehicle device, wherein the portable device detects the surrounding electric field state and increases the transmission intensity of the transmission signal when the detected electric field state is defective. Keyless entry system.

According to a fifth aspect of the present invention, there is provided an on-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, and a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation in which the on-vehicle device locks or unlocks the vehicle door by the on-vehicle device, wherein the surrounding electric field state is detected by the on-vehicle device and information on the electric field state is transmitted to the portable device as a request signal. It is an entry system.

According to a sixth aspect of the present invention, in addition to the configuration of the fourth aspect, the portable device has a keyless entry system for shortening a transmission cycle of a transmission signal when a detected electric field condition is defective. It is characterized by being.

According to a seventh aspect of the present invention, in addition to the configuration of the second, third, fourth or sixth aspect of the present invention, when the electric field intensity is extremely large, the portable device transmits a transmission signal. It is a keyless entry system that stops.

According to an eighth aspect of the present invention, there is provided an in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, and a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation in which the on-vehicle device locks or unlocks the vehicle door by the on-vehicle device. The on-vehicle device detects the surrounding electric field state and shortens the transmission cycle of the request signal when the detected electric field state is defective. Keyless entry system.

According to a ninth aspect of the present invention, there is provided an on-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, and a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation in which the on-vehicle device locks or unlocks the vehicle door by the on-vehicle device. The on-vehicle device detects the surrounding electric field state and increases the transmission strength of the request signal when the detected electric field state is defective. Keyless entry system.

According to a tenth aspect of the present invention, there is provided a keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door by using a received electric field strength of a transmission signal from a portable device, without a switch operation. Is a keyless entry system that detects a surrounding electric field state and shortens a reception cycle when the detected electric field state is defective.

According to an eleventh aspect of the present invention, there is provided an in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, and a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation for locking or unlocking a vehicle door by an on-vehicle device, wherein the portable device is a keyless entry system for increasing the number of transmissions of a transmission signal when an electric field condition is defective. .

According to a twelfth aspect of the present invention, there is provided a keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door by using a received electric field intensity of a transmission signal from a portable device, without a switch operation. A keyless entry system in which detection means for detecting a state is provided on the portable device side, the electric field intensity information is inserted in the transmission signal, and the control content is made variable based on the electric field intensity information on the in-vehicle device side receiving the transmission signal. There is a feature.

[0030]

According to the first aspect of the present invention, the above-described on-vehicle device locks or unlocks the vehicle door according to the received electric field intensity of the transmission signal from the portable device. Is detected by the in-vehicle device, and when the detected electric field state is defective (bad), the in-vehicle device reduces the lock or unlock threshold.

As described above, since the threshold value is changed, the distance for locking and unlocking the vehicle door does not change even if the surrounding electric field strength changes, and the discomfort given to the occupant can be eliminated. In addition to this, there is an effect that locking and unlocking operations can be performed at an accurate distance to achieve both security and convenience.

According to the invention described in claim 2 of the present invention,
The above-described portable device detects the surrounding electric field state and increases the transmission strength of the transmission signal when the detected electric field state is defective. Therefore, even if the surrounding electric field strength changes, the vehicle door is locked,
The unlocking distance does not change, the occupant can feel uncomfortable, and the locking and unlocking operation can be performed at a precise distance that achieves both security and convenience. is there.

According to the third aspect of the present invention,
Since the above-described portable device detects the surrounding electric field state and shortens the transmission cycle of the transmission signal when the detected electric field state is defective,
Even if the surrounding electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupants can be eliminated, and accurate security that is compatible with security and convenience There is an effect that locking and unlocking operations can be performed at a long distance.

According to the fourth aspect of the present invention,
The above-described in-vehicle device transmits a request signal, the portable device that has received the request signal transmits a transmission signal, and the in-vehicle device locks or unlocks the vehicle door according to the received electric field strength when the transmission signal is received. Portable equipment detects the surrounding electric field condition, and when the detected electric field condition is defective,
Increase the transmission strength of the transmission signal.

As described above, since the transmission intensity is increased,
Even if the surrounding electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and accurate security that balances security and convenience There is an effect that locking and unlocking operations can be performed at a long distance.

According to the fifth aspect of the present invention,
In a keyless entry system equipped with a two-way communication device, the in-vehicle device detects the surrounding electric field state and transmits the information on the electric field state to the portable device as a request signal. There is an effect that the means is not required and the portability of the portable device can be improved, and further, there is an effect that appropriate control can be performed based on the electric field state information in the request signal received by the portable device.

According to the sixth aspect of the present invention,
In addition to the effect of the fourth aspect of the present invention, the above-mentioned portable device increases the transmission intensity of the transmission signal and shortens the transmission cycle when the detected electric field state is defective, so that the peripheral electric field intensity deteriorates. Also, the distance for locking and unlocking the vehicle door does not fluctuate at all, so it is possible to more effectively eliminate the discomfort given to the occupant, and at an accurate distance that achieves both security and convenience. Thus, there is an effect that a reliable locking and unlocking operation can be performed.

According to the seventh aspect of the present invention,
In addition to the effects of the second, third, fourth, or sixth aspect of the present invention, when the surrounding electric field strength is extremely large and communication becomes impossible, the portable device stops transmitting a transmission signal. This has the effect of eliminating unnecessary power consumption below.

According to the eighth aspect of the present invention,
In a keyless entry system having a two-way communication function, an in-vehicle device detects a surrounding electric field state and shortens a request signal transmission cycle when the electric field state is defective. As described above, since the transmission cycle of the request signal is shortened,
Even if the surrounding electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and accurate security that balances security and convenience There is an effect that locking and unlocking operations can be performed at a long distance.

According to the ninth aspect of the present invention,
In a keyless entry system having a two-way communication function, the above-mentioned in-vehicle device detects the surrounding electric field state, and increases the transmission intensity of the request signal when the electric field state is defective. As described above, since the transmission intensity of the request signal is increased, the distance for locking and unlocking the vehicle door does not change even if the intensity of the surrounding electric field changes, and the discomfort given to the occupant can be eliminated. At the same time, there is an effect that locking and unlocking operations can be performed at an accurate distance to achieve both security and convenience.

According to the tenth aspect of the present invention, in the keyless entry system having at least the one-way communication function, the above-mentioned on-vehicle device detects a surrounding electric field state, and detects a failure in the detected electric field state. Since the reception cycle is shortened, the distance for locking and unlocking the vehicle door does not change even if the surrounding electric field strength changes, eliminating the discomfort given to the occupants, as well as crime prevention and convenience. Thus, there is an effect that the locking and unlocking operations can be performed at an accurate distance to achieve both.

According to the eleventh aspect of the present invention, in the keyless entry system having the two-way communication function, the above-mentioned portable unit increases the number of transmissions of the transmission signal when the electric field condition is poor, so that the surroundings can be easily read. Even if the electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and an accurate distance that achieves both security and convenience. This has the effect that locking and unlocking operations can be performed.

According to the twelfth aspect of the present invention, in a keyless entry system having at least a one-way communication function, a means for detecting an electric field state is provided on the portable device side, and the detection means detects the electric field state in a transmission signal. The detected electric field strength information is inserted and transmitted, and the in-vehicle device changes the control content based on the electric field strength information in the transmission signal. Therefore, the electric field state is detected by a single detection means provided on the portable device side. In addition to the appropriate lock on the in-vehicle device side,
There is an effect that the unlock control can be executed.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a keyless entry system, FIG.
In this keyless entry system, the in-vehicle device 1 transmitting the request signal β and the request signal β
The vehicle-mounted device 1 receives the above-described transmission signal α and transmits the transmission signal α when the reception signal intensity is received. Locking or unlocking of the vehicle door is performed via the switch 3. Here, the above-mentioned in-vehicle device 1 is provided with an electric field strength sensor 4 as a detecting means for detecting a surrounding electric field state.

FIG. 2 shows a control circuit of the portable device 2 described above.
The CPU 10 driven by the battery 5 drives and controls the timer 8 and the transmission / reception antenna 6 according to a program stored in the ROM 7 based on a signal from the transmission / reception antenna 6, and the RAM 9 stores necessary data such as an on-vehicle device ID code. And so on. Here, a portable device ID code as a unique identification code for specifying the portable device 2 is stored in the ROM 7 in advance.

FIG. 3 shows a control circuit of the vehicle-mounted device 1. The CPU 20 driven by the battery 11 reads data from the transmission / reception antenna 12 and the electric field strength sensor 4 based on the input from the ROM 1.
3, the door lock actuator 3, the timer 14, the random number generator 15, and the transmission / reception antenna 12 are driven and controlled.
Necessary data such as a D code and an encryption code is stored.
Here, the on-board device ID code as a unique identification code for specifying the on-board device 1 is stored in the ROM 13 in advance.

Here, the above-mentioned electric field strength sensor 4 can be used also as the transmission / reception antenna 12, but for convenience of description below, the sensor and the antenna will be described with different reference numerals. A map M1 as shown in FIG. 10 is stored in the above-described RAM 16 of the in-vehicle device 1 or the RAM 9 of the portable device 2 or both.

The map M1 has the electric field strength D on the horizontal axis and the parameters on the vertical axis. The transmission intensity of the request signal β and the transmission signal α increases as the surrounding electric field strength D increases (deteriorates). So that the transmission signal α
The transmission cycle of the request signal β and the transmission signal α is further increased so that the number of transmissions of the request signal β and the first determination level J1 and the second determination level J2 as the thresholds for the lock / unlock determination become smaller. Is a map that is set so that is shorter, and the receiving cycle for receiving the transmission signal α is also shorter. In addition, when the surrounding electric field intensity D is extremely large (see Dmax), the transmission intensity of the transmission signal α is set to zero, and the transmission of the transmission signal α is set to be substantially stopped.

As shown in the data format of FIG. 4, the request signal β includes a start bit 21, an on-vehicle device ID bit 22, a random number bit 23, a time bit 24, and an electric field intensity bit 25 for transmitting the magnitude of the electric field intensity D. , A parity bit 26, and an end bit 27.

On the other hand, as shown in the data format in FIG. 5, the transmission signal α includes a start bit 28, an on-vehicle device ID bit 29, a portable device ID bit 30, an encryption code bit 31, a parity bit 32, and an end bit 33. Have.

Here, the encryption code in the above-mentioned encryption code bit 31 is created by a predetermined calculation process based on the information of the random number bit 23 and the time bit 24 of the request signal β shown in FIG.

The operation of the keyless entry system of the two-way communication type configured as described above will be described with reference to FIGS.
This will be described in detail below with reference to the respective flowcharts shown in FIG. First, with reference to the flowchart shown in FIG. 6, the transmission processing of the request signal β on the vehicle-mounted device 1 will be described.

In the first step A1 (determination means), the CPU 2
0 determines whether or not the set cycle has elapsed, and shifts to the next second step A2 only when YES is determined. This processing may be configured to always make a determination at each set cycle, or set within a predetermined time from the time of door handle operation (an operation that touches or presses the door handle unlike normal door handle operation). You may comprise so that it may determine for every period.

In the above-described second step A2 (electric field intensity detecting means), the CPU 20 detects the surrounding electric field intensity D (see FIG. 10) based on the input from the electric field intensity sensor 4. Next, in a third step A3 (cycle, intensity setting means), the CPU 20
Sets the transmission cycle of the request signal β and the transmission intensity in accordance with the magnitude of the detected electric field intensity D. That is, the setting is made so that the transmission intensity of the request signal is increased and the transmission cycle is shortened as the electric field intensity D increases.

Next, in a fourth step A4 (random number generating means),
The CPU 20 drives the random number generator 15 to generate a random number (random number). Next, in a fifth step A5, C
The PU 20 reads the in-vehicle device ID code from the ROM 13, and executes the next sixth step A6 (request signal generating means).
Then, the CPU 20 creates a request signal β as shown in FIG. Information of the electric field strength D is input into the request signal β.

Next, in a seventh step A7 (request signal transmitting means), the CPU 20 sets the transmission / reception antenna 12 to the transmission state, and transmits the above-described request signal β at the set transmission intensity and transmission period. Next, the eighth step A
In step 8 (encryption code creation means), the CPU 20 creates an encryption code a predetermined number of times by a predetermined operation (so-called processing) based on the random number information and the time information for the purpose of making a match determination described later.

Next, in a ninth step A9, the CPU 20 stores the created encryption code for a predetermined number of times in a predetermined area of the RAM 16. Next, transmission processing of the transmission signal α on the portable device 2 side will be described with reference to the flowchart shown in FIG.

In the first step B1 (determination means), the CPU 1
0 determines whether or not the set period has elapsed, and shifts to the next second step B2 only when YES is determined. In the second step B2 (reception detecting means), the CPU 10 sets the transmission / reception antenna 6 to the reception state, and detects the reception of the request signal β.

Next, in a third step B3 (reception determining means),
The CPU 10 determines whether or not the request signal β has been received. When the determination is NO, the process returns to the first step B1, and when the determination is YES, the process proceeds to the next fourth step B4.

In the fourth step B4 (coincidence determining means),
CPU10 is the on-board unit ID code in the request signal β
It is determined whether or not the in-vehicle device ID bit 22 in FIG. 4 matches the in-vehicle device ID code in the RAM 9. When the determination is NO, the process returns to the first step B1, while the determination is YES.
When the determination is made, the process proceeds to the next fifth step B5.

In the above-described fifth step B5, the CPU 10 reads out information on the electric field strength D from the request signal β, and in the next sixth step B6, the CPU 10 reads out the electric field strength D
The transmission intensity of the transmission signal α is set in accordance with the magnitude of.

Next, in a seventh step B7, the CPU 10 sets the number of transmissions of the transmission signal α in accordance with the read electric field strength D. For example, when the electric field strength D is small, the number of transmissions is set to one as shown in FIG. 10, and when the electric field strength D is large, the number of transmissions is set to two as shown in FIG. It goes without saying that the number of transmissions may be larger than that.

Next, in an eighth step B8, the CPU 10 creates an encryption code based on the random number information and the time information in the request signal β. When creating the encryption code, the encryption code is created using the same equation as the calculation in the eighth step A8 in FIG.

Next, in a ninth step B9, the CPU 10
The portable device ID code is read from the OM 7, and in the next tenth step B10 (transmission signal creation means), the CPU 10 creates the transmission signal α as shown in the data format in FIG.

Next, in an eleventh step B11 (transmission signal transmission means), the CPU 10 transmits the transmission signal α via the transmission / reception antenna 6 at the transmission intensity and the number of transmissions set in the above steps B6 and B7.

Next, referring to the flowchart (main routine) shown in FIG.
The unlock control will be described. In a first step C1 (judgment means), the CPU 20 judges whether or not it is a set cycle, and
The process shifts to the next second step C2 only at the time of ES determination.

In the second step C2 (reception detecting means),
The CPU 20 executes the reception detection of the transmission signal α, and
In step C3 (lock / unlock determination means), the CPU
Reference numeral 20 executes lock / unlock determination corresponding to the transmission intensity J of the transmission signal α. This determination will be described later with reference to a subroutine shown in FIG.

Next, in a fourth step C4, the CPU 20 determines the result of the determination. When the lock is determined, the process proceeds to the fifth step C5, and when the unlock is determined, the process proceeds to another sixth step C6. In the above-described fifth step C5, C
The PU 20 locks the door by operating the door lock actuator 3 to lock the vehicle door. In the above-described sixth step C6,
The CPU 20 unlocks the door lock actuator 3 to unlock the vehicle door.

Next, with reference to the flowchart (subroutine) shown in FIG. 9, the lock / unlock determination processing corresponding to the above-described third step C3 will be described. In a first step E1 (level setting means), the CPU 20 sets a first determination level J1 and a second determination level J2 according to the electric field intensity D detected by the electric field intensity sensor 4, as shown in FIG. That is, when the surrounding electric field strength D is large, the levels J1 and J2 are set to be small. Next, in a second step E2 (reception determining means), the CP
The U20 determines whether or not the transmission signal α has been received based on the input from the transmission / reception antenna 12, and shifts to the eighth step E8 when the determination is NO, and shifts to the next third step E3 when the YEE determination is made.

The above-mentioned third step E3 (coincidence determining means)
The CPU 20 transmits the portable device ID code of the transmission signal α (FIG. 5).
It is determined whether the portable device ID code previously stored in the RAM 16 and the portable device ID code stored in the RAM 16 match each other. When the determination is NO, the process proceeds to the eighth step E8. The process moves to the next fourth step E4.

Next, a fourth step E4 (receiving intensity detecting means)
The CPU 20 detects the reception intensity J of the transmission signal α, and in the next fifth step E5 (comparing means), the CPU 20 determines the detected reception intensity J and the first determination level J1 for unlock determination.
Compare with Thus, when the YEE determination of J> J1 is performed, the process proceeds to the sixth step E6. When the determination of J <J1 is NO, the process proceeds to another seventh step E7.

In the above-described sixth step E6 (unlock determination means), the CPU 20 executes the unlock determination corresponding to J> J1, while in the above-described seventh step E7 (comparison means), the CPU 20 determines the reception strength. J and second for lock determination
Comparison with the judgment level J2, and when NO judgment is made (when J> J2)
Ends the processing while the YEE judgment is made (when J <J2)
The process proceeds to the eighth step E8.

This eighth step E8 (lock determination means)
Then, the CPU 20 executes the lock determination corresponding to J <J2. Then, the processing content of the subroutine shown in FIG. 9 is reflected in the main routine of FIG.

As described above, the keyless entry system of the two-way communication type shown in FIGS.
According to the embodiments corresponding to 6, 7, 8, 9, 11), the above-mentioned on-vehicle device 1 transmits a request signal β, and the portable device 2 which has received the request signal β transmits a transmission signal α,
The in-vehicle device 1 locks or unlocks the vehicle door according to the reception intensity J when the transmission signal α is received. However, the above-described portable device 2 detects the surrounding electric field state (in this case, FIG.
The transmission / reception antenna 6 is used as an electric field strength sensor), and when the detected electric field state is defective, the transmission strength of the transmission signal α is increased.

As described above, since the transmission intensity is increased,
Even if the surrounding electric field strength changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and accurate security that balances security and convenience There is an effect that locking and unlocking operations can be performed at a long distance.

Further, in the keyless entry system provided with the two-way communication device, the electric field strength sensor 4 on the on-vehicle device 1 side
Detects the surrounding electric field state (see step A2) and transmits information on the electric field state to the portable device 2 as a request signal β.
(See step A7), the portable device 2 does not need a detecting means for detecting the state of the electric field, so that there is an effect that the portability of the portable device 2 can be improved. There is an effect that appropriate control can be performed based on the electric field state information (see the electric field strength bit 25 in FIG. 4) in the request signal β.

Further, the above-described portable device 2 (in this case, the transmitting / receiving antenna 6 of FIG. 2 is used as an electric field intensity sensor) increases the transmission intensity of the transmission signal α when the detected electric field state is defective and increases the transmission cycle. , The distance for locking and unlocking the vehicle door does not change at all even if the electric field strength D in the surroundings deteriorates. There is an effect that a reliable locking and unlocking operation can be performed at an accurate distance that achieves both convenience and convenience.

In addition, when the surrounding electric field strength D is extremely large and communication is impossible (see Dmax shown in FIG. 10),
Since the portable device 2 stops transmitting the transmission signal α, there is an effect that unnecessary power consumption under a communication disabled condition can be eliminated.

In the keyless entry system having the two-way communication function, the electric field strength sensor 4 on the vehicle-mounted device 1 detects the surrounding electric field state (see step A2). Is shortened (see FIG. 10) (see step A3). Since the transmission cycle of the request signal β is shortened in this manner, even if the surrounding electric field strength D changes, the distance for locking and unlocking the vehicle door does not change, and the uncomfortable feeling given to the occupant is eliminated. In addition to this, there is an effect that locking and unlocking operations can be performed at an accurate distance to achieve both security and convenience.

Further, in the keyless entry system having the two-way communication function, the electric field intensity sensor 4 on the on-vehicle device 1 detects the surrounding electric field state (see step A2).
Then, the transmission intensity of the request signal β (see FIG. 10) is increased when the electric field state is defective (see step A3). As described above, since the transmission intensity of the request signal β is increased, even if the surrounding electric field intensity D changes, the distance for locking and unlocking the vehicle door does not change, and the uncomfortable feeling given to the occupant is eliminated. In addition to this, there is an effect that locking and unlocking operations can be performed at an accurate distance to achieve both security and convenience.

Further, in the keyless entry system having the two-way communication function, the above-described portable device 2 increases the number of transmissions of the transmission signal α when the electric field condition is defective (see step B7). Even if the distance changes, the distance for locking and unlocking the vehicle door does not fluctuate, which can eliminate the discomfort given to the occupant, and can be used at an accurate distance that provides both security and convenience. There is an effect that locking and unlocking operations can be performed.

FIGS. 11 to 18 show another embodiment of the keyless entry system. That is, in the previous embodiment, the keyless entry system of the two-way communication type is shown, but in the embodiments of FIGS. 11 to 18, the keyless entry system of the one-way communication type is shown.

Referring to FIG. 11, the keyless entry system includes a portable device 2 for transmitting and outputting a transmission signal α, a reception of the transmission signal α, and a door lock actuator 3 corresponding to the reception intensity J through a door lock actuator 3. And an on-vehicle device 1 for executing locking or unlocking. Here, the above-mentioned in-vehicle device 1 and portable device 2 are provided with electric field strength sensors 4 and 34, respectively, as detecting means for detecting the electric field state around them.

FIG. 12 shows a control circuit of the portable unit 2 described above. The CPU 10 driven by the battery 5 transmits a signal from the electric field intensity sensor 34 and transmits a transmission antenna 35 and a timer in accordance with a program stored in the ROM 7. The RAM 9 controls driving of the RAM 8 and stores necessary data and the like.
Here, information of the transmission signal α shown in the data format in FIG. 14 is stored in the ROM 7 described above.

FIG. 13 shows a control circuit of the on-vehicle device 1. The CPU 20 driven by the battery 11 outputs an RO signal based on input signals from the electric field intensity sensor 4 and the receiving antenna 36.
In accordance with the program stored in M13, the door lock actuator 3 is driven and controlled, and the RAM 16 stores a portable device ID code as an identification code for specifying the portable device 2, other necessary data, and the like.

A map M2 as shown in FIG. 18 is stored in the RAM 26 of the on-vehicle device 1 or the RAM 9 of the portable device 2 or both.

The map M2 has the electric field strength D on the horizontal axis and the parameters on the vertical axis. The larger the surrounding electric field strength D (the worse the worse), the larger the transmission strength of the transmission signal α. In addition, the first determination level J1 and the second determination level J2 as thresholds for lock / unlock determination are reduced, the transmission cycle of the transmission signal α is further shortened, and the transmission signal α is further reduced. Is a map that is set so that the reception cycle for receiving is shortened. In addition, when the surrounding electric field strength D is extremely large (see Dmax),
The transmission intensity of the transmission signal α is set to zero, and the transmission of the transmission signal α is set to be substantially stopped.

The above-mentioned electric field strength sensors 4 and 34 can be used also for the antennas 36 and 35. However, for convenience of the following description, different reference numerals are given to the sensor and the antenna, respectively.

On the other hand, the transmission signal α described above has a start bit 28, ID
Bit 29, field strength bit 37, parity bit 32
(A check bit for checking a bit error), and an end bit 33.

The operation of the keyless entry system of the one-way communication type configured as described above will be described in detail below with reference to the respective flowcharts shown in FIGS. 15, 16 and 17. First, the transmission process of the transmission signal α on the portable device 2 side will be described with reference to the flowchart shown in FIG.

In the first step U1 (determination means), the CPU 1
0 determines whether or not the set period has elapsed, and shifts to the next second step U2 only when YES is determined. Here, the setting cycle: the determination as to whether or not the time has elapsed may be configured to be always performed every time the setting cycle has elapsed, and a transmission signal output command switch (not shown) is separately provided in the portable device 2, and this determination is performed. It may be configured to be executed every time a set period elapses within a predetermined time after the switch is turned on.

Next, a second step U2 (electric field intensity detecting means)
The CPU 10 detects the electric field strength D based on the input from the electric field strength sensor 34. Next, the third step U3
In (period and intensity setting means), the CPU 10 sets the transmission period and the transmission intensity of the transmission signal α in accordance with the detected electric field intensity D (see FIG. 18). That is, the detected electric field strength D
Is worse, the transmission cycle is set shorter and the transmission intensity is set higher.

Next, in the fourth step U4 (reading means), C
PU 10 reads out transmission signal α (see FIG. 14) from ROM 7. Next, in a fifth step U5 (writing means), the CPU 10
Writes the information of the electric field strength D in the electric field strength bit 37 of the transmission signal α. Next, in a sixth step U6 (transmission means), the CPU
10 transmits and outputs the transmission signal α via the transmission antenna 35 at the set transmission cycle and transmission intensity.

Next, referring to the flowchart (main routine) shown in FIG.
The unlock control will be described. In the first step S1 (determination means), the CPU 20 determines whether or not the set cycle has elapsed, and proceeds to the next second step S2 only when YES is determined.

This second step S2 (electric field intensity detecting means)
The CPU 20 detects the surrounding electric field strength D (see FIG. 18) based on the input from the electric field strength sensor 4. Next, in a third step S3 (setting means), the CPU 20 sets each of the first determination level J1 and the second determination level J2 according to the detected electric field strength D, and sets the reception cycle when the transmission signal α is received. Set.

Next, in a fourth step S4 (reception detecting means),
The CPU 20 executes the reception detection of the transmission signal α, and
At step S5 (lock / unlock determination means), the CPU
20 executes a lock / unlock determination in accordance with the transmission strength J of the transmission signal α.
Will be described later with reference to the subroutine shown in FIG.

Next, in a sixth step S6, the CPU 20 determines the result of the determination. When the lock is determined, the process proceeds to the seventh step S7, and when the unlock is determined, the process proceeds to another eighth step S8. In the above-described seventh step S7, C
The PU 20 locks the vehicle door by operating the door lock actuator 3 to lock the vehicle door. In the above-described eighth step S8,
The CPU 20 unlocks the door lock actuator 3 to unlock the vehicle door.

Next, a lock / unlock determination process corresponding to the fifth step S5 will be described with reference to a flowchart (subroutine) shown in FIG. In the first step Q1 (reception determination means), the CPU 20 determines whether or not the transmission signal α has been received based on the input from the reception antenna 36, and when the determination is NO, the process proceeds to the ninth step Q9 (lock determination means). On the other hand, when the determination is YES, the process shifts to the next second step Q2.

The above-mentioned second step Q2 (coincidence determining means)
Then, the CPU 20 transmits the portable device ID code of the transmission signal α (FIG. 1).
It is determined whether or not the portable device ID code previously stored in the RAM 16 and the portable device ID code coincide with each other. When the determination is NO, the process proceeds to the ninth step Q9. The process proceeds to a third step Q3.

This third step Q3 (receiving cycle setting means)
Then, the CPU 20 determines the electric field intensity information of the transmission signal α shown in the data format in FIG.
Read) and set the reception cycle.

Next, a fourth step Q4 (level setting means)
Then, the CPU 20 reads the above-mentioned electric field intensity information (see the electric field intensity bit 37 in FIG. 14) and sets the first judgment level J1 and the second judgment level J2. In the subroutine of FIG. 17, when executing the processing of the routine R2 including the steps Q3 and Q4, the routine R1 including the steps S2 and S3 in the main routine of FIG. 16 is omitted. That is, each of these routines R
1 and R2 may be only one of them.

Next, a fifth step Q5 (receiving strength detecting means)
The CPU 20 detects the reception intensity J of the transmission signal α, and in the next sixth step Q6 (comparing means), the CPU 20 determines the detected reception intensity J and the first determination level J1 for unlock determination.
Compare with When J> J1 is determined to be YES, the process proceeds to the seventh step Q7. When J <J1 is determined to be NO, the process proceeds to another eighth step Q8.

In the above-described seventh step Q7 (unlock determination means), the CPU 20 executes the unlock determination corresponding to J> J1, while in the above-described eighth step Q8 (comparison means), the CPU 20 determines the reception strength. J is the second for lock determination
It is determined whether the level is smaller than the determination level J2.
> J2), the process ends, while a YES determination is made (J
If <J2), the process proceeds to the ninth step Q9.

In the ninth step Q9, the CPU 20 sets J
<Perform lock determination in response to J2. Then, the processing content of the subroutine shown in FIG. 17 is reflected in the main routine of FIG.

As described above, the unidirectional type keyless entry system shown in FIGS.
According to the embodiments corresponding to 7, 10, and 12), the above-described on-vehicle device 1 locks or unlocks the vehicle door according to the reception intensity J of the transmission signal α from the portable device 2, but detects the surrounding electric field condition on the vehicle. When the electric field strength sensor 4 of the device 1 detects (see step S2), and the detected electric field condition is bad (when bad), the vehicle-mounted device 1 sets the lock or unlock threshold (first
Decrease the judgment level J1 and the second judgment level J2) (see step S3).

As described above, the threshold value (level J1, J2
Therefore, even if the surrounding electric field strength D changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and security and convenience are improved. There is an effect that locking and unlocking operations can be performed at an accurate distance that balances the characteristics.

The portable device 2 detects the surrounding electric field state by the electric field strength sensor 34 (see step U2) and increases the transmission strength of the transmission signal α when the detected electric field state is defective (step U2). U3), even if the surrounding electric field strength D changes, the distance for locking and unlocking the vehicle door does not change, so that the uncomfortable feeling given to the occupant can be eliminated, and security and convenience are improved. There is an effect that locking and unlocking operations can be performed at an accurate distance that is compatible with each other.

Further, the portable device 2 detects the surrounding electric field state by the electric field strength sensor 34 (see step U2), and shortens the transmission cycle of the transmission signal α when the detected electric field state is defective (step U2). U3), surrounding electric field strength D
Even if the distance changes, the distance for locking and unlocking the vehicle door does not fluctuate, which can eliminate the discomfort given to the occupant, and can be used at an accurate distance that provides both security and convenience. There is an effect that locking and unlocking operations can be performed.

In addition, when the surrounding electric field strength D is extremely large and communication becomes impossible (see Dmax shown in FIG. 18),
Since the portable device 2 stops transmitting the transmission signal α, there is an effect that unnecessary power consumption (consumption of the battery 5) under the communication disabled condition can be eliminated.

On the other hand, in the above-described keyless entry system having the one-way communication function, the above-mentioned in-vehicle device 1 detects the surrounding electric field state by its electric field intensity sensor 4 (step S).
2), the reception cycle is shortened when the detected electric field condition is defective (see step S3), so that the distance for locking and unlocking the vehicle door may fluctuate even if the surrounding electric field strength D changes. Therefore, it is possible to eliminate the sense of incongruity given to the occupant, and it is possible to perform locking and unlocking operations at an accurate distance that achieves both security and convenience.

In addition, in the above-described keyless entry system, a means for detecting the electric field state (see electric field intensity sensor 34) is provided on the portable device 2 side (in this case, the on-vehicle device 1).
The electric field intensity sensor 4 on the side and the routine R1 in FIG. 16 are not used), and this detection means (the electric field intensity sensor 34) is included in the transmission signal α.
), And transmits the signal. The electric field intensity information (see electric field intensity bit 37 in FIG. 14) is input and transmitted.
Since the control content is changed based on the electric field intensity information (see the routine R2 in FIG. 17), the electric field state is detected by a single detecting means (see the electric field intensity sensor 34) provided on the portable device 2 side. In addition, there is an effect that the on-vehicle device 1 can execute appropriate lock / unlock control based on the reading of the electric field strength information by the above-described routine R2.

In the correspondence between the structure of the present invention and the above-described embodiment, the lock and unlock threshold values of the present invention are determined by the first and second judgment levels J1 and J2 of the embodiment.
Similarly, the means for detecting the surrounding electric field state on the on-vehicle device 1 side corresponds to the electric field strength sensor 4, and the means for detecting the surrounding electric field state on the portable device 2 side includes the electric field strength sensor 34. In the in-vehicle device 1 based on the information of the electric field strength D, the variable processing of the control content is performed by changing the reception cycle and performing the first and second control in the routine R2 shown in FIG.
However, the present invention is not limited to the configuration of the above-described embodiment.

For example, the above claims 1, 2, 3, 10, 12
It is needless to say that the technical idea described in the above can be sufficiently applied not only to the one-way communication type but also to the two-way communication type keyless entry system.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a keyless entry system of the present invention.

FIG. 2 is a control circuit block diagram of the portable device.

FIG. 3 is a block diagram of a control circuit of the vehicle-mounted device.

FIG. 4 is an explanatory diagram showing a data format of a request signal.

FIG. 5 is an explanatory diagram showing a data format of a transmission signal.

FIG. 6 is a flowchart showing a request signal transmission process on the vehicle-mounted device side.

FIG. 7 is a flowchart showing transmission processing of a transmission signal on the portable device side.

FIG. 8 is a flowchart showing lock and unlock control on the vehicle-mounted device side.

FIG. 9 is a flowchart showing a lock / unlock determination process on the vehicle-mounted device side.

FIG. 10 is an explanatory diagram of a map.

FIG. 11 is an explanatory view showing another embodiment of the keyless entry system of the present invention.

FIG. 12 is a control circuit block diagram of a portable device.

FIG. 13 is a control circuit block diagram of the vehicle-mounted device.

FIG. 14 is an explanatory diagram showing a data format of a transmission signal.

FIG. 15 is a flowchart showing transmission signal transmission processing on the portable device side.

FIG. 16 is a flowchart showing lock / unlock control on the vehicle-mounted device side.

FIG. 17 is a flowchart showing lock / unlock determination processing on the vehicle-mounted device side.

FIG. 18 is an explanatory diagram of a map.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... In-vehicle apparatus 2 ... Portable apparatus 4, 34 ... Electric field strength sensor (alpha) ... Transmission signal (beta) ... Request signal J1: ... 1st judgment level (threshold) J2 ... 2nd judgment level (threshold)

Continued on the front page (72) Inventor Yoshinori Otsubo 3-1 Fuchu-cho, Shinchu, Aki-gun, Hiroshima Pref. (72) Inventor Kunihiko Matsumura 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Pref. ) Inventor Atsushi Okamitsu 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda F-term (reference) 2E250 AA21 BB01 BB41 FF36 HH01 JJ03 KK02 5K012 AB05 AC09 AC11 AD01 BA07

Claims (12)

[Claims] 1. A keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door based on a received electric field strength of a transmission signal from a portable device, wherein the vehicle-mounted device detects a surrounding electric field state. A keyless entry system that reduces the lock / unlock threshold when the detected electric field condition is defective. 2. A keyless entry system in which an in-vehicle device locks or unlocks a vehicle door based on a received electric field strength of a transmission signal from a portable device, wherein the portable device detects a surrounding electric field state and detects a surrounding electric field state. A keyless entry system that increases the transmission strength of a transmission signal when a detected electric field condition is defective. 3. A keyless entry system without a switch operation, wherein an in-vehicle device locks or unlocks a vehicle door based on a received electric field strength of a transmission signal from a portable device, wherein the portable device detects a surrounding electric field state. A keyless entry system that shortens the transmission cycle of a transmission signal when a detected electric field condition is defective. 4. An in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, wherein the on-vehicle device locks or locks a vehicle door by a reception electric field strength of the transmission signal from the portable device. A keyless entry system for unlocking a switch without a switch operation, wherein the portable device detects a surrounding electric field state and increases a transmission intensity of a transmission signal when the detected electric field state is defective. 5. An in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, wherein the in-vehicle device locks or locks a vehicle door by a reception electric field strength of the transmission signal from the portable device. A keyless entry system for unlocking a switch without a switch operation, wherein the on-vehicle device detects the surrounding electric field state and transmits information of the electric field state to the portable device as a request signal. 6. The keyless entry system according to claim 4, wherein the portable device shortens the transmission cycle of the transmission signal when the detected electric field condition is defective. 7. The keyless entry system according to claim 2, wherein the portable device stops transmitting the transmission signal when the electric field intensity is extremely large. 8. An in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, wherein the on-vehicle device locks or locks a vehicle door by a reception electric field strength of the transmission signal from the portable device. A keyless entry system for unlocking without a switch operation, wherein the on-vehicle device detects a surrounding electric field state and shortens a transmission cycle of a request signal when the detected electric field state is defective. 9. An in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, wherein the in-vehicle device locks or locks a vehicle door by a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation for unlocking, wherein the on-vehicle device detects a surrounding electric field state and increases a transmission intensity of a request signal when the detected electric field state is defective. 10. A keyless entry system without a switch operation, wherein an in-vehicle device locks or unlocks a vehicle door based on a received electric field strength of a transmission signal from a portable device,
A keyless entry system in which the on-vehicle device detects a surrounding electric field state and shortens a reception cycle when the detected electric field state is defective. 11. An in-vehicle device for transmitting a request signal, and a portable device for transmitting a transmission signal when the request signal is received, wherein the in-vehicle device locks or locks a vehicle door by a reception electric field strength of the transmission signal from the portable device. A keyless entry system without a switch operation for unlocking, wherein the in-vehicle device increases the number of transmissions when a surrounding electric field condition is defective. 12. A keyless entry system in which a vehicle-mounted device locks or unlocks a vehicle door based on a received electric field strength of a transmission signal from a portable device, wherein the detection means for detecting a surrounding electric field state is a portable device. A keyless entry system that is provided on the side of the vehicle and that receives electric field strength information in a transmission signal and makes the control content variable on the vehicle-mounted device side that receives the transmission signal based on the electric field strength information.