JP2007065881A - Communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication terminal whose communication efficiency is improved. <P>SOLUTION: An electronic key 2 is a wrist watch itself. A virtual line L1 passing a crown 2a and a center O of an electronic key 2 is defined as L1. On the other hand, a virtual line following the axial line of a first Y axial antenna 21ya is defined as L21. In this case, an angle θ1 made by the virtual line L1 and the virtual line L21 is set at about 15 degrees. Also, when a virtual line following the axial line of a second Y axial antenna 21yb is defined as L22, an angle θ2 made by the virtual line L1 and the virtual line L22 is set as about 15 degrees. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication terminal having a communication function.

  In recent years, there has been proposed an electronic key system that permits an operation of a controlled object by an operation control device when a corresponding communication terminal (electronic key) is used. In Patent Document 1, when a corresponding electronic key (a portable device carried by the driver) is brought into the vehicle, the on-board engine is automatically started by an operation control device (a transmission / reception device disposed in the vehicle). An electronic key system (a smart ignition device which is an example of a vehicle remote control device) is disclosed. If the engine switch (push switch) button is pressed while depressing the brake pedal while the start of the in-vehicle engine is permitted, the in-vehicle engine is started.

  According to this type of electronic key system, the owner of the electronic key does not need to perform a complicated operation using the mechanical key when starting the engine. Therefore, the electronic key system is excellent in convenience. Moreover, according to the electronic key system, the start of the vehicle-mounted engine is not permitted unless an electronic key that is much more difficult to duplicate than a mechanical key is used. Therefore, the electronic key system has a high security level.

  An electronic key provided for such an electronic key system includes a battery as a power source for transmitting an ID code signal in response to a request signal transmitted from the operation control device. For this reason, when the battery has run out of the electronic key, even if such an electronic key is brought into the vehicle, the start of the in-vehicle engine is not permitted.

Therefore, by placing the electronic key over the engine switch, the electronic key obtains electric power from the radio wave transmitted from the antenna built in the engine switch, and the electric code is used to obtain the ID code signal from the electronic key. Is considered to be sent. Thereby, even when the battery has run out of the electronic key, the start of the vehicle-mounted engine is permitted while maintaining a high security level.
JP 2001-31333 A (paragraph numbers 0002 to 0005)

  However, the radio wave transmitted from the antenna built in the engine switch reaches only a point about 20 mm to 50 mm away from the engine switch. Therefore, in order to transmit the ID code signal from the electronic key based on such narrow area communication, it is necessary to reliably receive the radio wave transmitted from the antenna by the electronic key. In other words, bidirectional communication between the electronic key and the antenna needs to be performed efficiently.

  The present invention has been made paying attention to such problems, and an object thereof is to provide a communication terminal capable of improving communication efficiency.

  In order to achieve the above object, according to the first aspect of the present invention, an index serving as an index for specifying how the own communication terminal should be arranged with respect to the antenna provided in the communication terminal on the other side The first imaginary line passing through the index member and the center of the communication terminal exists on the axis of the counterpart antenna, and the distance from the counterpart antenna is the index member in the communication terminal. Is a communication terminal capable of communicating with the communication terminal on the other side when the own communication terminal is arranged with respect to the antenna on the other side so that the The indicator member is arranged with respect to the center of the communication terminal on the first imaginary line so as to have an axis along the second imaginary line whose absolute value of the angle is greater than 0 degree and less than 90 degrees. So that the second imaginary line intersects on the side Wherein the antenna to function as an intermediary for communication between the other party of the communication terminal is located.

  According to a second aspect of the present invention, in the communication terminal according to the first aspect, the first virtual line passing through the index member and the center of the own communication terminal exists on the axis of the other party's antenna, and the other party When the own communication terminal is arranged with respect to the other party's antenna so that the indicator member is the shortest distance from the other antenna in the own communication terminal, the length in the axial direction of the other party's antenna The antenna of the own communication terminal is disposed so as to have an axis along the direction of the magnetic field defined by the diameter of the antenna on the other side and the distance along the first imaginary line from the antenna on the other side. Features.

  According to a third aspect of the present invention, in the communication terminal according to the first or second aspect, the indicator member is arranged with respect to a third virtual line that passes through the center of the communication terminal and is orthogonal to the first virtual line. The antenna of the self-communication terminal is arranged so that a midpoint in the axial direction is present on the side where it is provided.

  In the invention according to claim 4, in the communication terminal according to any one of claims 1 to 3, the antenna functioning as a medium for performing communication with the communication terminal on the other side is: The first antenna and the second antenna are connected in series, and the first antenna and the second antenna are arranged so as to be symmetrical with respect to the first virtual line. And

  In the invention according to claim 5, in the communication terminal according to claim 3 or claim 4, another antenna is arranged on the side opposite to the side on which the index member is arranged with respect to the third virtual line. It is characterized by being.

The “action” of the present invention will be described below.
According to the first aspect of the present invention, when the other communication terminal is the transmission side and the own communication terminal is the reception side, the absolute value of the angle of the magnetic field direction with respect to the first virtual line exceeds 0 degree and 90 degrees. A radio wave that is less than 1 degree is transmitted from the communication terminal of the other party. Then, the radio wave is reliably received by the own communication terminal in which the arrangement of the antenna is devised in consideration of such radio wave being transmitted from the other party. In other words, communication between the own communication terminal and the communication terminal on the other side is performed efficiently. Therefore, communication efficiency can be improved.

  According to the second aspect of the present invention, the antenna of the communication terminal is arranged along the direction of the magnetic field. For this reason, it is possible to efficiently receive radio waves transmitted from the antenna of the other party by the antenna of the own communication terminal. Therefore, communication efficiency can be improved.

  According to the invention described in claim 3, the antenna of the own communication terminal is arranged so as to be biased toward the side where the index member is arranged with respect to the center of the own communication terminal. In other words, the antenna of the own communication terminal is arranged so that the distance from the antenna on the other party is shortened. For this reason, it becomes possible to receive the radio wave transmitted from the antenna of the other party at a high level by the antenna of the own communication terminal. Accordingly, the communication distance can be extended.

  According to the invention described in claim 4, the antenna that functions as a medium for performing communication with the communication terminal on the other side is divided into the first antenna and the second antenna. . For this reason, the effect | action of the invention of any one of Claims 1-3 is obtained by cooperation with a 1st antenna and a 2nd antenna. Moreover, even when the antenna must be arranged in a narrow space, it can be easily handled.

  According to the invention described in claim 5, an antenna functioning as a medium for performing communication with the communication terminal on the other side (referred to as the antenna of the own communication terminal in claim 3) and another antenna Is kept away. For this reason, when the radio wave transmitted from the antenna of the other party is received by the antenna of the own communication terminal, loss due to interference of other antennas is suppressed. Therefore, communication efficiency can be improved.

Since this invention is comprised as mentioned above, there exist the following effects.
According to the invention of any one of claims 1 to 5, communication efficiency can be improved.

Hereinafter, an embodiment in which the present invention is embodied in an electronic key system of an automobile will be described.
As shown in FIG. 1, the electronic key system 1 includes an electronic key 2 and an engine start control device 3. The electronic key 2 is possessed by the owner of the automobile. The engine start control device 3 is provided on the automobile side. The electronic key system 1 is capable of bidirectional communication between the electronic key 2 and the engine start control device 3. The electronic key system 1 permits the engine start control device 3 to start the vehicle-mounted engine when the corresponding electronic key 2 is used.

  The electronic key 2 has a reception function by wireless communication and a transmission function by wireless communication. The electronic key 2 includes a reception antenna 21, a reception circuit 22, a microcomputer 23, a transmission circuit 24, a transmission antenna 25, a battery 26, a transmission / reception antenna 27, a storage circuit 28, and a transmission / reception circuit 29.

  The receiving antenna 21 is a medium for receiving a request signal transmitted from the engine start control device 3. The receiving antenna 21 includes an X-axis antenna 21x, a Y-axis antenna 21y, and a Z-axis antenna 21z. The X-axis antenna 21x is particularly sensitive to the X-axis direction in three axial directions (X-axis direction, Y-axis direction, and Z-axis direction) orthogonal to each other. The Y-axis antenna 21y is particularly sensitive to the Y-axis direction. The Z-axis antenna 21z is particularly sensitive to the Z-axis direction. Therefore, the electronic key 2 can reliably receive the request signal transmitted from the engine start control device 3 by the cooperation of these three antennas (X-axis antenna 21x, Y-axis antenna 21y, Z-axis antenna 21z). .

  When the request signal is received by the reception antenna 21, the reception circuit 22 demodulates the request signal and generates a reception signal. Then, the reception circuit 22 outputs a reception signal to the microcomputer 23.

  The microcomputer 23 includes a nonvolatile memory 23a. In the memory 23a, an ID code (ID code of the electronic key 2) set individually for each electronic key 2 is stored. When the reception signal is input from the reception circuit 22, the microcomputer 23 generates a signal (ID code signal) including the ID code of the electronic key 2 in order to respond to the request signal. Then, the microcomputer 23 outputs an ID code signal to the transmission circuit 24. The transmission circuit 24 modulates the ID code signal input from the microcomputer 23 into a radio wave having a predetermined frequency (300 MHz in this embodiment). The transmission antenna 25 is a medium for transmitting the ID code signal modulated by the transmission circuit 24.

The battery 26 is a power source for transmitting the ID code signal in response to the request signal as described above. The battery 26 is a button type battery (primary battery).
The transmission / reception antenna 27 is a medium for receiving the activation radio wave transmitted from the engine start control device 3. Here, when the activation radio wave transmitted from the transmission / reception antenna 37 of the engine start control device 3 reaches the transmission / reception antenna 27, an electromotive force is generated at both ends of the transmission / reception antenna 27 by electromagnetic induction. In addition, an electromotive force is generated at both ends of the transmission / reception antenna 27 by mutual electromagnetic induction between the transmission / reception antenna 27 and the transmission / reception antenna 37. The storage circuit 28 accumulates the electromotive force generated at both ends of the transmission / reception antenna 27 as described above, that is, the electromagnetic wave energy obtained from the activation radio wave. The power storage circuit 28 is mainly composed of a capacitor.

  The electromagnetic wave energy accumulated in the capacitor of the power storage circuit 28 in this way is used as a backup power source when the battery 26 is consumed and the battery has run out in the electronic key 2. That is, the electromagnetic wave energy accumulated in the capacitor of the power storage circuit 28 is utilized as electric power for starting each of the transmission / reception circuit 29 and the microcomputer 23.

  When the transmitter / receiver circuit 29 is started by being covered with power by the electromagnetic energy stored in the capacitor of the power storage circuit 28, the transmitter / receiver antenna 29 also supplies power by the electromagnetic wave energy stored in the capacitor of the power storage circuit 28. The activation radio wave received by the terminal 27 is demodulated to generate a reception signal, and the reception signal is output to the microcomputer 23.

  When the microcomputer 23 is started by being covered with power by the electromagnetic energy stored in the capacitor of the power storage circuit 28, the microcomputer 23 generates the ID code signal by covering the power with the electromagnetic energy stored in the capacitor of the power storage circuit 28. Then, the ID code signal is output to the transmission / reception circuit 29. The transmission / reception circuit 29 modulates the ID code signal input from the microcomputer 23 into a radio wave having a predetermined frequency (110 KHz in this embodiment). The transmission / reception antenna 27 also functions as a medium for transmitting the ID code signal modulated by the transmission / reception circuit 29.

  The engine start control device 3 has a transmission function by wireless communication and a reception function by wireless communication. The engine start control device 3 includes a transmission circuit 31, a transmission antenna 32, a reception antenna 33, a reception circuit 34, a power feeding circuit 35, a transmission / reception circuit 36, a transmission / reception antenna 37, and a security electronic control unit (hereinafter referred to as security ECU) 38. ing. The transmission circuit 31 modulates the request signal input from the security ECU 38 into a radio wave having a predetermined frequency (134 KHz in this embodiment). The transmission antenna 32 is a medium for transmitting the request signal modulated by the transmission circuit 31.

  Here, the request signal is transmitted within a predetermined area A32 in the vehicle indicated by a two-dot chain line in FIG. In the present embodiment, the request signal is transmitted so as to extend over substantially the entire interior of the vehicle and hardly reach the outside of the vehicle. As a result, bidirectional communication between the electronic key 2 and the engine start control device 3 is possible within a predetermined area A32 in the vehicle. That is, the request signal is a trigger signal for establishing bidirectional communication between the electronic key 2 and the engine start control device 3. Thereby, when the electronic key 2 is brought into the range of the predetermined area A32 in the vehicle to which the request signal is transmitted, the request signal is received by the electronic key 2 and the ID code signal is transmitted from the electronic key 2. It will be.

  The receiving antenna 33 is a medium for receiving the ID code signal transmitted from the electronic key 2 in response to the request signal. When an ID code signal is received by the receiving antenna 33, the receiving circuit 34 demodulates the ID code signal to generate a received signal. Then, the reception circuit 34 outputs a reception signal to the security ECU 38.

  When a power supply command signal is input from the security ECU 38, the power supply circuit 35 supplies power necessary for generating the activation radio wave to the transmission / reception circuit 36. When the activation signal is input from the security ECU 38 and power is supplied from the power supply circuit 35, the transmission / reception circuit 36 generates an activation radio wave having a predetermined frequency (134 KHz in this embodiment). The transmission / reception antenna 37 is a medium for transmitting the activation radio wave generated by the transmission / reception circuit 36. The transmission / reception antenna 37 is built in an engine switch 52 described later.

  Here, the activation radio wave is transmitted within a predetermined area A37 in the vehicle, which is exaggerated by a two-dot chain line in FIG. In the present embodiment, the activation radio wave is transmitted so as to reach a point about 20 mm to 50 mm away from the engine switch 52. As a result, bidirectional communication between the electronic key 2 and the engine start control device 3 is possible within a predetermined area A37 in the vehicle. That is, the activation radio wave is a trigger signal for establishing bidirectional communication between the electronic key 2 and the engine start control device 3. As a result, when the electronic key 2 is brought within the predetermined area A37 in the vehicle where the activation radio wave is transmitted, the activation radio wave is received by the electronic key 2 and an ID code signal is transmitted from the electronic key 2. Will be.

  The transmission / reception antenna 37 also functions as a medium for receiving the ID code signal transmitted from the electronic key 2 based on the activation radio wave. When the ID code signal is received by the transmission / reception antenna 37, the transmission / reception circuit 36 demodulates the ID code signal to generate a reception signal. Then, the transmission / reception circuit 36 outputs a reception signal to the security ECU 38.

  The security ECU 38 includes a nonvolatile memory 38a. The memory 38 a stores the same ID code (reference ID code) as the ID code of the corresponding electronic key 2. A door courtesy switch 40 is electrically connected to the security ECU 38.

  The door courtesy switch 40 is for detecting the open / closed state of the in-vehicle door. When the vehicle door is open, the door courtesy switch 40 outputs a detection signal indicating that the vehicle door is open to the security ECU 38 over the period when the vehicle door is open. Further, the door courtesy switch 40 outputs a detection signal indicating that the in-vehicle door is closed to the security ECU 38 during the period in which the in-vehicle door is closed when the in-vehicle door is closed.

  When the detection signal indicating that the in-vehicle door is open is input from the door courtesy switch 40 while the detection signal indicating that the in-vehicle door is closed is input from the door courtesy switch 40, the security ECU 38 Recognize that the door has been opened. The security ECU 38 outputs a request signal to the transmission circuit 31 when recognizing that the vehicle-mounted door has been opened as described above. That is, in this case, the security ECU 38 executes the first in-vehicle communication control. When the security ECU 38 recognizes that the vehicle-mounted door has been opened, the security ECU 38 outputs a power supply command signal to the power supply circuit 35 and outputs a start signal to the transmission / reception circuit 36. That is, in this case, the security ECU 38 executes the second in-vehicle communication control.

  Here, when the security ECU 38 recognizes that the in-vehicle door has been opened, the security ECU 38 alternately executes the first in-vehicle communication control and the second in-vehicle communication control. As a result, the request signal transmitted from the transmission antenna 32 and the activation radio wave transmitted from the transmission / reception antenna 37 do not interfere with each other in the vehicle.

  The security ECU 38 determines whether the ID code included in the received signal matches the reference ID code when the received signal is input from the receiving circuit 34 based on the first in-vehicle communication control. To do. In addition, based on the second in-vehicle communication control, the security ECU 38 determines whether or not the ID code included in the received signal matches the reference ID code when the received signal is input from the transmission / reception circuit 36. To do. That is, in these cases, the security ECU 38 performs ID code verification.

  An engine electronic control unit (hereinafter referred to as engine ECU) 50 is electrically connected to the security ECU 38. The security ECU 38 outputs an ID code match signal to the engine ECU 50 when the two ID codes match by ID code verification. That is, in this case, the security ECU 38 recognizes that the corresponding electronic key 2 has been used and permits the start of the vehicle-mounted engine.

The engine ECU 50 starts an in-vehicle engine. A brake switch 51 and an engine switch 52 are electrically connected to the engine ECU 50.
The brake switch 51 is for detecting a brake operation. When the brake pedal is depressed, the brake switch 51 outputs a detection signal indicating that the brake pedal is depressed to the engine ECU 50 over a period during which the brake pedal is depressed. When the detection signal indicating that the brake pedal is depressed is input from the brake switch 51, the engine ECU 50 recognizes that the brake operation is being performed.

  The engine switch 52 is operated when starting the vehicle-mounted engine. The engine switch 52 is a push switch provided with a button that can be pressed from the outside. When the button is pressed, the engine switch 52 outputs a detection signal indicating that the button is pressed to the engine ECU 50 over a period during which the button is pressed. When the detection signal indicating that the button is pressed is input from the engine switch 52, the engine ECU 50 recognizes that the on-vehicle engine start operation has been performed.

  When the engine ECU 50 recognizes that the brake operation is being performed and the start operation of the in-vehicle engine has been performed in a state where the ID code match signal is input from the security ECU 38, the in-vehicle engine Start.

  As described above, the electronic key system 1 of the present embodiment automatically permits the start of the vehicle-mounted engine by the engine start control device 3 when the corresponding electronic key 2 is brought into the vehicle. In addition, the electronic key system 1 permits the engine start control device 3 to start the vehicle-mounted engine when the corresponding electronic key 2 is hit by the engine switch 52.

Next, features of the electronic key system 1 will be described.
Now, the electronic key 2 provided to the electronic key system 1 as described above is a wristwatch as shown in FIG. That is, the electronic key 2 (watch) is worn so as to surround the arm (generally, the wrist of the left arm). In other words, in this embodiment, a wristwatch provided with a receiving antenna 21, a receiving circuit 22, a microcomputer 23, a transmitting circuit 24, a transmitting antenna 25, a battery 26, a transmitting / receiving antenna 27, a storage circuit 28, and a transmitting / receiving circuit 29 is used as an electronic key. 2 is used.

  Incidentally, as is apparent from FIG. 3, the electronic key 2 of this embodiment is an analog wristwatch provided with an hour hand, a minute hand, and a second hand. And the crown 2a is provided corresponding to the position in which the hour hand indicates 3 o'clock. When the crown 2a is depleted of the battery in the electronic key 2, when the electronic key 2 is turned over to the engine switch 52, the crown 2a determines how to use the electronic key 2 with respect to the transmission / reception antenna 37 built in the engine switch 52. It corresponds to an index member that serves as an index for identifying whether or not to be arranged. In other words, when the battery has run out of the electronic key 2, the electronic key 2 is removed from the arm and the electronic key 2 is moved to the engine switch 52 so that the crown 2a is closest to the engine switch 52. Switch 52 turns on.

Next, the maximum feature point of the electronic key system 1 will be described.
As shown in FIGS. 4 to 6, a printed circuit board 70 having a disc shape is accommodated in the case 2 b of the electronic key 2. On one surface (upper surface) of the printed circuit board 70, electrical components such as an X-axis antenna 21x and a Y-axis antenna 21y (first Y-axis antenna 21ya and second Y-axis antenna 21yb) are mounted. The first Y-axis antenna 21ya and the second Y-axis antenna 21yb are connected in series. Each of the X-axis antenna 21x, the first Y-axis antenna 21ya, and the second Y-axis antenna 21yb is configured by a bar antenna. On the other surface (lower surface) of the printed circuit board 70, electrical components such as the Z-axis antenna 21z, the receiving circuit 22, and the microcomputer 23 are mounted. The Z-axis antenna 21z is configured by a loop antenna. A battery 26 is disposed on the other surface side of the printed circuit board 70.

  A movement 80 is accommodated above the printed circuit board 70 in the case 2b. The movement 80 includes a watch battery, a motor that obtains electric power from the watch battery, a plurality of gears that are rotated based on the rotational driving force of the motor, and a mounting plate for assembling the gears. Then, the movement 80 rotates the hour hand, the minute hand, and the second hand in a manner that keeps time by rotating a plurality of gears in conjunction with each other. In FIGS. 4 and 6, the components of the movement 80 are not shown individually, but a collection of them is shown as a movement 80 having a disk shape.

  Here, an imaginary line passing through the crown 2a and the center O of the electronic key 2 is assumed to be L1. On the other hand, an imaginary line along the axis of the first Y-axis antenna 21ya is L21. In such a case, the angle θ1 formed by the virtual line L1 and the virtual line L21 is set to about 15 degrees. When the virtual line along the axis of the second Y-axis antenna 21yb is L22, the angle θ2 formed by the virtual line L1 and the virtual line L22 is set to about 15 degrees.

  As described above, the first Y-axis antenna 21ya (second Y-axis antenna 21yb) has an axis along the virtual line L21 (L22) whose absolute value with respect to the virtual line L1 is about 15 degrees. Has been placed. In other words, the first Y-axis antenna 21ya and the second Y-axis antenna 21yb are arranged so as to be symmetric with respect to the virtual line L1. Incidentally, the virtual line L21 (L22) intersects the virtual line L1 on the side (point P) where the crown 2a is arranged with respect to the center O of the electronic key 2.

  When the virtual line passing through the center O of the electronic key 2 and orthogonal to the virtual line L1 is L3, the axial center point Q1 (Q2) on the side where the crown 2a is arranged with respect to the virtual line L3. The first Y-axis antenna 21ya (second Y-axis antenna 21yb) is arranged so that there exists. And the X-axis antenna 21x is arrange | positioned with respect to the virtual line L3 on the opposite side to the side by which the crown 2a is arrange | positioned.

Next, the operation when the electronic key 2 is pushed over the engine switch 52 will be described.
In this case, as shown in FIG. 7, the virtual line L1 exists on the axis M of the transmission / reception antenna 37 built in the engine switch 52, and the distance from the engine switch 52 (transmission / reception antenna 37) is small. The electronic key 2 is arranged with respect to the transmission / reception antenna 37 so that the crown 2 a is the shortest among the electronic keys 2.

  Here, an activation radio wave whose absolute value of the angle of the magnetic field direction with respect to the axis M (virtual line L1) exceeds 0 degree and less than 90 degrees is transmitted from the transmission / reception antenna 37. Incidentally, the direction of the magnetic field of the activation radio wave is defined by the axial length of the transmission / reception antenna 37, the diameter of the transmission / reception antenna 37, and the distance along the virtual line L1 from the transmission / reception antenna 37. Then, the activation radio wave is received by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb arranged so as to have an axis along the direction of the magnetic field defined in this way.

  In FIG. 1, for convenience of explanation, the Y-axis antenna 21y and the transmission / reception antenna 27 are shown separately, but the Y-axis antenna 21y (the first Y-axis antenna 21ya and the second Y-axis antenna 21yb) is shown. The transmitting / receiving antenna 27 is configured by being also used. Accordingly, when the activation radio wave is received by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb, the ID code is transmitted by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb. A signal is transmitted. The ID code signal thus transmitted is received by the transmission / reception antenna 37.

As described above, according to the present embodiment, the following operations and effects can be obtained.
(1) When the engine start control device 3 is set as the transmitting side and the electronic key 2 is set as the receiving side, the activation radio wave whose magnetic field direction has an absolute value of more than 0 degrees and less than 90 degrees with respect to the virtual line L1 It is transmitted from the engine start control device 3. Then, an electronic key in which the arrangement of each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb is devised in consideration of such a start-up radio wave being transmitted from the engine start control device 3 2, the activation radio wave is reliably received. In other words, communication between the electronic key 2 and the engine start control device 3 is efficiently performed. Therefore, communication efficiency can be improved.

  (2) Each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb is arranged along the direction of the magnetic field of the activation radio wave. Therefore, the activation radio wave transmitted from the transmission / reception antenna 37 can be efficiently received by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb. Therefore, communication efficiency can be improved.

  (3) Each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb is arranged so as to be biased toward the side where the crown 2a is arranged with respect to the center O of the electronic key 2. In other words, each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb is arranged so that the distance from the transmission / reception antenna 37 is shortened. Therefore, it is possible to receive the activation radio wave transmitted from the transmission / reception antenna 37 at a high level by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb. Accordingly, the communication distance can be extended.

  (4) The Y-axis antenna 21y is divided into a first Y-axis antenna 21ya and a second Y-axis antenna 21yb. Therefore, the actions and effects (1) to (3) above can be obtained by the cooperation of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb. Further, even when the Y-axis antenna 21y must be arranged in a narrow space, it can be easily handled.

  (5) Each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb is separated from the X-axis antenna 21x. Therefore, when the activation radio wave transmitted from the transmission / reception antenna 37 is received by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb, the loss due to the interference of the X-axis antenna 21x. Is suppressed. Therefore, communication efficiency can be improved.

  (6) Since the communication efficiency can be improved, even a weak activation radio wave can be received reliably. In this respect, there is an advantage over the configuration of FIG. 8 in which the angle θ1 (θ2) formed by the virtual line L1 and the virtual line L21 (L22) is set to 0 degrees.

  (7) Since the communication efficiency can be improved, the activation radio wave can be reliably received even when the distance from the engine switch 52 is increased. In short, the communication area is expanded and convenience is improved. In this respect, there is an advantage over the configuration of FIG. 8 in which the angle θ1 (θ2) formed by the virtual line L1 and the virtual line L21 (L22) is set to 0 degrees.

  (8) By causing the crown 2a, which tends to be a mark in the electronic key 2 (watch), to function as an index member, the operation of holding the electronic key 2 against the engine switch 52 can be reliably performed.

In addition, the said embodiment can also be changed and actualized as follows.
The index member is not limited to the crown 2a. An operation switch provided on the electronic key 2 so that the electronic key 2 functions as a remote controller may be used as an index member.

  The angles θ1 and θ2 are not limited to about 15 degrees. The angles θ1 and θ2 may be changed to arbitrary values within a range of 0 degrees <angles θ1 and θ2 <90 degrees. In this case, the values of the angles θ1 and θ2 are the directions of the magnetic field of the activation radio wave defined by the axial length of the transmission / reception antenna 37, the diameter of the transmission / reception antenna 37, and the distance along the virtual line L1 from the transmission / reception antenna 37. It is preferable to set according to.

  If the loss due to interference with the X-axis antenna 21x is not a problem when the activation radio wave is received by each of the first Y-axis antenna 21ya and the second Y-axis antenna 21yb, a virtual line The first Y-axis antenna 21ya (second Y-axis antenna 21yb) may be arranged so that the midpoint Q1 (Q2) exists on L3. Alternatively, the first Y-axis antenna 21ya (second Y-axis antenna 21yb) is arranged so that the midpoint Q1 (Q2) exists on the opposite side of the virtual line L3 from the side where the crown 2a is arranged. May be.

  The transmission / reception antenna 27 may be configured by dividing the X-axis antenna 21x into a first X-axis antenna and a second X-axis antenna and using them both.

The block diagram which shows the structure of an electronic key system. Explanatory drawing which shows the predetermined area | region in a vehicle. The front view which shows the external appearance shape of an electronic key. The front view which shows the internal structure of an electronic key. The rear view which shows the internal structure of an electronic key. Sectional drawing which shows schematic structure of an electronic key. Explanatory drawing for demonstrating the effect | action of the electronic key of this embodiment. Explanatory drawing for demonstrating the effect | action of the electronic key used as a comparison object with respect to the electronic key of this embodiment.

Explanation of symbols

  2 ... Electronic key (own communication terminal), 2a ... Crown (index member), 3 ... Engine start control device (other communication terminal), 21x ... X-axis antenna (other antenna), 21ya ... First Y-axis Antenna (antenna of own communication terminal, first antenna), 21yb ... second Y-axis antenna (antenna of own communication terminal, second antenna), 37 ... transmission / reception antenna (antenna on the other side), L1 ... virtual line (First virtual line), L21, L22 ... virtual line (second virtual line), L3 ... virtual line (third virtual line), M ... axis of transmission / reception antenna 37, O ... center of electronic key 2, Q1 ... first The midpoint of the first Y-axis antenna 21ya in the axial direction, Q2... The midpoint of the second Y-axis antenna 21yb in the axial direction.

Claims (5)

Provided with an index member that serves as an index for specifying how the own communication terminal should be arranged with respect to the antenna provided in the other party's communication terminal, the index member and the own communication terminal on the axis of the other party's antenna So that the first imaginary line passing through the center of the mobile station and the distance from the antenna on the other side is the shortest of the index members in the terminal on the other side, A communication terminal capable of communicating with a communication terminal on the other side when arranged,
The indicator member has an axis along the second imaginary line, the absolute value of the angle with respect to the first imaginary line being greater than 0 degrees and less than 90 degrees, and with respect to the center of the communication terminal on the first imaginary line A communication terminal characterized in that an antenna functioning as a medium for performing communication with a communication terminal on the other side is arranged so that the second virtual line intersects on the side where . The communication terminal according to claim 1,
The first virtual line passing through the index member and the center of the own communication terminal exists on the axis of the other party antenna, and the distance from the other party antenna is the shortest among the own communication terminals. As described above, when the communication terminal is arranged with respect to the antenna on the other side, the length in the axial direction of the antenna on the other side, the diameter of the antenna on the other side, and the first virtual line from the antenna on the other side A communication terminal, wherein the antenna of the communication terminal is arranged so as to have an axis along the direction of a magnetic field defined by the distance. In the communication terminal according to claim 1 or claim 2,
The antenna of the own communication terminal is arranged so that the midpoint of the axial direction exists on the side where the index member is arranged with respect to the third imaginary line passing through the center of the own communication terminal and orthogonal to the first imaginary line A communication terminal. In the communication terminal according to any one of claims 1 to 3,
The antenna that functions as a medium for performing communication with the communication terminal on the other side is a first antenna and a second antenna connected in series.
A communication terminal, wherein the first antenna and the second antenna are arranged so as to be line-symmetric with respect to the first virtual line. In the communication terminal according to claim 3 or claim 4,
A communication terminal, wherein another antenna is arranged on the side opposite to the side on which the index member is arranged with respect to the third virtual line.

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