JP2021082962A - Communication device and communication unit - Google Patents

Abstract

To provide a communication device and a communication unit that enable authentication of short-range radio with a few components.SOLUTION: A communication device 3 includes: an antenna 11 that performs short-range radio communication with a terminal; and a case 8 in which the antenna 11 is placed at a position where distance from one surface 8a is different from distance from another surface 8b. When a plurality of radio waves with different strength are transmitted from the antenna 11, responses of the terminal to the radio waves are received by the antenna 11, and a position of the terminal with respect to the case 8 is determined from a combination of areas where communication is established.SELECTED DRAWING: Figure 2

Description

The present invention relates to a communication device and a communication unit that perform short-range wireless communication with a terminal.

Conventionally, there is a well-known electronic key system that authenticates the correctness of an electronic key of a vehicle via wireless communication and enables an in-vehicle device to operate. As a general electronic key system, for example, a radio wave is transmitted from an LF antenna provided in a vehicle, and when the electronic key receives this radio wave, a radio wave including an electronic key ID is transmitted to the vehicle from the UHF antenna of the electronic key. When the vehicle receives the radio wave from the electronic key, the vehicle collates the electronic key ID included in the radio wave, and if the collation is successful, the vehicle permits or executes the operation of the on-board device.

In this type of electronic key system, it has been studied to use short-range wireless communication for communication between the vehicle and the electronic key (see Patent Document 1 and the like). Short-range wireless communication includes, for example, NFC (Near Field Communication) communication.

Japanese Unexamined Patent Publication No. 2016-82372

By the way, in the above-mentioned LF-UHF communication electronic key system, it is determined whether the electronic key is located outdoors or indoors, and when the electronic key is collated with the outdoor electronic key, the vehicle door is permitted to be locked or unlocked. Execute and allow the transition of the power state of the vehicle when the collation with the electronic key in the room is established. Whether the electronic key is located indoors or outdoors is determined by determining that the electronic key is located outdoors when the electronic key is communicated with the radio wave of the LF antenna that transmits radio waves outdoors, and the LF that transmits radio waves indoors. When the radio wave of the antenna communicates with the electronic key, it is determined that the electronic key is located in the room.

Even in the case of an electronic key system in which communication between the vehicle and the electronic key is short-range wireless communication, it is necessary to perform indoor / outdoor determination of the electronic key. In this case, it is necessary to provide a communication device (antenna) for short-range wireless communication in the vehicle indoors and outdoors, which leads to an increase in the number of parts.

An object of the present invention is to provide a communication device and a communication unit capable of short-range radio authentication with a small number of parts.

Communication devices that solve the above problems include an antenna for short-range wireless communication with a terminal, a case where the antenna is arranged at a position where the distance from one surface is different from the distance from the other surface, and the strength from the antenna. It is provided with a control unit that transmits a plurality of different radio waves and determines the position of the terminal with respect to the case from a combination of responses of the terminal to these radio waves.

A communication unit that solves the above problems includes an antenna that wirelessly communicates with a terminal over a short distance, and a case in which the antenna is arranged at a position where the distance from one surface is different from the distance from the other surface. When a plurality of radio waves having different intensities are transmitted from the above, the position of the terminal with respect to the case is determined from the combination of the responses of the terminal to these radio waves.

According to the present invention, short-range radio authentication can be performed with a small number of parts.

The perspective view which shows the mounting example of the communication device of 1st Embodiment. Perspective view of the communication device. Block diagram of communication equipment. Area diagram of radio waves formed by the antenna of the communication device. (A) is an operation diagram when the terminal is held over the antenna from the outside, and (b) is an operation diagram when the terminal is held over the antenna from the room. The perspective view of the communication apparatus of 2nd Embodiment. Area diagram of radio waves formed by the antenna of the communication device. (A) is an operation diagram when the terminal is held over the antenna from the outside, and (b) is an operation diagram when the terminal is stored in the recess of the case indoors. A perspective view of another example communication device.

(First Embodiment)
Hereinafter, the first embodiment of the communication device and the communication unit will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, the vehicle 1 is provided with a short-range wireless system 5 that executes wireless communication between the terminal 2 and the communication device 3 by holding the terminal 2 very close to the communication unit 4 of the communication device 3. ing. The short-range wireless system 5 of this example is a communication system using NFC (Near Field Communication). In the short-range wireless system 5, authentication of the terminal 2 is executed by wireless communication with the communication device 3. The communication device 3 is attached and fixed to the inner surface of the triangular window 6 of the vehicle 1.

As shown in FIG. 2, the communication device 3 (communication unit 4) includes a case 8 forming an outer shell of the communication device 3 and an antenna unit 9 for transmitting and receiving radio waves in the communication device 3. The case 8 is made of resin, for example, and has a rectangular outer shape. The antenna portion 9 is arranged inside the case 8. The inside of the case 8 may be either a space structure or a structure filled with a predetermined member that allows the passage of radio waves.

The antenna unit 9 includes a substrate 10 on which the electrical components of the antenna unit 9 are mounted, and an antenna 11 mounted on the substrate 10. The substrate 10 is arranged vertically in the case 8. The antenna 11 is, for example, a transmission / reception antenna capable of both transmitting and receiving various radio waves, and is a pattern antenna mounted on the substrate 10. The antenna 11 is provided in an annular shape along the edge of the substrate 10.

The antenna 11 (antenna portion 9) is arranged inside the case 8 at an asymmetrical position other than the center of the case (center of the case 8). That is, the antenna 11 (antenna portion 9) of this example is arranged at a position inside the case 8 where the distance from one surface 8a is different from the distance from the other surface 8b. In the case of this example, the antenna 11 (antenna portion 9) is offset at a position deviated from the center by a predetermined amount on one side (+ Y-axis direction in FIG. 2) along the width direction (Y-axis direction in FIG. 2) of the case 8. Has been done.

As shown in FIG. 3, the communication device 3 includes a control unit 14 that controls the operation of the communication device 3 (short-range wireless system 5). The control unit 14 is connected to the in-vehicle device 16 via a communication line 15 in the vehicle. Further, the control unit 14 operates the antenna 11 via the wireless communication circuit 17 provided in the communication device 3. The wireless communication circuit 17 includes various electronic circuits such as an oscillator, an amplifier, and a filter.

The communication unit 4 may have a configuration in which both the antenna 11 and the wireless communication circuit 17 of the antenna 11 are provided on the substrate 10, or only the antenna 11 is provided on the substrate 10, and the wireless communication circuit 17 is the substrate 10. Any configuration may be provided at another location. Incidentally, in the example of FIG. 3, both the antenna 11 and the wireless communication circuit 17 are mounted on the substrate 10, and the communication unit 4 includes both of them.

The control unit 14 executes short-range wireless authentication with the terminal 2 via the antenna 11, and controls the operation of the in-vehicle device 16 based on the authentication result. The communication line 15 is preferably, for example, CAN (Controller Area Network) or LIN (Local Interconnect Network). The device 16 includes, for example, a door lock device 18 for switching the lock / unlock of the vehicle door, an engine 19 of the vehicle 1, and the like. The authentication preferably includes, for example, verification for confirming the correctness of the ID code registered in the terminal 2, authentication using a predetermined encryption key, and the like.

As shown in FIG. 4, the control unit 14 controls the antenna 11 so that a plurality of communication areas E having different intensities (large and small ranges) of radio waves Sk are formed in the antenna 11. In the case of this example, the antenna 11 forms two, a first area E1 in which the intensity of the radio wave Sk is high and the area is set large, and a second area E2 in which the intensity of the radio wave Sk is low and the range is set small. .. It is preferable to set the communication area E of the radio wave Sk formed by the antenna 11 by, for example, adjusting the parameters of the elements of the LC circuit of the antenna unit 9 or adjusting the voltage supplied to the antenna 11 during communication. ..

In the case of this example, the control unit 14 has a plurality of communication areas (in this example, both the first area E1 and the second area E2) formed on one surface 8a of the case 8, while the other surface 8b of the case 8 is formed. A plurality of radio waves Sk are transmitted from the antenna 11 with an intensity such that a number of communication areas (in this example, only the first area E1) is formed on the surface 8a.

The communication device 3 forms both the first area E1 and the second area E2 inside the vehicle 1, and forms only the first area E1 outside the vehicle 1. The mounting direction of the case 8 and the case 8 The mounting position, the output strength of the antenna 11, and the like are set. In the case of this example, the mounting direction of the case 8 to the vehicle body (in this example, the triangular window 6) is such that the antenna 11 offset from the case 8 is on the indoor side. Further, when the communication device 3 of this example is attached to the triangular window 6 of the vehicle 1, one surface 8a of the case 8 faces indoors and the other surface 8b of the case 8 faces outdoors. ..

When a plurality of radio waves Sk having different intensities are transmitted from the antenna 11, the control unit 14 determines the position of the terminal 2 with respect to the case 8 from the combination of the responses of the terminal 2 to the radio waves Sk. In the case of this example, when the control unit 14 receives the response from the terminal 2 on the antenna 11 both when the first area E1 of the radio wave Sk is formed from the antenna 11 and when the second area E2 is formed, the control unit 14 receives the response from the terminal 2. It is determined that the terminal 2 is located indoors. When the first area E1 and the second area E2 are formed from the antenna 11, the control unit 14 positions the terminal 2 outdoors when the antenna 11 receives the response from the terminal 2 only when the first area E1 is formed. Then judge.

Next, the operation of the communication device 3 (short-range wireless system 5) of the present embodiment will be described with reference to FIG.
As shown in FIG. 5A, when the condition for starting the short-range radio is satisfied, the control unit 14 performs a plurality of communications with different output intensities (twice in this example) on the antenna 11 to obtain an antenna. Two communication areas E (first area E1 and second area E2) having different ranges are formed around the eleven. In the case of this example, the antenna 11 executes an operation of transmitting a request signal Sreq requesting the terminal 2 to start communication as a radio wave Sk to be transmitted to the terminal 2 via short-range radio. The request signal Sreq is preferably transmitted repeatedly, for example, a plurality of times.

Further, in the case of this example, the first area E1 is set in a large range centering on the antenna 11 so that the radio waves can reach the outside as well. That is, the first area E1 is an area where the request signal Sreq reaches not only indoors but also outdoors. Further, the second area E2 is set in a small range centering on the antenna 11 so that the radio waves do not leak from the boundary Pa between the inside and outside of the room and the radio waves reach only the room. That is, the second area E2 is an area where the request signal Sreq reaches only the inside of the vehicle. In the case of this example, the indoor / outdoor boundary Pa is the triangular window 6 of the vehicle 1.

The conditions for starting short-range radio are, for example, 1) the lock button provided on the outside door handle of the vehicle door was operated to lock the vehicle door, and 2) the vehicle door to unlock the vehicle door. The touch sensor provided on the door handle outside the vehicle was operated, and 3) the engine switch provided in the driver's seat was operated to switch the power supply state (engine starting state) of the vehicle 1.

The example shown in FIG. 5A is an example of the holding operation of the terminal 2 when locking or unlocking the vehicle door from the outside, for example. At this time, the terminal 2 is held over the communication device 3 from the outside. When the terminal 2 is held over the communication device 3 from outside the vehicle, the terminal 2 establishes communication in the first area E1. That is, in this case, the terminal 2 receives the request signal Sreq transmitted in the range of the first area E1 from the antenna 11, takes an action of responding to this radio wave, and obtains the ID signal Sid including its own ID code. Reply via short-range wireless communication.

When the control unit 14 receives the ID signal Sid from the antenna 11 as a response to the request signal Sreq, the control unit 14 executes authentication based on the received ID signal Sid group. This authentication preferably includes authentication using a predetermined encryption key in addition to verification of the ID code registered in the terminal 2. Authentication using an encryption key includes, for example, challenge-response authentication.

Further, the control unit 14 confirms whether the authentication is established in both the first area E1 and the second area E2, or whether the authentication is established only in the first area E1, so that the terminal 2 is indoors or outdoors. Determine if it is located in. When the control unit 14 confirms that the authentication with the terminal 2 is established only when the first area E1 is formed, the control unit 14 determines that the legitimate terminal 2 is located outside the room.

When the authentication (outdoor authentication) with the terminal 2 located outdoors is established, the control unit 14 permits or executes the locking / unlocking of the vehicle door. As a result, when the vehicle door is unlocked, if the lock button is operated and the terminal 2 is held over the communication device 3 from the outside to establish the authentication of the terminal 2, the vehicle door can be shifted to the lock. Further, when the vehicle door is locked, the vehicle door can be unlocked by touching the outside door handle and holding the terminal 2 from the outside to the communication device 3 to establish the authentication of the terminal 2.

The example shown in FIG. 5B is an example of a holding operation of the terminal 2 when switching the power supply state of the vehicle 1 from the room (when starting the engine 19), for example. At this time, the terminal 2 is held over the communication device 3 from the room. When the terminal 2 is held up from the room, the terminal 2 establishes communication in both the first area E1 and the second area E2. That is, in this case, the terminal 2 receives the request signal Sreq transmitted in the range from the antenna 11 to the first area E1 and the request signal Sreq transmitted in the range from the antenna 11 to the second area E2. At both times, the operation of returning the ID signal Sid is taken.

The control unit 14 uses both the ID signal Sid returned from the terminal 2 when the first area E1 is formed and the ID signal Sid returned from the terminal 2 when the second area E2 is formed. Authenticate. When the control unit 14 confirms that the authentication is established with both the ID signal Sid received from the terminal 2 when the first area E1 is formed and the ID signal Sid received from the terminal 2 when the second area E2 is formed. , It is determined that the legitimate terminal 2 is located in the room.

When the authentication (indoor authentication) with the terminal 2 located in the room is established, the control unit 14 permits the transition of the power supply state of the vehicle 1. Thereby, for example, when the engine switch in the driver's seat is pushed while depressing the brake pedal, the engine 19 can be started.

According to the communication device 3 (communication unit 4) of the above embodiment, the following effects can be obtained.
(1) The communication device 3 includes an antenna 11 for short-range wireless communication with the terminal 2, a case 8 in which the antenna 11 is arranged at a position where the distance from one surface 8a is different from the distance from the other surface 8b, and an antenna. A control unit 14 is provided which transmits a plurality of radio waves Sk (request signal Sreq) having different intensities from 11 and determines the position of the terminal 2 with respect to the case 8 from the combination of the responses of the terminal 2 to these radio waves.

According to the configuration of this example, during short-range wireless communication between the communication device 3 and the terminal 2, the radio wave Sk transmitted from the antenna 11 of the communication device 3 causes a plurality of communication areas E to overlap around the case 8. , A region of communication area E where only high-intensity radio waves Sk can reach is formed. At this time, if the terminals 2 are located in the areas of the plurality of communication areas E, the responses are received from all the terminals 2 when the communication areas E are formed, and the communication area E is in the area where only the high-intensity radio wave Sk can reach. When the terminal 2 is located, the response is received from the terminal 2 only when the communication area E of the high-intensity radio wave is formed. In this way, the position of the terminal 2 with respect to the case 8 can be recognized from the combination of the responses of the terminal 2 when the antenna 11 forms the plurality of communication areas E. Further, in determining the position of the terminal 2 with respect to the case 8, only one antenna 11 is required. Therefore, short-range wireless authentication can be performed with a small number of parts.

(2) The antenna 11 is housed inside the case 8. In this case, short-range wireless communication with the communication device 3 can be executed by an easy-to-understand operation of holding the terminal 2 around the case 8. The antenna 11 can also be protected by the case 8.

(3) In the control unit 14, a plurality of communication areas E are formed on one surface 8a of the case 8, and a smaller number of communication areas E than the one surface 8a are formed on the other surface 8b of the case 8. A plurality of radio waves Sk are transmitted from the antenna 11 with such an intensity. In this case, from the number of areas where communication between the terminal 2 and the antenna 11 is established, it can be determined whether the terminal 2 exists on one surface 8a or the other surface 8b of the case 8.

(4) One surface 8a is one outer surface of the case 8. The other surface 8b is the other outer surface of the case 8. Therefore, the shape of the case 8 can be as simple as, for example, a cube or a rectangular parallelepiped.

(5) When the antenna 11 and the wireless communication circuit 17 are provided on the substrate 10, they can be arranged at close positions, so that the signals transmitted and received by the antenna 11 and the wireless communication circuit 17 are less likely to be attenuated. be able to.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 6 to 8. The second embodiment is an example in which the shape of the case 8 of the first embodiment is changed. Therefore, the same parts as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the different parts will be described in detail.

As shown in FIG. 6, the case 8 of the communication device 3 includes a recess 25 capable of accommodating the terminal 2. The recess 25 is a hole formed in the upper surface of the case 8. The recess 25 is formed at a position avoiding the antenna portion 9 housed in the case 8. The opening range of the recess 25 may be any size or shape as long as it can accommodate the terminal 2.

As shown in FIG. 7, in the control unit 14, a plurality of areas (in this example, both the first area E1 and the second area E2) are formed inside the recess 25 of the case 8, and the wall portion 26 of the recess 25 is formed. A plurality of radio waves Sk are transmitted from the antenna 11 with such an intensity that a smaller number of areas (in this example, only the first area E1) is formed on the outer surface of the concave portion 25. In the case of this example, one surface 8a on which a plurality of communication areas E (in this example, both the first area E1 and the second area E2) are formed in the case 8 is the inner surface of the recess 25. Further, in the case 8, the other surface 8b on which a smaller number of communication areas E (only the first area E1 in this example) is formed than one surface 8a is the outer surface of the wall portion 26 forming the recess 25. ..

The communication device 3 forms both the first area E1 and the second area E2 in the interior of the vehicle 1, that is, the recess 25, and forms only the first area E1 outside the vehicle 1. It is attached to the triangular window 6). In the case of this example, the mounting direction of the case 8 to the vehicle body (in this example, the triangular window 6) is such that the antenna 11 offset with respect to the case 8 is on the indoor side and the recess 25 is on the outdoor side. is there.

Next, the operation of the communication device 3 (short-range wireless system 5) of the present embodiment will be described with reference to FIG.
As shown in FIG. 8A, when the vehicle door is locked or unlocked from the outside, the terminal 2 is held over the communication device 3 from the outside. At this time, the control unit 14 determines that the outdoor authentication with the terminal 2 has been established because the communication with the terminal 2 is executed when the first area E1 is formed and the authentication is recognized. Therefore, when the control unit 14 recognizes that the outdoor authentication has been established, the control unit 14 permits or executes the locking / unlocking of the vehicle door. This allows the user to lock and unlock the vehicle door from the outside.

As shown in FIG. 8B, for example, when switching the power supply state of the vehicle 1 from the room (when starting the engine 19), an operation of inserting the terminal 2 into the recess 25 of the case 8 is executed. When the terminal 2 is housed in the recess 25 of the case 8, the terminal 2 is held at a position close to the antenna 11 of the communication device 3. At this time, the terminal 2 can sequentially receive both the request signal Sreq transmitted from the antenna 11 in the range of the first area E1 and the request signal Sreq transmitted in the range of the second area E2.

The terminal 2 receives both the request signal Sreq transmitted in the range from the antenna 11 to the first area E1 and the request signal Sreq transmitted in the range from the antenna 11 to the second area E2. , Each returns the ID signal Sid. The control unit 14 uses both the ID signal Sid returned from the terminal 2 when the first area E1 is formed and the ID signal Sid returned from the terminal 2 when the second area E2 is formed. If the authentication is executed and it is confirmed that the authentication is established together, the transition operation of the vehicle power supply is permitted. This allows the user to operate the engine switch to start the engine.

According to the communication device 3 (communication unit 4) of the above embodiment, the following effects can be obtained in addition to (1) to (3) and (5) described in the first embodiment.
(6) The case 8 includes a recess 25 capable of accommodating the terminal 2. One surface 8a is the inner surface of the recess 25. The other surface 8b is the outer surface of the wall portion 26 forming the recess 25. In this case, if the terminal 2 is housed in the recess 25 of the case 8, it is possible to store the terminal 2 and also perform short-range wireless communication between the terminal 2 and the antenna 11. Therefore, convenience at the time of use can be ensured.

In addition, this embodiment can be implemented by changing as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
[About Case 8]
-In each embodiment, as shown in FIG. 9, in the second embodiment, the wall portion 26 may be omitted from the case 8 and a pair of projecting pieces 31 may be provided on the back surface of the case 8. In this structure, when the communication device 3 is installed at the attachment location, the projecting piece 31 is attached to the attachment location (for example, the triangular window 6), so that the recess 25 for accommodating the terminal 2 cooperates with the attachment location. To form. Also in the case of this structure, the storage portion (recess 25) of the terminal 2 can be formed in the case 8.

-In each embodiment, the shape of the case 8 is not limited to a cube or a rectangular parallelepiped, and may be, for example, a spherical shape or a shape obtained by cutting out a part of the spherical shape. Further, the shape of the case 8 may be asymmetrical.

-In each embodiment, the material of the case 8 may be any material that cannot transmit and receive radio waves.
-In each embodiment, one surface 8a and the other surface 8b are not limited to surfaces facing each other, and may be surfaces that intersect each other.

-In each embodiment, the antenna 11 may have a shape in which a part of the antenna 11 is exposed to the outside from the case 8.
-In the second embodiment, the recess 25 may be formed at a position other than the upper surface such as the side surface of the case 8.

[About antenna 11]
-In each embodiment, the antenna 11 is not limited to the pattern antenna provided on the substrate 10, and may be an antenna formed separately from the substrate 10.

-In each embodiment, the shape of the antenna 11 may be changed to another type of antenna such as a loop antenna.
-In each embodiment, the orientation and position of the antenna 11 in the case 8 can be appropriately changed according to the directivity of the radio wave required for communication.

[About the radio wave communication area E formed by the antenna 11]
-In each embodiment, the number of communication areas E formed by the antenna 11 is not limited to two, large and small, and may be, for example, three or more.

-In each embodiment, the antenna 11 may form a plurality of communication areas E having directivity in different directions.
[About the asymmetrical position that is not in the center of the case]
-In each embodiment, when the antenna 11 is arranged at an asymmetrical position other than the center of the case, the asymmetrical direction can be any of the width direction, the height direction, and the depth direction of the communication device 3 (communication unit 4). Good.

-In each embodiment, the asymmetric position includes asymmetry in line symmetry and asymmetry in point symmetry.
[About communication unit 4]
-In each embodiment, the mounting position of the communication unit 4 is not limited to the triangular window 6, and may be changed to other positions such as the windshield, window glass, rear glass, doorknob, and pillar of the vehicle body of the vehicle 1.

-In each embodiment, the communication unit 4 is not limited to being arranged at the boundary Pa between indoors and outdoors, and may be arranged at a desired location.
-In each embodiment, the communication unit 4 may be configured to include a control unit 14.

"About short-range wireless communication"
-In each embodiment, the response from the terminal 2 is not limited to the recognition condition that the collation by the ID signal Sid is established, and may simply receive the ID signal Sid, for example.

-In each embodiment, the short-range wireless communication is not limited to NFC, and may be changed to another communication format such as RFID (Radio Frequency IDentification).
[Other]
-In each embodiment, the control unit 14 (computer) is not limited to the one that performs software processing for all the processing executed by itself. For example, the control unit 14 may include a dedicated hardware circuit (for example, an integrated circuit for a specific application: ASIC) that performs hardware processing for at least a part of the processing executed by itself. That is, the control unit 14 is 1) one or more processors that operate according to a computer program (software), 2) one or more dedicated hardware circuits that execute at least a part of various processes, or 3). It can be configured as a circuitry including a combination thereof. The processor includes a CPU and a memory such as a RAM and a ROM, and the memory stores a program code or an instruction configured to cause the CPU to execute a process. Memory or computer-readable media includes any available medium accessible by a general purpose or dedicated computer.

-In each embodiment, it is preferable that the terminal 2 is a high-performance mobile phone capable of short-range wireless communication, such as a card for short-range wireless communication.
-In each embodiment, the communication device 3 (communication unit 4) is not limited to being used for the vehicle 1, and may be applied to other devices and devices other than the vehicle.

1 ... vehicle, 2 ... terminal, 3 ... communication device, 4 ... communication unit, 8 ... case, 8a ... one side, 8b ... other side, 11 ... antenna, 14 ... control unit, 25 ... recess, 26 ... wall Department, E ... Communication area.

Claims (6)

An antenna for short-range wireless communication with the terminal,
A case where the antenna is arranged at a position where the distance from one surface is different from the distance from the other surface, and
A communication device including a control unit that transmits a plurality of radio waves having different intensities from the antenna and determines the position of the terminal with respect to the case from a combination of responses of the terminal to these radio waves. The communication device according to claim 1, wherein the antenna is housed inside the case. The control unit has such an intensity that a plurality of communication areas are formed on one surface of the case and a smaller number of communication areas are formed on the other surface of the case than the one surface of the case. The communication device according to claim 1 or 2, which transmits a plurality of radio waves. The one surface is the one outer surface of the case.
The communication device according to claim 3, wherein the other surface is the other outer surface of the case. The case includes a recess capable of accommodating the terminal.
One of the surfaces is the inner surface of the recess.
The communication device according to claim 3, wherein the other surface is an outer surface of a wall portion forming the recess. An antenna for short-range wireless communication with the terminal,
A case is provided in which the antenna is arranged at a position where the distance from one surface is different from the distance from the other surface.
A communication unit in which, when a plurality of radio waves having different intensities are transmitted from the antenna, the position of the terminal with respect to the case is determined from a combination of responses of the terminal to these radio waves.

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