JP2005223802A - Mobile communication terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable telephone set in which an antenna of high reception sensitivity can be selected in accordance with the inclination of a mobile communication terminal. <P>SOLUTION: A mobile communication terminal is provided with: a plurality of antennas; a case which incorporates a radio unit including an antenna selection section for selecting one of the plurality of antennas; a sensor for detecting the inclination of the case; and a control section for controlling the radio unit. The inclination of the case is recognized by the control section on the basis of a signal of the sensor during a voice call, and the antenna of high reception sensitivity is selected out of the plurality of antennas depending on the inclination, so that the deterioration of antenna gains caused by the head of a human body or any other obstacle is reduced and speaking quality can be ensured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mobile communication terminal apparatus that improves call quality by improving deterioration of antenna gain due to a human head or other obstacles during a call.

  In a technical field related to a conventional mobile communication terminal apparatus, a diversity reception technique is known in which a mobile communication terminal apparatus is provided with two antennas, and each antenna is switched to improve reception sensitivity.

For example, as shown in FIG. 8, in the conventional mobile communication terminal device 80, a radio circuit unit 110 including a transmission circuit unit 111, a reception circuit unit 112, a transmission / reception switching circuit unit 114, and an antenna switching circuit unit 113, The first antenna 1, the second antenna 2 and the control unit 4 are provided, and the first antenna 1 and the second antenna 2 are switched by a control signal from the control unit 4 according to the level of the electric field received by the receiving circuit unit 112. Things have been done. (For example, Patent Document 1)
Further, focusing on the fact that the antenna sensitivity deteriorates due to the positional relationship between the mobile communication terminal device and the human body, as shown in FIG. The second antenna 2 is provided respectively, and the communication mode discriminating unit 90 provided in the control unit determines the operating communication mode. When the communication mode is data communication, the first antenna 1 that cannot be grasped by hand is used. In the case of voice communication, by switching to the second antenna 2 away from the head, the distance between the antenna and the human body can be increased to reduce the sensitivity deterioration of the antenna and ensure good communication. Are known. (For example, Patent Document 2)
JP-A-6-140971 (page 2-4, FIGS. 1 and 4) Japanese Unexamined Patent Publication No. 2003-163958 (4th and 5th pages, FIGS. 1-4)

  However, in a conventional mobile communication terminal apparatus, in a mobile communication system (PDC) in which a time for detecting a received electric field level is provided, by switching the first antenna and the second antenna according to the received electric field level, Although it is possible to reduce the deterioration of the antenna gain due to the human head and other obstacles and to ensure call quality, there is no time to detect the received electric field level and determine which antenna to use in the first place. In a mobile communication system such as GSM, there is a problem that it is difficult to switch antennas and it is difficult to ensure call quality.

  In the method of determining whether the communication mode discrimination unit is performing voice communication or data communication and switching the antenna to prevent the antenna sensitivity from deteriorating due to the positional relationship between the mobile communication terminal device and the human body, However, it has not been possible to cope with the deterioration of the reception sensitivity of the antenna depending on how the mobile communication terminal device is held in the right ear or the left ear.

  Therefore, the present invention has been made to solve the conventional problems, and depending on how the mobile communication terminal apparatus is held or which ear is used, the mobile communication terminal apparatus can be used during a call. Accordingly, an object of the present invention is to provide a mobile communication terminal device that can select a suitable antenna for reception sensitivity, reduce antenna gain degradation, and ensure call quality.

The present invention includes a housing containing a plurality of antennas, a radio unit including an antenna selection unit that selects one of the plurality of antennas, a sensor for detecting the tilt of the housing, A mobile communication terminal apparatus comprising a control unit for controlling a radio unit, wherein the control unit recognizes an inclination of the housing based on a signal of the sensor during a voice call, and the plurality of antennas from the inclination Among them, an antenna having good reception sensitivity is selected. As a result, it is possible to reduce the deterioration of the antenna gain due to the human head and other obstacles and to secure the call quality.

  According to the present invention, in the mobile communication terminal device, the control unit recognizes the signal of the sensor at regular intervals, and selects the antenna with good reception sensitivity based on the integrated value or average of the recognized signal. Is. As a result, it is possible to reduce deterioration of the antenna gain due to the human head and other obstacles, and to stably secure the call quality.

  According to the present invention, in the mobile communication terminal device, the control unit recognizes the signal of the sensor at regular intervals, and compares the integrated value or average of the recognized signal with each preset threshold value. Then, based on the comparison result, the antenna having the good reception sensitivity is selected. As a result, it is possible to reduce the deterioration of the antenna gain due to the human head and other obstacles and to secure the call quality.

  According to the present invention, in the mobile communication terminal device, the sensor is a gravity sensor or an acceleration sensor. Thereby, it is possible to accurately detect the inclination of the mobile communication terminal device, to reduce the deterioration of the antenna gain due to the human head and other obstacles, and to ensure the call quality.

  In the mobile communication terminal device, the present invention includes a first antenna and a second antenna as a plurality of antennas in the casing, the sensor detects a tilt in two directions of the casing, and the first antenna The second antenna is provided at a position where the receiving sensitivity is improved when the casing is tilted in one direction, and the second antenna is provided at a position where the receiving sensitivity is improved when the casing is tilted in the other direction. As a result, it is possible to reduce the deterioration of the antenna gain due to the human head and other obstacles and to secure the call quality.

  According to the present invention, depending on how the mobile communication terminal apparatus is held, or whether the mobile communication terminal apparatus is used by being applied to the right ear or the left ear, a plurality of mobile communication terminal apparatuses can be used depending on the inclination of the casing of the mobile communication terminal apparatus during a voice call Since the antenna with good reception sensitivity is selected from among the antennas, it is possible to select the antenna according to the use state of the mobile communication terminal device during a call, and it is possible to reduce the deterioration of the antenna gain and ensure the call quality. it can.

(Embodiment 1)
Hereinafter, a mobile communication terminal apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a mobile communication terminal apparatus according to a first embodiment of the present invention, and a housing 3 includes a first antenna 1 and a second antenna 2. The wireless unit 5 is connected to the first antenna 1 and the second antenna 2. The radio unit 5 includes an antenna selection unit 6, a reception / transmission switching unit 7, a reception circuit 8, and a transmission circuit 9. The antenna selection unit 6 is connected to the first antenna 1 and the second antenna 2 and selects an antenna to be transmitted / received. When the first antenna 1 is selected, signals can be transmitted / received to / from the outside by the first antenna 1 and when the second antenna is selected, the second antenna 2 can be used. The reception / transmission switching unit 7 connected to the antenna selection unit 6 is connected to the reception circuit 8 and the transmission circuit 9 and switches to the reception circuit 8 when a signal is received by the first antenna 1 (or the second antenna 2). The received signal is distributed to the receiving circuit 8. On the other hand, when the signal is transmitted by the first antenna 1 (or the second antenna 2), the transmission signal from the transmitting circuit 9 is transmitted by switching to the transmitting circuit 9.

  Then, the communication control unit 11 and the voice processing unit 12 are sequentially connected to the wireless unit 5, and the reception side speaker 14 and the transmission side microphone 13 are connected to the voice processing unit 12. The speaker 14 outputs the signal from the audio processing unit 12 to the outside as sound. The microphone 13 picks up sound from the outside and outputs a signal to the sound processing unit 12. The communication control unit 11 transmits / receives a signal to / from the wireless unit 5, controls audio data sent from the audio processing unit 12, and transmits a signal to the control unit 4. The audio processing unit 12 modulates the audio signal sent from the communication control unit 11 and outputs it to the speaker 14, and modulates the signal from the microphone 13 and outputs it to the communication control unit 11. A control unit 4 controls the wireless unit 5 and the communication control unit 11. The sensor 10 is a gravity sensor, detects the tilt of the housing 3, and transmits a signal to the control unit 4.

  FIG. 2 is an external view of the mobile communication terminal apparatus according to the first embodiment of the present invention. The configuration of the wireless unit 5, the control unit 4, the communication control unit 11, and the like shown in FIG. A numeric keypad 15, a call start key 16, an end call key 17, and a function button 18 are disposed on the housing 3 disposed inside the body 3, and a display 19 is disposed above the function button 18. 20 is a hole for the microphone 13, and a user who is talking makes a voice toward this hole, and 21 is a hole for the speaker 14, and the user who is talking is putting this hole on his ear. I can hear the voice. The first antenna 1 is attached to the housing 3 as an external antenna so as to protrude from the end of the housing 3, and the second antenna 2 is attached to the housing 3 as an internal antenna inside the housing 3.

  In FIG. 2, the casing 3 of the mobile communication terminal apparatus has a rectangular parallelepiped shape, and the second antenna 2 is provided at a position facing the position where the first antenna 1 is installed on the upper surface of the casing 3. The sensor 10 is provided in the lower part of the housing 3 while the first antenna 1 and the second antenna 2 are provided in the upper part of the housing 3. This sensor 10 detects the inclination of the housing 3 with respect to the direction of gravity. In addition, the sensor 10 is obtained when the lower part of the sensor 10 moves in the negative direction of the Y axis with reference to the case where the longitudinal direction of the housing 3 coincides with the Z axis as shown in FIG. The tilt, that is, the clockwise tilt rotated clockwise around the hole 21 for the speaker 14 on the operation surface side such as the numeric keypad 15 shown in FIG. 2, and the casing 3 as shown in FIG. 2 when the lower part of the sensor 10 moves in the positive direction of the Y axis, that is, the counterclockwise inclination rotated counterclockwise around the hole 21 for the speaker 14 on the operation surface side in FIG. To do. Then, the sensor 10 detects the inclination when the inclination of the Y axis in the negative direction and the inclination of the positive direction of the Y axis are detected, and sends the signal to the control unit 4 by distinguishing the signal. Thereby, the control part 4 can recognize the inclination of the housing | casing 3 based on the signal of the sensor 10. FIG. In addition, about Fig.3 (a), although the 2nd antenna 2 is incorporated in the housing | casing 3, it has drawn on the exterior of the housing | casing as a schematic diagram. The same applies to FIG.

  FIG. 4 is an operation explanatory diagram showing a usage state of the mobile communication terminal apparatus according to Embodiment 1 of the present invention. FIG. 4A shows a case where the user is using the mobile communication terminal device using the right ear, which is the same as the inclination of the housing 3 shown in FIG. Is located farther from the human head than the first antenna 1. On the other hand, FIG. 4B shows a case where the user uses the mobile communication terminal device using the left ear, which is the same as the inclination of the housing 3 shown in FIG. The antenna 1 is located farther from the human head than the second antenna 2. When the antenna transmits and receives signals, if the distance between an obstacle such as a human body and the antenna is short, the reception sensitivity of the antenna is deteriorated. Therefore, in the usage form as shown in FIG. On the other hand, the receiving sensitivity of the first antenna 1 is better than that of the second antenna 2 in the usage pattern as shown in FIG.

  The operation of the mobile communication terminal apparatus configured as described above will be described below with reference to FIG. FIG. 5 is a flowchart for explaining the operation of the mobile communication terminal apparatus according to Embodiment 1 of the present invention.

  First, the user presses the numeric keypad 15 and the call start key 16 to start a call. The user speaks with the other party, and the voice passes through the microphone 13 and the speaker 14 (step S1). Next, after confirming that the control unit 4 is in a voice call, the sensor 10 detects the tilt of the housing 3 and transmits a signal corresponding to the tilt to the control unit 4 (step S2). And the control part 4 recognizes the inclination of the housing | casing 3 by receiving the signal, transmits the signal according to the inclination to the radio | wireless part 5, and makes the antenna selection part 6 select an antenna with high receiving sensitivity. That is, in the case of the usage pattern as shown in FIG. 4A, the control unit 4 indicates that the inclination is clockwise with the hole 21 for the speaker 14 as the center point when viewed from the operation surface side of the mobile communication terminal device. The antenna selection unit 6 transmits a signal having information for selecting the second antenna 2 to the radio unit 5. Further, in the case of the usage pattern as shown in FIG. 4B, the control unit 4 is inclined in the counterclockwise direction with the hole 21 for the speaker 14 as the center point when viewed from the operation surface side of the mobile communication terminal device. Then, the antenna selection unit 6 transmits a signal having information for selecting the first antenna 1 to the radio unit 5 (step S3). The radio unit 5 receives a signal corresponding to the tilt of the housing 3, and the antenna selection unit 6 selects an antenna with good reception sensitivity. That is, the antenna selection unit 6 selects the second antenna 2 in the case of the usage pattern as shown in FIG. 4A (step S41). In the case of the usage pattern as shown in FIG. 4B, the first antenna 1 is selected (step S42). In the case of the usage pattern as shown in FIG. 4A, signals are transmitted / received by the second antenna 2 and voice communication is performed (step S51). In the case of the usage pattern as shown in FIG. 4B, a signal is transmitted / received by the first antenna 1 and voice communication is performed (step S52).

  When the user is making a call using the right ear as described above, that is, in the case of the usage form as shown in FIG. 4A, voice communication is performed by the second antenna 2, but it is used during the call. When the person uses the left ear from the right ear, the housing 3 is inclined clockwise with the hole 21 for the speaker 14 as the center point when viewed from the operation surface side. Will be tilted counterclockwise. Since the sensor 10 transmits a signal corresponding to the tilt to the control unit 4, the control unit 4 recognizes that the tilt is counterclockwise with the hole 21 for the speaker 14 as the center point when viewed from the operation surface side. Then, a signal having information for selecting the first antenna 1 is transmitted to the radio unit 5, the first antenna 1 is selected by the antenna selection unit 6 of the radio unit 5, and voice communication is performed using this antenna. Similarly, when the user makes a call using the right ear while using the left ear, the first antenna 1 is switched to the second antenna 2.

  Accordingly, since the mobile communication terminal apparatus according to the above invention selects an antenna according to the inclination of the housing 3, the antenna can be selected according to the use state of the mobile communication terminal apparatus during a call, and the antenna gain is deteriorated. And the quality of the call can be ensured.

  When the gain of each antenna during a call was measured using the above mobile communication terminal device, the antenna closer to the head of the human body (first antenna 1 in the case of use as shown in FIG. 4A) The antenna having a gain of −20 dB: 900 MHz and −15 dB: 1800 MHz at the time of use is the antenna farther from the human head (first antenna 1 in the case of use as shown in FIG. 4B) When used, the antenna gain was -18 dB: 900 MHz and -13 dB: 1800 MHz, resulting in an improvement of 2 dB. As can be seen from this result, by selecting the antenna according to the inclination of the housing 3, it is possible to prevent a gain reduction of 2 dB during a call.

  In addition, when the user moves the mobile communication terminal device from the right ear to the left ear during a call as described above, the inclination of the housing 3 changes, so that the mobile communication terminal device Accordingly, by selecting an antenna with good reception sensitivity, it is possible to prevent a decrease in antenna gain due to switching of the ear to be used, and to secure call quality.

  In addition, although said mobile communication terminal device is provided with two antennas as a plurality of antennas, it may be three or more. The shape of the housing 3 is not necessarily a rectangular parallelepiped. Further, it is not necessary to use one housing 3, and for example, it is used for a mobile communication terminal device that can be folded by connecting two housings 3 via hinges or the like, and according to the inclination of these housings 3. An antenna may be selected. The sensor 10 is not limited to a gravity sensor, and an acceleration sensor may be used. This is because the inclination can be detected according to the use conditions by using the acceleration sensor.

  Further, it is not necessary to provide the antenna on the upper surface of the rectangular housing 3. The first antenna 1 and the second antenna 2 are paired with the first antenna 1 on the upper surface of the housing 3 and the second antenna 2 on the lower surface. You may prepare to make it horn. That is, for example, when the first and second antennas 2 are provided as a plurality of antennas and the sensor 10 detects the two directions of the housing 3, the reception of the first antenna 1 with respect to the inclination in one direction of the two directions. In order to improve the sensitivity, each antenna may be arranged so that the reception sensitivity of the second antenna 2 is improved with respect to the inclination in the other direction.

  In addition, as an example of use for the above mobile communication terminal device, the case where the inclination of the housing 3 is changed by changing the ear used by the user during a call is exemplified. However, one of the ears is continuously used. Even if the angle of the housing 3 is changed in the above state, the distance between the housing 3 and the human head changes and the antenna gain also changes. Therefore, according to the inclination of the housing 3 accompanying the change in the angle of the housing 3 An antenna with good reception sensitivity may be selected.

(Embodiment 2)
Next, a mobile phone device according to a second embodiment of the present invention will be described. The basic configuration is the same as that of the first embodiment described above, but a memory is provided inside the housing 3. The mobile communication terminal device according to the first embodiment performs control to switch the antenna when the housing 3 is tilted in a different direction based on the signal of the sensor 10 during a voice call. In the mobile phone device according to the embodiment, the control unit 4 takes an average of signals corresponding to the inclination from the sensor 10 for a certain period of time, and determines the direction in which the housing 3 is inclined based on the average, The antenna is switched. Hereinafter, it demonstrates in detail using FIG.6 and FIG.7.

  FIG. 6 is a diagram showing a change in the tilt of the housing 3 at a predetermined time (t2). When the time t2 is divided at a certain time interval t1, the housing 3 is shown in FIG. As shown in FIG. 4 (a), it is inclined clockwise around the hole 21 for the speaker 14 as viewed from the operation surface side, or counterclockwise as shown in FIGS. 3 (b) and 4 (b). It represents the result of the sensor 10 detecting whether it is tilted. That is, on the time axis of FIG. 6, at the time of p0, the housing 3 is tilted clockwise as viewed from the operation surface side, and at time p1, the housing 3 is counterclockwise as viewed from the operation surface side. Leaning on. Furthermore, the housing 3 is inclined clockwise as viewed from the operation surface side at p2 after the elapse of t1. In the mobile phone device according to the second embodiment of the present invention, the state of the inclination of the housing 3 at a certain time interval t1 is digitized and integrated, an average is obtained from the integrated value, and the antenna is based on the average. Has been switched.

FIG. 7 is a flowchart showing the operation of the mobile phone device according to the second embodiment. First, the user presses the numeric keypad 15 and the call start key 16 to start a call. The user speaks with the other party, and the voice passes through the microphone 13 and the receiver (step S71). Next, after confirming that the control unit 4 is in a voice call, the sensor 10 detects the inclination of the housing 3 at a constant time interval (here, t1), and outputs a signal corresponding to the inclination. Send to control unit 4. Now, at time p0, the sensor 10 detects the inclination and sends a signal to the control unit 4 (step S72). The control unit 4 numerically stores a signal corresponding to the inclination as one value in the memory. Here, as shown in FIGS. 3B and 4B, the value is set to 1 when tilted clockwise as viewed from the operation surface as shown in FIGS. 3A and 4A. When tilted counterclockwise as viewed from the operation surface side, the value is stored as 0 in the memory. That is, at time p0, the value 1 is stored in the memory (step S73).

  Next, the control unit 4 measures the time from when the signal from which the tilt from the sensor 10 is detected is stored in the memory as the accumulated time t. When the accumulated time t has not reached the predetermined time (t2) set in advance (step S741), the process returns to step 72, and the sensor 10 detects the inclination of the housing 3. At time p0, since the accumulated time t is 0 and has not reached t2, the process returns to step 72 (step S741). The sensor 10 transmits a signal to the control unit 4 according to the inclination of the casing 3 at p1 after the lapse of t1 from p0 (step S72), and the control unit 4 views the casing 3 from the operation surface side at p1. If it is tilted counterclockwise, the value is set to 0 and stored in the memory (step S73). At this time, since the integration time t is t1 and has not reached t2, the process returns to step 72 again (step S741). Then, these steps are repeated, and when the integration time t reaches t2, that is, at time p4 (step S742), the control unit 4 calculates the integration value of the value stored in the memory, and calculates the average value from the integration value. R is obtained (step S75), and the average value R is compared with a preset threshold value Q (step S76).

  When the average value R is greater than or equal to the threshold value Q, the control unit 4 selects the second antenna 2 (step S761), and voice communication is performed by the second antenna 2 (step S771). On the other hand, when the average value R is less than the threshold value Q, the first antenna 1 is selected (step S762), and voice communication is performed by the first antenna 1 (step S772). Thereafter, the control unit 4 resets the average value R stored in the memory (step S78), and returns to step S71 to perform the series of steps described above.

  As described above, at a predetermined time t2, the inclination of the housing 3 is detected at every constant time t1, the signal values corresponding to the inclination are integrated, an average is obtained from the integrated value, and the average is calculated. By switching to an antenna with good reception sensitivity, deterioration of antenna gain due to the human head and other obstacles can be reduced, and call quality can be ensured. That is, when the average value R obtained from the integrated value is equal to or greater than the threshold value Q at a certain time t2, the user uses the mobile communication terminal device by tilting the casing 3 clockwise as viewed from the operation surface side. When the average value R obtained from the integrated value is less than the threshold value Q, the user should use the mobile communication terminal device by tilting the housing 3 counterclockwise when viewed from the operation surface side. There will be many.

  According to the mobile communication terminal device of the present invention, since the antenna is switched based on the result of accumulating and averaging signals corresponding to the inclination of the casing 3, the signal corresponding to the inclination of the casing 3 changes. Rather than switching the antenna each time, the user can more stably select an antenna with good reception sensitivity and talk. In addition, since the mobile communication terminal device according to the second embodiment takes an average from the integrated value per predetermined time using the signal detected by the sensor 10 as a value, the inclination of the housing 3 is counter to the operation surface side. It is not necessary to switch the antenna each time the clock is switched to the clockwise direction or the clockwise direction, and power consumption can be suppressed.

  The time t1, the time t2, the threshold value Q, and the average value R can be changed as appropriate. Further, in the above description, the state of the inclination of the housing 3 at a certain time interval t1 is converted into a numerical value and integrated, an average value is obtained from the integrated value, and the antenna is switched based on the average value. Instead of obtaining the average value, the state of the inclination of the housing 3 at a certain time interval t1 may be digitized and integrated, and the antenna may be switched based on the integrated value.

The mobile communication terminal device according to the present invention is based on the signal of the sensor that detects the inclination of the housing.
A mobile communication terminal equipped with a sensor that can select an antenna having good reception sensitivity from among a plurality of antennas, reduce antenna gain deterioration due to the human head and other obstacles, and ensure call quality. Useful for devices and the like.

The block diagram of the mobile communication terminal device in 1st embodiment of this invention 1 is an external view of a mobile communication terminal device according to a first embodiment of the present invention. (A) Operation explanatory diagram of the mobile communication terminal device in the first embodiment of the present invention (b) Operation explanatory diagram of the mobile communication terminal device in the first embodiment of the present invention (A) Operation explanatory diagram of the mobile communication terminal device in the first embodiment of the present invention (b) Operation explanatory diagram of the mobile communication terminal device in the first embodiment of the present invention The flowchart which shows the operation example of the mobile communication terminal device which concerns on 1st embodiment of this invention. Operation explanatory diagram of the mobile communication terminal device in the second embodiment of the present invention The flowchart which shows the operation example of the mobile communication terminal device which concerns on 2nd embodiment of this invention. Block diagram of a conventional mobile communication terminal device External view of conventional mobile communication terminal device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st antenna 2 2nd antenna 3 Case 4 Control part 5 Radio | wireless part 6 Antenna selection part 7 Reception transmission switching part 8 Reception circuit 9 Transmission circuit 10 Sensor 11 Communication control part 12 Audio | voice processing part 13 Microphone 14 Speaker

Claims (6)

A housing containing a plurality of antennas, a wireless unit including an antenna selection unit for selecting one of the plurality of antennas, a sensor for detecting the inclination of the housing, and controlling the wireless unit A control unit that recognizes an inclination of the housing based on a signal of the sensor during a voice call and receives the tilt from the plurality of antennas based on the inclination. A mobile communication terminal characterized by selecting a highly sensitive antenna. The mobile communication terminal apparatus according to claim 1, wherein the control unit recognizes the signal of the sensor at regular intervals and selects an antenna with good reception sensitivity based on an average value of the recognized signal. The mobile communication terminal apparatus according to claim 1, wherein the control unit recognizes the signal of the sensor at regular intervals, and selects an antenna with good reception sensitivity based on an integrated value of the recognized signal. The control unit recognizes the sensor signal as a value at regular intervals, compares the average value or integrated value of the recognized signal value with each preset threshold value, and results of the comparison 4. The mobile communication terminal apparatus according to claim 2 or 3, wherein the antenna having the good reception sensitivity is selected based on the frequency. The mobile communication terminal apparatus according to claim 1, wherein the sensor is a gravity sensor or an acceleration sensor. The mobile communication terminal device according to claim 1, wherein the housing includes a first antenna and a second antenna as the plurality of antennas, the sensor detects a tilt in two directions of the housing, and the first antenna Is provided at a position where the receiving sensitivity is improved when the casing is tilted in one direction, and the second antenna is provided at a position where the receiving sensitivity is improved when the casing is tilted in the other direction.

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