JP2006054502A - Mobile communication terminal and mobile terminal system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology that properly functions an antenna of a broadcast signal receiving tuner built in a mobile communication terminal, such as mobile phone. <P>SOLUTION: The mobile communication terminal 100, incorporated with a secondary battery 126 that uses the secondary battery for the power supply, is provided with power supply terminals 121, 122 through which a DC power supply is supplied, the DC power supply charging the secondary battery and making the circuits actuate in the mobile communication terminal; and a tuner 112 that uses a power supply cable 32 connected to the power supply terminals 121, 122 for the antenna to receive a broadcast signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile communication terminal suitable for application to a mobile phone terminal incorporating a tuner for receiving a broadcast signal such as radio broadcast, and a mobile terminal system using the mobile communication terminal.

  In recent years, it has been proposed and put into practical use that various functions are incorporated in a mobile phone terminal. For example, a mobile phone terminal has a built-in tuner for receiving radio broadcasts and television broadcasts, and the received radio broadcast or television broadcast audio is output from the built-in speaker or connected earphone, Displaying a received television broadcast video on a display panel built in the terminal is performed.

  FIG. 5 is a diagram showing a configuration example of a mobile phone terminal 10 incorporating a conventional radio broadcast tuner and its peripheral devices. The mobile phone terminal 10 includes a mobile phone function block 11, and in this mobile phone function block 11, wireless communication processing for a call, control processing for the wireless communication, display processing, input processing, and the like Various processes necessary for a mobile phone are performed. The power necessary for operating the cellular phone function block 11 is supplied from the battery 24 formed of a secondary battery to each unit via the power control unit 25.

  The battery 24 is charged by, for example, a power source supplied from a charging base 40 to which the AC adapter 31 is connected. That is, the mobile phone terminal 10 includes a charging terminal 21 and a ground (GND) terminal 22 as charging terminals, and when the mobile phone terminal 10 is placed on the charging stand 40, the charging terminal 41 and the ground on the charging stand 40 side. The (GND) terminal 42 is configured to come into contact.

  The charging terminal 41 and the ground terminal 42 of the charging base 40 are connected to a connector 43 in the charging base 40, and charging is performed by connecting the connector 33 connected to the AC adapter 31 and the cable 32 to the connector 43. DC power obtained by converting commercial AC power by the AC adapter 31 is supplied to the mobile phone terminal 10 placed on the table 40.

  The DC power supplied from the charging stand 40 to the charging terminal 21 of the mobile phone terminal 10 is supplied to the battery 24 via the charging circuit 23 and charged.

  In addition, the mobile phone terminal 10 includes a tuner 12 that receives radio broadcast (FM broadcast), and an audio signal obtained by receiving the broadcast signal with the tuner 12 is supplied to the speaker 14 via the switch 13 and output. I am trying to make it. Alternatively, the switch 13 can be switched to the connector 17 instead of the speaker 14, and output can be performed from the earphone 50 connected to the connector 17. In addition, the voice signal (audio signal) for a call received on the mobile phone function block 11 side can be output from the speaker 14 or the earphone 50 by switching with the switch 13.

  The configuration of the earphone 50 includes a connector 51 connected to the connector 17 on the mobile phone terminal 10 side and a receiver 53 connected to the connector 51 with a cable 52, and an audio signal supplied from the receiver 53 is output. The

  Here, in the case of a mobile phone terminal incorporating a conventional tuner, the cable 52 of the earphone 50 is used as an antenna that requires the tuner 12. That is, for example, in the case of a tuner that receives FM broadcasts, it is necessary to receive a frequency band of several tens of MHz, a frequency lower than the frequency band for wireless telephones, and a relatively long antenna is required. It is difficult to incorporate an antenna in the terminal body. Therefore, the cable 52 of the earphone 50 having a length of at least several tens of centimeters is used as an antenna for FM broadcast reception.

  As a configuration for using the cable 52 of the earphone 50 as an antenna, the ground side of the connector 17 is connected to the antenna input section of the tuner 12 as shown in FIG. Here, a bead 16 is connected between the ground side of the connector 17 and the ground potential portion of the terminal 10. This bead is an element that attenuates the radio transmission band of the broadcast signal and does not attenuate the band of the audio signal. Further, a bead 15 is connected between the switch 13 and the connector 17.

Since the beads 15 and 16 are connected to the connector 17, it is possible to eliminate interference with other circuits in the terminal 10 when the cable 52 of the earphone 50 connected to the connector 17 is used as an antenna. . Patent Document 1 discloses the use of an earphone cable connected to a mobile phone terminal as an antenna.
JP 2000-134298 A

  However, when the earphone cable is used as an antenna, there is a problem that when the earphone is not connected to the terminal, the antenna is not connected and the tuner cannot receive a good broadcast signal. Depending on the usage state of the user, there is a case where it is desired to output audio from the speaker (speaker 14 in FIG. 5) built in the terminal without using the earphone. Even in such a case, it is necessary to connect the earphone. It was not easy to use.

  In addition, there is a problem that the earphone cable is not necessarily used in a state suitable for an antenna, such as being used in a state of being wound short depending on the state of use.

  The present invention has been made in view of the above points, and an object of the present invention is to make an antenna of a broadcast signal receiving tuner built in a mobile communication terminal such as a mobile phone function well.

  The present invention provides a power supply terminal for charging a secondary battery with the obtained DC power source and operating a circuit inside the device in a portable communication terminal using the secondary battery as a power source. And a tuner that receives a broadcast signal using a power cable connected to the power supply terminal as an antenna.

  By doing in this way, power cables, such as AC adapter connected in order to charge a secondary battery, function as an antenna for broadcast signal reception.

  According to the present invention, a power cable such as an AC adapter connected to charge the secondary battery functions as an antenna for receiving broadcast signals, and the tuner can receive broadcast signals satisfactorily.

  In this case, the power cable can be used as an antenna by disposing an element that attenuates the transmission band of the broadcast signal and does not attenuate the DC power source between the power supply terminal and the circuit that charges the secondary battery. This has the effect of not adversely affecting other circuits in the terminal.

  For the audio cable connected to the audio output terminal that outputs the audio signal received by the tuner, either the power cable or the audio cable can be connected by using the tuner as an antenna. If there is, the tuner can receive the broadcast signal, and the possibility that it can be received well is increased.

  Furthermore, when either the power cable or audio cable is connected, the cable on the connected side is used as an antenna, and when both are connected, the cable on the predetermined side is used as an antenna. By providing the changeover switch, it is possible to preferentially use a cable that can be satisfactorily received.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In this example, the mobile phone terminal has a built-in tuner for receiving FM radio broadcasts.

  FIG. 1 is a diagram showing a configuration example of a mobile phone terminal 100 incorporating a radio broadcast tuner of this example and its peripheral devices. The cellular phone terminal 100 includes a cellular phone function block 111. In the cellular phone function block 111, a wireless communication process for a telephone call, a control process for the wireless communication, a display process, an input process, etc. Various processes necessary for a mobile phone are performed. The power necessary to operate the cellular phone function block 111 is configured to be supplied to each unit from the battery 126 configured by a secondary battery via the power control unit 127.

  The battery 126 is charged by, for example, a power source supplied from the charging stand 40 to which the AC adapter 31 is connected. That is, the mobile phone terminal 100 includes a charging terminal 121 and a ground (GND) terminal 122 as charging terminals, and when the mobile phone terminal 100 is placed on the charging base 40, the charging terminal 41 and the ground on the charging base 40 side. The (GND) terminal 42 is configured to come into contact.

  The charging terminal 41 and the ground terminal 42 of the charging base 40 are connected to a connector 43 in the charging base 40, and by connecting the connector 33 connected to the AC adapter 31 and the power cable 32 to the connector 43, The mobile phone terminal 100 mounted on the charging stand 40 is supplied with DC power obtained by converting commercial AC power with the AC adapter 31. The power cable 32 has a length of at least several tens of centimeters.

  The DC power supplied from the charging stand 40 to the charging terminal 121 of the mobile phone terminal 100 is supplied to the battery 126 via the beads 123 and the charging circuit 124 and charged. Note that the mobile phone terminal 100 is placed on the charging stand 40 to which the AC adapter 31 is connected and the power is supplied (that is, whether the power cable is connected). The internal control unit can judge.

  The mobile phone terminal 100 also includes a tuner 112 that receives radio broadcasts (FM broadcasts), and supplies an audio signal obtained by receiving the broadcast signal with the tuner 112 to the speaker 114 via the switch 113 for output. I am trying to make it. Alternatively, the switch 113 can be switched to the connector 117 instead of the speaker 114, and can be output from the earphone 50 connected to the connector 117. Further, the voice signal (audio signal) for a call received on the mobile phone function block 111 side can be output from the speaker 114 or the earphone 50 by switching with the switch 113.

  For example, when the earphone 50 is connected to the connector 117, the switch 114 is switched to the earphone 50 side, and when the earphone 50 is not connected, the switch 114 is switched to the speaker 114 side. Let The detection of the connection of the earphone 50 for this switching may be any detection, for example, when detecting from the electrical characteristics, or when detecting mechanically from the state of the contact in the connector 117, etc. . In any case, in the case of this example, the control unit in the mobile phone function block 111 of the terminal 100 can determine whether or not the earphone 50 is connected.

  The earphone 50 includes a connector 51 connected to the connector 117 on the mobile phone terminal 100 side, and a receiver 53 connected to the connector 51 with a cable 52, and an audio signal supplied from the receiver 53 is output. The

  In this example, both the audio cable 52 of the earphone 50 and the power cable 32 of the AC adapter 31 connected via the charging stand 40 are used as antennas that require the tuner 112. That is, the ground terminal 122 connected to the charging stand 40 and the ground side of the connector 117 to which the earphone is connected are connected to the switch 118. The switch 118 selectively connects the ground terminal 122 and the ground side of the connector 117 to each other. The antenna 112 is connected to the antenna input unit of the tuner 112. Switching of the switch 118 is controlled by a switch control signal supplied from, for example, a control unit on the mobile phone function block 111 side.

  As the switching by the switch control signal, for example, when only the earphone 50 is connected, the switch 118 is switched so that the connector 117 side to which the earphone is connected is connected to the antenna input of the tuner 112. Further, when only the charging stand 40 is connected, the switch 118 is switched so that the ground terminal 122 side connected to the charging stand 40 is connected to the antenna input of the tuner 112.

  Further, when both the earphone 50 and the charging stand 40 are connected, the switch 118 is switched so that a predetermined line (cable) is used as an antenna line. In the case of this example, when both the earphone 50 and the charging stand 40 are connected at the same time, the connector 117 side to which the earphone is connected is connected to the antenna input of the tuner 112. As will be described later, another cable may be used for the cable used at the time of simultaneous connection.

  Then, by connecting the antenna input of the tuner 112 in this way, in order to prevent interference with other circuits in the terminal 100, the high frequency signal is attenuated and a low frequency signal such as a DC signal or an audio signal is attenuated. Beads as elements that allow the signal to pass through without being attenuated are connected to each part.

  That is, as shown in FIG. 1, on the connector 117 side, a bead 116 is connected between the ground side of the connector 117 and the ground potential portion of the terminal 100, and also between the switch 113 and the connector 117. Beads 115 are connected. Further, a bead 123 is connected between the charging terminal 121 connected to the charging base 40 and the charging circuit 124, and between the ground (GND) terminal 122 connected to the charging base 40 and the ground potential portion. , Beads 125 are connected.

  Each bead 115,116,123,125 has the characteristic shown in FIG. 4, for example. That is, the high-frequency signal of several tens to several hundreds of MHz is greatly attenuated, and a low-frequency signal such as a DC signal or an audio signal is hardly attenuated. The characteristics shown in FIG. 4 are examples, and elements having other characteristics may be used.

  An example of a state in which the cellular phone terminal 100 configured as described above is placed on the charging stand 40 is, for example, a state illustrated in FIG. That is, the terminal 100 is mounted on the charging stand 40, the connector 33 of the AC adapter 31 is connected to the charging stand 40, and the DC low-voltage power source converted from the commercial AC power source by the AC adapter 31 is connected to the cable 32. To the charging stand 40 and also to the mobile phone terminal 100. In the state of FIG. 2, the earphone 50 is also connected to the connector 117 of the mobile phone terminal 100.

  In the state shown in FIG. 4, when FM broadcast is received by the tuner 112, the audio cable 52 of the earphone 50 or the power cable 32 of the AC adapter 31 is used by the tuner 112 as a broadcast wave receiving antenna.

  The AC adapter 31 has a configuration shown in FIG. 3, for example. That is, an AC plug 34 from which a commercial AC power source is obtained is connected to the primary side of a transformer 35 for transformation, and the secondary side of the transformer 35 is connected to the cable 32. Here, a smoothing capacitor 38 and a direct current diode 37 are connected to the secondary side of the transformer 35, and noise is removed between the primary side and the secondary side of the transformer 35. A capacitor 36 is connected.

  The power cable 32 of the AC adapter 31 configured as described above is used as an antenna of the tuner 112 for receiving broadcast signals in the mobile phone terminal 100, thereby improving the reception characteristics of the tuner 112 in the terminal 100. be able to. That is, for example, when the terminal 100 is placed on the charging stand 40 in a state where the earphone 50 is not connected to the mobile phone terminal 100, the antenna is not connected to the tuner in the conventional configuration shown in FIG. In this example, the power cable 32 is connected to the tuner 112 as an antenna, and good reception can be performed.

  In addition, since the power cable 32 is used as an antenna, it is suitable for the case where a broadcast signal is received simultaneously with the charging of the battery 126. In addition, in the case of a configuration in which only an earphone is used as an antenna line as in the past, it was necessary to always sell the terminal 100 with an earphone attached, but by using an AC adapter as in this example, There is no need to sell the terminal 100 with earphones attached.

  Further, as shown in FIG. 3, the AC adapter 31 is also connected in signal manner to the AC power supply line side to which the AC plug 34 is connected via a noise removing capacitor 36. The connected AC power supply line also functions as an antenna, and a very long antenna is connected, so that reception performance can be improved.

  In the above-described embodiment, when the AC adapter (power cable) and the earphone are connected at the same time, the earphone is used as an antenna. However, in the case of simultaneous connection, the switch is used to use the power cable. 118 may be switched. In addition, when the AC adapter (power cable) and the earphone are connected at the same time, when the reception with the tuner 12 is attempted with either connection and the reception is not satisfactory, the switch 118 is switched, and another cable is connected to the antenna. May be switched to use as

  Further, instead of switching with the switch 118, in the case of simultaneous connection, a configuration may be used in which both cables are used simultaneously as antennas.

  Further, in the above-described embodiment, beads are used as an element for preventing interference between a line used as an antenna and other circuits in the terminal, but the band of the broadcast wave is attenuated and the direct current is reduced. Another element such as a coil may be used as long as it is an element that passes a power source, an audio signal band, and the like. In addition, with respect to the position where the element such as the bead is arranged, in the example of FIG. 1, the element (bead) is connected to both the + side (signal side) and the ground side of each terminal (connector). For example, it may be connected only to the ground side.

  In the above-described embodiment, the AC adapter 31 is connected to the mobile phone terminal 100 via the charging stand 40, and the cable 32 of the AC adapter 31 is used as an antenna. Even when the connector 33 is directly connected to an AC adapter connector (not shown) of the mobile phone terminal 100, the cable 32 of the AC adapter 31 may be used as an antenna.

  In the above-described embodiment, an AC adapter that converts a commercial AC power source into a DC power source is used. However, for example, a so-called DC / DC that transforms a DC power source such as an automobile 12V or 24V into a low-voltage power source. When the DC converter is connected (or directly connected) via the charging stand 40, the power cable of the DC / DC converter can also be used as an antenna.

  In the above-described embodiment, the present invention is applied to a mobile phone terminal having a built-in tuner for receiving FM broadcast. However, the present invention is also applicable to a terminal having a built-in tuner for receiving other broadcast signals. The present invention can also be applied to tuners that receive other broadcast signals such as television broadcasts. Furthermore, although the example is applied to a mobile phone terminal, the present invention can also be applied to an antenna for a tuner built in another portable communication terminal of this type.

It is the block diagram which showed the structural example of the mobile telephone terminal by one embodiment of this invention. It is the perspective view which showed the structural example of the portable terminal by one embodiment of this invention, and its peripheral device. It is the block diagram which showed the structural example of the AC adapter by one embodiment of this invention. It is the characteristic view which showed the example of the frequency characteristic of the bead by one embodiment of this invention. It is the block diagram which showed an example of the conventional mobile telephone terminal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 31 ... AC adapter, 32 ... Power cable, 33 ... Connector, 40 ... Charging stand, 41 ... Charging terminal, 42 ... Grounding terminal, 43 ... Connector, 50 ... Earphone, 51 ... Connector, 52 ... Audio cable, 53 ... Receiver , 100 ... mobile phone terminal, 111 ... mobile phone functional block, 112 ... tuner, 113 ... switch, 114 ... speaker, 115, 116 ... beads, 117 ... connector, 118 ... switch, 121 ... charging terminal, 122 ... ground terminal, 123 ... Bead, 124 ... Charging circuit, 125 ... Bead, 126 ... Battery, 127 ... Power supply control unit

Claims (7)

In a mobile communication terminal that has a built-in secondary battery and uses the secondary battery as a power source,
While charging the secondary battery with the obtained DC power supply, a power supply terminal for operating the circuit inside the device,
A mobile communication terminal comprising: a tuner that receives a broadcast signal using a power cable connected to the power supply terminal as an antenna. The mobile communication terminal according to claim 1,
A portable communication terminal in which an element that attenuates the transmission band of the broadcast signal and does not attenuate the DC power supply is disposed between the power supply terminal and a circuit that charges the secondary battery. The mobile communication terminal according to claim 1,
A portable communication terminal in which the tuner is also used as an antenna for an audio cable connected to an audio output terminal for outputting an audio signal received by the tuner. The mobile communication terminal according to claim 3, wherein
When either the power cable or the audio cable is connected, the connected cable is used as an antenna, and when both are connected, the predetermined cable is used as an antenna. Mobile communication terminal equipped with a changeover switch. In a portable terminal system comprising a portable communication terminal that has a built-in secondary battery and uses the secondary battery as a power source, and a power adapter that supplies power to the secondary battery of the portable communication terminal.
A portable terminal system including a tuner that receives a broadcast signal using a power cable connected to the power adapter as an antenna. The mobile terminal system according to claim 5, wherein
The power supply adapter is a mobile terminal system connected to the mobile communication terminal via a charging stand that holds the mobile communication terminal. The mobile terminal system according to claim 5, wherein
The portable communication terminal includes an audio output terminal for outputting an audio signal received by the tuner,
The portable terminal system in which the tuner is also used as an antenna for the audio cable connected to the audio output terminal.

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