JP2008022294A - Portable equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress influence of a clock signal and a portion of a harmonic signal from portable equipment which has a screen like a mobile phone, a portable game machine, a portable computer and a portable dictionary, and generates an image to be displayed on the screen with a signal from an image forming means. <P>SOLUTION: The portable equipment is provided with an image receiver 5 which is detachably mounted on the main body 1 thereof, and the image receiver 5 is provided with an antenna 7, an antenna matcher 11, and a tuner 12 in order from an input side, a noise canceling signal from a noise canceling means 17 is supplied to between the antenna matcher 11 and the tuner 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a portable device having a screen, such as a mobile phone, a portable game machine, a portable computer, and a portable dictionary, and forming an image on the screen by a signal from image forming means. It is about.

  In recent years, the above-mentioned portable devices are very light and are becoming smaller due to miniaturization of parts and integration of semiconductor elements.

  In addition, since it is very light and miniaturized, attempts are being made to enhance its functions more and more actively.

For example, there is a portable device in which, for example, a card-type image receiver is detachably attached so as to be able to receive a television broadcast (for example, Patent Document 1 below is present).
JP-A-8-237154

  As described above, for example, if a card-type image receiver is detachably attached to a portable device, it will become more convenient because it will be able to receive television broadcasts. As a result of increasing functionality, noise from this portable device has become a problem.

  That is, in this type of upgraded mobile device, a clock signal is always formed to take the operation timing, and this clock signal and part of its harmonic signal interfere with the image receiver. As a result, the image and sound at the time of television broadcast reception may be greatly disturbed.

  Especially in so-called one-segment broadcasting that has recently started, the power of the transmission signal is low in the first place in consideration of interference with the analog signal. Therefore, when watching a television broadcast in a place where the reception level of the broadcast wave is low, the clock signal from the portable device is used. In addition, the influence of a part of the harmonic signal is large, and not only the image and sound are greatly disturbed but also the broadcast itself cannot be received.

  Accordingly, an object of the present invention is to suppress the influence of a clock signal from a portable device and a part of its harmonic signal.

  In order to achieve this object, the present invention provides an image receiver that is detachably attached to the main body of the portable device. The image receiver includes an antenna, an antenna matching unit, and a tuner in order from the input side. The noise canceling signal is supplied from the noise canceling means between the antenna matching unit and the tuner, thereby achieving the initial purpose.

  As described above, the present invention provides an image receiver that is detachably attached to the main body of a portable device, and this image receiver includes an antenna, an antenna matching unit, and a tuner in order from the input side. Since it is configured to supply a noise cancellation signal from the noise cancellation means, even if a part of the clock signal from the portable device and its harmonic signal invades from the antenna of the image receiver, The influence is greatly suppressed by the noise canceling signal supplied from the noise canceling means supplied between the antenna matching unit and the tuner.

  In FIG. 1, reference numeral 1 denotes a main body of a portable device such as a mobile phone, a portable game machine, a portable computer, a portable dictionary, and the like. An operation button 3 is provided.

  A plug 6 of the image receiver 5 is detachably inserted into the insertion port 4 provided on the side surface of the main body 1. That is, when viewing a television broadcast on the screen 2 of the main body 1, the plug 6 of the image receiver 5 is first inserted into the insertion port 4, and then the antenna 7 of the image receiver 5 is connected to the main body 1 as shown by a broken line. The desired channels are drawn out so as to be orthogonal to each other, and then the desired channel is selected by the operation button 3.

  FIG. 2 shows an electrical block diagram of the main part. First, in the main body 1, an image / sound output unit 8 to the screen 2 is provided, and the image / sound output unit 8 includes a signal processing unit. 9 and the control unit 10 are connected.

  A signal line and a control line are connected between the main body 1 and the image receiver 5. Further, a ground line 5 b is connected between the ground 1 a of the main body 1 and the ground 5 a of the image receiver 5.

  Next, an antenna matching unit 11, a tuner 12, and a demodulation unit 13 are sequentially connected to the antenna 7 of the image receiver 5.

  The output signal of the demodulating unit 13 is processed by the signal processing unit 9 and supplied to the image / sound output unit 8 so that the television broadcast can be viewed through the screen 2 and the speaker 14.

  By the way, the antenna matching unit 11 includes a matching unit 15 on the antenna 7 side and an amplifier 16 subsequent thereto, thereby improving the receiving sensitivity and achieving impedance matching even with the short antenna 7.

  Now, a noise canceling means 17 is connected between the antenna matching unit 11 and the tuner 12 configured as described above, and the noise canceling means 17 causes a noise cancellation between the antenna matching unit 11 and the tuner 12. The signal is supplied.

  That is, the noise canceling means 17 supplies a noise signal similar to that which enters the antenna 7 from the main body 1 to the phase controller 19 from the ground 18 of the main body 1 of the portable device. Make a signal.

  Note that the noise cancellation signal supplied to the noise canceling means 17 may use the ground in the image receiver 5 instead of the ground 18 of the main body 1.

  FIG. 3 shows another embodiment of the present invention. In this example, the noise cancellation signal to the noise canceling means 17 is one of a signal line and a control line connecting the main body 1 and the image receiver 5. Is supplied via a coupling capacitor 17a.

  The coupling capacitor 17a can use, for example, 1 to 20 pF as a capacitance value that passes a UHF band signal. Since the noise signal superimposed on these signal lines and control lines has a signal level higher than that of the ground 18, the noise signal can be sufficiently large with respect to the noise canceling means 17. Further, since the coupling capacitor 17a is used, it does not affect the signal line and control line that handle a sufficiently low frequency.

  FIG. 4 shows another embodiment of the present invention. In this example, a noise cancellation signal to the noise canceling means 17 is supplied from the ground 18 of the main body 1. Further, an impedance element 5c is connected between the ground 1a of the main body 1 and the ground 5a of the image receiver 5 instead of the ground line 5b.

  The impedance element 5c can use a high-frequency choke coil that blocks the UHF band, and can have a large attenuation characteristic with respect to the UHF band. The impedance element 5c may be used by connecting the ground 1a and the ground 5a with a conductor and inserting a ferrite core for blocking the UHF band into the conductor. In this case, a large attenuation characteristic can be provided over a wide frequency band.

  In this way, by using the impedance element 5c, the main body 1 and the image receiver 5 are connected in a direct current, but are separated at a frequency higher than the UHF band. That is, since the noise signal in the UHF band is supplied through the ground 18 instead of the ground 1a, a sufficiently large noise cancellation signal can be supplied to the noise canceling means 17.

  The noise cancel signal is then subjected to level adjustment as noise cancellation by the gain controller 20 and finally passed through the band pass filter 21 that passes the UHF band signal, as described above, the antenna matching unit 11 and the tuner 12. In the meantime, a noise cancellation signal is supplied.

  In this way, the control unit 22 of the noise canceling means 17 is for performing the phase control by the phase controller 19 and the level adjustment by the gain controller 20 described above. If the noise canceling signal formed by the noise canceling means 17 is supplied between the antenna matching unit 11 and the tuner 12, even if a noise signal enters the antenna 7 from the main body 1 side, the phase is reversed from that. It is substantially canceled by the noise cancellation signal at substantially the same level, and the influence of the noise signal entering the antenna 7 from the main body 1 side can be greatly suppressed.

  The noise signal that enters the antenna 7 from the main body 1 side is an obstacle when the signal received by the antenna 7 is small. Therefore, when the reception signal level is good, it is not necessary to operate the noise canceling means 17. For example, the noise canceling means 17 can be controlled to start and stop based on the signal quality data output from the demodulator 13 or the signal processor 9. For example, BER or C / N may be used as the signal quality data.

  The output of the noise canceling means 17 is connected to the connection point between the antenna matching unit 11 and the tuner 12. The output impedance of the antenna matching unit 11 is 75Ω, which is the input impedance of the tuner 12. On the other hand, the output impedance of the noise canceling means 17 is set to a high impedance of 6 KΩ, for example. Since this high output impedance is connected to the input impedance 75Ω of the tuner 12, the input impedance 75Ω of the tuner 12 is not affected. That is, the reception sensitivity is not impaired by the noise canceling means 17.

  The same effect can be obtained by connecting the output of the noise canceling means 17 between the input of the tuner 12 and the input of a gain controller (not shown) built in the tuner 12.

  FIG. 5 shows an example of a noise signal when the television broadcast is a so-called one-segment broadcast.

  First, this one-segment broadcasting is a one-channel broadcasting in which 470 MHz to 770 MHz are divided every 6 MHz, and in the present embodiment, a state in which 40 channels are currently received is shown.

  A is the received signal level in the current use environment, B is the noise signal level that has entered the antenna 7 from the main body 1, and in the state where noise cancellation is not performed as in this embodiment, the noise signal level B is the received signal level A. Therefore, the desired 40 channels cannot be received.

  Therefore, in this embodiment, a noise cancellation signal is supplied between the antenna matching unit 11 and the tuner 12 as described above. As a result, the noise signal level B is sufficiently higher than the received signal level A as indicated by the broken line b. As a result, the desired 40 channels can be clearly received.

  In other words, the control unit 10 can determine that the current 40 ch is being received. Therefore, the control unit 10 performs phase control by the phase controller 19 and level adjustment by the gain controller 20. It is possible to selectively reduce the noise signal level B portion.

  FIG. 6 shows another embodiment of the present invention. In this example, the image receiver 5A is a vertical type and is inserted into the insertion port 4A of the main body 1.

  In this vertical image receiver 5A, the antenna 7A is already orthogonal to the main body 1 in a state where the image receiver 5A is inserted into the insertion port 4A of the main body 1, so that the main body 1 is connected to the antenna 7A. Noise is less likely to enter.

  As described above, the present invention provides an image receiver that is detachably attached to the main body of a portable device, and this image receiver includes an antenna, an antenna matching unit, and a tuner in order from the input side. Since it is configured to supply a noise cancellation signal from the noise cancellation means, even if a part of the clock signal from the portable device and its harmonic signal invades from the antenna of the image receiver, The influence is greatly suppressed by the noise canceling signal supplied from the noise canceling means supplied between the antenna matching unit and the tuner.

  Therefore, the television broadcast can be easily enjoyed by the portable device.

The top view which shows the portable apparatus of one Embodiment of this invention 1 is an electrical block diagram of a portable device according to an embodiment of the present invention. Electrical block diagram of portable device of another embodiment of the present invention Electrical block diagram of portable device of another embodiment of the present invention The figure which shows the receiving state by the portable apparatus of one Embodiment of this invention The top view which shows the portable apparatus of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Screen 5 Image receiver 7 Antenna 11 Antenna matching device 12 Tuner 17 Noise cancellation means

Claims (7)

A main body having a screen; an image forming means for forming an image on the screen; and an image receiver detachably attached to the main body. A portable device in which an antenna, an antenna matching unit, and a tuner are provided in order, and a noise cancellation signal from a noise canceling unit is supplied between the antenna matching unit and the tuner. The portable device according to claim 1, wherein the noise canceling unit is configured to cancel noise propagating from the image forming unit in the main body to the antenna. The portable device according to claim 1, wherein the noise canceling unit is configured to detect noise from the image forming unit from a signal line or a control line. The portable device according to claim 1, wherein the noise canceling unit is configured to detect noise from the image forming unit from the first ground of the main body. The portable device according to claim 4, wherein an impedance element for blocking a UHF band is inserted between the second ground of the main body and the third ground of the image receiver. The portable device according to claim 5, wherein the impedance element has a high-frequency choke coil inserted therein. The portable device according to claim 5, wherein the impedance element uses a conductor, and a ferrite core is inserted into the conductor.

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