JP2005347882A - Broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast receiver maintaining high reception performance even at a low frequency without hindering downsizing. <P>SOLUTION: The broadcast receiver is provided with: a housing 12; a first antenna element 16a arranged in the housing 12 in a loop form; a dipole antenna 16 comprising the first antenna element 16a and a second antenna element 16b located in the housing 12 side by side to the first antenna element 16a so that a direction of a current flowing through the second antenna element 16b is the same as that of a current flowing through the first antenna element 16a; and a reception circuit 17 for receiving a broadcast signal received by the dipole antenna 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a broadcast receiving apparatus suitable for use in, for example, a portable broadcast receiving terminal that receives terrestrial digital broadcasting.

  As is well known, terrestrial digital broadcasting has been put into practical use in recent years. In this terrestrial digital broadcasting, low data rate broadcasting, so-called mobile broadcasting (one-segment broadcasting), which mainly targets a mobile object such as a portable broadcast receiving terminal, is also performed.

  By the way, in the terrestrial digital broadcasting, the broadcast frequency is lower than the frequency of the mobile phone, and the wavelength is longer. For this reason, it is necessary for a broadcast receiving terminal that receives mobile broadcasts to take measures to efficiently receive radio waves having a long wavelength while moving.

  In Patent Documents 1 and 2, by providing a parasitic radiation electrode for creating a double resonance state in the antenna electrode structure that is excited by the antenna operation of the feeding radiation electrode and the ground portion of the mounting substrate also performs the antenna operation, A configuration for reducing the size and increasing the bandwidth is disclosed.

However, both of these Patent Documents 1 and 2 are directed to mobile phones, and no description is given of taking measures to make them particularly suitable for receiving mobile broadcasts having a frequency lower than that of mobile phones. It has not been made.
JP 2002-299933 A US Pat. No. 6,614,401

  Accordingly, the present invention has been made in consideration of the above circumstances, and an object thereof is to provide a broadcast receiving apparatus capable of maintaining high reception performance even at a low frequency without impairing downsizing.

  The broadcast receiving apparatus according to the present invention includes: a housing; a first antenna element arranged in a loop in the housing; and a direction in which a current flows in the housing is the same as the first antenna element. A dipole antenna comprising a second antenna element arranged in parallel with the first antenna element; and a receiving circuit to which a broadcast signal received by the dipole antenna is supplied.

  According to the above-described invention, the first antenna element is arranged in a loop shape in the casing, and the first antenna element is arranged so that the direction of current flow in the casing is the same as that of the first antenna element. Since a dipole antenna composed of the second antenna elements arranged in parallel is provided, it is possible to maintain high reception performance even at a low frequency without impairing downsizing.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the appearance of the broadcast receiving terminal 11 described in the first embodiment. This broadcast receiving terminal 11 has a portable thin box-shaped casing 12.

  The housing 12 of the broadcast receiving terminal 11 is provided with a display unit 13 and an operation unit 14 on one flat surface 12a, and an audio output connector 15 for connecting headphones or the like to one side surface 12b. Is installed.

  Here, as shown in FIG. 2, the broadcast receiving terminal 11 receives a broadcast signal with a dipole antenna 16 built in the housing 12 and supplies it to a receiving circuit 17, so that channel selection and demodulation processing, etc. To do.

  In this case, the first antenna element 16 a constituting the dipole antenna 16 is arranged such that one end thereof is connected to the receiving circuit 17 and the other end forms a loop along the inner wall of the housing 12.

  The second antenna element 16b constituting the dipole antenna 16 has one end connected to the receiving circuit 17 and the other end along the inner wall of the housing 12 in the direction opposite to the first antenna element 16a. The first antenna element is juxtaposed so as to form a loop.

  Thus, by arranging the first and second antenna elements 16a and 16b constituting the dipole antenna 16 in a loop shape along the inner wall of the housing 12, the antenna length is increased without impairing the miniaturization. Therefore, it becomes possible to sufficiently cope with a low frequency.

  The first and second antenna elements 16a and 16b are arranged side by side so as to form loops in opposite directions. For this reason, in the part where the first and second antenna elements 16a and 16b are arranged side by side, the flowing currents are in the same direction as shown by the arrow a and act so as to strengthen each other. be able to.

  Next explained is the second embodiment of the invention. 3 and 4 show the appearance of the broadcast receiving terminal 18 described in the second embodiment. The broadcast receiving terminal 18 has two thin box-like casings 19 and 20 connected to each other by a hinge mechanism 21 so as to be rotatable.

  In this case, the broadcast receiving terminal 18 rotates the casing 20 with respect to the casing 19 around the Y axis by the hinge mechanism 21, thereby folding the overlapping positions as shown in FIG. The unfolded position shown can be taken.

  Moreover, the display part 22 is installed in the housing | casing 19 in the surface 19a which opposes the housing | casing 20 in a folding position. Further, the operation unit 23 is installed on the surface 20 a of the housing 20 that faces the housing 19 at the folding position. An audio output connector 24 for connecting headphones or the like is also provided on one side surface 20b of the housing 20.

  Here, as shown in FIG. 5, the broadcast receiving terminal 18 receives a broadcast signal with a dipole antenna 25 built in one housing 19 and supplies it to a receiving circuit 26, thereby selecting and demodulating. Processing is performed.

  In this case, the first antenna element 25 a constituting the dipole antenna 25 is arranged so that one end thereof is connected to the receiving circuit 26 and the other end forms a loop along the inner wall of the housing 19.

  The second antenna element 25b constituting the dipole antenna 25 has one end connected to the receiving circuit 26 and the other end along the inner wall of the housing 19 in the direction opposite to the first antenna element 25a. The first antenna element is juxtaposed so as to form a loop.

  Thus, by arranging the first and second antenna elements 25a and 25b constituting the dipole antenna 25 in a loop shape along the inner wall of the housing 19, the antenna length is increased without impairing the miniaturization. Therefore, it becomes possible to sufficiently cope with a low frequency.

  The first and second antenna elements 25a and 25b are arranged side by side so as to form loops in opposite directions. For this reason, in the part where the first and second antenna elements 25a and 25b are arranged side by side, the flowing currents are in the same direction as shown by the arrow b and act to strengthen each other, thereby improving the reception performance. be able to.

  Of course, the dipole antenna 25 and the receiving circuit 26 may be installed in the housing 20.

  FIG. 6 shows a third embodiment of the present invention. In FIG. 6, the same reference numerals are given to the same parts as those in FIG. 5, and the first antenna element 25 a extending from the receiving circuit 26 built in the housing 19 extends along the inner wall of the housing 20. It arrange | positions so that a loop may be formed. The second antenna element 25 b extending from the receiving circuit 26 is arranged so as to form a loop along the inner wall of the housing 19.

  Further, by rotating the housing 20 by 180 ° about the X axis from the deployed position shown in FIG. 4, as shown in FIG. 11, the display unit 22 of the housing 19 and the operation unit 23 ( (Not visible in FIG. 11) can be directed in opposite directions. From this state, the two housings 19 and 20 can be folded.

  Here, when the two casings 19 and 20 are movably connected by the hinge mechanism 21, the number of axes of the hinge mechanism 21 is increased, so that the two casings 19 and 20 can be moved in a plurality of directions. For example, the housing 20 is rotated 90 ° about the X axis as shown in FIG. 9 from the deployed position where the housing 20 is rotated 180 ° about the Y axis with respect to the housing 19 shown in FIG. Furthermore, as shown in FIG. 10, it is also possible to rotate the housing 20 by 90 ° about the Z axis.

  Further, as shown in FIG. 12, the housing 20 is slid in the Z-axis direction by the thickness from the unfolded position shown in FIG. 4, and is rotated 180 ° from the position about the Z-axis. Accordingly, the casings 19 and 20 are configured such that the surface of the casing 19 opposite to the surface 19a on which the display unit 22 is installed faces the surface 20a of the casing 20 on which the operation unit 23 is installed. Can be superimposed on each other.

  Here, as shown in FIGS. 9 to 12, when the casings 19 and 20 are configured to take various movable forms, the first and second antenna elements 25a and 25b are folded in a folded state. May not be arranged in parallel with each other in opposite loops, but may be arranged in parallel with loops in the same direction.

  In such a case, it is impossible to obtain the effect that the flowing currents are in the same direction and strengthen each other in the juxtaposed portion of the first and second antenna elements 25a and 25b.

  Therefore, in order to arrange the first and second antenna elements 25a, 25b in a loop in the same direction, a structure that cannot be folded is used, or the side surfaces of the casings 19, 20 are marked. It may be possible to encourage the user to fold the marks so that the marks coincide with each other.

  As described above, the first and second antenna elements 25a and 25b constituting the dipole antenna 25 are respectively arranged in a loop shape in the two casings 20 and 19 that are rotatably connected to each casing. The bodies 19 and 20 can be thinned.

  In addition, the first and second antenna elements 25a and 25b are arranged side by side in a loop opposite to each other with the two casings 19 and 20 folded. For this reason, in the part in which the first and second antenna elements 25a and 25b are arranged in parallel, the flowing currents are in the same direction and act so as to strengthen each other, so that reception performance can be improved.

  The dipole antenna 25 can obtain the most advantageous gain by setting the lengths of the first and second antenna elements 25a and 25b to ¼ of the wavelength λ of the received signal.

  However, as shown in FIG. 7, by inserting a matching circuit 27 made of a coil or the like between the dipole antenna 25 and the receiving circuit 26, the lengths of the first and second antenna elements 25a and 25b are reduced to λ. Even if the length is shorter than / 4, it is possible to provide performance equivalent to that of a dipole antenna having a total length of λ / 2. This also applies to the first and second embodiments.

  Further, the first and second antenna elements 25a and 25b constituting the dipole antenna 25 are respectively disposed in two casings 20 and 19 that are rotatably connected. For this reason, the V-shaped dipole antenna 25 can be formed by changing the opening angle of the housings 19 and 20.

  In this V-shaped dipole antenna 25, it is known that the directivity in the V-shaped open end direction is enhanced. For this reason, it is possible to obtain even higher reception performance by adjusting the opening angle of the casings 19 and 20 and directing the open end of the V shape in the direction of arrival of radio waves.

  In addition, as the dipole antenna 25, as shown in FIG. 6, normally, when the opening angle of the casings 19 and 20 is 180 °, that is, the first and second antenna elements 25a and 25b are in a straight line. Therefore, it is set so that matching can be taken.

  Therefore, when the V-shaped dipole antenna 25 is formed by changing the opening angles of the casings 19 and 20, the reception performance is improved by correcting the deviation of the resonance frequency caused by the change in the opening angle. It becomes possible to make it.

  FIG. 8 shows an example of means for correcting a shift in the resonance frequency caused by forming the V-shaped dipole antenna 25. That is, the broadcast signal received by the dipole antenna 25 is corrected for the deviation of the resonance frequency by the matching circuit 29 that is controlled based on the detection result of the angle detector 28 that detects the open angle of the dipole antenna 25, and the receiving circuit 26. To be supplied.

  The matching circuit 29 is configured by, for example, a variable coil connected in series, and the resonance frequency shift can be corrected by changing the inductance of the variable coil in accordance with the opening angle of the dipole antenna 25.

  Specifically, when matching is performed in a state where the first and second antenna elements 25a and 25b are linearly arranged, the opening angle of the first and second antenna elements 25a and 25b is reduced from the position. As the operation proceeds, the resonance frequency increases.

  For this reason, in the matching circuit 29, it is possible to correct the deviation of the resonance frequency by increasing the inductance of the variable coil as the opening angle of the first and second antenna elements 25a and 25b decreases. Become.

  In addition, as the angle detector 28, for example, the opening angle of the casings 19 and 20 can be changed stepwise in a range of 0 ° to 180 °, and a method of detecting which stage is currently installed is detected. Alternatively, a method of detecting a resistance value by providing a slide resistance or the like whose resistance value changes according to the opening angle of the casings 19 and 20 can be considered.

  Note that the matching circuit 27 shown in FIG. 7 and the matching circuit 29 shown in FIG. 8 can be shared.

  It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by variously modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements according to different embodiments may be appropriately combined.

The perspective view shown in order to demonstrate the 1st Embodiment of this invention and to demonstrate the external appearance of a broadcast receiving terminal. The figure shown in order to demonstrate arrangement | positioning of the dipole antenna of the broadcast receiving terminal in the said 1st Embodiment. The perspective view which shows the 2nd Embodiment of this invention and is shown in order to demonstrate the folded appearance of a broadcast receiving terminal. The perspective view shown in order to demonstrate the expanded external appearance of the broadcast receiving terminal in the said 2nd Embodiment. The figure shown in order to demonstrate arrangement | positioning of the dipole antenna of the broadcast receiving terminal in the said 2nd Embodiment. The figure which shows 3rd Embodiment of this invention and is shown in order to demonstrate arrangement | positioning of the dipole antenna of a broadcast receiving terminal. The block block diagram shown in order to demonstrate shortening the antenna length of the broadcast receiving terminal in the said 3rd Embodiment using a matching circuit. The block block diagram shown in order to demonstrate correct | amending the shift | offset | difference of the resonant frequency accompanying the opening angle of the broadcast receiving terminal in the said 3rd Embodiment using a matching circuit. The perspective view shown in order to demonstrate an example of the movable form of the broadcast receiving terminal in the said 3rd Embodiment. The perspective view shown in order to demonstrate the other example of the movable form of the broadcast receiving terminal in the said 3rd Embodiment. The perspective view shown in order to demonstrate the other example of the movable form of the broadcast receiving terminal in the said 3rd Embodiment. The perspective view shown in order to demonstrate the other example of the movable form of the broadcast receiving terminal in the said 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Broadcast receiving terminal, 12 ... Housing | casing, 13 ... Display part, 14 ... Operation part, 15 ... Connector, 16 ... Dipole antenna, 17 ... Receiving circuit, 18 ... Broadcast receiving terminal, 19, 20 ... Housing | casing, 21 ... Hinge mechanism, 22 ... display section, 23 ... operation section, 24 ... connector, 25 ... dipole antenna, 26 ... receiving circuit, 27 ... matching circuit, 28 ... angle detector, 29 ... matching circuit.

Claims (9)

A housing,
The first antenna element arranged in a loop in the casing and the first antenna element are arranged in parallel so that the direction of current flow in the casing is the same as that of the first antenna element. A dipole antenna comprising a second antenna element,
A broadcast receiving apparatus comprising: a receiving circuit to which a broadcast signal received by the dipole antenna is supplied.   The broadcast receiving apparatus according to claim 1, wherein a display unit, an operation unit, and an audio output terminal are installed in the housing. First and second housings movably coupled;
The first antenna element arranged in a loop shape in the first casing, and the first antenna element so that the direction of current flow in the first casing is the same as that of the first antenna element. A dipole antenna composed of a second antenna element arranged in parallel with the antenna element;
A broadcast receiving apparatus comprising: a receiving circuit to which a broadcast signal received by the dipole antenna is supplied. First and second housings movably coupled so as to be able to assume overlapping folding positions;
A first antenna element arranged in a loop in the first casing and a second antenna arranged in the second casing, and in the folded position, the direction of current flow is the same as the first antenna element. A dipole antenna composed of a second antenna element juxtaposed with the first antenna element,
A broadcast receiving apparatus comprising: a receiving circuit to which a broadcast signal received by the dipole antenna is supplied.   5. The broadcast receiving apparatus according to claim 3, wherein a display unit is installed on one of the first and second casings, and an operation unit is installed on the other.   5. The broadcast receiving apparatus according to claim 4, wherein the first and second casings are supported so as to be rotatable about a plurality of axes.   7. The broadcast receiving apparatus according to claim 1, further comprising matching means for shortening the lengths of the first and second antenna elements constituting the dipole antenna. Angle detection means for detecting an open angle formed by the first antenna element and the second antenna element;
5. The broadcast receiving apparatus according to claim 4, further comprising a matching unit that corrects a deviation in resonance frequency from the matching state of the dipole antenna based on a detection result of the angle detection unit.   9. The broadcast receiving apparatus according to claim 1, wherein the dipole antenna is set so as to correspond to mobile broadcast reception.

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