JP2006109064A - Channel-selecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a channel-selecting device which restrains a wrong connection from occurring through simplification of the connection of an RF circuit. <P>SOLUTION: The channel selecting device is equipped with: RF input terminals 21 and 22 provided to each signal line transmitting TV signals; tuners 12, 13, and 14 which are formed corresponding to the modulation techniques of the TV signals transmitted through the signal lines; an RF switch 11 which selects and connects the RF input terminals and the tuners together; and a pilot signal detecting unit 20 which detects the transmitted pilot signals that are obtained by multiplexing signals indicating the modulation techniques of the transmitted TV signals to the above TV signals. The RF switch 11 is operated on the basis of the pilot signals detected by the pilot signal detecting unit 20 to connect the RF input terminals 21 and 22 to the tuner corresponding to the input signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a channel selection device, and more particularly, to a channel selection device capable of simplifying connection between a plurality of signal lines for transmitting broadcast signals and a plurality of broadcast signal input terminals.

  FIG. 5 is a diagram for explaining a conventional TV receiver including a channel selection device. In the figure, 1 is a TV receiver, 12 is a tuner for selecting an analog broadcast signal, 13 is a tuner for selecting an OFDM (Orthogonal Frequency Division Multiplexing) broadcast signal, and 14 is a channel for selecting a QAM (Quadrature Amplitude Modulation) broadcast signal. Tuner to do. 15 is an analog signal processing unit that performs demodulation processing on the channel selection output of the analog tuner, 16 is an OFDM signal processing unit that performs processing such as demodulation on the channel selection output of the OFDM tuner, and 17 is demodulated to channel selection output of the QAM tuner. A QAM signal processing unit 18 that performs processing such as the above is a signal output unit including a display unit that displays the output of each signal processing unit.

  Reference numeral 21 denotes an RF input terminal to which a signal line L1 from an antenna for receiving, for example, an analog broadcast signal or an OFDM broadcast signal which is a terrestrial broadcast signal is connected. An RF input terminal 22 is connected to a signal line L2 for receiving, for example, an analog broadcast signal or a QAM broadcast signal which is a broadcast signal of a cable television. A control unit 19 controls the entire receiver 1. Reference numeral 51 denotes an RF switch, which transmits either the input RF signal from the signal line L1 or L2 to the analog tuner 12 based on the channel selection signal from the control unit 19.

  In this receiver, the OFDM tuner 13 and the OFDM signal processing unit 16 are used when receiving a terrestrial OFDM broadcast signal, and the QAM tuner 14 and QAM signal processing are used when receiving a QAM broadcast signal that is a cable television broadcast signal. When using the unit 17 to receive an analog broadcast signal that is a terrestrial broadcast signal or an analog broadcast signal that is a cable television broadcast signal, the analog tuner 12 and the analog signal processing unit 15 are used via an RF switch. .

  According to the prior art, analog broadcast signals and OFDM broadcast signals, which are terrestrial broadcast signals, and analog broadcast signals and QAM broadcast signals, which are cable television broadcast signals, can be received and viewed. However, the signal line L1 from the antenna that receives an analog broadcast signal or OFDM broadcast signal that is a terrestrial broadcast signal is connected to the RF input terminal 21, and receives an analog broadcast signal or a QAM broadcast signal that is a cable television broadcast signal. If the signal line L2 to be connected is not properly connected to the RF input terminal 22, the OFDM broadcast signal and the QAM broadcast signal cannot be viewed.

  In FIG. 5, a signal line L1 from an antenna that receives an analog broadcast signal or OFDM broadcast signal that is a terrestrial broadcast signal and a signal line L2 that receives an analog broadcast signal or QAM broadcast signal that is a broadcast signal of cable television. Although the case where there are two signal lines has been described as an example, the number of signal lines to be input and the number of RF input terminals are expected to increase as the number of broadcast paths or modulation schemes increases in the future. In such a case, it becomes difficult for the user to know which signal line should be connected to which RF input terminal. For this reason, a connection error (insertion error with respect to the RF input terminal of each signal line) increases.

  The present invention has been made in view of such problems, and provides a channel selection device that can simplify the connection of an RF circuit and suppress the occurrence of a connection error.

  In order to solve the above problems, the present invention employs the following means.

  A plurality of RF input terminals provided for each signal line for transmitting a TV signal, a plurality of tuners each corresponding to a modulation system of a TV signal transmitted via the signal line, and the plurality of RF inputs An RF switch for selecting and connecting a terminal and a plurality of tuners; and a pilot signal detector for detecting a pilot signal transmitted by multiplexing a signal representing a modulation method of a transmitted TV signal with the TV signal, The RF switch is switched based on the pilot signal detected by the pilot signal detector, and the RF input terminal is connected to the tuner corresponding to the input signal.

  Since the present invention has the above-described configuration, it is possible to simplify the connection of the RF circuit and suppress the occurrence of a connection error.

  Hereinafter, the best embodiment will be described with reference to the accompanying drawings. FIG. 1 is a diagram illustrating a channel selection device according to an embodiment of the present invention. In the figure, the same parts as those shown in FIG. In FIG. 1, reference numerals 31 and 32 denote pilot signal addition units, which use a pilot signal for specifying the type of broadcast signal to propagate (for example, whether it is a terrestrial broadcast signal or a CATV broadcast signal) as a broadcast signal. Append.

  In the example shown in the figure, a pilot signal 1 indicating that the signal is a terrestrial broadcast signal is added to the terrestrial broadcast signal C1. In this case, the pilot signal 1 simultaneously indicates a combination of modulation methods (analog broadcast and OFDM broadcast) of the broadcast signal that propagates.

  A pilot signal 2 indicating that the signal is a CATV broadcast signal is added to the CATV broadcast signal C2. In this case, the pilot signal 2 simultaneously indicates a combination of modulation methods (analog broadcast or QAM broadcast) of the broadcast signal that propagates.

  Reference numeral 20 denotes a pilot signal detection unit that detects pilot signals propagating through the signal lines L1 and L2, and identifies the type of broadcast signal propagating through the signal lines L1 and L2. Reference numeral 11 denotes an RF switch having input terminals a and b and output terminals c, d and e. The control unit 19 switches the RF switch based on the signal detected by the pilot signal detection unit 20 and supplies the received broadcast signal to the optimum tuner. In this example, the input terminal a is connected to the output terminal c or d, and the input terminal b is connected to the output terminal c or e. At this time, when the modulation scheme of the channel to be selected is clear based on the channel selection information input by the user, for example, when receiving a terrestrial OFDM signal, only the input terminal a and the output terminal d are connected. Also good.

  Thus, the broadcast signal propagating through the signal lines L1 and L2 is identified based on the pilot signal, and the RF switch is switched based on the identification result. Therefore, the signal lines L1 and L2 and the RF input terminals 21 and 22 are Connections can be made in any combination. That is, the insertion error of the signal lines L1 and L2 is eliminated, and the user is not lost at the time of connection.

  FIG. 2 is a diagram for explaining processing for adding a pilot signal to a broadcast signal on the broadcast station side. In the figure, the same parts as those shown in FIG. 1 and FIG. In FIG. 2, 4 is a terrestrial broadcast station that transmits a terrestrial broadcast signal, 41 is an analog broadcast transmitter that transmits an analog broadcast signal, 42 is an OFDM broadcast transmitter that transmits an OFDM broadcast signal, and 44 is an analog broadcast transmission. Is a combiner for combining the pilot signal 1 that is the output of the transmitter, the output of the OFDM broadcast transmitter, and the output of the pilot signal 1 adding unit, and the output of the combiner 44 is transmitted as a terrestrial broadcast signal.

  5 is a CATV broadcast station, 51 is an analog broadcast transmitter that transmits an analog broadcast signal, 52 is a QAM broadcast transmitter that transmits a QAM broadcast signal, 54 is an output of the analog broadcast transmitter, an output of the QAM broadcast transmitter, and a pilot It is a multiplexer that synthesizes the pilot signal 2 that is the output of the signal 2 adding section, and the output of the multiplexer 54 is transmitted as a CATV broadcast signal.

  Thus, the pilot signal 1 indicating that the signal is a terrestrial broadcast signal is added to the broadcast signal transmitted from the terrestrial broadcast station 4 and transmitted. Further, a pilot signal 2 indicating that the signal is a CATV broadcast signal can be added to the broadcast signal transmitted from the CATV broadcast station 4 and transmitted. In this case, the pilot signal detector 20 of the receiver 1 only determines whether the pilot signal included in the broadcast signal is the pilot signal 1 or the pilot signal 2, and the type of the broadcast signal input to the RF input terminal (Whether it is a terrestrial broadcast signal or a CATV broadcast signal) can be determined. It is also possible to determine a combination of modulation schemes.

  FIG. 3 is a diagram for explaining processing for adding a pilot signal to a broadcast signal on the joint reception facility side. In the figure, the same parts as those shown in FIGS. In the figure, 44a is a multiplexer, which combines the output of the analog broadcast transmitter and the output of the OFDM broadcast transmitter to generate a terrestrial broadcast signal C1. A multiplexer 54a combines the output of the analog broadcast transmitter and the output of the QAM broadcast transmitter to form a CATV broadcast signal C2.

  A pilot signal 1 adding unit 31 adds the generated pilot signal 1 to the broadcast signal C1. Reference numeral 32 denotes a pilot signal 2 adding unit, which adds the generated pilot signal 2 to the broadcast signal C2. Reference numerals 51 and 52 denote distributors, which distribute the broadcast signals C1 and C2 and supply them to the receiver 1 of each household.

  In this way, when the pilot signal is added to the broadcast signals C1 and C2 on the broadcasting station side and is not broadcasted, the pilot signal adding units 31 and 32 are added to, for example, the joint receiving facility side of the apartment house 6 to generate The pilot signal may be added to the broadcast signals C1 and C2.

  Also in this case, the pilot signal detection unit 20 of the receiver 1 only determines whether the pilot signal included in the broadcast signal is the pilot signal 1 or the pilot signal 2, and the broadcast signal input to the RF input terminal is determined. The type (whether it is a terrestrial broadcast signal or a CATV broadcast signal) can be determined. Also, a combination of modulation schemes can be determined.

  FIG. 4 is a diagram illustrating an example of the frequency arrangement of pilot signals. FIG. 4 (a) is a diagram for explaining the frequency arrangement of the terrestrial broadcast signal. The OFDM broadcast signal is arranged on the high frequency side, the analog broadcast signal is arranged on the low frequency side, and the pilot signal 1 is further arranged on the low frequency side. Place. FIG. 4B is a diagram for explaining the frequency arrangement of the CATV broadcast signal. The QAM broadcast signal is arranged on the high frequency side, the analog broadcast signal is arranged on the low frequency side, and the pilot signal 2 is arranged on the low frequency side. To do. Pilot signal 1 and pilot signal 2 are set to different frequencies.

  As described above, according to the embodiment of the present invention, a device for adding a pilot signal having a specific frequency is added to each signal line for transmitting a TV signal. On the receiver side, a pilot signal detection device is provided between the RF input terminal and the tuner unit, and the RF signal input to each RF input terminal is distributed to each tuner according to a preset pilot signal. Thus, by adding pilot signals having different frequencies to the RF signals transmitted through different signal lines, the receiver can distribute the RF signals to the optimum tuners. As a result, erroneous insertion of the RF cable is eliminated, and the user is not lost at the time of connection, and the connection can be easily performed. Note that the processing of the control unit and the like can be realized by a program or hardware.

It is a figure explaining the channel selection apparatus which concerns on embodiment of this invention. It is a figure explaining the process which adds a pilot signal to the broadcast signal by the broadcast station side. It is a figure explaining the process which adds a pilot signal to the broadcast signal by the joint reception equipment side. It is a figure explaining the plant monitoring control apparatus which is a figure explaining the example of frequency arrangement | positioning of a pilot signal. It is a figure explaining the conventional TV receiver provided with the channel selection apparatus.

Explanation of symbols

1 Receiver 4 Terrestrial Broadcasting Station 5 CATV Broadcasting Station 11 RF Switch 12 Analog Tuner 13 OFDM Tuner 14 QAM Tuner 15 Analog Signal Processing Unit 16 OFDM Signal Processing Unit 17 QAM Signal Processing Unit 18 Output Unit 19 Control Unit 20 Pilot Signal Detection Unit 21 and 22 RF input terminal 31 Pilot signal 1 addition unit 32 Pilot signal 2 addition unit 41 and 51 Analog broadcast transmitter 42 OFDM signal transmitter 52 QAM signal transmitter

Claims (4)

A plurality of broadcast signal input terminals provided for each signal line for transmitting broadcast signals;
A plurality of receivers each configured to correspond to a modulation method of a broadcast signal transmitted through the signal line;
A broadcast signal switching unit for selecting and connecting the plurality of broadcast signal input terminals and a plurality of receiving units;
A pilot signal detection unit for detecting a pilot signal representing a modulation method of a broadcast signal multiplexed on a broadcast signal and transmitted through the signal line;
The pilot signal detecting unit switches the broadcast signal switching unit based on the detected pilot signal, and connects the broadcast signal input terminal to the receiving unit corresponding to the input signal. In the channel selection device according to claim 1,
The pilot signal detection unit switches the broadcast signal switching unit based on the detected pilot signal and the channel selection information input by the user, and the broadcast signal input terminal corresponding to the selected broadcast corresponds to the selected broadcast. A channel selection device connected to a receiving unit. In the channel selection device according to claim 1,
A channel selection apparatus, wherein a pilot signal is multiplexed with a broadcast signal in a broadcast station that transmits the broadcast signal. In the channel selection device according to claim 1,
A channel selection apparatus, wherein a pilot signal is multiplexed with a broadcast signal in a joint receiving facility for jointly receiving the broadcast signal.

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