Abstract:
Disclosed herein is a power supply adapter for supplying DC power to a broadcast receiver that processes a broadcast signal. The power supply adapter includes: a converter configured to generate the DC power from AC power; a broadcast signal reception section configured to receive the broadcast signal; a mixer configured to mix the broadcast signal received by the broadcast signal reception section with an output from the converter; and a supply section configured to supply an output from the mixer to the broadcast receiver.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    The present invention contains subject matter related to Japanese Patent Application JP 2008-000500, filed in the Japan Patent Office on Jan. 7, 2008, the entire contents of which being incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a power supply adapter and a power supply system for supplying power to a broadcast receiver such as a television receiver. 
         [0004]    2. Description of the Related Art 
         [0005]    Common broadcast receivers, such as common television receivers, especially small broadcast receivers, are driven by receiving DC power as supplied from a power supply adapter via a cable, and receive a broadcast signal as supplied from an outdoor antenna via a coaxial cable. Such common broadcast receivers have design constraints, e.g., difficulty in miniaturization, because of the need to secure space for an inlet, which is a connection section for receiving the power as supplied from the power supply adapter via the cable, and a connector, which is a connection section for receiving the broadcast signal as supplied from the outdoor antenna via the coaxial cable. In addition, it is not desirable in terms of visual appearance and for safety reasons that a plurality of cables, such as the power supply cable and the antenna coaxial cable, lie around the broadcast receiver. Moreover, that produces a constraint that limits locations where the broadcast receiver can be installed. 
         [0006]    There have already been proposed techniques for allowing both the power supply and the transmission of the broadcast signal to be achieved with use of a single cable. According to one such technique, for example, both supply of the DC power from the broadcast receiver, such as the television receiver, to a satellite broadcast antenna, which requires the power supply, and input of the broadcast signal from the satellite broadcast antenna into the broadcast receiver are achieved with use of a single coaxial cable. That is, the broadcast receiver supplies the DC power to the satellite broadcast antenna via the transmission cable, while the satellite broadcast antenna supplies the broadcast signal to the broadcast receiver via the same transmission cable (see Japanese Patent Laid-open No. Hei 7-128426). 
         [0007]    In the above known technique, both the supply of the DC power from the broadcast receiver to the antenna and the supply of the broadcast signal from the antenna to the broadcast receiver are achieved with the use of the single transmission cable, which connects the broadcast receiver and the antenna. This technique is applicable only when the antenna that requires the supply of the DC power from the broadcast receiver is used. 
       SUMMARY OF THE INVENTION 
       [0008]    As described above, the common broadcast receivers, such as the common television receivers, have the design constraints, e.g., difficulty in miniaturization, because of the need to secure the space for the inlet, which is the connection section for receiving the power as supplied from the power supply adapter via the cable, and the connector, which is the connection section for receiving the broadcast signal as supplied from the outdoor antenna via the coaxial cable. In addition, it is not desirable in terms of visual appearance and for safety reasons that the two cables, i.e., the power supply cable and the antenna coaxial cable, lie around the broadcast receiver. 
         [0009]    The present invention addresses the above-identified, and other problems associated with methods and apparatuses in related art, and provides a power supply adapter and a power supply system that allow the DC power and the broadcast signal to be supplied to the broadcast receiver via a single cable. 
         [0010]    According to one embodiment of the present invention, there is provided a power supply adapter for supplying DC power to a broadcast receiver that processes a broadcast signal, the power supply adapter including: a converter configured to generate the DC power from AC power; a broadcast signal reception section configured to receive the broadcast signal; a mixer configured to mix the broadcast signal received by the broadcast signal reception section with an output from the converter; and a supply section configured to supply an output from the mixer to the broadcast receiver. 
         [0011]    According to this embodiment of the present invention, the broadcast signal received by the broadcast signal reception section is mixed with the DC power generated by the converter from the AC power, and a mixture of the DC power and the broadcast signal is supplied to the broadcast receiver. Thus, the DC power and the broadcast signal can be supplied to an external device (i.e., the broadcast receiver) using a single cable. This eliminates the need to provide the broadcast receiver with a connection section for an antenna or a connection section for DC power supply, resulting in a reduction in product design constraints of the broadcast receiver. Moreover, because of a reduction in the number of cables connected to the broadcast receiver, complexity in appearance of surroundings of the broadcast receiver can be reduced, and constraints on selecting a location where the broadcast receiver is installed can be relaxed. 
         [0012]    According to another embodiment of the present invention, there is provided a power supply system including: a broadcast receiver configured to process a broadcast signal; and a power supply adapter configured to supply DC power to the broadcast receiver. The power supply adapter includes: a converter configured to generate the DC power from AC power; a broadcast signal reception section configured to receive the broadcast signal; a mixer configured to mix the broadcast signal received by the broadcast signal reception section with an output from the converter; and a supply section configured to supply an output from the mixer to the broadcast receiver. The broadcast receiver includes a splitting section configured to separate the DC power and the broadcast signal from an output from the power supply adapter. 
         [0013]    The present invention enables the DC power and the broadcast signal to be supplied to the broadcast receiver using a single cable. This eliminates the need to provide the broadcast receiver with the connection section for the antenna or the connection section for the DC power supply, resulting in a reduction in product design constraints of the broadcast receiver. Moreover, because of the reduction in the number of cables connected to the broadcast receiver, the complexity in the appearance of the surroundings of the broadcast receiver can be reduced, and the constraints on selecting the location where the broadcast receiver is installed can be relaxed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  illustrates the structure of a power supply system according to a first embodiment of the present invention; 
           [0015]      FIG. 2  illustrates exemplary specific circuit structures of an input filter, a switch circuit, an amplification circuit, and a mixer within a power supply adapter as shown in  FIG. 1 ; 
           [0016]      FIG. 3  illustrates an exemplary specific circuit structure of a splitter within a television receiver as shown in  FIG. 1 ; and 
           [0017]      FIG. 4  illustrates the structure of a power supply system according to a second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 
       First Embodiment  
       [0019]      FIG. 1  illustrates the structure of a power supply system  100  according to a first embodiment of the present invention. 
         [0020]    As shown in  FIG. 1 , the power supply system  100  includes a power supply adapter  10  and a television receiver  20 . The power supply adapter  10  generates, from commercial AC power, DC (Direct Current) power required for operation of the television receiver  20 , superimposes a broadcast signal (a radio frequency (RF) signal or an intermediate frequency (IF) signal) received by an outdoor antenna upon the DC power, and supplies a resultant mixture to the television receiver  20 . Examples of the broadcast signal include a terrestrial broadcast signal and a satellite broadcast signal. The television receiver  20  separates the mixture of the DC power and the broadcast signal as supplied from the power supply adapter  10  into the DC power and the broadcast signal for use thereof. 
         [0021]    The structure of the power supply adapter  10  will now be described below. 
         [0022]    The power supply adapter  10  includes an AC (Alternating Current) power supply cable  31 , an AC-DC converter circuit  11 , a coaxial cable connector  12 , an input filter  13 , an amplification circuit  14 , a mixer  15 , a switch circuit  16 , a switch operation section  17 , and a DC supply cable  32 . 
         [0023]    The AC power supply cable  31  has a power plug at one end thereof, and connects a commercial AC power supply to an input terminal of the AC-DC converter circuit  11  within the power supply adapter  10  via the power plug. 
         [0024]    The AC-DC converter circuit  11  is a circuit for generating specified DC power from the commercial AC power supply connected thereto via the AC power supply cable  31 . The AC-DC converter circuit  11  is similar in basic structure to an AC-DC converter circuit contained in a common power supply adapter. One difference is that the AC-DC converter circuit  11  outputs DC power required to drive the amplification circuit  14  within the power supply adapter  10 , in addition to the DC power for driving the television receiver  20 . An output of the AC-DC converter circuit  11  for the DC power for driving the television receiver  20  is connected to one of two input terminals of the mixer  15 . 
         [0025]    The coaxial cable connector  12  is a connector to which a connector provided at one end of a coaxial cable  33  is detachably connected. The other end of the coaxial cable  33  is connected to the outdoor antenna for receiving the broadcast signal, such as the terrestrial broadcast signal or the satellite broadcast signal. An internal terminal of the coaxial cable connector  12  is connected to an input terminal of the input filter  13 . 
         [0026]    The input filter  13  is, for example, a band-pass filter (BPF) for removing unnecessary band components from the broadcast signal inputted via the coaxial cable connector  12 . An output terminal of the input filter  13  is connected to an input terminal of the amplification circuit  14 . 
         [0027]    The amplification circuit  14  is a circuit for amplifying the broadcast signal that has passed through the input filter  13 . An output terminal of the amplification circuit  14  is connected to one of the two input terminals of the mixer  15 , the other one of the two input terminals of the mixer  15  being connected to the output terminal of the AC-DC converter circuit  11 . For example, an amplification circuit equipped with an automatic gain control (AGC) or the like may be used as the amplification circuit  14  in order to optimize output levels. 
         [0028]    The switch circuit  16  is a circuit for switching on and off the amplification circuit  14 . A switch between on and off states of the switch circuit  16  is achieved, for example, by a manual operation on the switch operation section  17 , which is exposed above the exterior of a housing of the power supply adapter  10 . 
         [0029]    The mixer  15  is a circuit for superimposing the broadcast signal inputted thereto from the amplification circuit  14  upon the DC power inputted thereto from the AC-DC converter circuit  11 . An output terminal of the mixer  15  is connected to one end of the DC supply cable  32 , which is used to supply the DC power to the television receiver  20 . 
         [0030]    The DC supply cable  32  is a cable for supplying, to the television receiver  20 , the DC power upon which the broadcast signal is superimposed. A shielded wire in which a power supply wire is shielded, a coaxial wire, or the like is used for the DC supply cable  32 , so as to reduce influence of external noise and prevent the broadcast signal superimposed upon the DC power from causing unwanted field emission toward an outside. 
         [0031]      FIG. 2  illustrates exemplary specific circuit structures of the input filter  13 , the switch circuit  16 , the amplification circuit  14 , and the mixer  15 . 
         [0032]    As shown in  FIG. 2 , the input filter  13  can be formed by a resonant circuit that is composed of a combination of inductors and capacitors connected in series and parallel, for example. In this embodiment, the input filter  13  is constructed as the BPF that passes a certain frequency range and attenuates frequency ranges outside that frequency range. The switch circuit  16  is composed of a line that bypasses the amplification circuit  14  and a switch element for switching between on and off states of this bypass line and turning on and off the DC power to the amplification circuit  14 . The switch element is switched on and off in accordance with the manual operation or the like on the switch operation section  17  as shown in  FIG. 1 , for example. While the bypass line is in the on state, the DC power to the amplification circuit  14  is off, so that the broadcast signal is not amplified thereby. Meanwhile, while the bypass line is in the off state, the DC power to the amplification circuit  14  is on, so that the broadcast signal is amplified thereby. The mixer  15  is constructed using an inductor and a capacitor, for example. The output terminal of the AC-DC converter circuit  11  is connected via the inductor to the terminal through which the mixture of the DC power and the broadcast signal is outputted, whereas the output terminal of the amplification circuit  14  is connected via the capacitor to the terminal through which the mixture of the DC power and the broadcast signal is outputted. This contributes to avoiding influence of unwanted AC components on the operation of the AC-DC converter circuit  11  and influence of unwanted DC components on the operation of the amplification circuit  14 . 
         [0033]    Returning to  FIG. 1 , the structure of a splitting section in the television receiver  20  will now be described below. 
         [0034]    The television receiver  20  includes a DC inlet  21  and a splitter  22 . 
         [0035]    The DC inlet  21  is a part to which a connector of the DC supply cable  32  of the power supply adapter  10  is detachably connected. The DC inlet  21  is similar to a DC inlet provided in a common television receiver. An output terminal of the DC inlet  21  is connected to an input terminal of the splitter  22 . 
         [0036]    The splitter  22  is a circuit for separating the DC power and the broadcast signal from the DC power upon which the broadcast signal is superimposed. The DC power separated by the splitter  22  is supplied via a DC distribution section  24  to various modules within the television receiver  20 , such as a circuit and a display, which operate on the DC power. The broadcast signal separated by the splitter  22  is supplied to a tuner section  23  within the television receiver  20 . 
         [0037]      FIG. 3  illustrates an exemplary specific circuit structure of the splitter  22 . As shown in  FIG. 3 , the splitter  22  is constructed using an inductor and a capacitor, for example. The tuner section  23 , which is a broadcast signal processing circuit, is connected via the capacitor to the terminal through which the mixture of the DC power and the broadcast signal is inputted, whereas the DC distribution section  24 , which distributes the DC power among the various modules, such as the circuit and the display, which operate on the DC power, is connected via the inductor to the terminal through which the mixture of the DC power and the broadcast signal is inputted. This contributes to avoiding influence of unwanted AC components on the operation of the various modules and influence of unwanted DC components on the operation of the tuner section  23 . 
         [0038]    The operation of the power supply system  100  will now be described below. 
         [0039]    It is assumed here that the power supply adapter  10  is connected to the commercial AC power supply via the AC power supply cable  31  and is also connected to the television receiver  20  via the DC supply cable  32 , and that the connector of the coaxial cable  33 , which is connected to the outdoor antenna, is connected to the coaxial cable connector  12  of the power supply adapter  10 . 
         [0040]    In the power supply adapter  10  in the above situation, the AC-DC converter circuit  11  generates the specified DC power from the commercial AC power supplied via the AC power supply cable  31 . At this time, the AC-DC converter circuit  11  generates the DC power for driving the television receiver  20  and the DC power for driving the amplification circuit  14  at the same time. The DC power generated for driving the television receiver  20  is applied to one of the two input terminals of the mixer  15 , whereas the DC power generated for driving the amplification circuit  14  is applied to the switch circuit  16  for controlling the on and off of the operation of the amplification circuit  14 . 
         [0041]    In addition, the broadcast signal received by the outdoor antenna is inputted to the power supply adapter  10  via the coaxial cable connector  12 . The broadcast signal inputted to the power supply adapter  10  via the coaxial cable connector  12  is inputted to the input filter  13 , and then inputted to the amplification circuit  14  after the input filter  13  removes the unnecessary band components from the broadcast signal. The broadcast signal is amplified by the amplification circuit  14 , and then inputted to one of the two input terminals of the mixer  15 , the other one of the two input terminals of the mixer  15  being the input terminal to which the DC power is applied. As a result, the DC power upon which the broadcast signal is superimposed is obtained by the mixer  15  and supplied to the television receiver  20  via the DC supply cable  32 . 
         [0042]    Note that the above description assumes that the operation of the amplification circuit  14  is switched on by the switch circuit  16 . When reception by the outdoor antenna of radio waves is poor, resulting in a reduction in quality of images displayed by the television receiver  20 , for example, a user may perform the manual operation or the like on the switch operation section  17  to configure the switch circuit  16  to switch on the operation of the amplification circuit  14 . Meanwhile, when the reception by the outdoor antenna of the radio waves is excellent, the user may perform the manual operation or the like on the switch operation section  17  to configure the switch circuit  16  to switch off the operation of the amplification circuit  14 . This will contribute to preventing electric field intensity from increasing beyond the performance of the amplification circuit or the tuner, and also to preventing unnecessary power consumption. 
         [0043]    In the television receiver  20 , the DC power upon which the broadcast signal is superimposed as supplied thereto via the DC supply cable  32  is separated by the splitter  22  into the DC power and the broadcast signal. The separated DC power is supplied to the various modules (including the tuner section  23 ) within the television receiver  20 , such as the circuit and the display, which operate on the DC power. Meanwhile, the separated broadcast signal is supplied to the tuner section  23 . The tuner section  23  performs processes such as detection and demodulation of a broadcast signal corresponding to a channel selected by the user, and outputs a resultant signal to a signal processing circuit (not shown) in a subsequent stage. The signal processing circuit in the subsequent stage subjects the signal to processes such as separation of video and audio, decoding, D/A conversion, and/or the like, so that the video is displayed by the display and the audio is outputted via a loudspeaker. 
         [0044]    As described above, in the power supply system  100  according to this embodiment, the broadcast signal received by the outdoor antenna is superimposed upon the DC power within the power supply adapter  10 , and the mixture of the broadcast signal and the DC power is supplied to the television receiver  20  using the single DC supply cable  32 . This eliminates the need to provide the television receiver  20  with an external antenna terminal, resulting in a reduction in product design constraints. Moreover, in the case of television receivers in related art, two cables, i.e., a power supply cable and a coaxial cable for the broadcast signal, are connected to the television receiver, which is likely to result in complicated appearance of surroundings of the television receiver. In contrast, in the case of the power supply system  100  according to this embodiment, only the power supply cable (i.e., the DC supply cable  32 ) needs to be connected to the television receiver  20 , eliminating the complicated appearance. 
         [0045]    Note that the broadcast signal that is superimposed upon the DC power and supplied to the television receiver  20  is not limited to the terrestrial broadcast signal, but may be the satellite broadcast signal, a terrestrial digital radio broadcast signal, or a CATV digital broadcast signal. 
       Second Embodiment  
       [0046]    Next, a power supply system  200  according to a second embodiment of the present invention will now be described below. 
         [0047]      FIG. 4  illustrates the structure of the power supply system  200  according to the second embodiment of the present invention. 
         [0048]    The power supply system  200  and a power supply adapter  10 A according to this embodiment are preferable in the case where a television receiver  20 A that is capable of receiving broadcast signals in accordance with a plurality of different broadcasting systems. 
         [0049]    As shown in  FIG. 4 , the power supply system  200  includes the power supply adapter  10 A and the television receiver  20 A. The power supply adapter  10 A generates, from the commercial AC power, DC power required for operation of the television receiver  20 A, superimposes broadcast signals (the radio frequency (RF) signal or the intermediate frequency (IF) signal) received by a plurality of outdoor antennas  41  and  42  in conformity with the different broadcasting systems upon the generated DC power, and supplies a resultant mixture to the television receiver  20 A. The television receiver  20 A separates the mixture of the DC power and the broadcast signals as supplied from the power supply adapter  10 A into the DC power and the individual broadcast signals in accordance with the different broadcasting systems for use thereof. 
         [0050]    The structure of the power supply adapter  10 A will now be described below. 
         [0051]    In this embodiment, it is assumed that the broadcast signals in accordance with the different broadcasting systems that are superimposed upon the DC power within the power supply adapter  10 A are the terrestrial broadcast signal and the satellite broadcast signal. 
         [0052]    The power supply adapter  10 A includes the AC power supply cable  31 , the AC-DC converter circuit  11 , a terrestrial broadcast coaxial cable connector  12 A, a terrestrial broadcast input filter  13 A, a terrestrial broadcast amplification circuit  14 A, a terrestrial broadcast switch circuit  16 A, a terrestrial broadcast switch operation section  17 A, a satellite broadcast coaxial cable connector  12 B, a satellite broadcast input filter  13 B, a satellite broadcast amplification circuit  14 B, a satellite broadcast switch circuit  16 B, a satellite broadcast switch operation section  17 B, a broadcast signal mixer  18 , the mixer  15 , a satellite antenna DC power supply circuit  19 , a mixer/splitter  9 , and the DC supply cable  32 . 
         [0053]    The AC power supply cable  31  has the power plug at one end thereof, and connects the commercial AC power supply to the input terminal of the AC-DC converter circuit  11  within the power supply adapter  10 A via the power plug. 
         [0054]    The AC-DC converter circuit  11  is a circuit for generating the specified DC power from the commercial AC power supplied from the commercial AC power supply connected thereto via the AC power supply cable  31 . The AC-DC converter circuit  11  is similar in structure to an AC-DC converter circuit contained in a common power supply adapter. One difference is that the AC-DC converter circuit  11  outputs DC power required to drive the terrestrial broadcast amplification circuit  14 A within the power supply adapter  10 A, DC power required to drive the satellite broadcast amplification circuit  14 B, and DC power required to drive a satellite broadcast reception antenna  42  for receiving the satellite broadcast signal, in addition to the DC power for driving the television receiver  20 A. The output terminal of the AC-DC converter circuit  11  for the DC power for driving the television receiver  20 A is connected to one of the two input terminals of the mixer  15 . 
         [0055]    The terrestrial broadcast coaxial cable connector  12 A is a connector to which a connector provided at one end of a coaxial cable  33 A is detachably connected. The other end of the coaxial cable  33 A is connected to a terrestrial broadcast reception antenna  41  for receiving the terrestrial broadcast signal. An internal terminal of the terrestrial broadcast coaxial cable connector  12 A is connected to an input terminal of the terrestrial broadcast input filter  13 A. 
         [0056]    The terrestrial broadcast input filter  13 A is, for example, a BPF filter for removing unnecessary band components from the terrestrial broadcast signal inputted via the terrestrial broadcast coaxial cable connector  12 A. An output terminal of the terrestrial broadcast input filter  13 A is connected to an input terminal of the terrestrial broadcast amplification circuit  14 A. 
         [0057]    The terrestrial broadcast amplification circuit  14 A is a circuit for amplifying an output from the terrestrial broadcast input filter  13 A. An output terminal of the terrestrial broadcast amplification circuit  14 A is connected to one of two input terminals of the broadcast signal mixer  18 . For example, an amplification circuit equipped with an automatic gain control (AGC) or the like may be used as the terrestrial broadcast amplification circuit  14 A in order to optimize output levels. 
         [0058]    The terrestrial broadcast switch circuit  16 A is a circuit for switching on and off the terrestrial broadcast amplification circuit  14 A. A switch between on and off states of the terrestrial broadcast switch circuit  16 A is achieved, for example, by a manual operation on the terrestrial broadcast switch operation section  17 A, which is exposed above the exterior of a housing of the power supply adapter  10 A. 
         [0059]    The satellite broadcast coaxial cable connector  12 B is a connector to which a connector provided at one end of a coaxial cable  33 B is detachably connected. The other end of the coaxial cable  33 B is connected to the satellite broadcast reception antenna  42  for receiving the satellite broadcast signal. An internal terminal of the satellite broadcast coaxial cable connector  12 B is connected to an input terminal of the mixer/splitter  9 . 
         [0060]    The mixer/splitter  9  is a circuit for supplying the DC power supplied from the satellite antenna DC power supply circuit  19  to the satellite broadcast reception antenna  42  via the satellite broadcast coaxial cable connector  12 B and the coaxial cable  33 B, and also separating, from the DC power, the satellite broadcast signal inputted thereto from the satellite broadcast reception antenna  42  via the coaxial cable  33 B and the satellite broadcast coaxial cable connector  12 B and supplying the separated satellite broadcast signal to an input terminal of the satellite broadcast input filter  13 B. 
         [0061]    The satellite broadcast input filter  13 B is, for example, a BPF filter for removing unnecessary band components from the satellite broadcast signal inputted via the mixer/splitter  9 . An output terminal of the satellite broadcast input filter  13 B is connected to an input terminal of the satellite broadcast amplification circuit  14 B. 
         [0062]    The satellite broadcast amplification circuit  14 B is a circuit for amplifying an output from the satellite broadcast input filter  13 B. An output terminal of the satellite broadcast amplification circuit  14 B is connected to one of the two input terminals of the broadcast signal mixer  18 , the other one of the two input terminals of the broadcast signal mixer  18  being the input terminal to which the output terminal of the terrestrial broadcast amplification circuit  14 A is connected. For example, an amplification circuit equipped with an automatic gain control (AGC) or the like may be used as the satellite broadcast amplification circuit  14 B in order to optimize output levels. 
         [0063]    The satellite broadcast switch circuit  16 B is a circuit for switching on and off the satellite broadcast amplification circuit  14 B. A switch between on and off states of the satellite broadcast switch circuit  16 B is achieved, for example, by a manual operation on the satellite broadcast switch operation section  17 B, which is exposed above the exterior of the housing of the power supply adapter  10 A. 
         [0064]    The broadcast signal mixer  18  mixes the terrestrial broadcast signal and the satellite broadcast signal inputted thereto via the two input terminals thereof to output a resulting mixed broadcast signal. An output terminal of the broadcast signal mixer  18  is connected to one of the two input terminals of the mixer  15 . 
         [0065]    The mixer  15  is a circuit for superimposing the mixed broadcast signal, i.e., the mixture of the terrestrial broadcast signal and the satellite broadcast signal, outputted from the broadcast signal mixer  18  upon the DC power outputted from the AC-DC converter circuit  11 . The output terminal of the mixer  15  is connected to one end of the DC supply cable  32 , which is used to supply the DC power to the television receiver  20 A. 
         [0066]    The DC supply cable  32  is a cable for supplying, to the television receiver  20 A, the DC power upon which the mixed broadcast signal, i.e., the mixture of the terrestrial broadcast signal and the satellite broadcast signal, is superimposed. A shielded wire in which a power supply wire is shielded, a coaxial wire, or the like is used for the DC supply cable  32 , so as to reduce influence of external noise and prevent the broadcast signals superimposed upon the DC power from causing unwanted field emission toward the outside. 
         [0067]    The structure of a splitting section in the television receiver  20 A will now be described below. 
         [0068]    The television receiver  20 A includes the DC inlet  21 , a DC/broadcast signal splitter  22 A, and a broadcast signal splitter  22 B. 
         [0069]    The DC inlet  21  is a part to which the connector of the DC supply cable  32  of the power supply adapter  10 A is detachably connected. The DC inlet  21  is similar to a DC inlet provided in a common television receiver. The DC inlet  21  is connected to an input terminal of the DC/broadcast signal splitter  22 A. 
         [0070]    The DC/broadcast signal splitter  22 A separates the DC power and the mixed broadcast signal from the DC power upon which the mixed broadcast signal, i.e., the mixture of the terrestrial broadcast signal and the satellite broadcast signal, is superimposed. The DC power separated by the DC/broadcast signal splitter  22 A is supplied via the DC distribution section  24  to various modules within the television receiver  20 A, such as a circuit and a display, which operate on the DC power. The mixed broadcast signal separated by the DC/broadcast signal splitter  22 A is supplied to the broadcast signal splitter  22 B. 
         [0071]    The broadcast signal splitter  22 B separates the terrestrial broadcast signal and the satellite broadcast signal from the mixed broadcast signal separated by the DC/broadcast signal splitter  22 A, and supplies the terrestrial broadcast signal and the satellite broadcast signal to a terrestrial broadcast tuner section  23 A and a satellite broadcast tuner section  23 B, respectively, within the television receiver  20 A. 
         [0072]    The operation of the power supply system  200  will now be described below. 
         [0073]    It is assumed here that the power supply adapter  10 A is connected to the commercial AC power supply via the AC power supply cable  31  and is also connected to the television receiver  20 A via the DC supply cable  32 . In addition, it is assumed here that the coaxial cable  33 A extending from the terrestrial broadcast reception antenna  41  is connected to the terrestrial broadcast coaxial cable connector  12 A of the power supply adapter  10 A, and that the coaxial cable  33 B extending from the satellite broadcast reception antenna  42  is connected to the satellite broadcast coaxial cable connector  12 B. 
         [0074]    In the power supply adapter  10 A in the above situation, the AC-DC converter circuit  11  generates the specified DC power from the commercial AC power supplied via the AC power supply cable  31 . At this time, the AC-DC converter circuit  11  generates the DC power for driving the television receiver  20 A and applies the generated DC power to one of the two input terminals of the mixer  15 , and also generates the DC power for driving the terrestrial broadcast amplification circuit  14 A and the satellite broadcast amplification circuit  14 B and applies the generated DC power to power input terminals of the terrestrial broadcast amplification circuit  14 A and the satellite broadcast amplification circuit  14 B. Further, the AC-DC converter circuit  11  generates the DC power required to drive the satellite broadcast reception antenna  42 , and applies the generated DC power to the satellite antenna DC power supply circuit  19 . 
         [0075]    The satellite antenna DC power supply circuit  19  supplies the DC power supplied from the AC-DC converter circuit  11  to the satellite broadcast reception antenna  42  via the mixer/splitter  9 , the satellite broadcast coaxial cable connector  12 B, and the coaxial cable  33 B. As a result, the satellite broadcast reception antenna  42  is driven to be able to receive the satellite broadcast signal. The satellite broadcast signal received by the satellite broadcast reception antenna  42  is inputted to the coaxial cable  33 B, then to the satellite broadcast coaxial cable connector  12 B, and then to the mixer/splitter  9 . The satellite broadcast signal is separated from the DC power in the mixer/splitter  9 , and then inputted to the satellite broadcast input filter  13 B, and in the satellite broadcast input filter  13 B, the unnecessary band components are removed from the satellite broadcast signal. After passing through the satellite broadcast input filter  13 B, the satellite broadcast signal is amplified by the satellite broadcast amplification circuit  14 B, and then inputted to one of the two input terminals of the broadcast signal mixer  18 . 
         [0076]    Meanwhile, the terrestrial broadcast signal received by the terrestrial broadcast reception antenna  41  is inputted to the power supply adapter  10 A via the terrestrial broadcast coaxial cable connector  12 A. The unnecessary band components are removed from the inputted terrestrial broadcast signal in the terrestrial broadcast input filter  13 A, and the resulting terrestrial broadcast signal is inputted to the terrestrial broadcast amplification circuit  14 A and amplified therein. The resulting terrestrial broadcast signal is applied to one of the two input terminals of the broadcast signal mixer  18 , the other one of the two input terminals of the broadcast signal mixer  18  being the input terminal to which the satellite broadcast signal is applied. 
         [0077]    The broadcast signal mixer  18  mixes the terrestrial broadcast signal and the satellite broadcast signal inputted thereto via the two input terminals thereof, and applies the resulting mixed broadcast signal to one of the two input terminals of the mixer  15 , the other one of the two input terminals of the mixer  15  being the input terminal to which the DC power is applied. As a result, the DC power upon which the mixed broadcast signal, i.e., the mixture of the terrestrial broadcast signal and the satellite broadcast signal, is superimposed is obtained from the mixer  15 , and the DC power upon which the mixed broadcast signal is superimposed is supplied to the television receiver  20 A via the DC supply cable  32 . 
         [0078]    Note that the above description assumes that the operation of the terrestrial broadcast amplification circuit  14 A is switched on by the terrestrial broadcast switch circuit  16 A, and that the operation of the satellite broadcast amplification circuit  14 B is switched on by the satellite broadcast switch circuit  16 B. When reception of radio waves by the satellite broadcast reception antenna  42  or the terrestrial broadcast reception antenna  41  is poor, resulting in a reduction in quality of images displayed on the television receiver  20 A, for example, the user may perform the manual operation or the like on the terrestrial broadcast switch operation section  17 A or the satellite broadcast switch operation section  17 B to configure the terrestrial broadcast switch circuit  16 A or the satellite broadcast switch circuit  16 B to switch on the operation of the terrestrial broadcast amplification circuit  14 A or the satellite broadcast amplification circuit  14 B. This will contribute to preventing the electric field intensity from increasing beyond the performance of the amplification circuits or the tuner, and also to preventing unnecessary power consumption. 
         [0079]    The television receiver  20 A is supplied with the DC power upon which the mixed broadcast signal, i.e., the mixture of the terrestrial broadcast signal and the satellite broadcast signal, is superimposed via the DC supply cable  32  connected to the DC inlet  21 . In the television receiver  20 A, the DC power and the broadcast signals are separated from each other in the DC/broadcast signal splitter  22 A. The separated DC power is supplied via the DC distribution section  24  to the various modules (including the terrestrial broadcast tuner section  23 A and the satellite broadcast tuner section  23 B) within the television receiver  20 A, such as the circuit and the display, which operate on the DC power. Meanwhile, the broadcast signals separated in the DC/broadcast signal splitter  22 A is supplied to the broadcast signal splitter  22 B, and separated into the terrestrial broadcast signal and the satellite broadcast signal. The terrestrial broadcast signal is supplied to the terrestrial broadcast tuner section  23 A, and the satellite broadcast signal is supplied to the satellite broadcast tuner section  23 B. 
         [0080]    Each of the terrestrial broadcast tuner section  23 A and the satellite broadcast tuner section  23 B performs processes such as detection and demodulation of a broadcast signal corresponding to a channel selected by the user, and outputs a resultant signal to a signal processing circuit (not shown) in a subsequent stage. The signal processing circuit in the subsequent stage subjects the signal to processes such as the separation of video and audio, the decoding, the D/A conversion, and/or the like, so that the video is displayed by the display and the audio is outputted via a loudspeaker. 
         [0081]    As described above, in the power supply system  200  according to this embodiment, the terrestrial broadcast signal received by the terrestrial broadcast reception antenna  41  and the satellite broadcast signal received by the satellite broadcast reception antenna  42  are superimposed upon the DC power within the power supply adapter  10 A, and the mixture of the terrestrial broadcast signal, the satellite broadcast signal, and the DC power is supplied to the television receiver  20 A using the single DC supply cable  32 . This eliminates the need to provide the television receiver  20 A with external antenna terminals for the terrestrial broadcast and the satellite broadcast, resulting in a reduction in product design constraints. Moreover, in the case of television receivers in related art, the power supply cable and several antenna coaxial cables are connected to the television receiver  20 A, which is likely to result in complicated appearance of surroundings of the television receiver. In contrast, in the case of the power supply system  200  according to this embodiment, only the power supply cable (i.e., the DC supply cable  32 ) needs to be connected to the television receiver  20 A, eliminating the complicated appearance. 
         [0082]    Further, in the power supply system  200  according to this embodiment, the DC power for driving the satellite broadcast reception antenna  42  is generated within the power supply adapter  10 A, and the generated DC power is supplied by the satellite antenna DC power supply circuit  19  to the satellite broadcast reception antenna  42  via the mixer/splitter  9 , the satellite broadcast coaxial cable connector  12 B, and the coaxial cable  33 B. This eliminates the need to provide a path for supplying the DC power from the television receiver  20 A to the satellite broadcast reception antenna  42 , resulting in a further reduction in the connection sections in the television receiver  20 A. 
         [0083]    Note that the broadcast signals that are superimposed upon the DC power and supplied to the television receiver  20 A are not limited to the terrestrial broadcast signal and the satellite broadcast signal. The terrestrial digital radio broadcast signal and the CATV digital broadcast signal may also be superimposed upon the DC power and supplied to the television receiver  20 A, for example. 
         [0084]    The broadcast receiver may be any device containing a tuner. For example, a radio receiver, a recorder/player containing a tuner, a PC having a tuner function installed therein, as well as the television receiver, fall within the scope of the broadcast receiver to which the present invention is applicable. 
         [0085]    Note that the present invention is not limited to the above-described embodiments. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.