Abstract:
A television signal-receiving module includes a first slot for disposing a network interface module detachably. The network interface module receives a television signal. The television signal-receiving module further includes a switch electrically connected to the network interface module for switching a transmission route of the television signal, a decoder electrically connected to the switch for decompressing and decoding the television signal, and a second slot for disposing a cable television decryptor detachably. The second slot is electrically connected to the decoder and the switch. The switch is switched to the decoder or the cable television decryptor so as to decode or decrypt the television signal after the network interface module downconverts and demodulates the television signal.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a television signal-receiving module, and more particularly, to a television signal-receiving module capable of receiving television signals at different standards.  
         [0003]     2. Description of the Prior Art  
         [0004]     Please refer to  FIG. 1 .  FIG. 1  is a functional block diagram of a television  10  at a first standard in the prior art. Radio frequency signals are received via an antenna  11  (or a cable) and transmitted to a signal-receiving module  12 . A NTSC/ATSC network interface module  121  of the signal-receiving module  12  receives the radio frequency signals, such as NTSC analog signals of terrestrial broadcast and cable television and ATSC digital signals of terrestrial broadcast. The NTSC/ATSC network interface module  121  includes a tuner and a demodulator (not shown in  FIG. 1 ). The tuner transforms the radio frequency signals into intermediate frequency signals. Then the demodulator demodulates the intermediate frequency signals so as to transform the intermediate frequency signals into baseband signals. The baseband signals include audio and image signals. Then a decoder  122  decompresses and decodes the baseband signals. The decoder  122  includes a MPEG-2 decoder  1221  and an image decoder  1222 . The audio and image signals of the baseband signals are transmitted to a display device  13  (such as a LCD device, a plasma display panel, and a liquid crystal projector) and a speaker  14 . A central processing unit  123  is electrically connected to the NTSC/ATSC network interface module  121  and the decoder  122  for controlling the NTSC/ATSC network interface module  121  and the decoder  122 .  
         [0005]     Please refer to  FIG. 2 .  FIG. 2  is a functional block diagram of a television  20  at a second standard in the prior art. Radio frequency signals are received via an antenna  21  (or a cable) and transmitted to a signal-receiving module  22 . A NTSC/ATSC/QAM network interface module  221  of the signal-receiving module  22  receives the radio frequency signals, such as NTSC analog signals of terrestrial broadcast and cable television, ATSC digital signals of terrestrial broadcast, and unencrypted digital cable television/QAM signals. The NTSC/ATSC/QAM network interface module  221  downconverts and demodulates the radio frequency signals into baseband signals and then transmits the baseband signals to a decoder  222 . The decoder  222  decompresses and decodes the baseband signals. Audio and image signals of the baseband signals are transmitted to a display device  23  and a speaker  24 . A central processing unit  223  is electrically connected to the NTSC/ATSC/QAM network interface module  221  and the decoder  222  for controlling the NTSC/ATSC/QAM network interface module  221  and the decoder  222 .  
         [0006]     Please refer to  FIG. 3 .  FIG. 3  is a functional block diagram of a television  30  at a third standard in the prior art. Radio frequency signals are received via an antenna  31  (or a cable) and transmitted to a signal-receiving module  32 . A NTSC/ATSC/QAM/OOB network interface module  321  of the signal-receiving module  32  receives the radio frequency signals, such as NTSC analog signals of terrestrial broadcast and cable television, ATSC digital signals of terrestrial broadcast, encrypted and unencrypted digital cable television/QAM signals, and management message. The OOB (out of band) signal includes the management message. The NTSC/ATSC/QAM/OOB network interface module  321  downconverts and demodulates the radio frequency signals into baseband signals and then transmits the baseband signals to a cable television decryptor  322 . The cable television decryptor  322  decrypts the baseband signals and then transmits the decrypted baseband signals to a decoder  323 . The decoder  323  decompresses and decodes the decrypted baseband signals. Audio and image signals of the decrypted baseband signals are transmitted to a display device  33  and a speaker  34 . A central processing unit  324  is electrically connected to the NTSC/ATSC/QAM/OOB network interface module  321  and the decoder  322  for controlling the NTSC/ATSC/QAM/OOB network interface module  321  and the decoder  322 .  
         [0007]     The network interface module and the cable television decryptor of the conventional television are fixed on a circuit board of the signal-receiving module, and the network interface module only can receive television signals at a designated standard. Following the trend of television signal digitization, it is inconvenient for users to purchase a new television or a setup box for receiving television signals at different standards. There is a need to increase flexibility in receiving television signals at different standards of the television.  
       SUMMARY OF THE INVENTION  
       [0008]     It is a primary objective of the claimed invention to provide a television signal-receiving module capable of receiving television signals at different standards for solving the above-mentioned problem.  
         [0009]     According to the claimed invention, a television signal-receiving module includes a first slot for disposing a network interface module detachably. The network interface module receives a television signal. The television signal-receiving module further includes a switch electrically connected to the network interface module for switching a transmission route of the television signal, a decoder electrically connected to the switch for decompressing and decoding the television signal, and a second slot for disposing a cable television decryptor detachably. The second slot is electrically connected to the decoder and the switch. The switch is switched to connect to the decoder or the cable television decryptor so as to decode or decrypt the television signal after the network interface module downconverts and demodulates the television signal.  
         [0010]     According to the claimed invention, a television signal-receiving module includes a first slot for disposing a network interface module detachably. The network interface module receives a television signal. The television signal-receiving module further includes a switch electrically connected to the network interface module for switching a transmission route of the television signal, a decoder electrically connected to the switch for decompressing and decoding the television signals, and a cable television decryptor electrically connected to the decoder and the switch. The switch is switched to connect to the decoder or the cable television decryptor so as to decode or decrypt the television signal after the network interface module downconverts and demodulates the television signal.  
         [0011]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a functional block diagram of a television at a first standard in the prior art.  
         [0013]      FIG. 2  is a functional block diagram of a television at a second standard in the prior art.  
         [0014]      FIG. 3  is a functional block diagram of a television at a third standard in the prior art.  
         [0015]      FIG. 4  is a functional block diagram of a television of an embodiment according to the present invention.  
         [0016]      FIG. 5  is a functional block diagram of a television of another embodiment according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     Please refer to  FIG. 4 .  FIG. 4  is a functional block diagram of a television of an embodiment according to the present invention. A television  40  includes an antenna  41  (or a cable), a television signal-receiving module  42  electrically connected to the antenna  41 , a display device  43  (such as a LCD device, a plasma display panel, and a liquid crystal projector), and a speaker  44 . The television signal-receiving module  42  includes a network interface module  421 , a first slot  421   a , a switch  422  electrically connected to the network interface module  421 , a decoder  423 , and a central processing unit  424  electrically connected to the network interface module  421 , the switch  422 , and the decoder  423  for controlling the network interface module  421 , the switch  422 , and the decoder  423 . The television signal-receiving module  42  further includes a cable television decryptor  425 , and a second slot  425   a . The network interface module  421  includes a tuner and a demodulator (not shown in  FIG. 4 ). The decoder  423  includes a MPEG-2 decoder  4231  and an image decoder  4232 . The network interface module  421  is disposed in the first slot  421   a  detachably for receiving television signals at all kinds of standards received by the antenna  41 , such as NTSC analog signals of terrestrial broadcast and cable television, ATSC digital signals of terrestrial broadcast, cable television signals, encrypted and unencrypted digital cable television signals, management message, and so on. The cable television decryptor  425  is disposed in the second slot  425   a  detachably. The tuner of the network interface module  421  transforms the radio frequency signals received by the antenna  41  into intermediate frequency signals. Then the demodulator of the network interface module  421  demodulates the intermediate frequency signals so as to transform the intermediate frequency signals into baseband signals. The baseband signals include audio and image signals. Then the central processing unit  424  switches the switch  422  according to the type of the television signal received by the antenna  41  so as to switch a transmission route of the baseband signals. In this way, the baseband signals are transmitted to the decoder  423  directly, or transmitted to the cable television decryptor  425  first. And then the baseband signals are transmitted to the decoder  423 . The audio and image signals of the baseband signals are transmitted to the display device  43  and the speaker  44  respectively. The central processing unit  424  can be integrated with the decoder  423 .  
         [0018]     When the television signal received by the antenna  41  corresponds with a first standard, the television signal includes NTSC analog signals of terrestrial broadcast and cable television or ATSC digital signals of terrestrial broadcast, the NTSC/ATSC network interface module  421  is disposed in the first slot  421   a . It is no need to dispose the cable television decryptor  425  in the second slot  425   a  when the television signal does not include an encrypted signal. The tuner of the NTSC/ATSC network interface module  421  transforms the radio frequency signals received by the antenna  41  into intermediate frequency signals. Then the demodulator of the NTSC/ATSC network interface module  421  demodulates the intermediate frequency signals so as to transform the intermediate frequency signals into baseband signals. The baseband signals include audio and image signals. The central processing unit  424  switches the switch  422  so as to transmit the baseband signals to the decoder  423  directly. The decoder  423  decompresses and decodes the audio and image signals of the baseband signals, and then the audio and image signals are transmitted to the display device  43  and the speaker  44  respectively.  
         [0019]     When the television signal received by the antenna  41  corresponds with the second standard, the television signal includes NTSC analog signals of terrestrial broadcast or cable television, ATSC digital signals of terrestrial broadcast, or unencrypted digital cable television/QAM signals, the NTSC/ATSC/QAM network interface module  421  is disposed to the first slot  421   a . There is no need to dispose the cable television decryptor  425  in the second slot  425   a  when the television signal does not include an encrypted signal. The tuner of the NTSC/ATSC/QAM network interface module  421  transforms the radio frequency signals received by the antenna  41  into intermediate frequency signals. Then the demodulator of the NTSC/ATSC/QAM network interface module  421  demodulates the intermediate frequency signals so as to transform the intermediate frequency signals into baseband signals. The baseband signals include audio and image signals. The central processing unit  424  switches the switch  422  so as to transmit the baseband signals to the decoder  423  directly. The decoder  423  decompresses and decodes the audio and image signals of the baseband signals, and then the audio and image signals are transmitted to the display device  43  and the speaker  44  respectively.  
         [0020]     When the television signal received by the antenna  41  corresponds with the third standard, the television signal includes NTSC analog signals of terrestrial broadcast and cable television, ATSC digital signals of terrestrial broadcast, unencrypted or encrypted digital cable television/QAM signals, or management messages, the NTSC/ATSC/QAM/OOB network interface module  421  is disposed in the first slot  421   a . Furthermore, the cable television decryptor  425  is disposed in the second slot  425   a . The central processing unit  424  switches the switch  422  to connect with the cable television decryptor  425 . The tuner and the demodulator of the NTSC/ATSC/QAM network interface module  421  downconvert and demodulate the radio frequency signals received by the antenna  41  into baseband signals. When receiving the encrypted digital cable television signal, the central processing unit  424  switches the switch  422  to connect the NTSC/ATSC/QAM network interface module  421  and the cable television decryptor  425  and controls the cable television decryptor  425  to decrypt the baseband signals. The decoder  423  decompresses and decodes the baseband signals, and then audio and image signals are transmitted to the display device  43  and the speaker  44  respectively. When receiving the unencrypted ATSC/Cable(QAM) signals, the central processing unit  424  switches the switch  422  to connect the NTSC/ATSC/QAM network interface module  421  and the decoder  423  so that the baseband signals downconverted and demodulated by the NTSC/ATSC/QAM/OOB network interface module  421  are transmitted to the decoder  423  directly. The decoder  423  decompresses and decodes the baseband signals, and then audio and image signals of the baseband signals are transmitted to the display device  43  and the speaker  44  respectively.  
         [0021]     The different network interface modules can be disposed in the first slot  421   a  according to the transmission standard of the television signal or design demand for receiving television signals at different standards. In addition, the cable television decryptor  425  is disposed in the second slot  425   a  selectively according to whether the television signal includes encrypted cable television signals. The present invention increases flexibility in receiving television signals at different standards of the television and can upgrade the television easily.  
         [0022]     Please refer to  FIG. 5 .  FIG. 5  is a functional block diagram of a television  50  of another embodiment according to the present invention. A difference between  FIG. 4  and  FIG. 5  is that a cable television decryptor  525  is installed inside a television signal-receiving module  52  directly. The television  50  includes the television signal-receiving module  52 , a display device  53 , and a speaker  54 . The television signal-receiving module  52  includes a network interface module  521 , a first slot  521   a , a switch  522  electrically connected to the network interface module  521 , a decoder  523 , and a central processing unit  524  electrically connected to the network interface module  521 , the switch  522 , and the decoder  523  for controlling the network interface module  521 , the switch  522 , and the decoder  523 . A tuner and a demodulator of the network interface module  521  downconvert and demodulate the radio frequency signals into the baseband signals. The central processing unit  524  switches the switch  522  to switch a transmission route of the television signal according to the selected network interface module  521 . The baseband signals are transmitted to the decoder  523  directly. Otherwise the baseband signals are transmitted to the cable television decryptor  425 , decrypted by the cable television decryptor  425 , and then transmitted the decrypted baseband signals to the decoder  523 . Audio and image signals of the baseband signals or the decrypted baseband signals are transmitted to the display device  53  and the speaker  54  respectively.  
         [0023]     In contrast to the conventional television, the present invention increases flexibility in receiving television signals at different standards of the television and can upgrade the television easily.  
         [0024]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.