MULTIPLEX BROADCAST RECEIVING METHOD AND RECEIVER

Abstract: A multiplex broadcast receiving method can simultaneously receive a general radio broadcast and an additional information broadcast. In the method, one among a general radio mode, an additional broadcast mode, and a multiplex broadcast mode is selected. Broadcasting station according to the selected mode is selected and a wave of the selected broadcasting station is outputted. At least one among the audio signal, the additional information signal, and the multiplex broadcast signal is detected and processed from the outputted broadcasting station wave according to the selected mode. It is discriminated whether a different mode is selected among the modes. Execution of the different mode is controlled according to a discrimination result. According to the method, the method can display additional information in a form of a character, a graphic, or an image on a display device tuned by one tuner while listening to a general radio program tuned by the other tuner.

Description: MULTIPLEX BROADCAST RECEIVING METHOD AND RECEIVER TECHNICAL FIELD The present invention relates to a multiplex broadcast, more particularly, to a multiplex broadcast receiving method and receiver capable of simultaneously receiving a general radio broadcast and an additional information broadcast. BACKGROUND ART In general, a frequency modulation (FM) multiplex broadcast is a broadcast which broadcasts a data signal in a form of a character, a graphic, or an image overlapped in an FM broadcast wave as an additional broadcast information. The additional broadcast information includes traffic, music, and a weather. A subcarrier which resides outside the band occupied by the FM modulation signal and which is the third harmonic of 19 kHz stereo pilot signal, is amplitude modulated by the data signal which is filtered and biphase-coded, representative of the program contents to thereby provide radio data signals. FIG. 1 shows a conventional FM multiplex broadcast receiver. The conventional FM multiplex broadcast receiver 10 includes a key input section 102, a tuner 104, a demodulator 106, a stereo signal output section 108, a band pass filter 110, a decoder 112, a controller 114, and a memory section 116, and a liquid crystal display device (LCD) 118. The key input section 102 generates one between a general radio mode select signal and an additional broadcast mode select signal so as to select a general radio mode or an additional broadcast mode. The mode select signals are applied to the controller 114. The tuner 104 selects one of desired broadcasting stations according to the mode selected by the key input section 102 and converts a broadcast wave of the selected broadcasting station into an intermediate frequency signal . The intermediate frequency signal is inputted into the demodulator 106 and a decoder 112. The demodulator 106 FM demodulates the intermediate frequency signal from the tuner 104 to output a subcarrier signal and a baseband signal . The stereo signal output section 108 outputs an FM stereo signal divided into a right side signal and a left side signal from the baseband based on the subcarrier. The band pass filer 110 band pass filters the intermediate frequency signal from the tuner 104 to obtain an additional broadcast signal. The additional broadcast signal is fed to a decoder 112. The decoder 112 decodes the additional broadcast signal from the band pass filter 110 into prescribed readable data. The additional broadcast signal decoded into the prescribed readable data is provided into the controller 114. The controller 114 feeds the additional broadcast signal decoded into the prescribed readable data from the decoder 112 to the memory 116 and generates operation control signals of the tuner 104 and the decoder 112. The memory 116 stores the additional broadcast signal from the controller 114 therein. The LCD 118 displays the additional broadcast information in a form of a character code on the basis of the additional broadcast signal . FIG. 2 illustrates a multiplex broadcast receiving method according to the multiplex broadcast receiver shown in FIG. 1. In step S201, the controller 114 discriminates whether or not a general radio mode is selected. According to a result of the discrimination in step S201, when general radio mode is selected, the controller 114 controls the tuner 104 and the demodulator 106 to execute the general radio mode (step S202) , and the routine is completed. Alternatively, when it is ' discriminated that the general radio mode is not selected, the controller 114 judges whether or not a multiplex broadcast mode is selected(step S203) . According to a result of the judgement in step 203, when the multiplex broadcast mode is not selected, the routine finishes. Alternatively, when it is judged that the multiplex broadcast mode is selected, the controller 114 checks whether or not a character data signal is included in a radio signal received in the tuner 104 (step S204) . According to a result of the check in step S204, when the character data signal is not included in the radio signal, the routine is completed. Alternatively, when it is checked that the character data signal is included in the radio signal, the controller 114 controls the tuner 104 and the decoder 112 to perform the multiplex broadcast mode (step S205) . Since the conventional multiplex broadcast receiving method and receiver have one tuner, a user receives a general radio broadcast or a multiplex broadcast through one tuner. However, when a user cannot receive an additional broadcast such as a character broadcast while receiving a general radio broadcast such as a music broadcast by using one tuner. U.S. Patent No 5,428,825 (issued to Ryou Tomohiro on June 27, 1995) discloses a method of selecting receiving frequency for an RDS receiver. In the conventional method of selecting receiving frequency for an RDS receiver, a list of alternative frequencies being transmitted by former broadcasting stations are stored in a memory. The RDS receiver chases the same broad program based on the stored list of alternative frequencies whenever the motor vehicle returns to the same broadcasting service area of the network wherein the stored list of alternative frequencies is effective for use. Further, the stored list of alternative frequencies data relating to frequencies of the received broadcast waves during the operation of chasing the same radio program are also ' utilized together with the stored list of alternative frequencies transmitted by the broadcasting stations for chasing the same broadcast program. DISCLOSURE OF INVENTION Therefore, it is an object of the present invention, for the purpose of solving the above mentioned problems, to provide a multiplex broadcast receiving method and receiver capable of simultaneously receiving a general radio broadcast and a character broadcast . In order to attain the object, according to the present invention, there is provided a multiplex broadcast receiving method, the method comprising the steps of: a) selecting one among a general radio mode which outputs a first audio signal, an additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and additional information signals; b) selecting a broadcasting station according to the mode selected in step a) and outputting a wave of the selected broadcasting station; and c) detecting and processing at least one among the first audio signal, the first additional information signal, and the multiplex broadcast signal from the broadcasting station wave outputted in step b) , according to the mode selected in step a) ; d) discriminating whether a different mode is selected among the modes; and e) controlling execution of the different mode according to a discrimination result of step d) . Also, there is provided a multiplex broadcast receiver comprising: a mode select section for selecting at least one among a general radio mode which outputs a first audio signal, an additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and information signals; at least one tuner for selecting at least one broadcasting station according to the at least one mode selected by the mode select selection and outputting one wave or more of the at least one broadcasting station selected; a mode executing section for detecting and processing at least one among the first audio signal, the first additional information signal, and the multiplex broadcast signal from the one wave or more of the at least one broadcasting station outputted from the at least one tuner, according to the at least one mode selected by the mode select section; and a controller for sequentially discriminating whether the modes are selected and controlling operations of the at least one tuner and mode executing section according to a discrimination result. In accordance with the present invention, the present invention can display additional information in a form of a character, a graphic, or an image on a display device tuned by the one tuner while listening to a general radio program tuned by the other tuner. Other objects and further features of the present invention will become apparent from the detailed description when read in conjunction with the attached drawings. BRIEF DESCRIPTION OF DRAWINGS Other features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, wherein: FIG. 1 is a block diagram for showing a conventional FM multiplex broadcasting receiver; FIG. 2 is a flow chart for illustrating an operation of a conventional FM multiplex broadcasting method; FIG. 3 is a view for showing a structure of an FM multiplex broadcast spectrum which is used in the present invention; FIG. 4 is a block diagram for showing an FM multiplex broadcasting receiver according to an embodiment of the present invention; and FIG. 5 is a flow chart for illustrating an FM multiplex broadcast receiving method according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION The preferred embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings . FIG. 3 shows a block diagram of FM signal spectrum. A stereo multiplexing used in FM stations is an example of a pilot tone system. An FM station is permitted the use of 75 kHz before using frequency modulation to transmit the composite signal. Upon reception, two demodulators are used in tandem, one for the FM, the other to separate the audio signals. In stereo broadcasting, it is necessary to transmit and receive both the left (L) and the right (R) audio channels while also furnishing the sum (L + R) to monophonic receivers. To serve both types of receivers, the (L + R) signal occupies the normal audio spectrum up to 15 kHz and the (L - R) signal, also in the same spectral range, is shifted up in frequency using DSB-SC modulation. The carrier frequency used in 38 kHz and a sketch of the resulting composite spectrum is shown in FIG. 3. This leaves the frequency band 15-23 kHz unoccupied and a pilot carrier is placed at 19 kHz. In the receiver, a narrow bandpass filter centered at 19 kHz picks out the pilot carrier. This frequency is doubled to 38 kHz and used to synchronize the demodulator. Finally, an addition and subtraction of the two signals yields the desired L and R audio signals. In a radio data system (RDS) which is standardized in the Europe Broadcasting Union (EBU) , data signals such as a character data signal which is used for the present invention are carried on a 57 kHz subcarrier which is added to the stereo multiplex signal (or monophonic signal as appropriate) at the input to the VHF/FM transmitter. During stereo broadcasts the subcarrier frequency will be locked to the third harmonic of the 19-kHz pilot-tone. The subcarrier is amplitude-modulated by the shaped and biphase coded data signal. The subcarrier is suppressed. This method of modulation may alternatively by thought of as a form of two- phase phase-shift-keying (PSK) with a phase deviation of ±90°. As shown in FIG. 3, data signals such as a character data signal are carried on a 76 kHz, 57 kHz, and 67 kHz and 92 kHz subcarriers which are added to the stereo multiplex signal, in a data radio channel system (DARC) of Japan, a radio broadcast data system (RBDS) of USA, and a subsidiary communication authorization (SCA) of USA, respectively. FIG. 4 shows a multiplex broadcasting receiver 40 according to an embodiment of the present invention. The multiplex broadcasting receiver 40 includes a mode select section 402, a first tuner 404, a second tuner 406, a mode executing section 407, and a controller 412. The mode select section 402 selects at least one among a general radio mode, an additional broadcast mode, and a multiplex broadcast mode. The general radio mode, the additional broadcast mode, and the multiplex broadcast mode outputs a first audio signal, displays a first additional information signal, and outputs a second audio signal and displays second additional information signal, respectively. The mode select section 402 includes a general radio mode select key 402a, an additional broadcast mode select key 402b, a multiplex broadcast mode select key 402c, a tape mode select " key 402d, and a compact disc (CD) mode select key 402e. The general radio mode select key 402a generates a general radio mode select signal GR. The additional broadcast mode select key 402b generates an additional broadcast mode select signal CB . The multiplex broadcast mode select key 402c generates a multiplex broadcast mode select signal MB. The tape mode select key 402d generates a tape mode select signal. The CD mode select key 402e generates a CD mode select signal. The mode select signals GR, CB, MB, TM, and CM generated by the mode select section 402 are fed to the controller 416. At least one tuner selects at least one broadcasting station according to the at least one mode selected by the mode select selection 402 and outputs one wave or more of the at least one broadcasting station selected. Here, there are two tuners, that is, first and second tuners 404 and 406 as shown. The first tuner 404 selects a first desired broadcasting station according to the general radio mode select signal GR generated by the general radio mode select key 402a of the mode select section 402, and converts a wave of the first selected broadcasting station into a first intermediate frequency signal IF1 having a first predetermined intermediate frequency. The second tuner 406 selects a second or third desired broadcasting station according to the additional broadcast mode select signal CB or the multiplex broadcast mode select signal MB generated by the additional broadcast mode select key 402b or the multiplex broadcast mode select key 402c of the mode select section 402, and converts a wave of the second or third selected broadcasting station into a second or third intermediate frequency signal IF2 or IF3 having a second or third predetermined intermediate frequency. The mode executing section 407 detects and processes at least one among the audio signal, the additional information signal, and the multiplex broadcast signal from the at least one broadcast station wave outputted from the first or second tuner 404 or " 406, according to the at least one mode selected by the mode select section 402. The mode executing section 407 includes an audio signal processor 408 and an additional information processor 410. The audio signal processor 408 detects and processes an audio signal from the first broadcast station wave from the first tuner 404 or the second broadcast station wave from the second tuner 406. The audio signal processor 408 includes a demodulator 408a and a stereo signal output circuit 408b. The demodulator 408a is connected to an output terminal of the first tuner 404 and FM demodulates the first intermediate frequency signal IF1 from the first tuner 404 to output a subcarrier signal SC and a baseband signal BB . The subcarrier signal SC and baseband signal BB from the demodulator 408a are fed to the stereo signal output circuit 408b. The stereo signal output circuit 408b is connected to an output terminal of the demodulator 408a and outputs a frequency modulation stereo signal divided into a right channel signal R and a left channel signal L from the baseband signal BB based on the subcarrier signal SC, from the demodulator 408a. The additional information processor 410 decodes and displays a first additional information signal from the first broadcasting station wave from the first tuner 404 and a second additional information signal from the second broadcasting station wave from the second tuner 406. The additional information processor 410 includes a band pass filter 410a, a decoder 410b, and a liquid crystal display device (LCD) 410c. The band pass filter 410a is connected to an output terminal of the second tuner 406 and bandpass-filters the second or third intermediate frequency signal IF2 or IF3 from the second tuner 406 to obtain a first or second additional information signal CD1 or CD2. For example, when the multiplex broadcast receiver according to the present invention is a radio data system (RDS) receiver, as shown in FIG. 3, an RDS data signal which is an example of the character data signal is carried on a 57 kHz subcarrier. The first or second additional information signal CD1 or CD2 obtained by the band pass filer 410a is applied to the decoder 410b. The decoder 410b is connected to an output terminal of the band pass filter 410a and decodes the first or second additional information signal CD1 or CD2 obtained by the band pass filter 412 into first or second prescribed readable data DCD1 or DCD2. The first or second additional information signal DCD1 or DCD2 decoded by the decoder 410b is applied to the controller 412. The LCD 410c displays the first or second additional information on the basis of the first or second additional information signal DCD1 or DCD2 decoded by the decoder 414 responsive to an operation control signal LC of the LCD 410c generated by the controller 412. The additional information processor 410 further includes a memory 410d for storing the first or second additional information signal DCD1 or DCD2 decoded by the decoder 414 responsive to an operation control signal MC of the memory 410d generated by the controller 412. The controller 412 is connected to an output terminal of the mode select section 402. The controller 412 generates operation control signals TCI, TC2 , DC, TC, and CC of the first tuner 404, a second tuner 406, the mode executing section 407, a tape deck 414, a CD player 416, responsive to mode select signals GR, CB, MB, TM, and CM generated by the mode select section 402, respectively. The controller 416 also generates generation control signals LC and MC for controlling the LCD 410c and memory 410d and applies them to the LCD 410c and memory 410d. Hereinafter, a multiplex broadcast receiving method according to an embodiment of the present invention with reference to FIGs . 4, 5A and 5B will be described. FIGs . 5A and 5B illustrate a multiplex broadcast receiving method according to an embodiment of the present invention. In step S501, when a power button 400 is repressed, the multiplex broadcast receiver 40 is initialized so that the first and second tuner 404 and 406 receive a radio signal of an initial broadcasting station through an antenna (not shown) . In step S502, the controller 416 discriminates whether or not a general radio mode is selected, that is, whether or not a general radio mode key 402a of the mode select section 402 is repressed. As a result of the discrimination in step S502, when the general radio mode is not selected, the controller 412 discriminates whether or not a multiplex broadcast mode is selected in step S503, that is whether or not a multiplex broadcast mode key 402b of the mode select section 402 is repressed. As a result of the discrimination in step S503, when it is discriminated that the multiplex broadcast mode is not selected, the controller 416 discriminates whether or not a tape mode is selected in step S504, that is, whether or not a tape mode key 402c of the mode select section 402 is repressed. As a result of the discrimination in step S504, when the tape mode is not selected, the controller 412 controls the CD player 416 to execute the compact disc mode in step S505. Alternatively, when it is discriminated that the tape mode is selected, the tape deck 414 executes the tape mode under the control of the controller 412 in step S506. On the other hand, as a result of the discrimination in step S502, when the general radio mode is selected, the controller 412 controls the first tuner 404 to select a first desired broadcasting station and to convert a wave of the first selected broadcasting station into a first intermediate signal IF1 including a first predetermined intermediate frequency in step S507. The first IF signal IF1 from the first tuner 404 is fed to a multiplex demodulator 408a of the audio signal processor 408 of the mode executing section 407. Accordingly, the multiplex demodulator 408 FM-demodulates the first IF signal IF1 from the first tuner 404 to output a subcarrier SC and a baseband signal BB in step S508. The subcarrier SC and baseband signal BB from the multiplex demodulator 408 are fed to a stereo signal output section 408b. Accordingly, the stereo signal output section 408b outputs an FM stereo signal divided into a right side signal R and a left side signal L from the baseband signal BB based on the subcarrier SC, from the multiplex demodulator 408 (step S509) . In step S510, the controller 412 judges whether or not an additional broadcast mode is selected while executing the general radio mode, that is, whether or not an additional broadcast mode select key 402b of the mode select section 402 is pressed. As a result of the judgement in step S510, when the additional broadcast mode is not selected, the routine is completed. Alternatively, when it is judged that the additional broadcast mode is selected, the controller 412 controls the second tuner 406 to select a second desired broadcasting station and to convert a wave of the second selected broadcasting station into a second intermediate frequency signal IF2(step S511) . The second intermediate frequency signal IF2 from the second tuner 406 is supplied to band pass filter 410a of the additional information processor 410. Accordingly, the band pass filter 410a band pass filters the second intermediate frequency signal IF2 from the second tuner 406 to obtain a first additional information signal CDl(step S512) . The first additional information data signal CD1 obtained by the band pass filter 410a is provided to a decoder 410b. Accordingly, the decoder 410b decodes the first additional information signal CD1 from the band pass filter 410a into first prescribed readable data DCDl(step S513) . The first additional information signal DCD1 decoded by the decoder 410b is applied to the controller 412. The controller 412 receives the first decoded additional information signal DCDl from the decoder 410b. And the controller 412 controls the memory 410d to store the first decoded additional information signal DCDl by generating an operation control signal MC of the memory 410d and providing it thereto (step S514) . Then the controller 412 controls the LCD 410c to display a first additional information based on the first additional information signal DCDl stored in the memory 410d, by generating an operation control signal LC of the LCD 410c and supplying it thereto (step S515) . On the other hand, as a result of the discrimination in step S503, when the multiplex broadcast mode is selected, the controller 412 controls the second tuner 406 to select a third desired broadcasting station and to convert a wave of the third selected broadcasting station into a third intermediate frequency signal IF3 (step S516) . The third intermediate frequency signal IF3 is fed to a multiplex demodulator 408a of the audio signal processor 408 and the band pass filter 410b of the additional information processor 410. Accordingly, the multiplex demodulator 408 FM-demodulates the third IF signal IF3 from the second tuner 406 to output a subcarrier SC and a baseband signal BB . The subcarrier SC and baseband signal BB from the multiplex demodulator 408 are fed to a stereo signal output section 408b. Accordingly, the stereo signal output section 408b outputs an FM stereo signal divided into a right side signal R and a left side signal L from the baseband signal BB based on the subcarrier SC from the multiplex demodulator 408. At the same time, band pass filter 410a band pass filters the third intermediate frequency signal IF3 from the second tuner 406 to obtain a second additional information signal CD2. The second additional information signal CD2 obtained by the band pass filter 410a is provided to a decoder 410b. Accordingly, the decoder 410b decodes the second additional information signal CD2 from the band pass filter 410a into second prescribed readable data DCD2. The second additional information signal DCD2 decoded by the decoder 410b is applied to the controller 412. The controller 412 receives the second decoded additional information signal DCD2 from the decoder 410b. And the controller 412 controls the memory 410d to store the second decoded additional information signal DCD2 by generating an operation control signal MC of the memory 410d and providing it thereto. Then the controller 412 controls the LCD 410c to display a second additional information based on the second additional information signal DCD2 stored in the memory 410d by generating an operation control signal LC of the LCD 410c and supplying it thereto so that the multiplex broadcast mode is completed (step S517) . As mentioned above, the present invention includes a first tuner for receiving a general radio broadcast and a second tuner for receiving an additional FM broadcast such as a character broadcast, and can display additional information in a form of a character, a graphic, or an image on a display device tuned by one tuner while listening to a general radio program tuned by the other tuner. While the invention has been described with reference to specific embodiments, the description is illustrated and is not to be constructed as limiting the scope of the invention. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims .

Claims: CLAIMS 1. A multiplex broadcast receiving method, said method comprising the steps of : a) selecting one among a general radio mode which outputs a first audio signal, an additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and additional information signals; b) selecting a broadcasting station according to the mode selected in step a) and outputting a wave of the selected broadcasting station; c) detecting and processing at least one among the first audio signal, the first additional information signal, and the multiplex broadcast signal from the broadcasting station wave outputted in step b) , according to the mode selected in step a) ; d) discriminating whether a different mode is selected among the modes; and e) controlling execution of the different mode according to a discrimination result of step d) . 2. The multiplex broadcast receiving method as defined in claim 1, contents according to the additional information signal include traffic, music, and weather. 3. The multiplex broadcast receiving method as defined in claim 1, wherein when the different mode is selected in step d) , simultaneously executing the mode selected in step a) and the different mode. 4. The multiplex broadcast receiving method as defined in claim 1, wherein when the general radio mode, the additional broadcast mode, and the multiplex broadcast mode are selected in step a) , step c) includes detecting and processing the first audio signal, the first additional information signal, and the multiplex broadcast signal from the broadcasting station " wave outputted in step b) , respectively. 5. The multiplex broadcast receiving method as defined in claim 4, wherein the step of detecting and processing the first audio signal includes demodulating the broadcasting station wave; and detecting the first audio signal from the demodulated broadcast wave. 6. The multiplex broadcast receiving method as defined in claim 4, wherein the step of detecting and processing the first additional information signal includes filtering the broadcasting station wave to obtain the first additional information signal; decoding the first additional information signal obtained; and displaying the first decoded additional information signal. 7. The multiplex broadcast receiving method as defined in claim 4, wherein the step of detecting and processing the multiplex broadcast signal includes detecting the second audio and additional information signals from the broadcast program wave. 8. The multiplex broadcast receiving method as defined in claim 7, wherein the step of detecting and processing the second audio signal includes demodulating the broadcasting station wave; and detecting the second audio signal from the demodulated broadcasting station wave . 9. The multiplex broadcast receiving method as defined in claim 7, wherein the step of detecting and processing the second additional information signal includes filtering the broadcasting station wave to obtain the second additional information signal; decoding the second obtained additional information signal; and displaying the second decoded additional information signal. 10. A multiplex broadcast receiving method, said method comprising the steps of : i) selecting one among a general radio mode which outputs a first audio signal, a first additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and additional information signals; ii) selecting a broadcasting station according to the mode selected in step i) and outputting a wave of the selected broadcasting station; iii) detecting and processing the first audio signal when the general radio mode is selected, detecting and processing the first additional information signal when the additional broadcast mode is selected, and detecting and processing the multiplex broadcast signal when the multiplex broadcast mode are selected, from the broadcasting station wave outputted in step ii) ; iv) discriminating whether a different mode is selected among the modes; and v) repeating steps ii) , iii) , and iv) when the different mode is selected. 11. The multiplex broadcast receiving method as defined in claim 10, wherein the step of detecting and processing the first additional information signal in step iii) includes filtering the broadcasting station wave to obtain the first additional information signal; decoding the first obtained additional information signal; and displaying the first decoded additional information signal. 12. The multiplex broadcast receiving method as defined in claim 10, wherein the step of detecting and processing the multiplex broadcast signal in step iii) includes detecting the second audio and additional information signals from the broadcasting station wave. 13. A multiplex broadcast receiver comprising: a mode select section for selecting at least one among a general radio mode which outputs a first audio signal, an additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and information signals; at least one tuner for selecting at least one broadcasting station according to the at least one mode selected by the mode select selection and outputting one wave or more of the at least one broadcasting station selected; a mode executing section for detecting and processing at least one among the first audio signal, the first additional information signal, and the multiplex broadcast signal from the one wave or more of the at least one broadcasting station outputted from the at least one tuner, according to the at least one mode selected by the mode select section; and a controller for sequentially discriminating whether the modes are selected and controlling operations of the at least one tuner and mode executing section according to a discrimination result. 14. The multiplex broadcast receiver as defined in claim 13, wherein the mode select section includes a general mode select key, an additional broadcast mode key, and a multiplex broadcast mode select key for generating a general mode select signal to select the general radio mode, for generating an additional broadcast mode select signal to select the additional broadcast mode, and for generating a multiplex broadcast mode select signal to select the multiplex broadcast mode, respectively. 15. The multiplex broadcast receiver as defined in claim 13, wherein the mode executing section includes an audio signal processor for detecting and processing the first audio signal and the second audio signal included in the multiplex broadcast signal from the one broadcasting station wave or more outputted from the at least one tuner; and an additional information processor for decoding and displaying the first additional information signal and the second additional information signal included in the multiplex broadcast signal from the one the one broadcasting station wave or more outputted from the at least one tuner. 16. The multiplex broadcast receiver as defined in claim 15, wherein the audio signal processor includes a multiplex demodulator for demodulating the one broadcast station wave or more outputted from the at least one tuner to output a subcarrier signal and a baseband signal; and a stereo signal output section for outputting the first or second audio signal each divided into right and left channel signals from the baseband signal based on the subcarrier signal, from the multiplex demodulator. 17. The multiplex broadcast receiver as defined in claim 15, wherein the additional information processor includes a filter for filtering the one broadcasting station wave or more outputted from the at least one tuner to obtain the first or second additional information signal; a decoder for decoding the first or second additional information signal from the filter " into prescribed readable data; and a display device for displaying the first or second additional information signal decoded by the decoder. 18. The multiplex broadcast receiver as defined in claim 17, wherein the additional information processor further includes a memory for storing the first or second additional information signal decoded by the decoder. 19. A multiplex broadcast receiver comprising: a mode select section for selecting at least one among a general radio mode which outputs a first audio signal, an additional broadcast mode which displays a first additional information signal, and a multiplex broadcast mode which outputs a multiplex broadcast signal having second audio and additional information signals; first and second tuners for selecting first and broadcast stations according to the at least one mode selected by the mode select section, and outputting waves of the first and second broadcasting stations selected, respectively; an audio signal processor for detecting and processing the first audio signal and the second audio signal included in the multiplex broadcast signal from the first and second broadcasting station waves outputted from the first and second tuners, respectively; an additional information processor for decoding and displaying the first additional information signal and the second additional information signal included in the multiplex broadcast signal from the first and second broadcasting station waves outputted from the first and second tuners, respectively; and a controller for sequentially discriminating whether the modes are selected and controlling operations of the first and tuner, the audio signal processor, and the additional information processor according to a discrimination result. 20. The multiplex broadcast receiver as defined in claim 19, wherein the additional information processor includes a filter for filtering the one broadcasting station wave or more outputted from the first and second tuners to obtain the first or second additional information signal; a decoder for decoding the first or second additional information signal from the filter into prescribed readable data; and a display device for displaying the first or second additional information signal decoded by the decoder.

Inventors: KANG SEOK-WON, KANG, SEOK-WON
Applicants: DAEWOO ELECTRONICS CO LTD, DAEWOO ELECTRONICS CO., LTD.
Application year: 1998
Main classification: H04B1
IPC codes: H04B1, H04H20, H04H40