Abstract:
A multimedia television is provided. The multimedia television includes a video playback apparatus, an audio processing device, M front loudspeakers, a rear audio playback apparatus, and a mixing device. The video playback apparatus is used for displaying a video signal. The audio processing device processes an audio signal into a multi-channel audio signal consisting of M front sub-audio signals and N rear sub-audio signals. Each front loudspeaker plays back one corresponding front sub-audio signal. And, the mixing device mixes the N rear sub-audio signals into a mixed audio signal, which is then wirelessly transmitted to the rear audio playback apparatus. After the mixed audio signal is processed into N rear sub-audio signals, N rear loudspeakers in the rear audio playback apparatus playback the N rear sub-audio signals.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a multimedia system and, more particularly, to a multimedia television which can playback an audio/video signal. 
         [0003]    2. Description of the Prior Art 
         [0004]    In recent years, with the vigorous development of various electronic products, multimedia systems, such as a home theater, become more and more popular. In a multimedia system, except a monitor for displaying images, the most important hardware is a stereo. Taking a 5.1-channel stereo for example, it includes a left loudspeaker, a right loudspeaker, a middle loudspeaker, a left rear loudspeaker, a right rear loudspeaker, and a bass loudspeaker. The loudspeakers are located at appropriate locations and directions and allowed to playback different or the same audio signals. By doing so, a user can experience stereophonic sound effects. 
         [0005]    Although the stereo can provide sound effect better than that of a traditional 2-channel stereo, the complicated connecting lines between these loudspeakers always make users inconvenient. In addition, the connecting lines with considerable length are not pleasing to the eye. 
       SUMMARY OF THE INVENTION 
       [0006]    In order to solve the above problems, the invention provides a novel multimedia system. The multimedia system according to the invention transmits an audio signal in a wireless way between an audio processing/controlling device and parts of loudspeakers. Thus, the problems induced from using wires to connect the loudspeakers in the prior art can be prevented. 
         [0007]    According to the invention, a preferred embodiment is a multimedia television. The multimedia television includes a receiver, a video playback apparatus, an audio processing/controlling device, M front loudspeaker, a mixing device, a first antenna, a transmitting device, and a rear audio playback apparatus. 
         [0008]    The receiver is used to receive an audio/video signal; the audio/video signal includes an audio signal and a video signal. The receiver outputs the audio signal and the video signal respectively. The video playback apparatus is electrically connected to the receiver and is used to receive and display the video signal outputted by the receiver. The audio processing/controlling device is used to receive the audio signal outputted by the receiver and selectively process the audio signal into a multi-channel audio signal. The multi-channel audio signal includes M front sub-audio signals and N rear sub-audio signals, wherein M and N are positive integers. The audio processing/controlling device outputs the M front sub-audio signals and the N rear sub-audio signals respectively. 
         [0009]    Each of the front loudspeakers is corresponding to one of the M front sub-audio signals and is used to receive and playback the corresponding front sub-audio signal respectively. The mixing device is used to receive the N rear sub-audio signals and process the N rear sub-audio signals into at least one mixed audio signal. The transmitting device is electrically connected between the mixing device and the first antenna. The transmitting device receives the at least one mixed audio signal from the mixing device and transmits the at least one mixed audio signal via the first antenna. 
         [0010]    The rear audio playback apparatus includes a second antenna, a receiving device, an anti-mixing device, and N rear loudspeakers. The receiving device receives the at least one mixed audio signal via the second antenna. The anti-mixing device receives the at least one mixed audio signal from the receiving device, processes the at least one mixed audio signal into the N rear sub-audio signals, and outputs the N rear sub-audio signals respectively. Each of the rear loudspeakers is corresponding to one of the N rear sub-audio signals and is used to receive and playback the corresponding rear sub-audio signal respectively. 
         [0011]    The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. 
     
     
       BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
         [0012]      FIG. 1  is a functional block diagram of the multi-media television according to a preferred embodiment of the invention. 
           [0013]      FIG. 2  is a functional block diagram of the multi-media television including a three-channel amplifier. 
           [0014]      FIG. 3  is a functional block diagram of the multi-media television including a first mixer and a second mixer. 
           [0015]      FIG. 4  is a functional block diagram of the multi-media television including a first amplifier and at least one second amplifier. 
           [0016]      FIG. 5  is a functional block diagram of the multi-media television according to another preferred embodiment of the invention. 
           [0017]      FIG. 6  is a functional block diagram of the rear audio playback apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The invention provides a multi-media system. The multi-media system, based on the invention, transmits audio signals in a wireless way between an audio processing/controlling device and parts of loudspeakers. Thus, the problems induced from using wires to connect the loudspeakers in the prior art can be prevented. 
         [0019]    According to the invention, a preferred embodiment is a multimedia television. Referring to  FIG. 1 ,  FIG. 1  is a functional block diagram of the multi-media television. The multimedia television  10  includes a receiver  11 , a video playback apparatus  12 , an audio processing/controlling device  13 , M front loudspeaker  14 , a mixing device  15 , a transmitting device  16 , a first antenna  17 , and a rear audio playback apparatus  18 . 
         [0020]    The rear audio playback apparatus  18  includes a second antenna  18 A, a receiving device  18 B, an anti-mixing device  18 C, and N rear loudspeakers  18 D. 
         [0021]    The receiver  11  is used to receive an audio/video signal; the audio/video signal includes an audio signal and a video signal. And the receiver  11  outputs the audio signal and the video signal respectively. The video playback apparatus  12  is electrically connected to the receiver  11  and is used to receive and display the video signal outputted by the receiver  11 . The audio processing/controlling device  13  is used to receive the audio signal outputted by the receiver  11  and selectively process the audio signal into a multi-channel audio signal. The multi-channel audio signal includes M front sub-audio signals and N rear sub-audio signals, wherein M and N are positive integers. The audio processing/controlling device  13  outputs the M front sub-audio signals and the N rear sub-audio signals respectively. 
         [0022]    Each of the front loudspeakers  14  is corresponding to one of the M front sub-audio signals and is used to receive and playback the corresponding front sub-audio signal respectively. The mixing device  15  is used to receive the N rear sub-audio signals and process the N rear sub-audio signals into at least one mixed audio signal. The transmitting device  16  is electrically connected between the mixing device  15  and the first antenna  17 . The transmitting device  16  receives the at least one mixed audio signal from the mixing device  15  and transmits the at least one mixed audio signal via the first antenna  17 . 
         [0023]    The receiving device  18 B of the rear audio playback apparatus  18  receives the at least one mixed audio signal via the second antenna  18 A. Then, the anti-mixing device  18 C receives the at least one mixed audio signal from the receiving device  18 B, processes the at least one mixed audio signal into the N rear sub-audio signals, and outputs the N rear sub-audio signals respectively. Each of the rear loudspeakers  18 D is corresponding to one of the N rear sub-audio signals and is used to receive and playback the corresponding rear sub-audio signal respectively. 
         [0024]    If the stereo apparatus of the multi-media television  10  is a 5.1-channel stereo, both M and N will be equal to 3. The three front loudspeaker  14  are a left loudspeaker  14 A, a right loudspeaker  14 B, and a middle loudspeaker  14 C respectively; the three rear loudspeaker  18 D are a left rear loudspeaker  18 D 1 , a bass loudspeaker  18 D 2 , and a right rear loudspeaker  18 D 3  respectively. Besides, the three rear sub-audio signals can include a first rear sub-audio signal corresponding to the left rear loudspeaker  18 D 1 , a second rear sub-audio signal corresponding to the bass loudspeaker  18 D 2 , and a third rear sub-audio signal corresponding to the right rear loudspeaker  18 D 3 . 
         [0025]    As shown in  FIG. 2 , the multi-media television  10  can further include a three-channel amplifier  20  in practical applications. The three-channel amplifier  20  is electrically connected between the audio processing/controlling device  13  and the three front loudspeakers  14 , and it is used to amplify the three front sub-audio signals. 
         [0026]    As shown in  FIG. 3 , the mixing device  15  can include a first mixer  15 A and a second mixer  15 B in practical applications. The first mixer  15 A is used to receive the first rear sub-audio signal and the second rear sub-audio signal, and to mix the first rear sub-audio signal and the second rear sub-audio signal into a first mixed audio signal of the at least one mixed audio signal. The second mixer  15 B is used to receive the second rear sub-audio signal and the third rear sub-audio signal, and to mix the second rear sub-audio and the third rear sub-audio signal into a second mixed audio signal of the at least one mixed audio signal. 
         [0027]    As shown in  FIG. 3 , the anti-mixing device  18 C relatively includes a low-pass filter  18 C 1  and at least one high-pass filter  18 C 2 . The low-pass filter  18 C 1  is electrically connected between the receiving device  18 B and the bass loudspeaker  18 D 2 , and it is used to filter the first mixed audio signal and the second mixed audio signal to obtain the second rear sub-audio signal. Moreover, the high-pass filter  18 C 2  is electrically connected among the receiving device  18 B, the left rear loudspeaker  18 D 1  and the right rear loudspeaker  18 D 3 , and it is used to filter the first mixed audio signal and/or the second mixed audio signal to selectively obtain the first rear sub-audio signal and/or the third rear sub-audio signal. 
         [0028]    In addition, as shown in  FIG. 4 , the rear audio playback apparatus can further include a first amplifier  18 E and at least one second amplifier  18 F. The first amplifier  18 E is electrically connected between the low-pass filter  18 C 1  and the bass loudspeaker  18 D 2 , and it is used to amplify the second rear sub-audio signal. Moreover, the second amplifier is electrically connected among the high-pass filter  18 C 2 , the left rear loudspeaker  18 D 1 , and the right rear loudspeaker  18 D 3 , and it is used to amplify the first rear sub-audio signal and the third rear sub-audio signal. 
         [0029]    According to the invention, another preferred embodiment is also a multimedia television. Referring to  FIG. 5 ,  FIG. 5  is a functional block diagram of the multi-media television. The multimedia television  50  includes a receiver  51 , a video playback apparatus  52 , an audio processing/controlling device  53 , M front loudspeaker  54 , a mixing device  55 , a transmitting device  56 , a first antenna  57 , and N rear audio playback apparatus  58 . 
         [0030]    The receiver  51  is used to receive an audio/video signal; the audio/video signal includes an audio signal and a video signal. And, the receiver  51  outputs the audio signal and the video signal respectively. The video playback apparatus  52  is electrically connected to the receiver  51 , and it is used to receive and display the video signal outputted by the receiver  51 . The audio processing/controlling device  53  is used to receive the audio signal outputted by the receiver and selectively processes the audio signal into a multi-channel audio signal. The multi-channel audio signal includes M front sub-audio signals and N rear sub-audio signals, wherein M and N are positive integers. And, the audio processing/controlling device  53  outputs the M front sub-audio signals and the N rear sub-audio signals respectively. 
         [0031]    Each of the front loudspeakers  54  is corresponding to one of the M front sub-audio signals and is used to receive and playback the corresponding front sub-audio signal respectively. The mixing device  55  is used to receive the N rear sub-audio signals, and processes the N rear sub-audio signals into at least one mixed audio signal. The transmitting device  56  is electrically connected between the mixing device  55  and the first antenna  57 . The transmitting device  56  receives the at least one mixed audio signal from the mixing device  55  and transmits the at least one mixed audio signal via the first antenna  57 . 
         [0032]    As shown in  FIG. 6 , each of the rear audio playback apparatus  58  is corresponding to one of the N rear sub-audio signals respectively, and it includes a second antenna  58 A, a receiving device  58 B, an anti-mixing device  58 C, and a rear loudspeaker  58 D respectively. 
         [0033]    The receiving device  58 B of each rear audio playback apparatus  58  is used to receive the at least one mixed audio signal via the second antenna. Then, the anti-mixing device  58 C receives and filters the at least one mixed audio signal from the receiving device  58 B to obtain the corresponding rear sub-audio signals of the rear audio playback apparatus  58 . And, the rear loudspeaker  58 D is used to receive and playback the corresponding rear sub-audio signal from the anti-mixing device  58 C. 
         [0034]    According to the invention, the stereo apparatus in the multi-media television  10  and the multi-media television  50  can be a stereo having 4.1 channels, 5.1 channels, 7.1 channels, or even more channels. And, the only difference among them is the different values of M and N. As above mentioned, the audio signal is wirelessly transmitted between the rear audio playback apparatus and the audio processing/controlling device. Thus, the complex and inaesthetic connecting lines in the prior art can be prevented. 
         [0035]    With the above example and explanation, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.