Patent Publication Number: US-2007100484-A1

Title: Television system with saving function of output power

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority from Korean Patent Application No. 10-2005-0099205, filed on Oct. 20, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      Methods and apparatuses consistent with the present invention relate to a television system, more specifically, to a television system capable of controlling supply of output power for the television system according to a connection state of an output terminal.  
      2. Description of the Related Art  
      A digital television is an apparatus which receives audio and video signals (A/V signals) in the form of digital signals and outputs images and sounds. Generally, a digital television has an advantage that the properties of its reproduced images and sounds are excellent compared with related art signal processing apparatuses which output analog signals. Accordingly, recent broadcast signals are generated as digital signals as well as conventional analog signals.  
      Many currently manufactured digital televisions have an additional function of receiving analog signals in order to cope with analog broadcast signals in addition to digital broadcast signals. Additionally, the digital television comprises a digital audio output terminal for the output of digital audio signals in addition to a sound signal processor for the output of analog sounds.  
      Therefore, a user can hear sounds which are reproduced not only in an analog mode through the sound signal processor provided in the digital television, but also reproduced through an external device connected to the digital audio output terminal to receive a digital sound source.  
      However, according to the related art digital television, even in the case that the audio signals are output to the external device through the digital audio output terminal, the output power is still supplied to the sound signal processor, which leads to an unnecessary consumption of electric power.  
     SUMMARY OF THE INVENTION  
      Exemplary embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an exemplary embodiment of the present invention may not overcome any of the problems described above.  
      The present invention provides a television system capable of preventing the unnecessary consumption of electric power during the output of audio signals.  
      According to an aspect of the present invention, there is provided a digital television system comprising: a sound signal supply unit which processes digital signals received from an external source to generate digital audio signals; a sound signal processor which receives and converts the digital audio signals generated by the sound signal supply unit to analog audio signals and outputs the analog audio signals; a power supply unit which supplies electric power to the sound signal processor; a digital output terminal which outputs the digital audio signals from the sound signal supply unit; and a controller which controls the power supply unit to terminate a supply of electric power to the sound signal processor if the digital output terminal is connected to an external device.  
      According to an aspect of the present invention, the sound signal processor comprises a sound processor which receives and converts the digital audio signals to the analog audio signals, and an amplifying unit which amplifies the analog audio signals, and the controller controls the power supply unit to terminate the supply of electric power to at least one of the sound processor and the amplifying unit.  
      According to an aspect of the present invention, the amplifying unit comprises a signal processor which converts and optimizes the analog audio signals, and an amplifier which amplifies the optimized analog audio signals to have an appropriate strength for output, and the controller controls the power supply unit to terminate the supply of electric power to at least one of the sound processor, the signal processor, and the amplifier.  
      According to an aspect of the present invention, the sound processor further comprises an analog output terminal which outputs the analog audio signals, and the controller controls the power supply unit to terminate the supply of electric power to the amplifying unit if the analog output terminal is connected to an external device.  
      According to an aspect of the present invention, the amplifying unit comprises a signal processor which converts and optimizes the analog audio signals, and an amplifier which amplifies the optimized analog audio signals to have an appropriate strength for output, and the controller controls the power supply unit to terminate the supply of electric power to at least one of the signal processor and the amplifier.  
      According to another aspect of the present invention, there is provided a television system comprising: a sound processor which processes and outputs analog audio signals received from the outside; an amplifying unit which amplifies the processed analog audio signals; a power supply unit which supplies electric power to the sound processor and the amplifying unit; an analog output terminal connected to which outputs the analog audio signals processed by the sound processor; and a controller which controls the power supply unit to terminate a supply of electric power to the amplifying unit if the analog output terminal is connected to an external device.  
      According to an aspect of the present invention, the amplifying unit comprises a signal processor which converts and optimizes the analog audio signals, and an amplifier which amplifies the optimized analog audio signals to have an appropriate strength for output, and the controller controls the power supply unit to terminate the supply of electric power to at least one of the signal processor and the amplifier. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and/or other aspects of the prevent invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompany drawings, in which:  
       FIG. 1  is a block diagram partly showing a constitution of a digital television system according to an exemplary embodiment of the present invention; and  
       FIG. 2  is a block diagram showing in detail a portion of  FIG. 1 . 
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION  
      Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below so as to explain the present invention by referring to the figures.  
      A digital television system  100  according to an exemplary embodiment of the present invention, as shown in  FIG. 1 , comprises a demultiplexer  110 , an Moving Pictures Expert Group (MPEG) decoder  120 , a sound signal processor  130 , a speaker  140 , and a controller  150 . Also, the digital television system  100  further comprises a power supply unit  160  that provides electric power to the above elements. As described below, the controller  150  controls a supply of electric power of the power supply unit  160 .  
      The demultiplexer  110  separates audio and video (A/V) signals from digital signals which have been received through a tuner provided in the digital television system  100 . The A/V signals separated by the demultiplexer  110  are divided into digital audio signals and digital video signals by the MPEG decoder  120 . The digital video signals are transmitted to an image signal processor (not shown) to be processed, and finally are displayed through a display unit (not shown).  
      The digital audio signals obtained through the separation operation by the MPEG decoder  120  are processed through the sound signal processor  130 , and then converted to analog signals and amplified, to thereby be output through the speaker  140 .  
      As described above, it can be seen that, in view of audio signals, the MPEG decoder  120  functions as a sound signal supply unit which generates digital audio signals.  
      The controller  150  detects and controls the sound signal processor  130  and the MPEG decoder  120 , and controls the output power of the sound signal processor  130  as described below.  FIG. 2  is a block diagram partly showing in more detail the digital television system  100  of  FIG. 1 .  
      The MPEG decoder  120  receives the A/V signals and generates digital audio signals from the received A/V signals, and transmits the generated digital audio signals to a sound processor  131  that is an element of the sound signal processor  130 . Additionally, the MPEG decoder  120  further comprises a digital output terminal  121  through which the generated digital audio signals can be transmitted to an external device. Through the digital output terminal  121 , signals of Sony Phillips Digital Interface (SPDIF) mode may be output to maintain compatibility with the external device. The external device may be a digital audio, a digital TV, a computer, or the like.  
      The sound signal processor  130  comprises the sound processor  131  and an amplifying unit  133  which includes a signal processor  134  and an amplifier  135 , as shown in  FIG. 2 .  
      The sound processor  131  receives the digital audio signals from the MPEG decoder  120  and converts the digital audio signals into analog audio signals. Also, the sound signal processor  130  receives audio signals which are input as analog signals directly from an outside source, and performs a predetermined process. Therefore, it can be seen that the digital audio signals are processed by the sound processor  131  through the MPEG decoder  120 , and the analog audio signals are directly processed by the sound processor  131 .  
      The sound processor  131  comprises an analog output terminal  132  which may enable transmission of the analog audio signals directly to an external device. The analog output terminal  132  is connected to the external device, which is provided with an analog input terminal, such as an audio, a television, or the like.  
      The analog audio signals converted or processed by the sound processor  131  may be processed by the amplifying unit  133 . That is, the analog audio signals may be converted into optimized analog signals through Pulse Width Modulation (PWM) processing by the signal processor  134  of the amplifying unit  133 , and may be amplified to have an appropriate strength for output by the amplifier  135  and transmitted to the speaker  140 .  
      The controller  150  is electrically connected to the digital output terminal  121  of the MPEG decoder  120  and the analog output terminal  132  of the sound processor  131 . Through the connections, the controller  150  may determine whether external devices are connected to the terminals  121  and  132 .  
      Also, the controller  150  controls a supply of electric power by the power supply unit  160  to the sound processor  131  and the amplifying unit  133 .  
      That is, in the case that the digital output terminal  121  is connected to an external device and thus an audio output is accomplished through the external device, the controller  150  controls the power supply unit  160  to terminate a supply of power to the sound processor  131  and the amplifying unit  133 , that is, the signal processor  134  and the amplifier  135 . Therefore, unnecessary power consumption at the sound processor  131  and the amplifying unit  133  may be prevented.  
      Although the controller  150  may terminate all electric power supplied to the sound processor  131  and the amplifying unit  133 , a supply of electric power to at least one of the sound processor  131 , the signal processor  134  and the amplifier  135  may be terminated according to another exemplary embodiment of the present invention.  
      In the case that the analog output terminal  132  connected to the sound processor  131  is connected to an external device and thus an audio output is accomplished through the external device, the controller  150  controls the power supply unit  160  to terminate a supply of electric power to the amplifying unit  133 . In this case as well, as described above, although the controller  150  may terminate all electric power supplied to the signal processor  134  and the amplifier  135  which constitute the amplifying unit  133 , the supply of power to one of the signal processor  134  and the amplifier  135  may be terminated according to another exemplary embodiment of the present invention.  
      Although the control of the output power has been described only for the digital television system  100  in the foregoing exemplary embodiment of the present invention, the exemplary embodiments of the present invention are not limited to the digital television system but are also applicable to an analog television system.  
      That is, if digital elements, including the MPEG decoder  120 , are excluded from the digital television system  100  of  FIG. 2 , the television system of the analog mode including the sound processor  131  which receives the analog signals, and the amplifying unit  133  which amplifies analog audio signals processed by the sound processor  131  may be utilized.  
      With such a television system of analog mode, in the case that the analog output terminal  132  connected to the sound processor  131  is connected to an external device, the controller  150  may detect the connection of the external device and terminate a supply of electric power to the amplifying unit  133  to prevent unnecessary consumption of electric power.  
      As described above, according to the television system of the exemplary embodiments of the present invention, unnecessary consumption of electric power in the television system may be prevented by terminating the output power when an external device connected to the digital output terminal or the analog output terminal is detected.  
      Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.