Patent Publication Number: US-2006009984-A1

Title: Computer apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims the benefit of Korean Patent Application No. 2004-0048357, filed Jun. 25, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a computer apparatus and control method thereof, and more particularly, to a computer apparatus and control method thereof improving sound by maintaining output of a main speaker when an auxiliary speaker is connected thereto.  
      2. Description of Related Art  
      Generally, an audio system of a computer apparatus includes an audio compressor/decompressor (codec), an audio amplifier, and a main speaker. Also, a user may selectively connect a pair of headphones to a headphone jack and listen to an audio signal through the headphones.  
       FIG. 1  illustrates an audio amplifier and a peripheral circuit of a conventional computer apparatus.  
      As shown in  FIG. 1 , an audio amplifier  300  of a conventional computer apparatus includes a headphone connection detecting pin (hereinbelow, referring to “HP-IN pin”). When the HP-IN pin is in a low state, the audio amplifier  300  is operated in a speaker mode in which an audio signal is outputted through a main speaker. When the HP-IN pin is in a high state, the audio amplifier  300  is operated in a headphone mode in which output of the main speaker is cut off and the audio signal is outputted through a headphone.  
      When a headphone plug  318  (of the 3 band (2 ring) type having Audio R  318   b,  Audio L  318   a,  Ground  318   c  portions) is connected to a headphone jack  316  (of a 2 position type), a control pin  306  in the headphone jack  316  is opened, and the HP-IN pin will be in a pull-up state by a resistor R 1   302  and a resistor R 4   304 . When the headphone plug  318  is not connected to the headphone jack  316 , the control pin  306  in the headphone jack  316  is connected to an end of a resistor R 2   308 . Herein, the value of the resistor R 1   302  is larger than the value of the resistor R 2   308 , so that the HP-IN pin is in a low state. Accordingly, when the headphone is connected thereinto, a computer apparatus is operated in the headphone mode. Also, when the headphone is not connected thereto, the computer apparatus is operated in the speaker mode.  
      Meanwhile, an audio plug of an auxiliary speaker such as a subwoofer may be connected to the headphone jack  316  so as to improve the sound quality of the computer apparatus.  
      Because the audio plug of the auxiliary speaker includes a 3 band- (2 ring-) typed audio plug having the same type as the headphone plug  318 , the HP-IN pin of the audio amplifier  300  receives a high signal so that the audio amplifier  300  drives in the headphone mode and the main speaker is mute. Accordingly, there is a limit in improving the sound.  
     BRIEF SUMMARY  
      Accordingly, it is an aspect of the present invention to provide a computer apparatus and control method thereof improving sound by maintaining output of a main speaker when an auxiliary speaker is connected thereto.  
      According to an aspect of the present invention, there is provided a computer apparatus including: a computer main body including a main output device outputting an audio signal, a controller, and a connecting part; a first auxiliary output device to output an audio signal; and a second auxiliary output device to output the audio signal. The first auxiliary output device and the second auxiliary output device are selectively connectable to the connecting part. The connecting part detects whether either the first auxiliary output device or the second auxiliary output device is connected thereto. The controller controls the output of the audio signal so that the audio signal is concurrently output through the main output device and the first auxiliary device when the connecting part detects that the first auxiliary output device is connected to the connecting part.  
      The controller controls the output of the audio signal so that the audio signal is output only through the second auxiliary output device when the connecting part detects that the second auxiliary output device is connected to the connecting part.  
      The first auxiliary output device may include a 4 band- (3 ring-) typed connector connected to the connecting part.  
      The first output device may include a connection detecting signal generator outputting a connection detecting signal through the connector when the connector of the first auxiliary output device is connected to the connecting part.  
      The connection detecting signal generator may include a pull-down resistor outputting a pull-down signal through the connector when the connector of the first auxiliary output device is connected to the connecting part.  
      The connecting part may include a pull-up/pull-down circuit to output a pull-up signal or a pull-down signal when one of the auxiliary output devices is connected to the connecting part, and a connecting detector including a logic element performing a logic operation based on a combination of the pull-up signal and the pull-down signal which are outputted from the pull-up/pull-down circuit and outputting as result of the logic operation to the controller.  
      The pull-up/pull-down circuit may include a first output part outputting the pull-down signal when the first auxiliary output device is connected to the connecting part and outputting the pull-up signal when the first auxiliary output device is not connected thereto, and a second output part outputting the pull-up signal when the first auxiliary output device or the second auxiliary output device is connected to the connecting part.  
      The pull-up/pull-down circuit may output the pull-down signal from the pull-down resistor of the connection detecting signal generator to the first output part when the first auxiliary output device is connected to the connecting part.  
      The auxiliary output devices may include a power supply connector to receive power from the computer main body.  
      According to another aspect of the present invention, there is provided a control method of a computer apparatus including a computer main body, and a main output device in the computer main body outputting an audio signal, including: providing a connecting part to which a first auxiliary output device and a second auxiliary output device are selectively connectable; and detecting whether either the first auxiliary output device or the second auxiliary output device is connected to the connecting part. The detecting includes concurrently outputting the audio signal to the main output device and to the first auxiliary output device when the first auxiliary output device is detected to be connected.  
      The detecting may also include outputting the audio signal only to the second auxiliary output device when the second auxiliary output device is detected to be connected thereto.  
      According to another aspect of the present invention, there is provided a computer control method, including: determining whether a subwoofer is connected to a computer and outputting an audio signal to the subwoofer and a main speaker when a subwoofer is determined to be connected; and determining whether a pair of headphones is connected to the computer and outputting an audio signal only to the headphones when a pair of headphones is determined to be connected.  
      According to another aspect of the present invention, there is provided a computer including: an audio signal input part to receive an audio signal; an audio compressor/decompressor (codec) to process the input audio signal; an audio amplifier to amplify the processed input audio signal; a main speaker to output the processed audio signal; a connection part to which auxiliary output devices are connectable; a connecting detector to detect a type of auxiliary output device connected to the connection part; and a controller to control an output path of the output audio signal based on the detected type of connected auxiliary output device, the audio signal being outputted through the main speaker and a first auxiliary output device when the connecting part detects that the first auxiliary part is connected to the connecting part and being outputted only through a second auxiliary output device when the connecting part detects that the second auxiliary connection device is connected to the connecting part.  
      Additional and/or other aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is an audio amplifier and a peripheral circuit of a conventional computer apparatus;  
       FIG. 2  is a control block diagram of a computer apparatus according to an embodiment of the present invention;  
       FIG. 3  illustrates a subwoofer connectable to the computer apparatus of  FIG. 2 ;  
       FIG. 4  is a partially detailed circuit diagram of when the subwoofer of  FIG. 3  is connected to an audio jack of  FIG. 2 ; and  
       FIG. 5  is a flowchart of a control method of computer apparatus according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENT  
      Reference will now be made in detail to an embodiment of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiment is described below in order to explain the present invention by referring to the figures.  
      As shown in  FIG. 2 , a computer apparatus according to an embodiment of the present invention includes: an audio signal input part  10  to receive an audio signal; an audio codec  12  and an audio amplifier  14  to process the audio signal inputted through the audio signal input part  10 ; a main speaker section  16  to output the audio signal processed by the audio codec  12  and the audio amplifier  14 ; an audio jack  18  to which a pair of headphones  24  and a subwoofer  30  are selectively connectable; a connecting detector  20  to detect whether either the headphones  24  or the subwoofer  30  is connected to the audio jack  18 ; and a controller  22  to control an outputting direction of the audio signal based on a detecting result of the connecting detector  20 . Herein, the main speaker section  16  may be used as a main output device, and the headphone  24  and the subwoofer  30  may be used as auxiliary output devices. The audio jack  18  and the connecting detector  20  may be used as a connecting part to which the auxiliary output devices are selectively connected, and to detect connecting or disconnecting of the auxiliary output devices thereto.  
      The audio signal input part  10  may include a connecting terminal to which an external audio apparatus is connected, or an OS transmitting a digital audio data to the audio codec  12  through a driver.  
      The audio codec  12  receives the digital audio data from the audio signal input part  10 , decodes the digital audio data into an analog audio signal, and then transmits the analog audio signal to the audio amplifier  14 .  
      The audio amplifier  14  outputs the analog audio signal after amplifying the analog audio signal from the audio codec  12 , and includes an HP-IN pin. When a low signal is inputted to the HP-IN pin, the audio amplifier  14  is operated in a speaker mode. When a high signal is inputted to the HP-IN pin, the audio amplifier  14  is operated in a headphone mode.  
      As shown in  FIG. 3 , the subwoofer  30  includes a 4 band- (3 ring-) type plug  32  which is connectable to the audio jack  18 , and a USB connector  34  to supply power from a computer  50  (shown in  FIG. 4 ). The subwoofer  30  includes the 4 band- typed plug  32  so as to respectively receive right, left, and woofer audio signals from an Audio R signal portion  32   b,  an Audio L signal portion  32   a,  a woofer-in signal portion  32   c,  and a Ground signal portion  32   d.  While a USB connector is shown and described as supplying the power, it is to be understood that other types of connectors may be used. The subwoofer  30  uses the power of the computer  50  through the USB connector  34  so that the subwoofer  30  does not need a separate power adaptor.  
      Referring to  FIGS. 2 and 3 , controller  22  provided in the audio amplifier  14 , outputs the audio signal through the headphone  24  when the connecting detector  20  detects that the headphone  24  is connected to the audio jack  18  like a conventional controller. Then, the controller  22  cuts off output of the audio signal to the main speaker section  16  (a so-called headphone mode).  
      The controller  22  outputs the audio signal through the subwoofer  30  and the main speaker section  16  when the connecting detector  20  detects that the subwoofer  30  is connected to the audio jack  18  (a so-called speaker mode).  
      The audio jack  18 , the subwoofer  30 , and the connecting detector  20  will be described in detail by referring to  FIG. 4 .  
      As shown in  FIG. 4 , a plug  32  of the subwoofer  30  is connected to the audio jack  18 , and the USB connector  34  of the subwoofer  30  is connected to an USB port (not shown). The subwoofer  30  is supplied with the power from the computer  50  through the USB connector  34 , and outputs the audio signal inputted through the audio jack  18  after processing the audio signal.  
      The audio jack  18  to which the plug  32  of the subwoofer  30  is connected, is a 3 position-typed jack, and includes a control pin  52  to be opened/closed according to the condition of connecting of the plug  32 .  
      The subwoofer  30  includes a mono converter  42  converting a stereo audio signal into a mono audio signal; a Band Pass Filter (BPF)  40  modulating a frequency bandwidth of the audio signal inputted from the computer  50 ; an amplifier  38  amplifying the audio signal; and a limiter  36  to limit excessive increasing of a level of the audio signal with respect to frequency below predetermined band. A gain of the BPF  40  and cut-off frequency of the BPF  40  are modulated according to a crossover frequency/volume control  44  provided in the computer  50 .  
      The subwoofer  30  includes a pull-down resistor  46  to output a low signal when the subwoofer  30  is connected to the audio jack  18 . Specifically, the low signal is outputted from a grounded circuit including the pull-down resistor  46 . Accordingly, the pull-down resistor  46  outputs a connection detecting signal so that the connecting detector  20  may detect connection or disconnection of the subwoofer  30 .  
      The connecting detector  20  comprises an AND gate  68  connected to the HP-IN pin of the audio amplifier  14 , and a plurality of resistors  62 ,  64 , and  66  respectively connected to first and second input parts  70  and  72  of the AND gate  68  and constituting a pull-up/pull-down circuit.  
      When the 4 band- (3 ring-) typed plug  32  of the subwoofer  30  is connected to the audio jack  18 , the low signal is inputted to a first input part  70  of the AND gate  68  by the pull-down resistor  46  in the subwoofer  30 . The high signal is inputted to a second input part  72  of the AND gate  68 , because when the plug  32  of the subwoofer  30  is connected to the audio jack  18 , the control pin  52  of the audio jack  18  is opened and the second input part  72  of the AND gate  68  is in a pull-up state.  
      Accordingly, the high signal and the low signal inputted into the respective first and second input parts  70  and  72  of the AND gate  68  are calculated by logic AND, and the low signal is outputted into an output part of the AND gate  68  and the low signal which is an output of the AND gate  68 , is transmitted to the HP-IN pin. Accordingly, the HP-IN pin is in a low state, and the controller  22  performs the speaker mode so that the controller  22  maintains the output of the main speaker section  16  and at the same time outputs the audio signal to the subwoofer  30 . Herein, the audio signal of a mid- to high-frequency is outputted through the main speaker section  16  and the audio signal of a low- to mid-frequency is outputted through the subwoofer  30 .  
      When a 3 band- (2 ring-) typed plug (not shown) which is widely used in a headphone is connected to the audio jack  18 , the 3 band-typed plug is not connected to a part of the audio jack  18  to which the pull-down resistor  46  of the subwoofer  30  is connected, so that the first input part  70  of the AND gate  68  is always in the pull-up state.  
      When the 3 band formed plug is connected to the audio jack  18 , the control pin  52  in the audio jack  18  is opened. Accordingly, the second input part  72  of the AND gate  68  becomes in the pull-up state and the high signal is outputted to the output part of the AND gate  68 .  
      Accordingly, the high signal is inputted into the HP-IN pin of the audio amplifier  14 , and the controller  22  performs the headphone mode so that the controller  22  controls the audio signal outputted only to the headphone  24 .  
      Reference numerals  54  and  58  are capacitors, and reference numerals  56  and  60  are resistors. A circuit comprising the capacitors  54  and  58  and the resistors  56  and  60  is employed for a filter.  
      As described above, according to connecting or disconnecting of the subwoofer  30  and the headphone  24 , the first input part  70  of the AND gate  68  receives the pull-up signal or the pull-down signal outputted from a first output part of a pull-up/pull-down circuit. The second input part  72  receives the pull-up signal outputted from a second output part of the pull-up/pull-down circuit. However it is understood that other configurations can be possible.  
      A controlling flow of the computer apparatus according to an embodiment of the present invention will be described by referring to  FIG. 5  as follows.  
      When at the connecting detector  20  it is detected that the subwoofer  30  is connected thereto at operation  100 , the controller  22  controls the audio signal to be outputted through the subwoofer  30  and the main speaker section  16  at operation  102 . When the connecting detector  20  detects that headphones  24  are connected thereto at operation  104 , the controller  22  controls the audio signal to be outputted through the headphone  24  at operation  106 .  
      As describe above, the auxiliary speaker includes the subwoofer  30 . However, the auxiliary speaker may include an external speaker and it is to be understood that other mechanism can be used.  
      As described above, the connecting detector  20  includes the plurality of resistors  62 ,  64 , and  66  and the AND gate  68 . However, it is to be understood that other configurations can be used.  
      According to the above-described embodiment of the present invention, when the auxiliary speaker is connected to the audio jack to which the auxiliary speaker and the headphone are selectively connected, the audio signal is outputted through the auxiliary speaker and the main speaker. When the headphone is connected to the audio jack, the audio signal is outputted through the headphone. Accordingly, the above-described embodiment of the present invention improves sound of the low- to mid frequency by maintaining output of the main speaker when the auxiliary speaker is connected thereto.  
      Although an embodiment of the present invention have been shown and described, the present invention is not limited to the described embodiment. Instead, it would be appreciated by those skilled in the art that changes may be made to the embodiment without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.