Abstract:
A sound output device with an earphone mode and a speaker mode is provided. The sound output device changes a circuit resistance value of loudspeaker modules by adjusting a connecting state of the loudspeaker modules in the sound output device. Thus the sound output device is set to an output volume value of the earphone mode or of the speaker mode, so as to meet the requirements of the user, and to improve the convenience in use of the sound output device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a sound output device, and more particularly, to a sound output device with an earphone mode and a speaker mode. 
         [0003]    2. Related Art 
         [0004]    With the coming of the multimedia era, a user can enjoy the entertaining effect brought about by the multimedia anywhere and anytime. For example, the user can play and enjoy audio and video with an audio/video player device or the like, and the above described manners for enjoying the entertaining effect are achieved through a display, a speaker or an earphone according to the user&#39;s demands. In an environment that allows high volume, a user outputs a sound effect by connecting the speaker to a speaker output of the video player device, and controls the output volume with a volume adjusting knob on the speaker. While, in an environment that allows lower volume only or when the user intends to appreciate the music alone, the user needs to connect the earphone to an earphone jack of the video player device for outputting the sound effect. However, most of the earphones don&#39;t have volume adjusting knobs. Therefore, when the user wants to adjust the output volume of an earphone, a volume output value on the video player device must be set to adjust the volume output by the earphone, which is inconvenient in use. 
         [0005]    Furthermore, the speaker and the earphone are generally two independent products. That is to say, when the two products are needed, the user has to buy both them and connect/disconnect the speaker or the earphone to the video player device according to the requirement in use. Moreover, if the user forgets to carry the speaker or the earphone, the user can only appreciate the audio and video played by the video player device with one of speaker or the earphone only. Therefore, in addition to the inconvenience in use, the convenience in carrying is also to be improved. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the above described problems, the present invention is to provide a sound output device with an earphone mode and a speaker mode, which changes a circuit resistance value of loudspeaker modules by adjusting a connecting state of the loudspeaker modules in the sound output device. Thus, the sound output device is set to the earphone mode or the speaker mode, so as to meet the requirements in use. 
         [0007]    The sound output device with an earphone mode and a speaker mode according to the disclosure of the present invention includes a first loudspeaker module and a second loudspeaker module. The first loudspeaker module has a sound source signal input interface for receiving a sound source signal, and a first connecting point for adjusting an output volume value. The second loudspeaker module is electrically coupled to the sound source signal input interface and has a second connecting point for adjusting the output volume. 
         [0008]    When the first connecting point is not electrically coupled to the second connecting point, the circuit resistance values of the first loudspeaker module and the second loudspeaker module are invariable, and the first loudspeaker module and the second loudspeaker module output a first volume value respectively. Therefore, the sound output device is set to a speaker mode. While the first connecting point is electrically coupled to the second connecting point, the circuit resistance values of the first loudspeaker module and the second loudspeaker module reduce, and the first loudspeaker module and the second loudspeaker module output a second volume value which is lower than the first volume value respectively. Therefore, the sound output device is set to an earphone mode. 
         [0009]    The sound output device with an earphone mode and a speaker mode according to the disclosure of the present invention integrates the earphone and the speaker into a same sound output device. Therefore, the user will not have the trouble of forgetting to carry the speaker or the earphone, and it is more convenient in carrying than the prior art. 
         [0010]    In the sound output device with an earphone mode and a speaker mode according to the disclosure of the present invention, when the sound output device is set to the earphone mode, the user can still adjust the output volume value through a volume adjusting unit. 
         [0011]    By using the sound output device with an earphone mode and a speaker mode, in an environment that allows a high volume, the sound output device is set to the speaker mode through electrically coupling the volume adjusting connecting points of each of the loudspeaker modules to one another. While in an environment that allows a low volume or when the user intends to appreciate the music alone, the sound output device is set to the earphone mode through separating the electrically coupled volume adjusting connecting points of each of the loudspeaker modules. Therefore, the user achieves the objection of setting the output mode of the sound output device rapidly through a simple operating manner, and avoids the trouble of forgetting to carry the speaker or the earphone. Therefore, it is more convenient in carrying than the prior art. 
         [0012]    As for features and practices of the present invention, the preferred embodiments are illustrated below in detail with reference to the drawings. 
         [0013]    Further scope, of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus is not limitative of the present invention, and wherein: 
           [0015]      FIG. 1  is a schematic circuit diagram of a first embodiment of the present invention; 
           [0016]      FIG. 2  is a schematic circuit diagram of a second embodiment of the present invention; 
           [0017]      FIG. 3  is a schematic circuit diagram of a third embodiment of the present invention; and 
           [0018]      FIG. 4  is a schematic circuit diagram of a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]      FIG. 1  is a schematic circuit diagram of a first embodiment of the present invention. As shown in  FIG. 1 , a sound output device with an earphone mode and a speaker mode of the first embodiment of the present invention includes a first loudspeaker module  10  and a second loudspeaker module  20 . Each module will be illustrated below. 
         [0020]    The first loudspeaker module  10  includes a sound source signal input interface  11 , a first connecting point  12 , a first speaker  13 , a first resistor. R 1 , a second resistor R 2 , and a volume adjusting unit R 3 . Wherein, the sound source signal input interface  11  is electrically coupled to the volume adjusting unit R 3  for receiving a sound source signal from an external equipment (for example, a video player device), and the sound source signal input interface  11 , for example, can be an audio jack. The first connecting point  12  is electrically coupled to the first resistor R 1  and the second resistor R 2 , for adjusting an output volume value. The first speaker  13  is electrically coupled to the volume adjusting unit R 3 , for producing a sound effect corresponding to the sound source signal. The first resistor R 1  and the second resistor R 2  are electrically coupled to the volume adjusting unit R 3 , for changing the circuit resistance values of the first loudspeaker module  10  and the second loudspeaker module  20  when the first connecting point  12  is electrically coupled to a second connecting point  21 . The volume adjusting unit R 3  is electrically coupled with the sound source signal input interface  11 , the first resistor R 1 , the second resistor R 2 , the first speaker  13 , and a second speaker  22  respectively. Therefore, a user can adjust the circuit resistance values of the first loudspeaker module  10  and the second loudspeaker module  20 . Wherein, the volume adjusting unit R 3 , for example, can be a variable resistor component. 
         [0021]    The second loudspeaker module  20  has the second connecting point  21  and the second speaker  22 . The second loudspeaker module  20  is electrically coupled to the sound source signal input interface  11  through the volume adjusting unit R 3 . Wherein, the second connecting point  21  is electrically coupled to the second speaker  22  for adjusting the output volume value. The second speaker  22  is electrically coupled to the volume adjusting unit R 3  for producing the sound effect corresponding to the sound source signal. 
         [0022]    Hereafter, the operating principle of the circuit will be illustrated. 
         [0023]    Firstly, when the first connecting point  12  is not electrically coupled to the second connecting point  21 , the sound output device is set to the speaker mode, and the circuit resistance values of the first loudspeaker module  10  and the second loudspeaker module  20  are decided by the volume adjusting unit R 3 , the first resistor R 1 , and the second resistor R 2 . That is to say, when the first connecting point  12  is not electrically coupled to the second connecting point  21 , the volume adjusting unit R 3  is connected with the first resistor R 1  and the second resistor R 2  in series, so the circuit resistance value is higher. Therefore, the output power of the first loudspeaker module  10  and the second loudspeaker module  20  is higher, and relatively, the volume output value (i.e., the first volume value) of the first speaker  13  and the second speaker  22  is also higher. 
         [0024]    When the first connecting point  12  is electrically coupled to the second connecting point  21 , the sound output device is set to the earphone mode. The volume adjusting unit R 3  is in parallel connection with the first resistor R 1  and the second resistor R 2 , so the circuit resistance value is lower. Therefore, the output power of the first loudspeaker module  10  and the second loudspeaker module  20  is lower, and relatively, the volume output value (i.e., the second volume value) of the first speaker  13  and the second speaker  22  is also lower. Wherein, the electrically coupling between the first connecting point  12  and the second connecting point  21  can be realized, for example, through a metal wire or a fixing frame with metal wires buried in. While the fixing frame can be a slightly arc-shaped spatial structure for fixing the first loudspeaker module  10  and the second loudspeaker module  20  on two sides of the fixing frame respectively, such that the first loudspeaker module  10  and the second loudspeaker module  20  become a headphone (but not limited to the forms). 
         [0025]      FIG. 2  is a schematic circuit diagram of a second embodiment of the present invention. As shown in  FIG. 2 , the sound output device with an earphone mode and a speaker mode of the second embodiment of the present invention includes the sound source signal input interface  11 , the volume adjusting unit R 3 , a first signal amplifying unit  30 , a second signal amplifying unit  40 , the first connecting point  12 , the second connecting point  21 , the first speaker  13 , and the second speaker  22 . Each of the modules and units will be illustrated below. 
         [0026]    The sound source signal input interface  11  is electrically coupled to the volume adjusting unit R 3 , for receiving a sound source signal from an external equipment (for example, the video player device), and the sound source signal input interface  11  can be, for example, the audio jack. 
         [0027]    The volume adjusting unit R 3  is electrically coupled to the sound source signal input interface  11 , the first signal amplifying unit  30 , and the second signal amplifying unit  40 . Thus, the user can adjust the circuit resistance values of the first speaker  13  and the second speaker  22 . Wherein, the volume adjusting unit R 3  can be, for example, a variable resistor component. 
         [0028]    The first signal amplifying unit  30  is electrically coupled to the sound source adjusting unit R 3 , for amplifying the sound source signal, and outputting the amplified sound source signal to the first speaker  13 . Wherein, the first signal amplifying unit  30  includes a first operational amplifier OP 1 , a sixth resistor R 6 , and a seventh resistor R 7 . A first input terminal (i.e., a non-inverted input terminal) of the first operational amplifier OP 1  is electrically coupled to a first terminal of the volume adjusting unit R 3 . A second input terminal (i.e., an inverted input terminal) of the first operational amplifier OP 1  is electrically coupled to a second terminal of the sixth resistor R 6 , a first terminal of the seventh, resistor R 7 , and a first terminal of the eighth resistor R 8 . An output terminal of the operational amplifier OP 1  is electrically coupled to a first terminal of a second capacitor C 2  and a first terminal of the sixth resistor R 6 . A second terminal of the seventh resistor R 7  is electrically coupled to a ground terminal, and a second terminal of the eighth resistor R 8  is electrically coupled to a first terminal of the first connecting point  12 . 
         [0029]    The second signal amplifying unit  40  is electrically coupled to the sound source adjusting unit R 3  for amplifying the sound source signal, and outputting the amplified sound source signal to the second speaker  22 . Wherein, the second signal amplifying unit  40  includes a second operational amplifier OP 2 , a fourth resistor R 4  and a fifth resistor R 5 . A first input terminal (i.e., the non-inverted input terminal) of the second operational amplifier OP 2  is electrically coupled to a second terminal of the volume adjusting unit R 3 . A second input terminal (i.e., an inverted input terminal) of the second operational amplifier OP 2  is electrically coupled to a second terminal of the fourth resistor R 4 , a first terminal of the fifth resistor R 5 , and a first terminal of a ninth resistor R 9 . An output terminal of the operational amplifier OP 2  is electrically coupled to a first terminal of a first capacitor C 1  and a first terminal of the fourth resistor R 4 . A second terminal of the fifth resistor R 5  is electrically coupled to a ground terminal, and a second terminal of the ninth resistor R 9  is electrically coupled to a second terminal of the first connecting point  12 . 
         [0030]    The first speaker  13  is electrically coupled to the first signal amplifying unit  30  for producing the sound effect corresponding to the amplified sound source signal. A first input terminal of the first speaker  13  is electrically coupled to a second terminal of the second capacitor C 2 , and a second input terminal of the first speaker  13  is electrically coupled to the ground terminal. 
         [0031]    The second speaker  22  is electrically coupled to the second signal amplifying unit  40  for producing the sound effect corresponding to the amplified sound source signal. A first input terminal of the second speaker  22  is electrically coupled to a second terminal of the first capacitor C 1 , and the second input terminal of the first speaker  13  is electrically coupled to the ground terminal and the second connecting point  21 . 
         [0032]    Hereafter, the operating principle of the circuit will be illustrated. 
         [0033]    Firstly, when the first connecting point  12  is not electrically coupled to the second connecting point  21 , the sound output device is set to the speaker mode. The circuit resistance value of the first signal amplifying unit  30  is decided by connecting the sixth resistor R 6  and the seventh resistor R 7  in series, and the circuit resistance value of the second signal amplifying unit  40  is decided by connecting the fourth resistor R 4  and the fifth resistor R 5  in series, so the circuit resistance values are higher. Therefore, the output power of the first speaker  13  and the second speaker  22  is higher, and relatively, the volume output value (i.e., the first volume value) of the first speaker  13  and the second speaker  22  is also higher. 
         [0034]    When the first connecting point  12  is electrically coupled to the second connecting point  21 , the sound output device is set to the earphone mode. The circuit resistance value of the first signal amplifying unit  30  is decided by connecting the seventh resistor R 7  and the eighth resistor R 8  in parallel and then connecting them with the sixth resistor R 6  in series. While the circuit resistance value of the second signal amplifying unit  40  is decided by connecting the fourth resistor R 4  and the fifth resistor R 5  in parallel and then connecting them to the ninth resistor R 9  in series, so the circuit resistance values are lower. Therefore, the output power of the first speaker  13  and the second speaker  22  is lower, and relatively, the volume output value (i.e., the second volume value) of the first speaker  13  and the second speaker  22  is also lower. The first capacitor C 1  and the second capacitor C 2  are used to isolate a direct current (DC) bias, and to prevent the DC current from entering the first speaker  13  and the second speaker  22 . 
         [0035]      FIG. 3  is a schematic circuit diagram of a third embodiment of the present invention. As shown in  FIG. 3 , the sound output device with an earphone mode and a speaker mode of the third embodiment of the present invention includes a volume output control module having a universal serial bus (USB) transmission interface  15  and a USB coder/decoder  50 , the first connecting point  12 , the second connecting point  21 , the first speaker  13  and the second speaker  22 . Each of the modules will be illustrated below. 
         [0036]    The USB transmission interface  15  is electrically coupled to the USB coder/decoder  50  for receiving the sound source from an external equipment (for example, the video play equipment) and a power Vcc. 
         [0037]    The USB coder/decoder  50  is electrically coupled to the USB transmission interface  15  for amplifying the sound source signal and outputting it to the first speaker  13  and the second speaker  22 . 
         [0038]    The first connecting point  12  is electrically coupled to the USB coder/decoder  50 . Wherein, a first terminal of a tenth resistor R 10  is electrically coupled to the USB coder/decoder  50  and the first connecting point  12 , and the second connecting point  21  is electrically coupled to the second speaker  22 . 
         [0039]    The first terminal of the first speaker  13  is electrically coupled to the USB coder/decoder  50 . Wherein, a third capacitor C 3  is serially connected between the first speaker  13  and the USB coder/decoder  50 , and the second terminal of the first speaker  13  is electrically coupled to the ground terminal. 
         [0040]    The first terminal of the second speaker  22  is electrically coupled to the USB coder/decoder  50 . Wherein, a fourth capacitor C 4  is serially connected between the second speaker  22  and the USB coder/decoder  50 , and the second terminal of the first speaker  13  is electrically coupled to the ground terminal and the second connecting point  21 . 
         [0041]    Hereafter, the operating principle of the circuit will be illustrated. 
         [0042]    Firstly, when the first connecting point  12  is not electrically coupled to the second connecting point  21 , the sound output device is set to the speaker mode. The USB coder/decoder  50  decides an amplitude value for amplifying the sound source signal according to a divided voltage value of the tenth resistor R 10 . Therefore, according to the divided voltage value (for example, a high level voltage signal) of the tenth resistor RIO, the USB coder/decoder  50  outputs the sound source signal with a first amplitude value to the first speaker  13  and the second speaker  22 . Therefore, the first speaker  13  and the second speaker  22  output the first volume value. In each embodiment of the present invention, the first volume value is higher than the second volume value. 
         [0043]    When the first connecting point  12  is electrically coupled to the second connecting point  21 , the sound output device is set to the earphone mode. The USB coder/decoder  50  decides the amplitude value for amplifying the sound source signal according to a divided voltage value of the tenth resistor R 10 . Thus, according to the divided voltage value (for example, a low level voltage signal) of the tenth resistor R 10 , the USB coder/decoder  50  outputs the sound source signal with a second amplitude value to the first speaker  13  and the second speaker  22 . Therefore, the first speaker  13  and the second speaker  22  output the second volume value. In each embodiment of the present invention, the second volume value is lower than the first volume value. The third capacitor C 3  and the fourth capacitor C 4  are used to isolate the DC bias, and to prevent the direct current from entering the first speaker  13  and the second speaker  22 . 
         [0044]      FIG. 4  is a schematic circuit diagram of the fourth embodiment of the present invention. As shown in  FIG. 4 , the sound output device with an earphone mode and a speaker mode of a fourth embodiment of the present invention includes a volume output control module having the USB transmission interface  15 , the USB coder/decoder  50 , the first connecting point  12 , the second connecting point  21 , the first speaker  13 , the second speaker  22 , a third speaker  14 , and a fourth speaker  23 . Each of the modules will be illustrated below. 
         [0045]    The USB transmission interface  15  is electrically coupled to the USB coder/decoder  50  for receiving the sound source signal from the external equipment (for example, the video player device) and a power Vcc. 
         [0046]    The USB coder/decoder  50  is electrically coupled to the USB transmission interface  15  for amplifying the sound source signal and outputting it to the first speaker  13 , the second speaker  22 , the third speaker  14 , and the fourth speaker  23 . 
         [0047]    The first connecting point  12  is electrically coupled to an enable pin  51  of the USB coder/decoder  50 . While the second connecting point  21  is electrically coupled to the second speaker  22 . 
         [0048]    The first terminal of the first speaker  13  is electrically coupled to the USB coder/decoder  50 , and the second terminal of the first speaker  13  is electrically coupled to the ground terminal. 
         [0049]    The first terminal of the second speaker  22  is electrically coupled to the USB coder/decoder  50 , and the second terminal of the first speaker  13  is electrically coupled to the ground terminal and the second connecting point  21 . 
         [0050]    The first terminal of the third speaker  14  is electrically coupled to the USB coder/decoder  50 , while the second terminal of the third speaker  14  is electrically coupled to the ground terminal. 
         [0051]    The first terminal of the fourth speaker  23  is electrically coupled to the USB coder/decoder  50 , and the second terminal of the fourth speaker  23  is electrically coupled to the ground terminal. 
         [0052]    Hereafter, the operating principle of the circuit will be illustrated. 
         [0053]    Firstly, when the first connecting point  12  is not electrically coupled to the second connecting point  21 , the sound output device is set to the speaker mode, and the USB coder/decoder  50  decides whether to output the amplified sound source signal to the first speaker  13 , the second speaker  22 , the third speaker  14 , or the fourth speaker  23  according to a level signal of the speaker enable pin  51 . Thus, according to the relationship that the speaker enable pin  51  is electrically coupled to the ground terminal, the USB coder/decoder  50  enables to output the amplified sound source signal to the first speaker  13 , the second speaker  22 , the third speaker  14 , and the fourth speaker  23 . Therefore, the volume value output simultaneously by the four speakers is higher than the volume value output simultaneously by the two speakers. 
         [0054]    When the first connecting point  12  is electrically coupled to the second connecting point  21 , the sound output device is set to the earphone mode, and the USB coder/decoder  50  decides whether to output the amplified sound source signal to the first speaker  13 , the second speaker  22 , the third speaker  14  or the fourth speaker  23  according to the level signal of the speaker enable pin  51 . Thus, according to the relationship that the speaker enable pin  51  is not electrically coupled to the ground terminal, the USB coder/decoder  50  disables to not output the amplified sound source signal to the third speaker  14  and the fourth speaker  23 . Therefore, the volume value output simultaneously by the two speakers is lower than the volume value output simultaneously by the four speakers. 
         [0055]    To sum up, by using the sound output device with an earphone mode and a speaker mode of the present invention, in an environment that allows a high volume, the sound output device is set to the speaker mode by electrically coupling the volume adjusting connecting points in each loudspeaker module to one another; in the environment that allows a low volume or when the user intends to appreciate the music alone, the sound output device is set to the earphone mode through separating the electrically coupled volume adjusting connecting points in each loudspeaker module. Thus, the user can set the output mode of the sound output device rapidly through an easy operating manner, and avoids the trouble of forgetting to carry the speaker or the earphone. Therefore, the convenience in carrying is also better than the prior art. 
         [0056]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.