Abstract:
A multiple channel earphone is provided with an external tube disposed on the earphone main body. The earphone includes a case, a case extension unit, and a cover. A main sound field is formed in an interior chamber enclosed by the case, the case extension unit and the cover. By adjusting the space in the external tube, the spatial effect of the sound field is significantly increased. The proposed multiple channel earphone selectively has a mechanism for sound field balancing by the sounds generated from these two sub-speakers spaced apart from each other for better sound quality. The sound field of the proposed multiple channel earphone can also be spaced apart into two physically separated sound fields by disposing an external chamber on the earphone main body.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the priority benefit of Taiwan applications serial no. 93107621, filed on Mar. 22, 2004, serial no. 93111985, filed on Apr. 29, 2004, and serial no. 94103553, filed on Feb. 4, 2005. This application is a continuation-in-part of a prior application Ser. No. 10/709,956, filed Jun. 9, 2004. All disclosures are incorporated herewith.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a multiple channel earphone, and more particularly, to a multiple channel earphone having an extended sound field.  
         [0004]     2. Description of the Related Art  
         [0005]     Along with continuous progress of digital technology, the entertainment of the ordinary people had been gradually digitalized. For example, the DVD (Digital Video Disc, also known as Digital Versatile Disc) player is very popular in many households nowadays. Since DVD player has basically provided decoding functions such as Dolby Digital or Digital Theater System (DTS), it is capable of decoding digital signals and outputting analog signals to the speakers.  
         [0006]     The multiple channel speaker is an inevitable device for enjoying the high quality digital AV entertainment program, and the 5.1 channel speaker is a fundamental component of the multiple channel speaker.  
         [0007]      FIG. 1  schematically shows a diagram of a home theater with a 5.1 channel speaker. Referring to  FIG. 1 , when the DVD player  100  is playing an AV program, the DVD player  100  provides different audio signals to a front left speaker  102   a  and a front right speaker  102   b , a center speaker  104 , a left surround speaker  106   a  and a right surround speaker  106   b , and a subwoofer  108 , so as to create a  3 D spatial sound effect for providing a realistic setting for the listener.  
         [0008]     However, it is required to use an earphone to listen music under the circumstance of not suitable for using the speaker (for example, using speaker may disturb others). Referring to  FIG. 2A , since a typical earphone  200   a  only has one speaker  210  in its both sides, respectively, it is not possible for the listener to enjoy the multiple channel sound effect provided by the DVD player.  
         [0009]     Therefore, an earphone having a plurality of speakers in its main body had been proposed in the prior art. The conventional earphone  200   b  has a main channel speaker  202 , a center speaker  204 , and a surround speaker  206  in its both sides, respectively. By cooperated with a special design plug  208 , the DVD player provides different channel&#39;s audio signal to different speaker through the plug  208 , so as to further create the spatial sound effect of the 5.1 channel speaker in home theater environment. Since the delaying output of the audio signal is controlled in a digital way (e.g. with a circuit design) in the conventional earphone  200   b , the spatial sound effect provided by it is not so good. It is far behind when compared with the spatial sound effect provided by the 5.1 channel speaker in home theater environment as shown in  FIG. 1 , and it cannot present the quality and function of the multiple channel surrounding sound effect.  
       SUMMARY OF THE INVENTION  
       [0010]     Therefore, it is an object of the present invention to provide a multiple channel earphone. The multiple channel earphone improves the quality of the sound effect, and provides a saturated sound filed as well as a multiple channel surrounding sound effect.  
         [0011]     The multiple channel earphone provided by the present invention comprises an external chamber tube or an external tube disposed on the earphone main body. The case and the cover of the earphone togetherly form an interior chamber, and the spatial sound effect is improved by adjusting the space in the external tube.  
         [0012]     Besides the earphone having an external chamber tube or an external tube mentioned above, an earphone having an effect of balance sound field is further provided. The earphone with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, and these two speakers, one is disposed on a speaker holder in the interior chamber and the other one is disposed in the external tube. In other words, at least one speaker is disposed inside the case of the earphone, and one or more than one speaker is disposed on the external tube coupled to the main body. With such arrangement, a sound field is formed by these two or more than two speakers, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These two or more than two speakers may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0013]     Besides the earphone having an external chamber tube mentioned above, an earphone having a function of dividing the sound field is further provided. In this earphone, a tube is externally coupled to the earphone main body, and an interior chamber is formed on the outermost edge of the external tube. In addition, any one of the signal entities provided by the 5.1 channel sound sources from the DVD player is disposed in any direction or angle with respect to the case of the interior chamber, such that a resonance is formed inside the interior chamber.  
         [0014]     In another embodiment of the present invention, a tube is further coupled on the case of the interior chamber, such that the resonance is not directly created in the interior chamber. Accordingly, the sound source on the case of the interior chamber provided by the 5.1 channel of the DVD player is pulled away from the main sound field formed by the 5.1 channel. In other words, in the earphone of the present embodiment, a resonant chamber is formed by the case of the main body, and the sound wave inside the resonant chamber is transmitted to the main sound field inside the case with air media through the external tube.  
         [0015]     In order to achieve the objects mentioned above, an earphone is provided by the present invention. The earphone comprises an earphone main body, a main speaker, a plurality of sub-speakers, and a first external tube. Wherein, the earphone main body comprises a case, a cover, and a case extension unit, which togetherly form a main chamber. The main speaker and some sub-speakers are disposed inside the case. The first external tube is disposed on the earphone main body, and the effect of the sound field formed in the earphone is adjusted by adjusting the space in the first external tube. The first external tube may be disposed on the case extension unit or on the case of the earphone main body.  
         [0016]     In the earphone mentioned above, one of the sub-speakers may be optionally disposed on the first external tube.  
         [0017]     In the earphone mentioned above, the space in the first external tube is adjusted by making good use of the adjustable length and foldable characteristics of the first external tube.  
         [0018]     In the earphone mentioned above, a second external tube may be further comprised and disposed on the earphone main body, so as to further adjust the characteristic of the sound field formed in the earphone. The space in the second external tube is adjusted by making good use of the adjustable length and foldable characteristics of the second external tube.  
         [0019]     In the earphone mentioned above, wherein two or more than two sub-speakers are coupled to a same sound source, and they can be selectively disposed in the earphone main body or disposed on the first external tube externally coupled to the earphone main body. The sub-speakers are either serially or parallelly coupled to a same sound source.  
         [0020]     In the earphone mentioned above, a tube and an interior chamber are further comprised. Wherein, the tube is coupled to the earphone main body. The interior chamber is disposed on the outermost edge of the tube for forming a resonant chamber inside the interior chamber, and the sound wave inside the resonant chamber is transmitted to the sound field inside the case with air media through the tube.  
         [0021]     In the earphone mentioned above, a curve tube is further comprised. The curve tube is coupled on the case of the interior chamber for adjusting the resonant chamber, and the angle of the curve tube is 10˜180 degrees. In an embodiment of the present invention, a sub-speaker may be disposed on the outer edge of the curve tube.  
         [0022]     In order to achieve the objects mentioned above, an earphone is provided by the present invention. The earphone comprises an earphone main body, a main speaker, and a plurality of sub-speakers. Wherein, the earphone main body comprises a case, a cover, and a case extension unit, which togetherly form a main chamber. The main speaker and the sub-speakers are disposed inside the case, and two of the sub-speakers are coupled to a same sound source, such that the earphone can provide balance sound field.  
         [0023]     In order to achieve the objects mentioned above, an earphone is provided by the present invention. The earphone comprises an earphone main body, a main speaker, a plurality of sub-speakers, a tube, and an interior chamber. Wherein, the earphone main body comprises a case, a cover, and a case extension unit, which togetherly form a main chamber. The main speaker and some sub-speakers are disposed inside the case. The tube is coupled on the earphone main body, and an interior chamber is on the outermost edge of the tube. A resonant chamber is formed inside the interior chamber, and the sound wave inside the resonant chamber is transmitted to the sound field inside the earphone main body with air media through the tube. Accordingly, the earphone can provide a function of dividing the sound field.  
         [0024]     The earphone mentioned above further comprises a curve tube. The curve tube is coupled on the case of the interior chamber for adjusting the resonant chamber, and the angle of the curve tube is  10 ˜ 180  degrees. In addition, one of the sub-speakers may be disposed on the outer edge of the curve tube. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention, and together with the description, serve to explain the principles of the invention.  
         [0026]      FIG. 1  schematically shows a diagram of a home theater with a 5.1 channel speaker.  
         [0027]      FIG. 2A  schematically shows a side view sectional diagram of a conventional earphone.  
         [0028]      FIG. 2B  schematically shows a side view sectional diagram of another conventional earphone.  
         [0029]      FIG. 3A  schematically shows a partial sectional decomposition diagram of an earphone  300 A in side view according to an embodiment of the present invention.  
         [0030]      FIG. 3B  schematically shows a partial sectional decomposition diagram of an earphone  300 B in side view according to another embodiment of the present invention.  
         [0031]      FIG. 3C  schematically shows a partial sectional decomposition diagram of an earphone  300 C in side view according to yet another embodiment of the present invention.  
         [0032]      FIG. 4A  schematically shows a partial sectional decomposition diagram of an earphone  400 A in side view according to yet another embodiment of the present invention.  
         [0033]      FIG. 4B  schematically shows a partial sectional decomposition diagram of an earphone  400 B in side view according to yet another embodiment of the present invention.  
         [0034]      FIG. 5A  schematically shows a partial sectional decomposition diagram of an earphone  500 A in side view according to yet another embodiment of the present invention.  
         [0035]      FIG. 5B  schematically shows a partial sectional decomposition diagram of an earphone  500 B in side view according to yet another embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]     The present invention provides an earphone having an external tube disposed on the earphone main body. The earphone main body comprises a case and a cover of the earphone. Wherein, the case and the cover of the earphone togetherly form an interior chamber, and the spatial sound effect is improved by adjusting the space in the external tube. The space in the external tube is adjusted either by changing the length of the external tube or folding the external tube. In an embodiment of the present invention, any one of signal entities of the 5.1 channel sound source provided by the DVD player can be independently pulled out from the interior chamber of the earphone main body, and the space in the interior chamber is adjusted by changing the length of the interior chamber formed by the length-length-adjustable external tube. The shorter the external tube, the less space it occupies in the whole earphone. The longer the external tube, the more space the sound field provided by the whole system. In addition, when the length of the external tube is extended, one of the signal entities may be independently pulled out and disposed on the interior chamber, such that the spatial sound effect is improved.  
         [0037]     Besides the earphone having an external chamber tube mentioned above, an earphone having an effect of balance sound field is further provided by the present invention. The earphone with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, and these two speakers, one is disposed on a speaker holder in the interior chamber and the other one is disposed in the external tube. In other words, at least one speaker is disposed inside the case of the earphone, and one speaker is disposed on the external tube coupled to the earphone main body. With such arrangement, a sound field is formed by these two or more than two speakers, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These two or more than two speakers may be coupled to the sound signal either in parallel or in serial. By arranging two or more than two speakers on different location or with different angle, the physical sound field is enlarged and the sound is more saturated.  
         [0038]     Besides the earphone having an external chamber tube mentioned above, an earphone having a function of dividing the sound field is further provided by the present invention. In this earphone, a tube is externally coupled to the earphone main body, and an interior chamber is formed on the outermost edge of the external tube. In addition, any one of the signal entities provided by the 5.1 channel sound sources from the DVD player is disposed in any direction or angle with respect to the case of the interior chamber, such that a resonance is formed inside the interior chamber. In another embodiment of the present invention, a curve tube is further coupled on the case of the interior chamber, such that the resonance is not directly created in the interior chamber. Accordingly, the sound source on the case of the interior chamber provided by the 5.1 channel of the DVD player is pulled away from the main sound field formed by the 5.1 channel. In other words, in the earphone of the present embodiment, a resonant chamber is formed by the case of the main body, thus the sound field is divided by changing the phase and frequency of the sound wave, and the sound wave inside the resonant chamber is transmitted to the main sound field inside the earphone main body with air media through the external tube.  
         [0039]     A plurality of preferred embodiments are exemplified hereinafter for explaining principles of the present invention. To be noted that these embodiments are used for describing the present invention, and should not be used to limit the scope of the present invention.  
         [0040]      FIG. 3A  schematically shows a partial sectional decomposition diagram of an earphone  300 A in side view according to a preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 3A , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 3A , thus its detail is omitted here.  
         [0041]     Referring to  FIG. 3A , the earphone  300 A comprises an earphone main body  310  and a connector  320 . Wherein, the connector  320  is used to connect the earphone main body  310  in its both sides (only one side is shown in the diagram). The earphone main body  310  mainly comprises a case  311 , a cover  313 , and a case extension unit  315 . The case extension unit  315  is actually an extension unit of the case  311 , and is coupled to the cover  313 . The earphone main body  310  further comprises a main speaker  330  and a plurality of sub-speakers  340 ,  350 ,  360 A, and  360 B, which are disposed inside the earphone main body  310 . In addition, the earphone main body further comprises the external tubes  375  and  385  where the sub-speakers  350  and  360 B are disposed on.  
         [0042]     Inside the earphone  300 A, as described above, it may only has one external tube  375  disposed on the case extension unit  315  of the earphone main body  310 . The case  311 , the cover  313 , and the case extension unit  315  of the earphone  300 A togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  375 . In addition, the space in the external tube in the present embodiment is adjusted by changing the length of the external tube.  
         [0043]     Inside the earphone  300 A of the present embodiment, as described above, it may be further comprised another external tube  385  disposed on the case extension unit  315  of the earphone main body  310 . The case  311 , the cover  313 , and the case extension unit  315  of the earphone  300 A togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  385 . In the present embodiment, the length of this additional added external tube  385  may be fixed, or may be adjustable or foldable based on the physical design requirement.  
         [0044]     In the earphone  300 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  350  of  FIG. 3A , may be independently pulled out and disposed on the external tube  375 , and the space in the interior chamber formed by the length-adjustable external tube is adjusted by changing the length of the external tube. The shorter the external tube, the less space it occupies in the earphone  300 A. The longer the external tube, the more space the sound field provided by the whole earphone  300 A. In addition, when the length of the external tube is extended, one of the signal entities may be independently pulled out and disposed on the interior chamber, such that the spatial sound effect is improved. On the additionally added external tube  385  in the earphone  300 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  360 B of  FIG. 3A , may be independently pulled out and disposed on the external tube  385 .  
         [0045]     Besides the earphone  300 A having an external tube mentioned above, an earphone  300 A having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone  300 A with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  360 A is disposed inside the case  311  of the earphone  300 A, and the other sub-speaker  360 B is disposed on the external tube  385  coupled to the earphone main body  310 .  
         [0046]     With such arrangement, a sound field is formed by these two or more than two sub-speakers  360 A and  360 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  360 A and  360 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0047]      FIG. 3B  schematically shows a partial sectional decomposition diagram of an earphone  300 B in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 3B , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 3B , thus its detail is omitted here.  
         [0048]     Referring to  FIG. 3B , the earphone  300 B comprises an earphone main body  310  and a connector  320 . Wherein, the connector  320  is used to connect the earphone main body  310  in its both sides (only one side is shown in the diagram). The earphone main body  310  mainly comprises a case  311 , a cover  313 , and a case extension unit  315 . The case extension unit  315  is actually an extension unit of the case  311 , and is coupled to the cover  313 . The earphone main body  310  further comprises a main speaker  330  and a plurality of sub-speakers  340 A,  340 B,  350 , and  360 , which are disposed inside the earphone main body  310 . The sub-speakers  340 B and  350  are disposed on the external tubes  335  and  337  on both side walls of a composite chamber  333 , respectively. Alternatively, the sub-speakers  340 B and  350  may be directly disposed on both side walls of a composite chamber  333 , respectively. In addition, an external tube  375  where the sub-speaker  360  is disposed on is further comprised in the present embodiment. The earphone structure with a composite sound field had been disclosed in contents of the ROC patent number 93107621 titled as “EARPHONE STRUCTURE WITH A COMPOSITE SOUND FIELD” by the same applicant on Mar. 22, 2004, the ROC patent number 93111985 as an extended application titled as “EARPHONE STRUCTURE WITH A COMPOSITE SOUND FIELD” by the same applicant on Apr. 29, 2004, and the U.S. Pat. Ser. No. 10/709,956 titled as “EARPHONE STRUCTURE WITH A COMPOSITE SOUND FIELD” by the same applicant on Jun. 9, 2004, which all disclosures are incorporated herewith. The applicant claims herein that the composite sound field disclosed in the applications mentioned above and the composite sound effect described in the present embodiments are all suitable for the earphone of the present invention.  
         [0049]     The difference between the earphone  300 B and the one shown in  FIG. 3A  is the external tube  375  of  FIG. 3A  is disposed on the case extension unit  315  of the earphone main body  310 . While in the present embodiment, the external tube  375  is disposed on the case  311  of the earphone main body  310  and directly extended from the composite chamber  333 . The case  311 , the cover  313 , and the case extension unit  315  of the earphone  300 B togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the composite chamber  333  and the external tube  375 . In addition, the space in the external tube in the present embodiment is adjusted by changing the length of the external tube.  
         [0050]     Inside the earphone  300 B of the present embodiment, the sub-speakers  340 B and  350  are disposed on the external tubes  335  and  337  on both side walls of the composite chamber  333 , respectively. The spatial sound effect is improved by adjusting the space in the external tubes  335  and  337 . In the present embodiment, the length of these additional added external tubes  335  and  337  may be fixed, or may be adjustable or foldable based on the physical design requirement.  
         [0051]     Besides the earphone  300 B having an external tube mentioned above, in another embodiment of the present invention, the earphone  300 B also provides an effect of balance sound field. The earphone  300 B with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  340 A is disposed inside the case  311  of the earphone  300 B, and the other sub-speaker  340 B is disposed on the external tube  335  on the composite chamber  333 . The sub-speakers  340 A and  340 B are coupled to the surrounding sound source of the 5.1 channel, the sub-speaker  350  is coupled to the center sound source of the 5.1 channel, and the sub-speaker  360  is coupled to the subwoofer of the 5.1 channel. With such arrangement, a sound field is formed by these two or more than two sub-speakers  340 A and  340 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  340 A and  340 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0052]      FIG. 3C  schematically shows a partial sectional decomposition diagram of an earphone  300 C in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 3C , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 3C , thus its detail is omitted here.  
         [0053]     Referring to  FIG. 3C , the earphone  300 C comprises an earphone main body  310  and a connector  320 . Wherein, the connector  320  is used to connect the earphone main body  310  in its both sides (only one side is shown in the diagram). The earphone main body  310  mainly comprises a case  311 , a cover  313 , and a case extension unit  315 . The case extension unit  315  is actually an extension unit of the case  311 , and is coupled to the cover  313 . The earphone main body  310  further comprises a main speaker  330  and a plurality of sub-speakers  340 A,  340 B,  350 , and  360 , which are disposed inside the earphone main body  310 . The sub-speakers  340 B and  350  are disposed on the external tubes  335  and  337  on both side walls of a composite chamber  333 , respectively. Alternatively, the sub-speakers  340 B and  350  may be directly disposed on both side walls of a composite chamber  333 , respectively. In addition, an external tube  339  where the sub-speaker  360  is disposed on is further comprised in the present embodiment.  
         [0054]     The difference between the earphone  300 C and the one shown in  FIG. 3B  is the external tube  339  is directly extended from the composite chamber  333 , such that the sub-speaker  360  is disposed on the case  311 . The case  311 , the cover  313 , and the case extension unit  315  of the earphone  300 C togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the composite chamber  333  and the external tubes  335 ,  337 , and  339 . In addition, the length of these additional added external tubes  335 ,  337 , and  339  may be fixed, or may be adjustable or foldable based on the physical design requirement.  
         [0055]      FIG. 4A  schematically shows a partial sectional decomposition diagram of an earphone  400 A in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 4A , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 4A , thus its detail is omitted here.  
         [0056]     Referring to  FIG. 4A , the earphone  400 A comprises an earphone main body  410  and a connector  420 . Wherein, the connector  420  is used to connect the earphone main body  410  in its both sides (only one side is shown in the diagram). The earphone main body  410  mainly comprises a case  411 , a cover  413 , and a case extension unit  415 . The earphone main body  410  further comprises a main speaker  430  and a plurality of sub-speakers  440 ,  450 A,  450 B, and  460 , which are disposed inside the earphone main body  410 . In addition, the external tubes  475  and  485  where the sub-speakers  460  and  450 B are disposed on are further comprised in the present embodiment.  
         [0057]     Inside the earphone  400 A, as described above, it may only has one external tube  475  disposed on the case extension unit  415  of the earphone main body  410 . The case  411 , the cover  413 , and the case extension unit  415  of the earphone  400 A togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  475 . The difference between the embodiments of  FIG. 4A  and  FIG. 3A  is the space in the external tube  475  in the present embodiment is adjusted by folding the external tube  475 . As described above, inside the earphone  400 A of the present embodiment, it may be further comprised another external tube  485  disposed on the case extension unit  415  of the earphone main body  410 . The case  411 , the cover  413 , and the case extension unit  415  of the earphone  400 A togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  485 . In the present embodiment, the length of this additional added external tube  485  may be fixed, or may be adjustable or foldable based on the physical design requirement.  
         [0058]     In the earphone  400 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  460  of  FIG. 4A , may be independently pulled out and disposed on the external tube  475 , and the space in the interior chamber formed by the foldable external tube is adjusted by folding the external tube with different angle. The closer the external tube is folded toward to the earphone  400 A, the less space it takes. On the additionally added external tube  485  in the earphone  400 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  450 B of  FIG. 4 , may be independently pulled out and disposed on the external tube  485 .  
         [0059]     Besides the earphone  400 A having an external tube mentioned above, an earphone  400 A having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone  400 A with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  450 A is disposed inside the case  411  of the earphone  400 A, and the other sub-speaker  450 B is disposed on the external tube  485  coupled to the case.  
         [0060]     With such arrangement, a sound field is formed by these two or more than two sub-speakers  450 A and  450 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  450 A and  450 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0061]      FIG. 4B  schematically shows a partial sectional decomposition diagram of an earphone  400 B in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 4B , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 4B , thus its detail is omitted here.  
         [0062]     Referring to  FIG. 4B , the earphone  400 B comprises an earphone main body  410  and a connector  420 . Wherein, the connector  420  is used to connect the earphone main body  410  in its both sides (only one side is shown in the diagram). The earphone main body  410  mainly comprises a case  411 , a cover  413 , and a case extension unit  415 . The earphone main body  410  further comprises a main speaker  430  and a plurality of sub-speakers  440 A,  440 B,  450 , and  460 , which are disposed inside the earphone main body  410 . The sub-speakers  440 B and  450  are disposed on the external tubes  435  and  437  on both side walls of a composite chamber  433 , respectively. In addition, an external tube  475  where the sub-speaker  460  is disposed on is further comprised in the present embodiment.  
         [0063]     The difference between the earphone  400 B and the one shown in  FIG. 4A  is the external tube  475  of  FIG. 4A  is disposed on the case extension unit  415  of the earphone main body  410 . While in the present embodiment, the external tube  475  is disposed on the case  411  of the earphone main body  410  and the chamber is an extension of the composite chamber  433  inside the earphone main body  410 . The case  411 , the cover  413 , and the case extension unit  415  of the earphone  400 B togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  475 . It is differed from the embodiment of  FIG. 3B  in that the space in the external tube  475  is adjusted by folding the external tube with different angle in the present embodiment.  
         [0064]     As described above, inside the earphone  400 B of the present embodiment, both side walls of the composite chamber  433  are extended to the external tubes  435  and  437  out the case  411 . The case  411 and the cover  413  of the earphone  400 B togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tubes  435  and  437 . In the present embodiment, the length of these additional added external tubes  435  and  437  may be fixed, or may be adjustable or foldable based on the physical design requirement.  
         [0065]     In the earphone  400 B of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  460  of  FIG. 4B , may be independently pulled out and disposed on the external tube  475 , and the space in the interior chamber formed by the foldable external tube is adjusted by folding the external tube with different angle. The closer the external tube is folded toward to the earphone  400 B, the less space it takes. On the external tubes  435  and  437 , which are extended from the both side walls of the composite chamber  433  in the earphone  400 B of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speakers  440 B and  450  of  FIG. 4B , may be independently pulled out and disposed on the external tubes  435  and  437 , respectively.  
         [0066]     Besides the earphone  400 B having an external tube mentioned above, an earphone  400 B having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone  400 B with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  440 A is disposed inside the case  411  of the earphone  400 B, and the other sub-speaker  440 B is disposed on the external tube  435  coupled to the composite chamber  433 . The sub-speakers  440 A and  440 B are coupled to the surrounding sound source of the 5.1 channel, the sub-speaker  450  is coupled to the center sound source of the 5.1 channel, and the sub-speaker  460  is coupled to the subwoofer of the 5.1 channel.  
         [0067]     With such arrangement, a sound field is formed by these two or more than two sub-speakers  440 A and  440 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  440 A and  440 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0068]      FIG. 5A  schematically shows a partial sectional decomposition diagram of an earphone  500 A in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 5A , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 5A , thus its detail is omitted here.  
         [0069]     Referring to  FIG. 5A , the earphone  500 A comprises an earphone main body  510  and a connector  520 . Wherein, the connector  520  is used to connect the earphone main body  510  in its both sides (only one side is shown in the diagram). The earphone main body  510  mainly comprises a case  511 , a cover  513 , and a case extension unit  515 . The earphone main body  510  further comprises a main speaker  530  and a plurality of sub-speakers  540  and  550 A, which are disposed inside the earphone main body  510 . In addition, an external tube  565  where the sub-speaker  550 B is disposed on is further comprised in the present embodiment. Alternatively, an interior chamber  570  coupled to an external tube  574  may be further comprised in the present embodiment, and its detail is described hereinafter.  
         [0070]     Inside the earphone  500 A, as described above, it may only has one external tube  565  disposed on the case extension unit  515  of the earphone main body  510 . The case  511  and the cover  513  of the earphone  500 A togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  565 . In addition, the space in the external tube in the present embodiment is adjusted by changing the length of the external tube.  
         [0071]     In the earphone  500 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  550 B of  FIG. 5A , may be independently pulled out and disposed on the external tube  565 , and the space in the interior chamber formed by the length-adjustable external tube is adjusted by changing the length of the external tube. The shorter the external tube, the less space it occupies in the earphone  500 A. The longer the external tube, the more space the sound field provided by the whole earphone  500 A. In addition, when the length of the external tube is extended, one of the signal entities may be independently pulled out and disposed on the interior chamber, such that the spatial sound effect is improved.  
         [0072]     Besides the earphone  500 A having an external tube mentioned above, an earphone  500 A having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone  500 A with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  550 A is disposed inside the case  511  of the earphone  500 A, and the other sub-speaker  550 B is disposed on the external tube  565  coupled to the case extension unit  515 .  
         [0073]     With such arrangement, a sound field is formed by these two or more than two sub-speakers  550 A and  550 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  550 A and  550 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0074]     Besides the earphone having an external tube mentioned above, an earphone  500 A having a function of dividing the sound field is further provided in the present embodiment. An external tube  574  is externally coupled to the case extension unit  515  of the earphone main body  510 . An interior chamber  570  is formed on the outermost edge of the external tube  574 , and a chamber  572  is formed in the interior chamber  570 . In the present embodiment, any one of the signal entities provided by the 5.1 channel sound sources from the DVD player may be disposed on the cover of the interior chamber  570  with any angle and direction, so as to form a resonance in the chamber.  
         [0075]     In an embodiment of the present invention, a curve tube  582  is further coupled on the case of the interior chamber  570  for not creating the resonance in the chamber  572  directly. Accordingly, the sound source on the case of the interior chamber provided by the 5.1 channel of the DVD player is pulled away from the main sound field formed by the 5.1 channel. The angle of the curve tube  582  is 10˜180 degrees, and preferably to be about 90 degrees for easily adjusting the phase of the sound field. In the earphone  500 A of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  580  of  FIG. 5A , may be independently pulled out and disposed on the outer edge of the curve tube  582 . In the earphone  500 A of the present embodiment, a resonant chamber is formed outside of the earphone main body  510 , and the resonant chamber is adjusted by the curve tube  582 . In the whole structure, the sound wave inside the resonant chamber is transmitted to the main sound field inside the case  511  with air media through the external tube  574 .  
         [0076]     As described above, the earphone provided by the present invention comprises an external tube disposed on the case. In addition, the case and the cover of the earphone togetherly form an interior chamber, and by adjusting the space in the external tube, the spatial sound effect is improved and the phase of the sound field is further adjusted.  
         [0077]      FIG. 5B  schematically shows a partial sectional decomposition diagram of an earphone  500 B in side view according to another preferred embodiment of the present invention. To be noted, although only one side of the earphone of the present invention is shown in  FIG. 5B , it will be apparent to one of the ordinary skill in the art that the other side of the earphone, which is not shown in the diagram, is the same as the one shown in  FIG. 5B , thus its detail is omitted here.  
         [0078]     Referring to  FIG. 5B , the earphone  500 B comprises an earphone main body  510  and a connector  520 . Wherein, the connector  520  is used to connect the earphone main body  510  in its both sides (only one side is shown in the diagram). The earphone main body  510  mainly comprises a case  511 , a cover  513 , and a case extension unit  515 . The earphone main body  510  further comprises a main speaker  530  and a plurality of sub-speakers  540 A,  540 B,  560 , and  570 , which are disposed inside the earphone main body  510 . The sub-speaker  540 B is disposed on the external tube  565  which is extended from the side wall of the composite chamber  533 . In addition, the external tube  565  where the sub-speaker  560  is disposed on is further comprised in the present embodiment. In addition, an interior chamber  570  coupled to the external tube  537  is further comprised in the present embodiment, and its detail is described in detail hereinafter.  
         [0079]     The difference between the earphone  500 B and the one shown in  FIG. 5A  is the external tubes  565  and  537  of  FIG. 5A  are disposed on the case extension unit  515  of the earphone main body  510 . While in the present embodiment, the external tubes  565  and  537  are disposed on the case  511  of the earphone main body  510  and extended from the composite chamber  533  in the earphone main body  510 .  
         [0080]     Inside the earphone  500 B, as described above, it may only has one external tube  565  disposed on the case  511  of the earphone main body  510 . The case  511  and the cover  513  of the earphone  500 B togetherly form a main chamber, and the spatial sound effect is improved by adjusting the space in the external tube  565 . In addition, the space in the external tube in the present embodiment is adjusted by changing the length of the external tube.  
         [0081]     In the earphone  500 B of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  560  of  FIG. 5B , may be independently pulled out and disposed on the external tube  565 , and the space in the interior chamber formed by the length-adjustable external tube is adjusted by changing the length of the external tube. The shorter the external tube, the less space it occupies in the earphone  500 B. The longer the external tube, the more space the sound field provided by the whole earphone  500 B. In addition, when the length of the external tube is extended, one of the signal entities may be independently pulled out and disposed on the interior chamber, such that the spatial sound effect is improved.  
         [0082]     Besides the earphone  500 B having an external tube mentioned above, an earphone  500 B having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone  500 B with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. For example, the sub-speaker  540 A is disposed inside the case  511  of the earphone  500 B, and the other sub-speaker  540 B is disposed on the external tube  535  that is extended from the side wall of the composite chamber  533 .  
         [0083]     With such arrangement, a sound field is formed by these two or more than two sub-speakers  540 A and  540 B, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These sub-speakers  540 A and  540 B may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles.  
         [0084]     Besides the earphone having an external tube mentioned above, an earphone  500 B having a function of dividing the sound field is further provided in the present embodiment. An external tube  537  is extended from the side wall of the composite chamber  533  of the earphone main body  510 . An interior chamber  570  is formed on the outermost edge of the external tube  537 , and a chamber  572  is formed in the interior chamber  570 . In the present embodiment, any one of the signal entities provided by the 5.1 channel sound sources from the DVD player may be disposed on the cover of the interior chamber  570  with any angle and direction, so as to form a resonance in the chamber.  
         [0085]     In an embodiment of the present invention, a curve tube  584  is further coupled on the case of the interior chamber  570  for not creating the resonance in the chamber  572  directly. Accordingly, the sound source on the case of the interior chamber provided by the 5.1 channel of the DVD player is pulled away from the main sound field formed by the 5.1 channel. The angle of the curve tube  584  is 10˜180 degrees, and preferably to be about 90 degrees for easily adjusting the phase of the sound field. In the earphone  500 B of the present embodiment, any one of the signal entities provided by the 5.1 channel of the DVD player, such as the sub-speaker  580  of  FIG. 5B , may be independently pulled out and disposed on the outer edge of the curve tube  584 . In the earphone  500 B of the present embodiment, a resonant chamber is formed outside of the earphone main body  510 , and the resonant chamber is adjusted by the curve tube  584 . In the whole structure, the sound wave inside the resonant chamber is transmitted to the main sound field inside the case  511  with air media through the external tube  537 .  
         [0086]     As described above, the earphone provided by the present invention comprises an external tube disposed on the case. In addition, the case and the cover of the earphone togetherly form an interior chamber, and by adjusting the space in the external tube, the spatial sound effect is improved and the phase of the sound field is further adjusted.  
         [0087]     In the earphone mentioned above, besides both earphone  500 A of  FIG. 5A  and earphone  500 B of  FIG. 5B  having an external tube, an earphone having an effect of balance sound field is further provided in another embodiment of the present invention. The earphone with a balance sound effect couples any one of the sound sources provided by the 5.1 channel sound sources from the DVD player to two or more than two speakers at the same time, wherein one speaker is disposed on a speaker holder in the interior chamber and the other speaker is disposed in the external tube. With such arrangement, a sound field is formed by these two or more than two speakers, which are coupled to a same sound source, based on the difference of the sounding point and the angle or physical location of the speakers, such that the sound field formed by this sound signal is enlarged and more saturated. These two or more than two speakers may be coupled to the sound signal either in parallel or in serial. Alternatively, a different level sound field can be formed by disposing these two or more than two speakers on different locations and with different angles. For example, the sub-speaker  540 A is disposed inside the case  511  of the earphone  500 A, and the other sub-speaker  540 B is disposed on the external tube  535  that is extended from the both side walls of the composite chamber  533 .  
         [0088]     Besides the earphone having an external tube mentioned above, an earphone having a function of dividing the sound field is further provided in an embodiment of the present invention. A tube is externally coupled to the earphone main body, and an interior chamber is formed on the outermost edge of the tube. Therefore, any one of the signal entities provided by the 5.1 channel sound sources from the DVD player may be disposed on the cover of the interior chamber with any angle and direction, so as to form a resonance in the chamber. In another embodiment of the present invention, a curve tube is further coupled on the case of the interior chamber for not creating the resonance in the chamber directly. Accordingly, the sound source on the case of the interior chamber provided by the 5.1 channel of the DVD player is pulled away from the main sound field formed by the 5.1 channel. In other words, in the earphone of the present embodiment, a resonant chamber is formed on the cover of the main body, and the sound wave inside the resonant chamber is transmitted to the main sound field inside the case with air media through the external tube.  
         [0089]     Although the invention has been described with reference to a particular embodiment thereof, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed description.